Number Of Vertebrae Research Articles

African cichlid fishes: morphological data and taxonomic insights from a genus-level survey of supraneurals, pterygiophores, and vertebral counts (Ovalentaria, Blenniiformes, Cichlidae, Pseudocrenilabrinae).

The iconic freshwater cichlid fishes (Cichlidae) comprise about 1750 validly named species and hundreds more that are known, but not yet described and named. Cichlids are an important source of protein for millions of people on several continents, are model organisms in studies of evolution, speciation, ecology, development, behaviour and physiology and are popular as aquarium fishes. Yet, comparative studies of cichlid internal anatomy are rare. Even their osteology has not been taxonomically surveyed. The cichlid postcranial skeleton has been especially neglected. Here, I provide the first survey in cichlids of the considerable variation in numbers of vertebrae, supraneurals and dorsal- and anal-fin supports (pterygiophores), as well as the patterns with which the pterygiophores insert between the neural or haemal spines. The study includes some 1700 specimens of nearly 400 cichlid species. Focusing on the largest subfamily, the African cichlids or Pseudocrenilabrinae, the survey furnishes data from species in all but one of its 166 genera. Limited data from species in the other cichlid subfamilies (Etroplinae, Ptychochrominae and Cichlinae) and from the related leaffishes, Polycentridae, are also presented. Key examples of pterygiophore insertion patterns from throughout the range of variation are illustrated and discussed. Detailed analytical tables and all raw data are provided in supplementary files.A bizarre specialisation in Cyprichromis is noted, evidently for the first time. Uniquely in this Lake Tanganyikan genus, five to seven anal pterygiophores are abdominal in position, located anterior to the anal fin and inserting toward or between successive pairs of pleural ribs.Taxonomic changes: The most speciose tribe of African cichlids, currently known as Haplochromini, is correctly called Pseudocrenilabrini. Based chiefly on the molecular phylogenetic findings of other workers, I propose four pseudocrenilabrine subtribes, one occurring in rivers and three endemic to Lake Malawi. I also re-assign the Lake Tanganyikan tribe Tropheini as another subtribe of Pseudocrenilabrini, in line with numerous molecular studies placing tropheines firmly within this tribe. The remaining genera of Pseudocrenilabrini remain incertae sedis in this tribe pending clarification of their phylogenetic relationships.The character complex here surveyed is a promising source of taxonomically and phylogenetically informative characteristics distinguishing or uniting cichlid taxa at multiple hierarchical levels, from species through subfamily. This reference set of novel character data can also provide information for palaeontological studies of African cichlids. These attributes are skeletal features potentially available for study in well preserved fossils and may help determine their correct taxonomic placement.

Meat Inspection Decisions Regarding Pig Carcasses Affected by Osteomyelitis at the Slaughterhouse: From Etiopathogenesis to Total Condemnation Criteria

Osteomyelitis is a significant cause of total carcass condemnation in pigs at the slaughterhouse. The decision for total condemnation of a pig carcass for osteomyelitis is often based on traditional perceptions of the risk of pyaemia, leading to controversy among Official Veterinarians (OV) in the industry. This review aims to provide a more comprehensive understanding of the etiopathogenesis of osteomyelitis in pigs, the microorganisms involved, and the risk factors. It also highlights the urgent need for a more uniform method to evaluate osteomyelitis cases, which could significantly reduce economic losses in the industry. Lesions originating from tail-biting, tail docking, castration, teeth resection, and raw management are described as risk factors for osteomyelitis. Osteomyelitis is caused by the entry of pathogens into the animal’s bloodstream through an open wound. Trueperella monocytogenes, Staphylococcus aureus, and Streptococcus spp. are the most described pathogens. At slaughter, OVs condemn carcasses with osteomyelitis due to pyaemia. Signs of acute disease are essential to identify pyaemia cases. In chronic cases, total carcass condemnation can be avoided depending on the number of lesions and vertebrae affected. A clear overall image of the problem would help authorities in various countries adopt a more homogenous approach.

12478 A Pilot Evaluation Of Automated Morphometry Performance On Vertebral Fracture Assessment (vfa) And Its Impact On Interpretation

Abstract Disclosure: S. Syed: None. N. Binkley: None. Introduction: Prevalent vertebral fractures convey increased fracture risk but are often clinically silent; thus, imaging is required for their detection. Vertebral fracture assessment (VFA) can be performed at the time of DXA. We hypothesized that VFA automated morphometry does not accurately identify the number of vertebrae visualized nor the number of fractures present and sought to begin exploring if morphometry impacted the formal interpretation. Methods: Patients seen by an Orthopedic bone health provider were studied. Their VFA images were independently assessed by two physicians, after which a consensus “gold standard” (GS) reading was reached. The number of vertebral bodies able to be assessed and the number of fractures identified by morphometry (M), the formal interpretation (I) and the GS result were compared by one way ANOVA. Results: The study cohort included 100 patients with mean (SD) age 77.6 (8.6) years, 81% female with BMI 26.7 (5.0) kg/m2, 91 of whom had prior clinical fracture. M reported visualizing more vertebral bodies than I and GS; 1243, 1168 and 1063 respectively. I identified numerically more (13) fractures than did M (150 vs. 137) but was lower than GS (167). The automated and formal reports were identical in 52 patients; in this subgroup, 8 patients (15%) had vertebral fractures that were not identified on the formal interpretation. In this same group of 52 patients, an additional 7 (13%) with vertebral fractures had 9 vertebral fractures missed. Conclusion: In this pilot study assessing VFA, automated vertebral morphometry reports identifying more vertebrae than are actually able to be evaluated while missing almost 18% of vertebral fractures that were actually present. That the formal interpretation is identical to that of morphometry in over 50% of patients, while missing vertebral fractures over 12% of the time, implies that morphometry is adversely impacting the formal interpretation and thereby potentially patient care. Further study with larger datasets is indicated. Presentation: 6/3/2024

Vertebral morphology and intracolumnar variation of the iconic African viperid snake Atheris (Serpentes, Viperidae).

