Morphological Polymorphism Research Articles

Platan seeds-derived PSC/Ni/Co composite with multi-morphologies as tunable microwave absorber

Biomass and its derived carbon materials, due to their glorious application value in the field of microwave absorption, have sparked a new round of research boom. Hereinto, platan seeds-derived carbon-based materials (PSC), offspring from direct carbonization of platan seeds, were ulteriorly processed and subjected to high-temperature carbonization treatment to synthesis PSC/Ni/Co composite with diversified morphology and tunable microwave absorption performance. The effect of nickel and cobalt ion concentrations on the absorption performance of composite materials was investigated in depth. The optimum reflection loss value (RLmin) of PSC/Ni can reach −47.36 dB, while its effective absorption broadband (EAB) is 5.8 GHz, ranging from 12–17.8 GHz, covering almost the whole Ku band. Compared with PSC/Ni composites, PSC/Co fulfils greater advantages in thickness and bandwidth. As for PSC/Ni/Co, the sample exhibits the optimal performance when Ni and Co ions are at equal concentrations, with an RLmin of −48.3 dB and an EAB of 5 GHz (13–18 GHz), which congealed the edges of both. Unequivocally, the morphological polymorphism of carbon-based-derived microwave absorbing materials with platan seeds as the carbon source is crucial to harvset lightweight, efficient and adjustable absorption properties, let alone its relatively simple and feasible preparation method. This may provide a new approach for engineering light-weight, cost effective and eco-friendly absorbing materials.

Study of Bio-ecological Indicators of Oak Species in Azerbaijan

For the first time in Azerbaijan, differences in the morphological parameters of oak trees growing in different regions have been determined, the agrochemical properties of soils under oak trees have been studied, and the influence of environmental pollution on tree leaves has been shown. In different regions of Azerbaijan, morphological polymorphism, caused by the influence of various environmental factors, is different in oak taxa. The level of intrapopulation polymorphism established by dispersion analysis is higher than that of traits with the greatest diversity of variability N (YU/YE) (CV=111.01%), F (CV=54.11%) and YS (CV=35.01%). The Jaccard similarity coefficient is 0.334 with a significant variation of genotypes from each other of 0.827, which indicates its difference in degree and adaptability in the studied taxa. The asymmetry index we calculated (coefficient of fluctuating asymmetry) for Q. petraea sp. and Q. robur sp. equal to 0.067 is considered a conditional norm. The highest indicators are typical for Q. petraea sp. both in areas with intense traffic flow and in the territory of the botanical garden. For Q. rubra, the highest coefficient of fluctuating asymmetry was noted in the botanical garden. The stomal fissure width and stomal fissure length of leaves Q. robur L. and Q. rubra L. are high in the area of Absheron Garadag highway. Intensity of damage to oak leaves spotting and rust high level are registered in Absheron Garadag highway region. Indicators obtained through scientific research are conveniently used in preliminary forecasting as a non-invasive test that protects the principles of "green technologies", without involving other more complex tests that require financial and labour resources, such as an indicative test that is sensitive to small changes within a plant organism.

Бактеріальний вагіноз як чинник ускладнень під час вагітності (огляд літератури)

Aim - to analyze the current literature on etiopathogenetic factors, diagnosis and treatment of bacterial vaginosis in cases of vaginosis and improve treatment methods for this pathology Changes in the size of the body due to the passage of vaginosis. The article shows the relevance of the problem of bacterial vaginosis in the whole world. The etiopathogenetic factors that determine the cause of illness during pregnancy are examined. The emphasis is placed on complications caused by bacterial vaginosis in vaginal patients. The effectiveness of methods for diagnosing bacterial vaginosis in women has been analyzed. The prospects for the use of antibacterial drugs and antibiotics in pregnant women with bacterial vaginosis are examined. The tactics for preventing pregnant women with bacterial vaginosis have been assessed. Conclusions. Despite modern diagnostics and pharmacological means, the problem of detecting and treating bacterial vaginosis in pregnant women remains difficult, as the morphological polymorphism, species diversity of pathogens complicates diagnosis, and the wide spread of drug-resistant strains reduces the effectiveness of treatment, leading to relapses of the disease. During pregnancy in patients with BV, only women with persistent symptoms are subject to observation and in cases where treatment is prescribed to reduce the risk of premature birth and other complications, re-diagnosis should be carried out after one month and further treatment should be offered in case of recurrence of bacterial vaginosis. The authors declare no conflicts of interest.

