Subtle Morphological Differences Research Articles

Morphometric and genetic evidence for cryptic diversity in Gyrodactylus (Monogenea) infecting non-native European populations of Ameiurus nebulosus and A. melas.

Gyrodactylid parasites were observed on non-native populations of North-American freshwater catfishes, Ameiurus nebulosus and Ameiurus melas (Siluriformes: Ictaluridae), at several sites in the Elbe River basin, Czech Republic, Europe. Using a combination of morphological and genetic analyses, the parasites infecting A. nebulosus were determined to be Gyrodactylus nebulosus, a North American parasite co-introduced to Europe along with its Ameiurus fish hosts. Subtle morphometrical differences, as well as seasonal variations, were observed among parasites collected from A. nebulosus and A. melas. The host-related variation was further supported through genetic analysis of the partial 18S rDNA, ITS1-5.8S-ITS2 and COI, showing 0.2, 3.0 and 4.8% divergence, respectively. Consistent genetic differences indicated there were two distinct genotypes. Subtle morphological differences associated with the shape of sickle toe, anchor root and ventral bar membrane, according to host species, also supported the description of a new cryptic species, Gyrodactylus melas n. sp., infecting A. melas. Multivariate morphometrical analysis of haptoral hard parts showed significant differences between the anchor lengths of G. nebulosus and G. melas n. sp. However, the measurements of the haptoral hard structures partially overlapped between species, limiting the usage of these parameters for species delineation.

Integrative taxonomic investigation ofPetaurus breviceps(Marsupialia: Petauridae) reveals three distinct species

AbstractThe Australian sugar glider, Petaurus breviceps s.l., is widely distributed across eastern and northern Australia. Examination of historical and contemporary collections of Petaurus specimens and phylogenetic analyses have revealed considerable taxonomic diversity within the genus. We aimed to utilize an integrative taxonomic approach, combining genetic and morphological evidence, to resolve the taxonomy of Australian gliders currently recognized as Petaurus breviceps. Herein, we confirm the existence of three distinct species: P. breviceps, P. notatus comb. nov. and P. ariel comb. nov.. Petaurus breviceps and P. notatus are each represented by major mtDNA lineages in P. breviceps, while P. ariel forms a sister-lineage to P. norfolcensis and P. gracilis. Subtle morphological differences distinguish P. breviceps from the closely related P. notatus, while the morphological distinctions between P. ariel and its genetically similar sister-taxa, P. norfolcensis and P. gracilis, are more obvious. Given the purported broad geographic distribution of the taxon, P. breviceps s.l. was not listed as threatened, but dividing this taxon into three species has important conservation implications for all taxa in the group, particularly given the lamentable record for mammal extinctions in Australia. Concerted and targeted conservation efforts are necessary to preserve these distinct, newly described species.

Unifying Charge Generation, Recombination, and Extraction in Low‐Offset Non‐Fullerene Acceptor Organic Solar Cells

AbstractEven though significant breakthroughs with over 18% power conversion efficiencies (PCEs) in polymer:non‐fullerene acceptor (NFA) bulk heterojunction organic solar cells (OSCs) have been achieved, not many studies have focused on acquiring a comprehensive understanding of the underlying mechanisms governing these systems. This is because it can be challenging to delineate device photophysics in polymer:NFA blends comprehensively, and even more complicated to trace the origins of the differences in device photophysics to the subtle differences in energetics and morphology. Here, a systematic study of a series of polymer:NFA blends is conducted to unify and correlate the cumulative effects of i) voltage losses, ii) charge generation efficiencies, iii) non‐geminate recombination and extraction dynamics, and iv) nuanced morphological differences with device performances. Most importantly, a deconvolution of the major loss processes in polymer:NFA blends and their connections to the complex BHJ morphology and energetics are established. An extension to advanced morphological techniques, such as solid‐state NMR (for atomic level insights on the local ordering and donor:acceptor ππ interactions) and resonant soft X‐ray scattering (for donor and acceptor interfacial area and domain spacings), provide detailed insights on how efficient charge generation, transport, and extraction processes can outweigh increased voltage losses to yield high PCEs.