We here provide a detailed description of the vertebral morphology of the African arboreal viperid snakes of the genus Atheris. Vertebrae of three different species of the genus, i.e., Atheris desaixi, Atheris hispida, and Atheris katangensis, were investigated via the aid of μCT (micro-computed tomography) scanning. We describe several vertebrae from different regions of the vertebral column for all three species, starting from the atlas-axis complex to the caudal tip, in order to demonstrate important differences regarding the intracolumnar variation. Comparison of these three species shows an overall similar general morphology of the trunk vertebrae among the Atheris species. We extensively compare Atheris with other known viperids. As the sole arboreal genus of Viperinae the prehensile nature of the tail of Atheris is reflected in its caudal vertebral morphology, which is characterized by a high number of caudal vertebrae but also robust and anteroventrally oriented pleurapophyses as a skeletal adaptation, linked with the myology of the tail, to an arboreal lifestyle. We anticipate that the extensive figuring of these viperid specimens will also aid identifications in paleontology.

Testing for heterogeneous rates of discrete character evolution on phylogenies

Abstract Many hypotheses in the field of phylogenetic comparative biology involve specific changes in the rate or process of trait evolution. This is particularly true of approaches designed to connect macroevolutionary pattern to microevolutionary process. We present a method to test whether the rate of evolution of a discrete character has changed in one or more clades, lineages, or time periods. This method differs from other related approaches (such as the “covarion” model) in that the “regimes” in which the rate or process is postulated to have changed are specified a priori by the user, rather than inferred from the data. Similarly, it differs from methods designed to model a correlation between two binary traits in that the regimes mapped onto the tree are fixed. We apply our method to investigate the rate of dewlap colour and/or caudal vertebra number evolution in Caribbean and mainland clades of the diverse lizard genus Anolis. We find little evidence to support any difference in the evolutionary process between mainland and island evolution for either character. We also examine the statistical properties of the method more generally and show that it has acceptable type I error, parameter estimation, and power. Finally, we discuss some general issues of frequentist hypothesis testing and model adequacy, as well as the relationship of our method to existing models of heterogeneity in the rate of discrete character evolution on phylogenies.

Relative muscle indices and healthy reference values for sarcopenia assessment using T10 through L5 computed tomography skeletal muscle area