Inter simple sequence repeat (ISSR) based genetic and morphological polymorphism of Azerbaijani grape (Vitis vinifera) genotypes

Inter simple sequence repeat (ISSR) based genetic and morphological polymorphism of Azerbaijani grape (Vitis vinifera) genotypes

Lilium liangiae, a new species in the genus Lilium (Liliaceae) that reveals parallel evolution within morphology.

The former genus Nomocharis, which has been merged as a clade within the genus Lilium (Liliaceae), represents one of the most complicated and unclear groups included in the latter. Research on members of the Nomocharis clade has been quite limited due to the sampling difficulties caused by its selective environmental preferences. In this study, we propose a new species within this clade, Lilium liangiae, as a further bridge connecting the former genus Nomocharis with other members of the genus Lilium. We conducted morphological clustering, phylogenetic, and comparative genomics analyses of nuclear internal spacers and the newly generated complete chloroplast genome, in conjunction with previously published sequences, and performed ancestral state reconstruction to clarify the evolutionary pattern of important traits in Lilium. The clustering results of 38 morphological traits indicated that the new species is allied to Nomocharis, further increasing the morphological polymorphism in the latter. The phylogenetic results and morphological clustering both supported L. liangiae belonging to the subclade Ecristata in Nomocharis, its closest affinity being Lilium gongshanense. Inconsistencies in phylogenetic relationships were detected between nuclear and plastid datasets, possibly due to ancient hybridization and ongoing introgression. Comparative genomics revealed the conservation and similarity of their chloroplast genomes, with variations observed in the expansion and contraction of the IR regions. A/T and palindromic repeat sequences were the most abundant. Seven highly variable regions (Pi≥0.015) were identified as potential molecular markers based on the chloroplast genomes of 47 species within Lilium. Both nuclear and plastid genes exhibited very low variability within the Nomocharis clade, contrasting with their highly variable morphological appearance. The ancestral state reconstruction analysis suggests that the campanulate flower form, as in L. liangiae, arose at least three times within the genus Lilium, revealing parallel evolution in the latter. Overall, this study adds important genetic and morphological evidence for understanding the phylogenetic relationships and parallel evolution patterns of species within the genus Lilium.

Taraxacum erythroboreale (Asteraceae) — новый вид предположительно межсекционного гибридного происхождения с широким распространением на севере Европейской России (Taraxacum Notulae Rossiae Boreali Europeae II)

Taraxacum erythroboreale Efimov, a new apomictic species, is described and illustrated. It occurs in Russia (North of the European part), in the Murmansk and Vologda regions, in the Komi Republic, being locally very abundant. It occupies mainly dry sandy roadsides and other similar ruderal places, and seems benefiting from the anthropogenic disturbance of the land. The new species may belong either to the section Erythrosperma (H. Lindb.) Dahlst., or have originated from the hybridization between this section and some species of Asiatic sections Stenoloba Kirschner et Štěpánek or Dissecta (Soest) R. Doll. The new species displays rather wide morphological polymorphism as to the presence/absence of purplish achene pigmentation, shape of outer phyllaries, corniculation of phyllaries, and in some other traits.

Phenotypic Diversity of a Leafroller Archips podana (Lepidoptera, Tortricidae) Does Not Change along an Industrial Pollution Gradient.

Morphological polymorphism offers rich opportunities for studying the eco-evolutionary mechanisms that drive the adaptations of local populations to heterogeneous and changing environments. In this study, I explore the association between pollution load, abundance of large fruit-tree tortrix Archips podana and its within-species diversity (expressed in the presence of apical and/or lateral prongs on the phallus in male genitalia) across 26 study sites located 0.5 to 31 km from the industrial city of Lipetsk in central Russia. The Shannon diversity index, calculated from the frequencies of four morphs, correlated neither with the distance to the nearest industrial polluter (a proxy of pollution load) nor with the number of moths captured by pheromone traps (a measure of population abundance). The statistical power of the correlation analysis was sufficient (67%) to detect a medium effect (i.e., Pearson correlation coefficient with an absolute value of 0.40), if it existed. I conclude that the four phenotypes of A. podana do not differ in tolerance to industrial pollution and similarly respond to pollution-induced environmental disturbance. This is the first study of industrial pollution impacts on within-species diversity of insects expressed in the discrete traits of their male genitalia.