Classical and computed tomographic anatomical analyses in a not-so-cryptic Alviniconcha species complex from hydrothermal vents in the SW Pacific

The chemosymbiotic gastropod Alviniconcha (Provannidae), first described in 1988, is one of the most emblematic hydrothermal-vent taxa described from the Central Indian Ridge and the Southwest (SW) Pacific. Symbiotic bacteria found in the gill of Alviniconcha are thought to be their principal source of nutrition. In the SW Pacific, species distributions for A. kojimai, A. boucheti – and to a lesser extent A. strummeri – overlap. While Alviniconcha species do not appear to truly co-exist in these highly energetic but spatially limited habitats, certain species regularly co-occur within a single vent field and in rare instances, the same edifice. Past research suggests that SW-Pacific Alviniconcha species might aggregate around fluids with distinct geothermal profiles. These small-scale distribution patterns have been attributed to differences in their symbiont assemblages or host physiologies. However, little is known about the anatomy of most Alviniconcha species, beyond that detailed for the type species Alviniconcha hessleri, whose geographic range does not overlap with other congeners. In fact, species within this genus are currently described as cryptic, despite the absence of any comparative morphological studies to assess this. To test whether the genus is genuinely cryptic and identify any functional differences in host anatomy that might also mediate habitat partitioning in SW Pacific species, the current study examined the morphoanatomy of A. kojimai, A. boucheti and A. strummeri from the Fatu Kapa vent field, an area of hydrothermal activity recently discovered north of the Lau Basin near the Wallis and Futuna Islands and the only known example where all three species occur within adjacent vent fields. A combination of detailed dissections, histology and X-ray computed tomography demonstrate that A. kojimai, A. strummeri and A. boucheti are readily identifiable based on shell morphology and ornamentation alone, and therefore not truly cryptic. These traits provide a rapid and reliable means for species identification. However, aside from some subtle differences in radular morphology, these species of Alviniconcha exhibit conserved anatomical features, providing no evidence that functional host anatomy is implicated in habitat partitioning. This provides support for the current belief that host-species distributions are probably governed by symbiont-mediated physiological factors.

Computational analysis of pathological images enables a better diagnosis of TFE3 Xp11.2 translocation renal cell carcinoma

TFE3 Xp11.2 translocation renal cell carcinoma (TFE3-RCC) generally progresses more aggressively compared with other RCC subtypes, but it is challenging to diagnose TFE3-RCC by traditional visual inspection of pathological images. In this study, we collect hematoxylin and eosin- stained histopathology whole-slide images of 74 TFE3-RCC cases (the largest cohort to date) and 74 clear cell RCC cases (ccRCC, the most common RCC subtype) with matched gender and tumor grade. An automatic computational pipeline is implemented to extract image features. Comparative study identifies 52 image features with significant differences between TFE3-RCC and ccRCC. Machine learning models are built to distinguish TFE3-RCC from ccRCC. Tests of the classification models on an external validation set reveal high accuracy with areas under ROC curve ranging from 0.842 to 0.894. Our results suggest that automatically derived image features can capture subtle morphological differences between TFE3-RCC and ccRCC and contribute to a potential guideline for TFE3-RCC diagnosis.