Sarcopenia is the age-related loss of skeletal muscle mass and function. Computed tomography (CT) assessments of sarcopenia utilize measurements of skeletal muscle cross-sectional area (SMA), radiation attenuation (SMRA), and intramuscular adipose tissue (IMAT). Unadjusted SMA is strongly correlated with both height and body mass index (BMI); therefore, SMA must be adjusted for body size to assess sarcopenic low muscle mass fairly in individuals of different heights and BMI. SMA/height (rather than SMA/height2\\documentclass[12pt]{minimal} \\usepackage{amsmath} \\usepackage{wasysym} \\usepackage{amsfonts} \\usepackage{amssymb} \\usepackage{amsbsy} \\usepackage{mathrsfs} \\usepackage{upgreek} \\setlength{\\oddsidemargin}{-69pt} \\begin{document}$$SMA/height^2$$\\end{document}) provides optimal height adjustment, and vertebra-specific relative muscle index (RMI) equations optimally adjust for both height and BMI. Since L3 measurement is not available in all CT scans, sarcopenic low muscle mass may be assessed using other levels. Both a mid-vertebral slice and an inferior slice have been used to define ‘L3 SMA’, but the effect of vertebral slice location on SMA measurements is unexplored. Healthy reference values for skeletal muscle measures at mid- and inferior vertebra slices between T10 and L5, have not yet been reported. We extracted T10 through L5 SMA, SMRA, and IMAT at a mid-vertebral and inferior slice using non-contrast-enhanced CT scans from healthy, adult kidney donor candidates between age 18 and 73. We compared paired differences in SMA between the mid-vertebral slice versus the inferior slice. We calculated the skeletal muscle gauge as SMGHT=SMRA∗SMIHT\\documentclass[12pt]{minimal} \\usepackage{amsmath} \\usepackage{wasysym} \\usepackage{amsfonts} \\usepackage{amssymb} \\usepackage{amsbsy} \\usepackage{mathrsfs} \\usepackage{upgreek} \\setlength{\\oddsidemargin}{-69pt} \\begin{document}$$SMG_{HT}=SMRA*SMI_{HT}$$\\end{document}. We used allometric analysis to find the optimal height scaling power for SMA. To enable comparisons with other published reference cohorts, we computed two height-adjusted measures; SMIHT=SMA/height\\documentclass[12pt]{minimal} \\usepackage{amsmath} \\usepackage{wasysym} \\usepackage{amsfonts} \\usepackage{amssymb} \\usepackage{amsbsy} \\usepackage{mathrsfs} \\usepackage{upgreek} \\setlength{\\oddsidemargin}{-69pt} \\begin{document}$$SMI_{HT}=SMA/height$$\\end{document} (optimal) and SMIHT2=SMA/height2\\documentclass[12pt]{minimal} \\usepackage{amsmath} \\usepackage{wasysym} \\usepackage{amsfonts} \\usepackage{amssymb} \\usepackage{amsbsy} \\usepackage{mathrsfs} \\usepackage{upgreek} \\setlength{\\oddsidemargin}{-69pt} \\begin{document}$$SMI_{HT2}=SMA/height^2$$\\end{document} (traditional). Using the young, healthy reference cohort, we utilized multiple linear regression to calculate relative muscle index z-scores (RMIHT\\documentclass[12pt]{minimal} \\usepackage{amsmath} \\usepackage{wasysym} \\usepackage{amsfonts} \\usepackage{amssymb} \\usepackage{amsbsy} \\usepackage{mathrsfs} \\usepackage{upgreek} \\setlength{\\oddsidemargin}{-69pt} \\begin{document}$$RMI_{HT}$$\\end{document}, RMIHT2\\documentclass[12pt]{minimal} \\usepackage{amsmath} \\usepackage{wasysym} \\usepackage{amsfonts} \\usepackage{amssymb} \\usepackage{amsbsy} \\usepackage{mathrsfs} \\usepackage{upgreek} \\setlength{\\oddsidemargin}{-69pt} \\begin{document}$$RMI_{HT2}$$\\end{document}), which adjust for both height and BMI, at each vertebra level. We assessed Pearson correlations of each muscle area measure versus age, height, weight, and BMI separately by sex and vertebra number. We assessed the differences in means between age 18–40 versus 20–40 as the healthy, young adult reference group. We reported means, standard deviations, and sarcopenia cutpoints (mean-2SD and 5th percentile) by sex and age group for all measures. Sex-specific allometric analysis showed that height to the power of one was the optimal adjustment for SMA in both men and women at all vertebra levels. Differences between mid-vertebra and inferior slice SMA were statistically significant at each vertebra level, except for T10 in men. SMIHT\\documentclass[12pt]{minimal} \\usepackage{amsmath} \\usepackage{wasysym} \\usepackage{amsfonts} \\usepackage{amssymb} \\usepackage{amsbsy} \\usepackage{mathrsfs} \\usepackage{upgreek} \\setlength{\\oddsidemargin}{-69pt} \\begin{document}$$SMI_{HT}$$\\end{document} was uncorrelated with height, whereas SMIHT2\\documentclass[12pt]{minimal} \\usepackage{amsmath} \\usepackage{wasysym} \\usepackage{amsfonts} \\usepackage{amssymb} \\usepackage{amsbsy} \\usepackage{mathrsfs} \\usepackage{upgreek} \\setlength{\\oddsidemargin}{-69pt} \\begin{document}$$SMI_{HT2}$$\\end{document} was negatively correlated with height at all vertebra levels. Both SMIHT\\documentclass[12pt]{minimal} \\usepackage{amsmath} \\usepackage{wasysym} \\usepackage{amsfonts} \\usepackage{amssymb} \\usepackage{amsbsy} \\usepackage{mathrsfs} \\usepackage{upgreek} \\setlength{\\oddsidemargin}{-69pt} \\begin{document}$$SMI_{HT}$$\\end{document} and SMIHT2\\documentclass[12pt]{minimal} \\usepackage{amsmath} \\usepackage{wasysym} \\usepackage{amsfonts} \\usepackage{amssymb} \\usepackage{amsbsy} \\usepackage{mathrsfs} \\usepackage{upgreek} \\setlength{\\oddsidemargin}{-69pt} \\begin{document}$$SMI_{HT2}$$\\end{document} were positively correlated with BMI at all vertebra levels. RMIHT\\documentclass[12pt]{minimal} \\usepackage{amsmath} \\usepackage{wasysym} \\usepackage{amsfonts} \\usepackage{amssymb} \\usepackage{amsbsy} \\usepackage{mathrsfs} \\usepackage{upgreek} \\setlength{\\oddsidemargin}{-69pt} \\begin{document}$$RMI_{HT}$$\\end{document} was uncorrelated with BMI, weight, and height (minimal positive correlation in women at L3inf\\documentclass[12pt]{minimal} \\usepackage{amsmath} \\usepackage{wasysym} \\usepackage{amsfonts} \\usepackage{amssymb} \\usepackage{amsbsy} \\usepackage{mathrsfs} \\usepackage{upgreek} \\setlength{\\oddsidemargin}{-69pt} \\begin{document}$$\\hbox {L3}_{inf}$$\\end{document}, L4mid\\documentclass[12pt]{minimal} \\usepackage{amsmath} \\usepackage{wasysym} \\usepackage{amsfonts} \\usepackage{amssymb} \\usepackage{amsbsy} \\usepackage{mathrsfs} \\usepackage{upgreek} \\setlength{\\oddsidemargin}{-69pt} \\begin{document}$$\\hbox {L4}_{mid}$$\\end{document}, and L5inf\\documentclass[12pt]{minimal} \\usepackage{amsmath} \\usepackage{wasysym} \\usepackage{amsfonts} \\usepackage{amssymb} \\usepackage{amsbsy} \\usepackage{mathrsfs} \\usepackage{upgreek} \\setlength{\\oddsidemargin}{-69pt} \\begin{document}$$\\hbox {L5}_{inf}$$\\end{document}) whereas RMIHT2\\documentclass[12pt]{minimal} \\usepackage{amsmath} \\usepackage{wasysym} \\usepackage{amsfonts} \\usepackage{amssymb} \\usepackage{amsbsy} \\usepackage{mathrsfs} \\usepackage{upgreek} \\setlength{\\oddsidemargin}{-69pt} \\begin{document}$$RMI_{HT2}$$\\end{document} was uncorrelated with BMI, but negatively correlated with height and weight at all levels. There were no significant differences in SMA between 18–40 versus 20–40 age groups. Healthy reference values and sarcopenic cutpoints are reported stratified by sex, vertebra level, and age group for each measure. Height to the power of one (SMA/height) is the optimal height adjustment factor for SMA at all levels between T10mid\\documentclass[12pt]{minimal} \\usepackage{amsmath} \\usepackage{wasysym} \\usepackage{amsfonts} \\usepackage{amssymb} \\usepackage{amsbsy} \\usepackage{mathrsfs} \\usepackage{upgreek} \\setlength{\\oddsidemargin}{-69pt} \\begin{document}$$\\hbox {T10}_{mid}$$\\end{document} through L5inf\\documentclass[12pt]{minimal} \\usepackage{amsmath} \\usepackage{wasysym} \\usepackage{amsfonts} \\usepackage{amssymb} \\usepackage{amsbsy} \\usepackage{mathrsfs} \\usepackage{upgreek} \\setlength{\\oddsidemargin}{-69pt} \\begin{document}$$\\hbox {L5}_{inf}$$\\end{document}. The use of SMA/height2\\documentclass[12pt]{minimal} \\usepackage{amsmath} \\usepackage{wasysym} \\usepackage{amsfonts} \\usepackage{amssymb} \\usepackage{amsbsy} \\usepackage{mathrsfs} \\usepackage{upgreek} \\setlength{\\oddsidemargin}{-69pt} \\begin{document}$$SMA/height^2$$\\end{document} should be discontinued as it retains a significant negative correlation with height and is therefore biased towards identifying sarcopenia in taller individuals. Measurement of SMA at a mid-vertebral slice is significantly different from measurement of SMA at an inferior aspect slice. Reference values should be used for the appropriate slice. We report sarcopenic healthy reference values for skeletal muscle measures at the mid-vertebral and inferior aspect slice for T10 through L5 vertebra levels. Relative muscle index (RMI) equations developed here minimize correlation with both height and BMI, producing unbiased assessments of relative muscle mass across the full range of body sizes. We recommend the use of these RMI equations in other cohorts.