A new species of the Drosophila tripunctata group (Diptera: Drosophilidae) associated with fallen flowers of six Lecythidaceae species in the Amazon Rainforest.

The tripunctata group falls under the subgenus Drosophila Falln, 1823 of the genus Drosophila Falln, 1823, and is composed of four subgroups and 17 species not assigned to subgroups. This group is widely distributed throughout tropical regions and is predominantly found in preserved forest environments. With a predicted high number of cryptic species, the occurrence of intraspecific morphological polymorphisms made it difficult to establish lines in the laboratory. The capture of males for comparison of the terminalia makes it hard to identify and delimit species; however, these difficulties can be overcome through the use of techniques such as searching for species in naturally occurring places, establishing isofemale lines in the laboratory, or using molecular techniques. In this work, we search for imagoes of species of the tripunctata group over present fallen flowers of the Lecythidaceae on the ground of the Amazon rainforest. The collected individuals were morphologically and molecularly analyzed. This species is described here under the binomial Drosophila lecythus sp. nov.

Sorting of persistent morphological polymorphisms links paleobiological pattern to population process

AbstractBiological variation fuels evolutionary change. Across longer timescales, however, polymorphisms at both the genomic and phenotypic levels often persist longer than would be expected under standard population genetic models such as positive selection or genetic drift. Explaining the maintenance of this variation within populations across long time spans via balancing selection has been a major triumph of theoretical population genetics and ecology. Although persistent polymorphisms can often be traced in fossil lineages over long periods through the rock record, paleobiology has had little to say about either the long-term maintenance of phenotypic variation or its macroevolutionary consequences. I explore the dynamics that occur when persistent polymorphisms maintained over long lineage durations are filtered into descendant lineages during periods of demographic upheaval that occur at speciation. I evaluate these patterns in two lineages: Ectocion, a genus of Eocene mammals, and botryocrinids, a Mississippian cladid crinoid family. Following origination, descendants are less variable than their ancestors. The patterns by which ancestral variation is sorted cannot be distinguished from drift. Maintained and accumulated polymorphisms in highly variable ancestral lineages such as Barycrinus rhombiferus Owen and Shumard, 1852 may fuel radiations as character states are sorted into multiple descendant lineages. Interrogating the conditions under which trans-specific polymorphism is either maintained or lost during periods of demographic and ecological upheaval can explain how population-level processes contribute to the emergent macroevolutionary dynamics that shape the history of life as preserved in the fossil record.

Relationship between variations in ecological conditions and the dynamics of intra-specific morphological diversity of Artemisia herba-alba Asso in Algeria

Abstract This research work focused on the study of morphological diversity in 270 types of Artemisia herba-alba, known as “white wormwood,” from different bioclimatic stages and its relationship with the distribution and adaptation of the species. The phenotypic parameters studied include the aerial vegetative part of the leaves and the flowers. The existing relationships between the ecological conditions and the genetic dynamics expressed by the morphological polymorphism of the populations concerned have been established. Results obtained allowed us to admit that we have two ecotypes in Algeria: the first one has five flowers per capitulum and can be found at the level of the three bioclimatic floors studied; whereas the second one has eight flowers per capitulum occupying only the territories with a Saharan climate. The analysis of variance (ANOVA) and UPGMA dendrogram allowed us to observe a very significant intra- and inter-population morphological polymorphism at the level of each site and between the different sites. This wide variability thus observed for A. herba-alba could help research on a large collection of individuals and therefore to choose the most effective ecotypes in order to reintroduce this species in the steppe areas of Algeria.