High functionality of DNA barcodes and revealed cases of cryptic diversity in Korean curved-horn moths (Lepidoptera: Gelechioidea)

Curved-horn moths or gelechioid moths (Lepidoptera: Gelechioidea) represent one of the most diverse lepidopteran groups. Due to the large number of species, generally small size of adults and subtle morphological differences, their confident identification requires tenacious and long-term dedication on their diversity. Over the past decade, DNA barcoding has repeatedly been used to elucidate boundaries of species in many large and difficult groups. Here, we conducted a test of DNA barcoding with the diverse fauna of Korean Gelechioidea with very little prior information of COI gene region from the area. Altogether 509 specimens representing 154 morphospecies were included in the study. The species assignments of all three tested species delimitation methods (ABGD, bPTP and PTP) were consistent with morphological identifications for 117 species (75.97%). A threshold of 2.5% genetic divergence was observed to differentiate the morphological species efficiently. Careful morphological examination of morphospecies exceeding 2.5% intraspecific variability prove cryptic diversity in three species (Neoblastobasis biceratala, Evippe albidoesella and Promalactis atriplagata). One morphospecies, Promalactis odaiensis, showed high intraspecific divergence while consisted of only a single MOTU. Overall, DNA barcoding was shown to provide a powerful tool to discriminate species of Korean Gelechioidea and reveal cases of cryptic diversity.

El capulín (Prunus serotina Ehrh.): árbol multipropósito con potencial forestal en México

El capulín (Prunus serotina Ehrh.) es un árbol nativo de Norteamérica y casi todas sus partes tienen algún uso potencial. Esta especie conforma un complejo botánico de cinco subespecies morfológicamente distintas que crecen en hábitats diversos. Varios aspectos biológicos del capulín son tema de debate o han sido poco estudiados, dificultando la toma de decisiones acertadas con fines de su conservación y aprovechamiento. Esta revisión tiene como objetivo resaltar la importancia biológica, cultural y comercial del capulín, y la necesidad de incluirlo en programas de conservación y aprovechamiento sostenible de recursos genéticos. Se revisaron siete aspectos concernientes a este objetivo: diferencias morfológicas sutiles entre las subespecies, relaciones filogenéticas inciertas, supuesta variación en el nivel de ploidía, variabilidad molecular, aprovechamiento tradicional y moderno, domesticación y relevancia etnobotánica y potenciación de sus recursos genéticos. Este artículo sostiene la necesidad de darle continuidad al estudio riguroso de estos y otros aspectos, para aprovechar mejor los recursos genéticos del capulín, y enfatiza que, en el corto plazo, México debe impulsar el aprovechamiento del potencial forestal y maderero de esta especie nativa

Evaluation of Statistical Shape Modeling in Quantifying Femoral Morphologic Differences Between Symptomatic and Nonsymptomatic Hips in Patients with Unilateral Femoroacetabular Impingement Syndrome

PurposeTo determine whether statistical shape modeling can detect subtle morphologic differences in the shape of the proximal femur that correlate with clinical findings of unilateral femoroacetabular impingement syndrome.MethodsPatients who had diagnoses of unilateral femoroacetabular impingement syndrome and who had existing computed tomography scans of their pelvises were included. Three-dimensional shape models in the form of triangle meshes were generated from the computed tomography images. Statistical shapes of cam-type and normal hips were compared to identify structural differences.ResultsThe study included 33 hips in 17 subjects. Of the subjects, 7 (41.1%) were male, and 10 (58.9%) were female. The subjects ranged in age from 17-60 years of age (mean 36.3 ± 11.0 years old). The statistical shape modeling found mean shapes and modes after optimizing the groupwise correspondence. Symptomatic hips demonstrated 1 mm of thickening as compared to the femoral necks of asymptomatic hips, corresponding to cam lesions.ConclusionsSymptomatic cam deformities were an average of 1 mm more prominent in the femoral neck region as compared to the asymptomatic hips when using statistical shape modeling. The present study provides a proof of the concept that statistical shape modeling can be used to examine and help define cam morphology and that subtle morphologic differences may account for developing femoroacetabular impingement syndrome.Clinical RelevanceUsing the methods presented in this study, it would be possible to define cam and pincer morphologies by creating statistical shape models, and this work could potentially lead to the development of a new classification system for femoroacetabular impingement syndrome lesions.