The osteology of the lacertid genus Darevskia Arribas, 1999 (Squamata, Lacertidae)

A total of 230 cleared and alizarin stained and 136 radiographed specimens of Darevskia belonging to 47 nominal taxa (species, subspecies or singular clades) including the seven parthenogenetic ones and a triploid hybrid were studied. Sixteen osteological characters in all the tried species were analyzed. These characters by corporal regions were: skull characters: 1.—number of premaxillary teeth; 2.—number of maxillary teeth; 3.—number of dentary teeth; 4.—teeth morphology; 5.—presence of anterolateral process in the postfrontal bone; 6.—presence of anteromedial process in the postorbital bone; 7.—comparative lengths of the postorbital and postfrontal bones; 8.—overlap degree between the postorbital and the squamosal bones. Postcranial characters: 9.—existence of visible (ossified) ribs associated with the third presacral vertebrae; 10.—sternal/xiphisternal costal formula and presence of inscriptional ribs; 11.—number of presacral vertebrae; 12.—number of posterior dorsal vertebrae (short presacral ribs); 13.—presence and form of the sternal fontanelle; 14.—form of the clavicles (emarginated or marginated); 15.—interclavicle form; 16.—morphology of first autotomic vertebrae of the tail. Our goals were to characterize osteologically the different species of Darevskia, to contrast their relationships traced from osteological traits with the available genetic-derived phylogenies of the group, to compare the osteological characteristics of the parthenogenetic species with their bisexual parental species, and to comment on their parentage and character polarity. Finally, we aimed to search for osteological characteristics of the different groups within Darevskia, diagnosing them for the first time. The results, commented on by characters, are available in the main text, and taxa characteristics are easily consultable and condensed in Table 1. Osteological characteristics of Darevskia, together with available phylogenetic trees, have permitted us to define some new groups within Darevskia (raddei, chlorogaster, defilippi, and parvula new groups) (Appendix 3), which are reciprocally monophyletic and have diagnostic characteristics. All of them are diagnosed and named as subgenera to be used if necessary, instead of the partial, old and not always comprehensive groups.

Does the coronal deformity angular ratio affect bracing outcome in adolescent idiopathic scoliosis?

To examine if coronal deformity angular ratio (C-DAR) serves as a predictor for progression to surgical magnitude in patients with Adolescent Idiopathic Scoliosis (AIS) treated with thoracolumbar sacral orthosis (TLSO). Patients with AIS, prescribed a full-time TLSO, Cobb angle 20-40°, Risser 0-2, who wore the brace ≥ 12.9 h and reached skeletal maturity/surgery were included retrospectively. C-DAR was defined as the Cobb angle divided by the number of vertebrae in the curve, yielding a larger value in short curves. The association between C-DAR and the risk of progression to surgical magnitude (> 45°) was assessed. Secondly, we evaluated the association between pre-treatment Cobb angle and in-brace correction on the risk of progression to > 45°. We included 165 patients with a mean Cobb angle of 30 ± 6°. Of these, 46/165 (28%) progressed ≥ 6° and 26/165 (16%) reached surgical magnitude at the end of treatment. C-DAR was a significant predictor for risk of progression to surgical magnitude with an OR of 1.9 (CI 1.2-2.9) per unit increase in C-DAR. A threshold value of 5.15 was established and demonstrated an OR 5.9 (CI 2.1-17.9) for curve progression to a surgical magnitude. Likewise, pre-treatment Cobb angle showed a significant OR 1.3(CI 1.2-1.4) per degree increase in Cobb, whereas in-brace % correction showed OR 0.96 (CI 0.93-0.98). C-DAR is an independent predictor for progression to a surgical magnitude in AIS patients treated with bracing. Patients with a higher C-DAR should be counseled to help set realistic expectations regarding the likelihood of curve progression despite compliance with brace wear.