Caroli syndrome in children: a brief review and clinical observation

A review of domestic and foreign literature on the disease and Caroli syndrome is presented. The review includes a historical background and a modern view on the etiology and pathogenesis of the disease, its place among fibrocystic diseases of the liver. Caroli’s disease is a rare genetic pathology, characterized by a wide clinical and morphological polymorphism from severe variants with fibrosis in the neonatal period to cases with manifestation at a late age. The genetic causes of pathology, in particular, mutations associated with autosomal recessive and autosomal dominant forms of polycystic kidney disease, have been studied. A large number of described mutations and the predominance of complex heterozygotes among patients explains the diversity of clinical forms of pathology. The relationship between the genotype and phenotypic variants of pathology has not been determined. In Caroli’s disease, in addition to cystic changes in the liver and kidneys, damage to other organs and systems, in particular cerebral vessels, can be observed. Extrahepatic and extrarenal symptoms of the disease are described, as well as combinations with various genetic diseases. A clinical case of Caroli syndrome in a child observed by the authors from birth is presented. The disease manifested as congenital cystic transformation of the kidney. Hepatic pathology was detected at the age of 5 years. Subsequently, there was a rapid progression of liver damage with the development of severe complications: cirrhosis of the liver, portal hypertension, edematous syndrome, hepatic encephalopathy. At the age of 11 years, the patient successfully underwent orthotopic liver transplantation. The presented case demonstrates the late detection of hepatic damage, its rapid progression. Despite the presence of severe complications, liver transplantation was a success and the patient is currently in a stable condition compensated for all functions.

Probing physical properties of single amyloid fibrils using nanofluidic channels.

Amyloid fibril formation is central to the pathology of many diseases, including neurodegenerative disorders such as Alzheimer's and Parkinson's disease. Amyloid fibrils can also have functional and scaffolding roles, for example in bacterial biofilms, and have also been exploited as useful biomaterials. Despite being linear protein homopolymers, amyloid fibrils can exhibit significant structural and morphological polymorphism, making it relevant to study them on the single fibril level. We here introduce the concept of nanofluidic channel analysis to the study of single, fluorescently-labeled amyloid fibrils in solution, monitoring the extension and emission intensity of individual fibrils confined in nanochannels with a depth of 300 nm and a width that gradually increases from 300 to 3000 nm. The change in fibril extension with channel width permitted accurate determination of the persistence length of individual fibrils using Odijk's theory for strongly confined polymers. The technique was applied to amyloid fibrils prepared from the Alzheimer's related peptide amyloid-β(1-42) and the Parkinson's related protein α-synuclein, obtaining mean persistence lengths of 5.9 ± 4.5 μm and 3.0 ± 1.6 μm, respectively. The broad distributions of fibril persistence lengths indicate that amyloid fibril polymorphism can manifest in their physical properties. Interestingly, the α-synuclein fibrils had lower persistence lengths than the amyloid-β(1-42) fibrils, despite being thicker. Furthermore, there was no obvious within-sample correlation between the fluorescence emission intensity per unit length of the labelled fibrils and their persistence lengths, suggesting that stiffness may not be proportional to thickness. We foresee that the nanofluidics methodology established here will be a useful tool to study amyloid fibrils on the single fibril level to gain information on heterogeneity in their physical properties and interactions.

Characteristic of Salvia officinalis L. Genotypes in the Steppe of South Ukraine

In this study gives the characteristic of Salvia officinalis L. genotypes (Lamiaceae)grown in the Southern Steppe of Ukraine. S. officinalis one of the most well-known plants from Salvia L. genus that is used as an aromatic, medicinal, and culinary herb. The plant raw material of this plant is characterized by numerous biological activities that allow use in the pharmacological industry. This plant is characterized by morphological polymorphism and the selection of new genotypes within S. officinalis has a polyfunctional meaning. The plant material of this study was the genotypes of S. officinalis (108-14, 109-14, 108-14-1, 108-14-2, and 113-16). It investigated 3d years of living plants at the flowering stage from the experimental collections of aromatic and medicinal plants in the Kherson region, v. Plodove (Institute of Climate Smart Agriculture of the National Academy of Agrarian Sciences of Ukraine). The height of plants of investigated genotypes was 65.02–86.37 cm, the diameter of the plant was 89.37–117.03 cm, the leaf length was 8.20–11.06 cm, the leaf width was 2.95–3.79 cm, the inflorescence length was 14.52–26.01 cm, the inflorescence diameter was 4.07–5.57 cm, the number of whorls in inflorescences was 8.12–10.55, and the number of flowers in the whorl was 10.02–12.14. The colour of the leaf surface, the character of the leaf surface (wrinkles), and colour of the flowers depended on genotype. The mass of raw from the shrub was determined from 350.11 to 560.27 g and the average mass of essential oil of one plant was from 1.37 to 2.01 g depending on genotype. The essential oil content in the herb, leaves, and inflorescences on dry mass was 1.0–1.5%, 1.09–1.79%, and 0.98–1.28%, respectively. In the herbs and leaves, minimal and maximal content of oil were found in genotypes 113–16 and 109–14, respectively. These results can be useful for further selective work within S. officinalis species and including other species of this genus.