DNA barcoding reveals cryptic diversity and peculiar phylogeographic patterns in mojarras (Perciformes: Gerreidae) from the Caribbean and South-western Atlantic

AbstractThe mojarras (Eucinostomus) are a widespread group of coastal fishes of controversial taxonomy because of similarities in their external morphology. In the present study, we assessed the genetic diversity of species and populations of Eucinostomus using DNA barcodes using a systematic and phylogeographic context. In total, 416 COI sequences of all valid Eucinostomus representatives were analysed based on public databases and collected specimens from the north-eastern coast of Brazil (Western South Atlantic). Several cases of misidentification were detected in the barcode dataset (E. argenteus, E. harengulus, E. gula, E. dowii and E. jonesii) that could account for the taxonomic issues in this genus. In contrast, we identified four molecular operational taxonomic units (MOTUs), with divergence above 2% in the Western Atlantic, that correspond to cryptic forms within E. argenteus, E. harengulus, E. gula and E. melanopterus. These data suggest that Plio-Pleistocene events (rise of the Panama isthmus, Amazonas outflow and sea-level fluctuations) played a major role in the diversification of mojarras. While subtle morphological differences have been used as proxies to discriminate Eucinostomus species, the genetic data proved to be efficient in differentiating them and revealing potentially undescribed taxa. Therefore, we recommend that further taxonomic studies in mojarras should incorporate DNA-based evidence.

Structure and Morphology of Poly(lactic acid) Stereocomplex Nanofiber Shish Kebabs.

We report the formation and structure of poly(lactic acid) (PLA) nanofiber shish kebabs (NFSKs) containing stereocomplex crystal (SC) shish and SC/homocrystal (HC) kebabs. PLA-based NFSKs were obtained by combining electrospinning and controlled polymer crystallization in order to investigate the interplay between PLA SC and HC formation. Nanofibers were produced by electrospinning poly(l-lactic acid)/poly(d-lactic acid) (PLLA/PDLA) blends and were used as the shish. A secondary polymer (either PDLA or PLLA/PDLA blends) was decorated on the nanofiber by an incubation method to form kebab lamellae. We show that both SC and HC kebab crystals can be formed using a SC shish following a soft epitaxy mechanism, while the subtle morphological differences in the resultant NFSKs reveal the propensity of SC nuclei in SC/HC crystallization.

Deep-LUMEN assay – human lung epithelial spheroid classification from brightfield images using deep learning

Three-dimensional (3D) tissue models such as epithelial spheroids or organoids have become popular for pre-clinical drug studies. In contrast to 2D monolayer culture, the characterization of 3D tissue models from non-invasive brightfield images is a significant challenge. To address this issue, here we report a deep-learning uncovered measurement of epithelial networks (Deep-LUMEN) assay. Deep-LUMEN is an object detection algorithm that has been fine-tuned to automatically uncover subtle differences in epithelial spheroid morphology from brightfield images. This algorithm can track changes in the luminal structure of tissue spheroids and distinguish between polarized and non-polarized lung epithelial spheroids. The Deep-LUMEN assay was validated by screening for changes in spheroid epithelial architecture in response to different extracellular matrices and drug treatments. Specifically, we found the dose-dependent toxicity of cyclosporin can be underestimated if the effect of the drug on tissue morphology is not considered. Hence, Deep-LUMEN could be used to assess drug effects and capture morphological changes in 3D spheroid models in a non-invasive manner.

Origin of High Activity and Durability of Twisty Nanowire Alloy Catalysts under Oxygen Reduction and Fuel Cell Operating Conditions.