Osteology and relationships of the Late Triassic giant dicynodont Lisowicia

Abstract Unexpectedly abundant remains of herbivorous therapsids in the Late Triassic strata of southern Poland have significantly supplemented knowledge of their evolution. The skeletal morphology of the Late Norian (or Rhaetian) dicynodont Lisowicia bojani supports its close relationship to the Carnian Woznikella, both known from the Polish part of the Germanic Basin. Three evolutionary lineages of dicynodonts—Laurasian–Gondwanan Rhadiodromus klimovi → Jachaleria candelariensis lineage, Laurasian lineage Shaanbeikannemeyeria xilougouensis → Lisowicia bojani, and the Gondwanan lineage Kannemeyeria simocephalus → Dinodontosaurus brevirostris—are distinguished based on characters of cranial and postcranial elements. In the lineages characterized by the parietal oval in cross-section and the two distinct articulations on the sternum, there is a tendency to exclude the frontal from the orbital margin and to reduce the number of sacral vertebrae. In the lineage with the parietal narrow and triangular in cross-section, the frontal forms part of the orbit margin, there is a single joint on the sternum, and there is a tendency towards flattening the skull roof. In both lineages the shoulder girdle is convergently modified, the acromion process decreased, and joints on the sternum moved posteriorly.

Meristic co-evolution and genomic co-localization of lateral line scales and vertebrae in Central American cichlid fishes.

Meristic traits are often treated as distinct phenotypes that can be used to differentiate and delineate recently diverged species. For instance, the number of lateral line scales and vertebrae, two traits that vary substantially among Neotropical Heroine cichlid species, have been previously suggested to co-evolve. These meristic traits could co-evolve due to shared adaptive, developmental, or genetic factors. If they were found to be genetically or developmentally non-independent, this might require a more general re-evaluation of their role in evolutionary or taxonomic studies. We expanded a previous analysis of correlated evolution of meristic traits (lateral line scales and vertebrae counts) in these fishes to include a range of phylogenetic reconstructions as well as the analyses of 13 Nicaraguan Midas cichlid species (Amphilophus spp.). Additionally, we performed qualitative traits locus (QTL) mapping in a F2 laboratory-reared hybrid population from two ecologically divergent Midas cichlid fish species to discover and evaluate whether genomic co-segregation might explain the observed patterns of meristic co-evolution. Meristic values for these traits were found to morphologically differentiate some species of the Midas cichlid adaptive radiation. Our QTL analysis pinpointed several genomic regions associated with divergence in these traits and highlighted the potential for genomic co-segregation of the lateral line and vertebrae numbers on two chromosomes. Further, our phylogenetic comparative analyses consistently recovered a significant positive evolutionary correlation between the counts of lateral line scale and vertebrae numbers in Neotropical cichlids. Hence, the findings of genomic co-segregation could partially explain the co-evolution of these two meristic traits in these species. Continuing to unravel the genetic architecture governing meristic divergence helps to better understand both trait correlations and the utility of meristic traits in taxonomic diagnoses and how traits in phenotypes might be expected to co-evolve.

Understanding molecular mechanisms of vertebral number of variations on Mongolian sheep using candidate genes analysis.

This study aimed to investigate the genetic link between variations in vertebral number and meat production traits, such as body weight and body measurements (body length, body height, heart girth, and shin width) in Mongolian (Bayantsagaan) sheep. Additionally, we examined the association of single-nucleotide polymorphisms (SNPs) in candidate genes, particularly Vertnin (VRTN), Nuclear receptor subfamily 6, group A, member 1 (NR6A1), and synapse differentiation-inducing 1-like (SYNDIG1L), with vertebral number variations and their potential impact on meat production traits. The study involved 220 Bayantsagaan sheep from Bayantsagaan soum, Tov province, Mongolia, including 104 sheep with extra vertebrae group and 116 individuals with typical vertebral number as the control group. Morphological data, including body weight and body measurements, were collected, and genetic samples were obtained. The impact of vertebral number on morphological traits was estimated using a general linear model. SNPs in the VRTN, NR6A1, and SYNDIG1L genes were sequenced, and their association with vertebral number was analyzed using one-way ANOVA. Bayantsagaan sheep with extra vertebrae were, on average, 4.45 kg heavier and exhibited higher variability in body size traits compared to the control group. Four polymorphic sites were identified at the VRTN gene, with one polymorphic locus (VRTN1716) showing a significant association with vertebrae number and body size. Sheep with C/C genotype at VRTN1716 locus, had more vertebrae and larger body size compared to other genotypes. The findings suggest that variations in vertebral number and VRTN gene polymorphisms are linked to favorable meat production traits in Bayantsagaan sheep. The identified SNP (VRTN1716) associated with vertebral number and body size offers the potential for marker-assisted selection in breeding programs. These results provide valuable insights into the genetic basis of meat production traits in Bayantsagaan sheep and may contribute to the development of more efficient breeding strategies.