Occurrence pattern and morphological polymorphism of Chinese weedy rice

Rice, the main food crop in China, has been sporadically reported to suffer from weedy rice infestation. However, the overall occurrence and distribution pattern of Chinese weedy rice remains unclear because a systematic survey has not been conducted. In order to reveal the infestation of Chinese weedy rice, a field survey was conducted in 999 sampling sites all over the rice-growing regions in China from 2009 to 2016 using seven-scale visual scoring of the level of weed infestation. Weedy rice was found 39% occurrence incidence in a total of 387 sites. The sampling sites with 50% or higher overall weedy rice infestation index mainly radiated from Jiangsu, Heilongjiang, Ningxia and Guangdong to the whole East China, Northeast China, Northwest China and South China. A total of 45 morphological characters from 287 populations (collected simultaneously with the field survey) out of those occurred sites were observed and analyzed using multivariate analysis in common gardens with the same cultivation conditions in 2017 and 2019. Canonical correlation analysis showed that 45 morphological characters were significantly related to the latitude, mean temperature, minimum temperature, precipitation and mean diurnal range factors. The 287 weedy rice populations were divided into three morphological groups with climate-dependent geographical differentiation: strong tiller type only in Jiangsu, large leaf type in South China and Central China and large grain type mainly in North China. Weedy rice seriously infested rice fields and had a geography, climate and cultivated rice type-dependent morphological and biotype differentiation in China. It is suggested to pay attention to the harmfulness of weedy rice and adopt comprehensive control strategies.

An Updated Genome Assembly Improves Understanding of the Transcriptional Regulation of Coloration in Midas Cichlid

Midas cichlid (Amphilophus citrinellus), a popular aquarium fish, attracts extensive attention from worldwide biologists mainly due to its morphological polymorphism (dark versus gold). Continuous efforts have therefore been paid to address mechanisms of its coloration variants, while it is far away from the detailed illustration of a clear regulatory network. Some limits may come from the absence of a high-quality genome assembly and a relatively accurate gene set. In this study, we sequenced about 149 Gb of nucleotide sequences of Midas cichlid, generating a genome assembly with a total size of 933.5 Mb, which exhibits a good genome continuity with a contig N50 of 10.5 Mb. A total of 25,911 protein-coding genes were annotated and about 90% completeness was achieved, which helps to build a good gene pool for understanding expressional differences of color variation. With the assistance of the final gene set, we identified a total of 277 differential expressional genes (DEGs), of which 97 up- and 180 downregulated were determined in dark-vs-gold comparisons. Two protein-protein interaction (PPI) networks were constructed from these DEGs, and three key functional modules were classified. Hub genes within each module were evaluated, and we found that the third key module contains tyrp1b, oca2, pmela, tyr, and slc24a5, which were previously proven to be associated with melanin formation. Two downregulated DEGs (myl1 and pgam2) in the first key module may be involved in muscle movement and spermatogenesis, implying that certain side effects could result from the morphological polymorphism. The first key module, consisting of proteins encoded by upregulated DEGs that were associated with MAPK signaling, Toll-like receptor signaling, and gonadotropin-releasing hormone pathways, may contribute to a negative upstream regulation or downstream influence on melanin biosynthesis. Taken together, our new genome assembly and gene annotation of Midas cichlid provide a high-quality genetic resource for biological studies on this species, and the newly identified key networks and hub genes in dark-vs-gold comparisons enhance our understanding of the transcriptional regulatory mechanisms underlying coloration changes not only in Midas cichlid but also in other fishes from freshwater to marine ecosystems.