The ability to control the surface composition and morphology of alloy catalysts is critical for achieving high activity and durability of catalysts for oxygen reduction reaction (ORR) and fuel cells. This report describes an efficient surfactant-free synthesis route for producing a twisty nanowire (TNW) shaped platinum-iron (PtFe) alloy catalyst (denoted as PtFe TNWs) with controllable bimetallic compositions. PtFe TNWs with an optimal initial composition of ∼24% Pt are shown to exhibit the highest mass activity (3.4 A/mgPt, ∼20 times higher than that of commercial Pt catalyst) and the highest durability (<2% loss of activity after 40 000 cycles and <30% loss after 120 000 cycles) among all PtFe-based nanocatalysts under ORR or fuel cell operating conditions reported so far. Using ex situ and in situ synchrotron X-ray diffraction coupled with atomic pair distribution function (PDF) analysis and 3D modeling, the PtFe TNWs are shown to exhibit mixed face-centered cubic (fcc)-body-centered cubic (bcc) alloy structure and a significant lattice strain. A striking finding is that the activity strongly depends on the composition of the as-synthesized catalysts and this dependence remains unchanged despite the evolution of the composition of the different catalysts and their lattice constants under ORR or fuel cell operating conditions. Notably, dealloying under fuel cell operating condition starts at phase-segregated domain sites leading to a final fcc alloy structure with subtle differences in surface morphology. Due to a subsequent realloying and the morphology of TNWs, the surface lattice strain observed with the as-synthesized catalysts is largely preserved. This strain and the particular facets exhibited by the TNWs are believed to be responsible for the observed activity and durability enhancements. These findings provide new insights into the correlation between the structure, activity, and durability of nanoalloy catalysts and are expected to energize the ongoing effort to develop highly active and durable low-Pt-content nanowire catalysts by controlling their alloy structure and morphology.

First barcode of Ryphila cancellus (Herbst, 1783), from the southwest coast of India

Ryphila cancellus (Herbst, 1783), belonging to the family Leucosiidae has very unique morphological characteristics compared with the other crab families. They are distributed along the intertidal regions of Indo-pacific and prefer soft-bottom sandy beaches with gentle wave action. Due to very subtle morphological differences with other genera in the same family, identification based on the taxonomical examination alone is quite challenging. In the present study, a detailed morphological examination and DNA barcoding has been performed. The amplified mitochondrial CO1 gene of the crab specimens were sequenced and the obtained sequences were deposited in the Genbank. The neighbour-joining and distance matrix tree revealed the relationship between relative genera. The CO1 gene sequence divergence of Ryphila cancellus with other related groups ranged from 0.1712 to 0.9.

The Eurasian steppe belt in time and space: Phylogeny and historical biogeography of the false flax (Camelina Crantz, Camelineae, Brassicaceae)

Stretching 8000 km from the Pannonian basin and the Danube delta in the West to the Manchuria region in the East and reaching up to 1000 km in width, the Eurasian steppe belt is the vastest steppe region worldwide. However, our knowledge about the temporal and spatial patterns of floral origin and evolution of the Eurasian Steppe is limited and inconclusive. Case studies on typical steppe flora may help us close such gaps. The study subject of this project was Camelina – a taxon which occupies open dry habitats in temperate zones of Eurasia. To infer the evolutionary history of this genus, maximum likelihood optimisation in RAxML and Bayesian Inference approach were carried out, based on the nuclear external transcribed spacer region. Furthermore, we performed a secondarily calibrated time estimation analysis using Bayesian optimisation in BEAST to infer potential influence of climatic shifts and paleogeographic events on the distribution patterns of Camelina and carried out an ancestral area reconstruction analysis using a Bayesian Binary Method. Our study resulted in a well-supported phylogeny that corresponds with the species morphology and uncovered several genetically distinct inter- and intraspecific lineages which appear to correlate geographically. Time divergence estimation argue for the diversification of Camelina to have taken place in the Middle East around the transition from Pliocene to Pleistocene (3-2 mya), and its historical biogeography to have been under a strong influence of several glacial periods and their palaeoclimatic and palaeoenvironmental consequences. Its young age also explains the subtle morphological character differences among species and high interspecific hybridisation potential. We further discuss the rediscovery of wild Camelina sativa populations and propose the external transcribed spacer as a ribotype identifying region for young and rapidly evolving core eudicot lineages.