Lumbarization and sacralization: Domains of their co-occurrence with other costal-vertebral transformations are not identical.

This study evaluates whether sacralization of a lumbar vertebra and lumbarization of a sacral vertebra are a paired duality but with opposite expressions; the former is associated with 23 presacral vertebrae (PSV) and the latter with 25 PSV. Are sacralization and lumbarization local phenomena, involving only vertebra (V) 24 and V25, or are they associated with other costal-vertebral transformations? Study sample is of skeletonized humans, 431 females and 1405 males, who were 20-49 years of age-at-death and who died in the United States in the 20th and 21st centuries. Data collected are numbers of PSV and sacral vertebrae, presence of rib of V7, position of diaphragmatic vertebra, and transverse process and rib lengths of V5-V9, V18-V19, and V21-V22. Females and males differ significantly in numbers of PSV. Both sexes show significant differences among individuals with 23 PSV, 24 PSV, and 25 PSV: (1) individuals with 23 PSV have the shortest ribs, whereas those with 25 PSV have the longest ribs, of V18 and V19; and (2) individuals with 23 PSV have the highest frequency of 6 sacral vertebrae, whereas those with 25 PSV have the highest frequency of 5 sacral vertebrae. Individuals with 23 PSV and 25 PSV show posterior and anterior homeotic transformation, respectively, of the thoracic-lumbar and lumbar-sacral boundaries, but only individuals with 25 PSV show transformation of the sacral-coccygeal boundary. As co-occurring costal-vertebral transformations differ between sacralization and lumbarization, inferentially the set of genes that influences these vertebrae also differs.

Gaidropsarus mauritanicus (Gadiformes, Gaidropsaridae) a new three-bearded rockling from a deep-water coral ecosystem with a genetically verified biogeographical distribution of the genus and notes to its ecology and behavior.

Gaidropsarus mauritanicus sp. nov. is described from one specimen collected using a grab sample from the Tanoûdêrt Canyon (ca. 20° N) off Mauritania at a depth of 595 m. The new species was further observed during eight remotely operated vehicle (ROV) dives along the Mauritanian slope southwards down to the Tiguent Coral Mound Complex (~17° N) in a bathymetric range between 613 and 416 m. It can be distinguished from congeners by a combination of characteristics, including large eyes (38.1% head length [HL]), large head (25.8% standard length [SL]), elongated pelvic fins (35.7% SL), low number of vertebrae (44), and coloration (pinkish with a dorsal darker brownish hue and bright blotches along the dorsal-fin base). A species-delimitation analysis performed with available cytochrome c oxidase subunit 1 (COI) sequences affiliated to the genus Gaidropsarus additionally supported the validity of the new species. Video analyses showed a deep-water coral-associated and protection-seeking behavior, which may explain why the species has remained undescribed until now. Additional ROV footage from separate deep-water coral sites in the North Atlantic and Mediterranean Sea further highlights the ecological behavior and hidden diversity of bathyal three-bearded rocklings. Here, we additionally discuss the biogeographical distribution of all genetically verified Gaidropsarus spp. in combination with genetic data and morphological characters. G. mauritanicus sp. nov. is closely related to a species from Tasmania (43° S), a geographical point furthest among the studied samples, which may hint to an important influence of (paleo-) oceanography on the distributions of Gaidropsarus species.

Genetic mechanisms of axial patterning in Apeltes quadracus

Abstract The genetic mechanisms underlying striking axial patterning changes in wild species are still largely unknown. Previous studies have shown that Apeltes quadracus fish, commonly known as fourspine sticklebacks, have evolved multiple different axial patterns in wild populations. Here, we revisit classic locations in Nova Scotia, Canada, where both high-spined and low-spined morphs are particularly common. Using genetic crosses and quantitative trait locus (QTL) mapping, we examine the genetic architecture of wild differences in several axial patterning traits, including the number and length of prominent dorsal spines, the number of underlying median support bones (pterygiophores), and the number and ratio of abdominal and caudal vertebrae along the anterior–posterior body axis. Our studies identify a highly significant QTL on chromosome 6 that controls a substantial fraction of phenotypic variation in multiple dorsal spine and pterygiophore traits (~15%–30% variance explained). An additional smaller-effect QTL on chromosome 14 contributes to the lengths of both the last dorsal spine and anal spine (~9% variance explained). 1 or no QTL were detected for differences in the numbers of abdominal and caudal vertebrae. The major-effect patterning QTL on chromosome 6 is centered on the HOXDB gene cluster, where sequence changes in a noncoding axial regulatory enhancer have previously been associated with prominent dorsal spine differences in Apeltes. The QTL that have the largest effects on dorsal spine number and length traits map to different chromosomes in Apeltes and Gasterosteus, 2 distantly related stickleback genera. However, in both genera, the major-effect QTL for prominent skeletal changes in wild populations maps to linked clusters of powerful developmental control genes. This study, therefore, bolsters the body of evidence that regulatory changes in developmental gene clusters provide a common genetic mechanism for evolving major morphological changes in natural species.

The Evolution of Three Schizothoracinae Species from Two Major River Systems in Northwest China Based on Otolith Morphology and Skeletal Structure.