Differences between tumor clones of B lymphocytes with restriction of kappa or lambda immunoglobulin light chains in patients with chronic lymphocytic leukemia.

e19520 Background: The purpose of this study was to compare morphological and immunophenotypic characteristics of the tumor population of B-lymphocytes with varying restrictions of immunoglobulin light chains in patients with chronic lymphocytic leukemia (CLL). Methods: We examined 30 patients with CLL (median age 64.9±8.6 years). All patients underwent CBC+DIFF blood tests (Sysmex XE 2100, Japan), morphological examinations (BioVision; Micros, Austria), and immunophenotyping (IPT) by multicolor flow cytometry (Navios 10/3, Beckman Coulter, USA) of the bone marrow and venous blood. According to the IPT results, the patients were divided into: group 1 - 22 patients (73.3%) with tumor cells expressing kappa immunoglobulin light chains, and group 2 - 8 patients (26.7%) with lambda immunoglobulin light chains. Statistical processing of results was performed in the STATISTICA 13.0 program. Results: Morphological tests revealed differences between tumor populations of B lymphocytes. In group 1, the tumor population was represented by small cells of the same type with scanty, often unvisible cytoplasm and nuclei with a lumpy chromatin structure, without distinct nucleoli. In group 2, the sizes of cells varied from small to large, with abundant cytoplasm, round or folded nuclei, smoothed chromatin structure and 1-2 nucleoli. Prolymphocytes were observed among tumor cells (8.1±1.7% of WBC). IPT also revealed differences in tumor clones: morphological uniformity of tumor cells in group 1 was observed in the distribution of tumor cells reflected in low parameters of light scattering on the diagram: location to the left along the FSC axis - from 200 to 400 units and below along the SSC axis - from 10 to 160 units. In group 2, the lymphoid zone was heterogeneous and stretched on the plot: location to the right along the FSC axis - from 200 to 1000 units and higher along the SSC axis - from 10 to 400 units, closer to the monocyte zone, which indicated morphological polymorphism of tumor cells. The expression of CD45 also differed: in group 1, the expression was higher and tumor B lymphocytes were higher by fluorescence intensity on a dot plot on the CD45 / SSC scale in the second half of the third decade and in the fourth decade - to the right compared with group 2, where aberrant B lymphocytes were in the third decade and more to the left. The CD45 expression allowed defining differentiation of the tumor clone: the population in group 1 was represented by mature cells, and in group 2 by less mature and/or intermediate forms. There were no significant differences in the expression of other markers. The revealed differences were typical of both the peripheral blood and bone marrow. Conclusions: The study established morphological and immunophenotypic differences between tumor clones of B lymphocytes expressing either kappa or lambda immunoglobulin light chains in patients with CLL.

Deep whole-genome resequencing sheds light on the distribution and effect of amphioxus SNPs

BackgroundAmphioxus is a model organism for vertebrate evolutionary research. The significant contrast between morphological phenotypic similarity and high-level genetic polymorphism among amphioxus populations has aroused scientists' attention. Here we resequenced 21 amphioxus genomes to over 100X depth and mapped them to a haploid reference.ResultsMore than 11.5 million common SNPs were detected in the amphioxus population, which mainly affect genes enriched in ion transport, signal transduction and cell adhesion, while protein structure analysis via AlphaFold2 revealed that these SNPs fail to bring effective structural variants.ConclusionsOur work provides explanation for “amphioxus polymorphism paradox” in a micro view, and generates an enhanced genomic dataset for amphioxus research.