Effect of PGC1-beta ablation on myonuclear organisation

Skeletal muscle fibres are large, elongated multinucleated cells. Each nucleus within a myofibre is responsible for generating gene products for a finite volume of cytoplasm—the myonuclear domain (MND). Variation in MND sizes during atrophy, hypertrophy and disease states, are common. The factors that contribute to definitive MND sizes are not yet fully understood. Previous work has shown that peroxisome proliferator-activated receptor gamma coactivator 1α (PGC1-α) modulates MND volume, presumably to support increased biogenesis of mitochondria. The transcriptional co-regulator peroxisome proliferator-activated receptor gamma coactivator 1β (PGC1-β) is a homologue of PGC1-α with overlapping functions. To investigate the role of this protein in MND size regulation, we studied a mouse skeletal muscle specific knockout (cKO). Myofibres were isolated from the fast twitch extensor digitorum longus (EDL) muscle, membrane-permeabilised and analysed in 3 dimensions using confocal microscopy. PGC1-β ablation resulted in no significant difference in MND size between cKO and wild type (WT) mice, however, subtle differences in nuclear morphology were observed. To determine whether these nuclear shape changes were associated with alterations in global transcriptional activity, acetyl histone H3 immunostaining was carried out. We found there was no significant difference in nuclear fluorescence intensity between the two genotypes. Overall, the results suggest that PGC-1α and PGC-1β play different roles in regulating nuclear organisation in skeletal muscle; however, further work is required to pinpoint their exact functions.

Human iPSC-Derived Cardiomyocyte Networks on Multiwell Micro-electrode Arrays for Recurrent Action Potential Recordings.

Cardiac safety screening is of paramount importance for drug discovery and therapeutics. Therefore, the development of novel high-throughput electrophysiological approaches for hiPSC-derived cardiomyocyte (hiPSC-CM) preparations is much needed for efficient drug testing. Although multielectrode arrays (MEAs) are frequently employed for field potential measurements of excitable cells, a recent publication by Joshi-Mukherjee and colleagues described and validated its application for recurrent action potential (AP) recordings from the same hiPSC-CM preparation over days. The aim here is to provide detailed step-by-step methods for seeding CMs and for measuring AP waveforms via electroporation with high precision and a temporal resolution of 1 µs. This approach addresses the lack of easy-to-use methodology to gain intracellular access for high-throughput AP measurements for reliable electrophysiological investigations. A detailed work flow and methods for plating of hiPSC-CMs on multiwell MEA plates are discussed emphasizing critical steps wherever relevant. In addition, a custom-built MATLAB script for rapid data handling, extraction and analysis is reported for comprehensive investigation of the waveform analysis to quantify subtle differences in morphology for various AP duration parameters implicated in arrhythmia and cardiotoxicity.

Different speciation processes in a cryptobenthic reef fish from the Western Tropical Atlantic

The saddled blenny Malacoctenus triangulatus is a widely distributed species of cryptobenthic reef fish that occurs from the Caribbean to southeastern Brazil, including the oceanic islands. Subtle morphological differences have been observed between populations, suggesting some degree of structuring along its distribution, especially between insular and coastal environments. In this study, we conducted phylogeographic analyses of M. triangulatus based on mitochondrial (cytochrome oxidase I and cytochrome b) and nuclear (rhodopsin) genes, including sequences of M. brunoi, a closely related species endemic to the oceanic islands of southeastern Brazil. Three highly structured lineages were identified within the M. triangulatus complex: one restricted to the Caribbean province probably isolated by the Amazon barrier, and two in the Brazilian province, one in the northeastern oceanic islands (NOI) and another along the coast (including M. brunoi). This result indicates that divergent evolutionary processes have driven the evolution of the saddled benny in the Tropical Southwestern Atlantic: an ancient isolation of the NOI lineage during the Neogene and a recent ecological speciation event in the southeastern oceanic islands, which were connected to the coast during Pleistocene marine regressions. Together, these results provide insights on the evolutionary patterns and oceanographic barriers in the Western Tropical Atlantic.