Schizothoracinae species are the largest group of Cypriniformes that readily adapt to the natural conditions of the Qinghai-Tibet Plateau. This group has habitat characteristics and distribution patterns centered on the Qinghai-Tibet Plateau. To study the evolution of three Schizothoracinae species in Northwest China, the evolutionary characteristics of these species were explored based on differences in otolith morphology and skeletal morphology. From 2020 to 2022, 138 samples (63 Aspiorhynchus laticeps, 35 Diptychus maculatus and 40 Schizothorax pseudaksaiensis) were collected from the Tarim River and Ili River, 6 basic morphological parameters of otoliths were measured and converted into 6 morphological factors and 7 morphological indices. A total of 77 Fourier transform coefficients of each otolith were selected The first three principal components accounted for 92.834% of the total variation in 13 otolith morphological indices of the three Schizothoracinae species, and the overall discrimination rate was 94.20%. According to the principal component analysis of 77 Fourier harmonic values of otoliths, the first 20 principal components explained 97.233% of the total variation, and the overall discrimination rate was 100%. The results of the cluster analysis directly reflected the relationships between related species. The differences in the bone morphology of the three Schizothoracinae species were particularly reflected in the number of whiskers, pharyngeal teeth and vertebrae, and there were also significant differences in the shapes of the sphenotic (SP), pterotic (PTE), preoperculum (PO), branchiostegal ray (BRA) and basibranchial (BB) bones. Their unique morphological and skeletal characteristics are closely related to geological changes and water system evolutionary trends. This study contributes to the understanding of species identification and the evolutionary status of plateau fishes, provides a reference for further evolutionary classification and for assessing the evolutionary mechanisms of plateau fishes, and provides a scientific basis for phylogeny and germplasm resource protection.

Alike but genetically divergent: The resurrection of Urotrygon asterias (Jordan & Gilbert, 1883) from its closest relatives, the Munda and the Blotched stingray.

The genus Urotrygon comprises small- to medium-sized endemic round rays on the American continent and has undergone several synonymization processes. Here, we used an integrative taxonomic approach, including meristic, morphometric, and mtDNA analyses, to resolve the particularly intricate relationship among Urotrygon munda Gill, 1863, Urotrygon chilensis (Günther, 1872), and Urotrygon asterias (Jordan & Gilbert, 1883). The latter species is currently a synonym of U. munda but is also considered the U. chilensis "northern morphotype." These taxonomic entities have historically been confounded, mainly due to their phenotypical resemblance along their geographic distribution in the eastern Pacific. We assessed 78 specimens (43 "northern" and 30 "southern morphotypes" of U. chilensis, as well as 5 U. munda) using 19 external variables for taxonomic and morphometric analysis. Distinct meristic patterns, including pectoral and pelvic ceratotrichia, vertebrae number, and thorn distribution along the dorsal midline, were observed in the series-type specimens of the three taxonomic entities. Our multivariate morphometric analyses consistently differentiated the three groups as distinct taxonomic entities, with an overall classification accuracy of 66.7%. The meristic results also provided reliable information distinguishing the three entities. Based on the nicotinamide adenine dinucleotide (NADH2) and cytochrome oxidase subunit I (COI) genes, our phylogenetic analysis were consistent with the morphometric and meristic data, supporting these three entities as distinct species having their own evolutionary lineages. Our comprehensive approach confidently demonstrated that the northern U. chilensis morphotype matched and corresponded to the description of the Starry round ray, U. asterias, confirming its taxonomic resurrection as a valid species distinct from U. chilensis and U. munda. The geographic distribution of U. asterias spans from the tropical west coast of Mexico (including the Gulf of California) to Costa Rica, revealing that microevolutionary processes have well-defined population clades within this range. Furthermore, U. chilensis is unequivocally established as the sole Urotrygon species occurring south of the Guayaquil marine ecoregion. In addition, the public COI and NADH2 sequences available for Urotrygon hosted in the ad hoc online databases were found to be misidentified, emphasizing the need for rigorous taxonomic scrutiny in this group. Finally, our research underscores the significance of an integrative approach that combines morphometric, meristic, and molecular techniques with historical data to disentangle the complexities of closely related taxa.

Hematologic Malignancies Influence the Accuracy of Prediction of Survival in Patients With Solid Tumor Spinal Metastases Undergoing Surgery.

There is no consensus on how to identify patients with multiple-level spinal metastases who would benefit from surgery. Previous studies have revealed that patients with hematologic malignancies have a significantly longer median survival time than those with solid tumor spinal metastases. We aimed to compare predictors and survival data between patients with spinal metastases, including hematologic malignancies (all-malignancies group), with only those with nonhematologic malignancies (nonhematologic malignancies group). This single-center retrospective study included all patients age >18 years who underwent surgery to treat spinal metastases in our department from 2008 to 2018. The patients' baseline characteristics, treatment modalities, and laboratory results were analyzed. Survival was calculated from the date of surgery to the date of confirmed death. Cox regression analysis was used to identify independent predictors of survival. The study cohort comprised 186 patients with a mean age of 57.1 ± 13.4 years, 101 of whom were male and 18 of whom had hematologic malignancies. The median survival time was 201 days in the all-malignancies group and 168 days in the nonhematologic malignancies group. Independent predictors of survival differed between the two groups. Eastern Cooperative Oncology Group status and response to preoperative chemotherapy were identified as independent factors in both groups. However, radiosensitivity and CNS metastases were identified only in the all-malignancies group, and tumor growth potential, albumin status, and number of vertebrae were identified only in the nonhematologic malignancies group. The receiver operating characteristics were comparable in the two groups: 0.75 in the all-malignancies group and 0.77 in the nonhematologic malignancies group. Longer survival in patients with hematologic malignancies influences the overall prediction of survival. Tumor-specific prognostic factors may improve the prediction of survival in patients with spinal metastases.