LA VARIATION LIBRE PHONOLOGIQUE ET MORPHOLOGIQUE DU DIALECTE NIÇOIS : ESSAI D’ILLUSTRATION

Phonological and Morphological Free Variation in the Dialect of Nice – an Illustration. A project has been launched to make a dialectal dictionary of Nice and its surroundings. As an important amount of data is being gathered from various texts and in the field, the proportion of free variation in the Occitan dialect spoken in the city of Nice appears to be significantly greater than what studies (especially grammars and dictionaries) report. Using a substantial set of examples, this descriptive article shares with the scientific community some important features of phonological and morphological polymorphism in urban Niçois. In the phonological part, it also shows the links that tie together polymorphism and diatopic variation in a relatively homogeneous dialectal area. Article history: Received 14 July 2021; Revised 1 January 2022; Accepted 10 January 2022; Available online 31 March 2022; Available print 31 March 2022. REZUMAT. Variaţia liberă fonologică şi morfologică în dialectul nisard – o prezentare. Un proiect de realizare a unui dicţionar dialectal din regiunea Nisei a fost lansat. În timp ce informaţiile de ordin dialectal sunt preluate masiv din sursele textuale şi din teren, fenomenele de variaţie liberă din dialectul occitan de la Nisa se dovedesc a fi mult mai numeroase decât cele prezente în studiile existente (mai ales în gramatici şi în dicţionare). Bazându-se pe un număr însemnat de exemple, acest articol descriptiv împărtăşeşte comunităţii ştiinţifice câteva aspecte importante ale polimorfismului fonologic şi morfologic al nisardei urbane. Perspectiva fonologică este, de altfel, o bună ocazie de a arăta legăturile care unesc polimorfismul şi variaţia diatopică într-o arie dialectală omogenă. Cuvinte-cheie: variaţie liberă, fonologie, morfologie, dialectul nisard, occitană

Genetic and ecomorphological divergence between sympatric Astyanax morphs from Central America.

Intraspecific ecological and morphological polymorphism can promote ecological speciation and the build-up of reproductive isolation. Here, we evaluate correlations among morphology, trophic ecology and genetic differentiation between two divergent morphs (elongate and deep-body) of the fish genus Astyanax in the San Juan River basin in Central America, to infer the putative evolutionary mechanism shaping this system. We collected the two morphs from three water bodies and analysed: (1) the correlation between body shape and the shape of the premaxilla, a relevant trophic morphological structure, (2) the trophic level and niche width of each morph, (3) the correspondence between trophic level and body and premaxillary shape, and (4) the genetic differentiation between morphs using mitochondrial and nuclear markers. We found a strong correlation between the body and premaxillary shape of the morphs. The elongate-body morph had a streamlined body, a premaxilla with acuter angles and a narrower ascending process, and a higher trophic level, characteristic of species with predatorial habits. By contrast, the deep-body morph had a higher body depth, a premaxilla with less acute angles and a broader trophic niche, suggesting generalist habits. Despite the strong correlation between morphological and ecological divergence, the morphs showed limited genetic differentiation, supporting the idea that morphs may be undergoing incipient ecological speciation, although alternative scenarios such as stable polymorphism or plasticity should also be considered. This study provides support for the role of ecological factors promoting diversification in both lake and stream-dwelling freshwater fish.

Sexual selection on population-level mating opportunities drives morph ratios in a fig wasp with extreme male dimorphism

BackgroundAlternative mating tactics are widespread in animals and associated with extreme morphological polymorphism in some insects. Some fig wasps have both highly modified wingless males and dispersing winged males. Wingless males mate inside figs before females disperse, while winged males mate elsewhere after dispersal. Hamilton proposed a model for this system with morphs determined by alternative alleles. This has an equilibrium where the proportion of winged males equals the proportion of females dispersing unmated; i.e. the proportion of matings that they obtain. Previously, we have shown qualitative support for this prediction across nine wing-dimorphic fig wasp species. Here I test the quantitative prediction in the fig wasp Pseudidarnes minerva. In addition, some fig wasp species that lack winged males, but have two wingless morphs, show a conditional strategy with morph determination influenced by the number of wasps developing in a patch. I also test for this alternative pattern in the wing-dimorphic P. minerva.ResultsI sampled 114 figs that contained a mean of 2.1 P. minerva wasps from 44 trees across four sites in Sydney, Australia. At the whole population level, the proportion of winged males (0.84 or 0.79 corrected for sampling bias) did not differ significantly from the proportion of unmated females (0.84), providing strong quantitative support for the prediction of Hamilton’s model. In addition, there was no evidence for other factors, such as local mate competition or fighting between wingless males, that could violate simplifying assumptions of the model. Meanwhile, the proportion of winged males was not correlated with the number of wasps per fig, providing no evidence for a conditional strategy.ConclusionThe morph ratio in P. minerva is consistent with Hamilton’s simple Mendelian strategy model, where morph ratios are set by average mating opportunities at the population level. This contrasts with some fig wasps from another subfamily that show conditional morph determination, allowing finer scale adaptation to fig-level mating opportunities. However, these conditional cases do not involve wing polymorphism. Male polymorphism is common and variable in fig wasps and has evolved independently in multiple lineages with apparently different underlying mechanisms.