Polymorphism and multiple correlated characters: Do flatfish asymmetry morphs also differ in swimming performance and metabolic rate?

Phenotypic polymorphisms often differ in multiple correlated traits including morphology, behavior, and physiology, all of which can affect performance. How selection acts on these suites of traits can be complex and difficult to discern. Starry flounder (Platichthys stellatus) is a pleuronectid flatfish that exhibits rare polymorphism for the direction of eye migration and resulting whole‐body asymmetry. P. stellatus asymmetry morphs differ subtly in several anatomical traits, foraging behavior, and stable isotope signatures, suggesting they may be ecologically segregated, yet performance and metabolic differences are unknown.Here we tested the hypothesis that sinistral and dextral P. stellatus asymmetry morphs diverge in performance and routine metabolic rate (RMR) by comparing prolonged swimming endurance (time to exhaustion at a constant swimming speed), fast‐start swimming velocity and acceleration, and rate of oxygen consumption. Based on subtle morphological differences in caudal tail size, we expected sinistral P. stellatus to have superior prolonged swimming endurance relative to dextral fish, but inferior fast‐start performance.Sinistral P. stellatus exhibited both significantly greater prolonged swimming performance and fast‐start swimming performance. However, sinistral P. stellatus also exhibited greater RMR, suggesting that their general swimming performance could be enhanced by an elevated metabolic rate.Divergence between P. stellatus asymmetry morphs in swimming performance and metabolic rates contributes to growing evidence of ecological segregation between them, as well as our understanding of possible ecological consequences of asymmetry direction in flatfishes. These data provide an example of the complexity of polymorphisms associated with multiple correlated traits in a rare case of asymmetry polymorphism in a marine flatfish species.

Sibling sex, but not androgens, shapes phenotypes in perinatal common marmosets (Callithrix jacchus)

When offspring share a womb, interactions among fetuses can impart lasting impressions on phenotypic outcomes. Such intrauterine interactions often are mediated by sex steroids (estrogens and androgens) produced by the developing fetuses. In many mammals, intrauterine interactions between brothers and sisters lead to masculinization of females, which can induce fitness consequences. Many litter-bearing primates, though, seem to escape androgen-mediated litter effects, begging why? Here, we investigated how the sex composition (i.e., same- or mixed-sex) of litters influences perinatal outcomes in the common marmoset monkey (Callithrix jacchus), using a combination of physiological, morphological, and behavioural assays. We hypothesized that androgens from male fetuses would mediate developmental differences across litter types. We found that newborns (24–36 hours old) from same- and mixed-sex litters were indistinguishable by urinary androgen profiles, birth weights, morphometrics, and behaviour. However, monkeys born into same- and mixed-sex litters exhibited subtle morphological and neurobehavioral differences later in the perinatal period, independent of their androgen profiles. Our findings suggest that while androgens from male fetuses likely do not organize their siblings’ phenotypes, perinatal stimuli may initiate divergent developmental trajectories among siblings, which, in turn, promotes inter-individual variability within families.

Techniques and tools for species identification in ciliates: a review.

Ciliates are highly divergent unicellular eukaryotic organisms with nuclear dualism and a highly specialized ciliary pattern. They inhabit all biotopes and play crucial roles in regulating microbial food webs as they prey on bacteria, protists and even on microscopic animals. Nevertheless, subtle morphological differences and tiny sizes hinder proper species identification for many ciliates. In the present review, an attempt has been made to elaborate the various approaches used by modern day ciliate taxonomists for species identification. The different approaches involved in taxonomic characterization of ciliates such as classical (using live-cell observations, staining techniques, etc.), molecular (involving various marker genes) and statistical (delimitation of cryptic species) methods have been reviewed. Ecological and behavioural aspects in species identification have also been discussed. In present-day taxonomy, it is important to use a 'total evidence' approach in identifying ciliates, relying on both classical and molecular information whenever possible. This integrative approach will help in the mergence of classical methods with modern-day tools for comprehensive species description in future.