Comparative characteristics of the postcranial skeleton of Rock lizards from the Darevskia (caucasica) and Darevskia (saxicola) complexes

Anatomical-morphological features of the postcranial skeleton of nine taxa of the rock lizards of the genus Darevskia Arribas, 1999 belonging to the Darevskia (caucasica) and Darevskia (saxicola) complexes were studied for the first time on representative samples. Specimens with the rib formula 3+1 were found in both complexes (previously, only two variants were known for the genus Darevskia 3+2 and 3+3). Differences between supraspecific groups and their members were described with the use of type specimens or topotypes of each taxon. The studied complexes are differentiated by the range of variability of presacral vertebrae (in the D. (caucasica) their minimum number is 26, in the D. (saxicola) – 27), the number of the posterior presacral vertebrae with ribs (the average value of this trait in the D. (caucasica) is less than 6, in D. (saxicola) – more than 6). B-type of the tail vertebrae in 5 times more common in the D. (saxicola) than in the D. (caucasica). In turn, the latter group is characterized by a larger share of individuals with ossified ribs at the third cervical vertebra and a greater variability of the sternal-xiphisternal costal (rib) formula. Skeletal morphology of D. alpina indicates its greater similarity with representatives of the D. (caucasica) complex. A certain originality of D. c. vedenica was recorded. The study of D. saxicola specimens from the zone of sympatry with D. c. caucasica (Chegem Gorge) did not reveal their similarity with the latter, except for the presence of two variants of the sternal-xiphisternal formula. Cryptic forms within D. lindholmi differ at least in two traits: the minimum number of posterior presacral vertebrae with short ribs and the presence of individuals with caudal vertebrae of B-type.

Are Bergmann's and Jordan's rules valid for a neotropical pitviper?

AbstractMorphological variation along the spatial distribution of species has been extensively investigated in ecological studies, and several ecogeographical rules explore the relationships between morphological traits and the environment. Many morphological traits are correlated, providing an opportunity to evaluate the validity of multiple ecogeographical rules simultaneously. Bergmann's rule predicts that endothermic animals in colder locations are larger than those in warmer locations. Jordan's rule predicts that fish from colder locations have more vertebrae than those from warmer locations. We tested the validity of Bergmann's and Jordan's rules for the neotropical lancehead snake Bothrops jararaca. We evaluated three morphological characters of 342 specimens: number of ventral scales (proxy for vertebrae number), snout–vent length (a linear measure of body size) and stoutness (volumetric body size). We implemented spatial regressions to evaluate the variation of morphological dimensions using climatic predictors: the minimum temperature and evapotranspiration. SVL was poorly related to minimum temperature and evapotranspiration. However, stouter individuals were found in colder places with greater evapotranspiration, following Bergmann's rule and the water conservation hypothesis. Individuals in warmer locations also had a greater number of ventral scales, reversing Jordan's rule. We showed that different selective pressures act on different morphological dimensions. Although stoutness follows Bergmann's rule, its variation would arise from an energy storage demand rather than heat conservation. Also, stoutness variation along evapotranspiration gradients could represent a mechanism to avoid hydric stress in environments with considerable climatic variations. The variation in vertebrae number along temperature gradients could be related to ecological factors and foraging. We highlight that physioecological mechanisms to deal with climatic variation and ecological aspects could be identified in snakes through intraspecific analyses, contrasting with interspecific studies that can hardly detect general trends. Due to different environmental effects on body size, we shed new light on the importance of exploring multiple morphological dimensions in macroecological studies.

Comparison of Traumatic Spinal Fracture Patterns Between Motorcyclists and Occupants of Other Nonheavy Motor Vehicles: A Report from the National Spinal Cord and Column Injury Registry of Iran

ObjectivesTo compare traumatic spinal injury patterns between motorcyclists and occupants of other non-heavy motor vehicles using data from the National Spinal Cord and Column Injury Registry of Iran (NSCIR-IR). MethodsAll drivers/riders and passengers of motorcycles, cars, pick-up trucks, and vans registered between January 2017 to July 2023, met the inclusion criteria for the present study. The logistic regression models were used to compare the patterns of vertebral fracture between the two groups. Results1726 spinal fracture patients were identified, 385 (22.3%) motorcyclists and 1341 (77.7%) car occupants with mean ages 33.2±14.3 and 36.1±13.6 years, respectively (P<0.001). Only 45 (11.7%) motorcyclists used helmets, whereas 856 (63.8%) car occupants used seat belts (P<0.001). The average numbers of fractured vertebrae were 3.9±1.4 and 3.7±1.1 among car occupants and motorcyclists, respectively (P=0.004). The proportions of motorcyclists and car occupants with injuries in each spinal region are as follows: lumbar (50.5% of motorcyclists vs. 40.4% of car occupants; P=0.003), thoracic (39.2% vs. 30.9%; P=0.01), cervical (24.3% vs. 37.0%; P<0.001) and sacral (1.3% vs. 7.5%; P<0.001). The AO Spine type C injuries were present in 6.1% of motorcyclists and 10.1% of car occupants (P=0.03). ConclusionMotorcyclists were younger, less educated, had a higher proportion of males, and less commonly used safety devices than car occupants. The most commonly fractured spine region among both groups was the lumbar region. The cervical and sacral vertebrae fractures were significantly more common in car occupants, whereas the thoracic and lumbar vertebrae fractures were significantly more common in motorcyclists.