Size, shape, and direction matters: Matching secondary genital structures in male and female mites using multiple microscopy techniques and 3D modeling.
Ontology highlight
ABSTRACT:
SUBMITTER: Combita-Heredia O
PROVIDER: S-EPMC8372888 | biostudies-literature |
REPOSITORIES: biostudies-literature
Similar Datasets
Project description:Comparisons of 3D shapes have recently been applied to diverse anatomical structures using landmarking techniques. However, discerning evolutionary patterns can be challenging for structures lacking homologous landmarks. We used alpha shape analyses to quantify vaginal shape complexity in 40 marine mammal specimens including cetaceans, pinnipeds, and sirenians. We explored phylogenetic signal and the potential roles of natural and sexual selection on vaginal shape evolution. Complexity scores were consistent with qualitative observations. Cetaceans had a broad range of alpha complexities, while pinnipeds were comparatively simple and sirenians were complex. Intraspecific variation was found. Three-dimensional surface heat maps revealed that shape complexity was driven by invaginations and protrusions of the vaginal wall. Phylogenetic signal was weak and metrics of natural selection (relative neonate size) and sexual selection (relative testes size, sexual size dimorphism, and penis morphology) did not explain vaginal complexity patterns. Additional metrics, such as penile shape complexity, may yield interesting insights into marine mammal genital coevolution. We advocate for the use of alpha shapes to discern patterns of evolution that would otherwise not be possible in 3D anatomical structures lacking homologous landmarks.
| S-EPMC8019040 | biostudies-literature
Project description:Most birds have simple genitalia; males lack external genitalia and females have simple vaginas. However, male waterfowl have a phallus whose length (1.5->40 cm) and morphological elaborations vary among species and are positively correlated with the frequency of forced extra-pair copulations among waterfowl species. Here we report morphological complexity in female genital morphology in waterfowl and describe variation vaginal morphology that is unprecedented in birds. This variation comprises two anatomical novelties: (i) dead end sacs, and (ii) clockwise coils. These vaginal structures appear to function to exclude the intromission of the counter-clockwise spiralling male phallus without female cooperation. A phylogenetically controlled comparative analysis of 16 waterfowl species shows that the degree of vaginal elaboration is positively correlated with phallus length, demonstrating that female morphological complexity has co-evolved with male phallus length. Intersexual selection is most likely responsible for the observed coevolution, although identifying the specific mechanism is difficult. Our results suggest that females have evolved a cryptic anatomical mechanism of choice in response to forced extra-pair copulations.
| S-EPMC1855079 | biostudies-literature
Project description:The adaptive canalization hypothesis predicts that highly fitness-relevant traits are canalized via past selection, resulting in low phenotypic plasticity and high robustness to environmental stress. Accordingly, we hypothesized that the level of phenotypic plasticity of male body size of the predatory mites Phytoseiulus persimilis (low plasticity) and Neoseiulus californicus (high plasticity) reflects the effects of body size variation on fitness, especially male lifetime reproductive success (LRS). We first generated small and standard-sized males of P. persimilis and N. californicus by rearing them to adulthood under limited and ample prey supply, respectively. Then, adult small and standard-sized males were provided with surplus virgin females throughout life to assess their mating and reproductive traits. Small male body size did not affect male longevity or the number of fertilized females but reduced male LRS of P. persimilis but not N. californicus. Proximately, the lower LRS of small than standard-sized P. persimilis males correlated with shorter mating durations, probably decreasing the amount of transferred sperm. Ultimately, we suggest that male body size is more strongly canalized in P. persimilis than N. californicus because deviation from standard body size has larger detrimental fitness effects in P. persimilis than N. californicus.
| S-EPMC4133644 | biostudies-literature
Project description:Introduction:Lichen sclerosus (LS) is a chronic inflammatory disease affecting mainly the genital mucous membranes in both sexes. In the past, different terms were used to describe the disease, rendering a unique and specific clinical classification impossible. Aim:New therapeutic approaches are being defined, which may contribute to a proper clinical management, however, a stage classification is essential to better define appropriate treatment for every stage of the disease. Material and methods:One hundred and fifteen patients (50 women and 65 men) with a diagnosis of LS were enrolled between January 2014 and September 2016. All patients underwent cutaneous biopsy to confirm the clinical diagnosis of LS. Clinical and symptomatological parameters were used in order to put the patients into the correct stage of LS. The Dermatology Life Quality Index (DLQI) was used to classify patients based on subjective symptoms. Different cutaneous alterations and structural modifications of the genital mucosa were also taken into consideration in order to assign every patient to a specific stage. Conclusions:Lichen sclerosus is clinically described differently in females and in males and every form of LS is put into one of two stages according to the degree of severity: early and late stages. Within the clinical practice, it is useful to screen patients for groups of early or late forms of the disease in order to obtain a uniform subdivision of patients: those who may benefit from localized treatments, require a systemic drug and must undergo physical treatments (surgical, stem cells infiltrations).
| S-EPMC6232547 | biostudies-other
Project description:BackgroundIn most animal groups, it is unclear how body size variation relates to genital size differences between the sexes. While most morphological features tend to scale with total somatic size, this does not necessarily hold for genitalia because divergent evolution in somatic size between the sexes would cause genital size mismatches. Theory predicts that the interplay of female-biased sexual size dimorphism (SSD) and sexual genital size dimorphism (SGD) should adhere to the 'positive genital divergence', the 'constant genital divergence', or the 'negative genital divergence' model, but these models remain largely untested. We test their validity in the spider family Nephilidae known for the highest degrees of SSD among terrestrial animals.ResultsThrough comparative analyses of sex-specific somatic and genital sizes, we first demonstrate that 99 of the 351 pairs of traits are phylogenetically correlated. Through factor analyses we then group these traits for MCMCglmm analyses that test broader correlation patterns, and these reveal significant correlations in 10 out of the 36 pairwise comparisons. Both types of analyses agree that female somatic and internal genital sizes evolve independently. While sizes of non-intromittent male genital parts coevolve with male body size, the size of the intromittent male genital parts is independent of the male somatic size. Instead, male intromittent genital size coevolves with female (external and, in part, internal) genital size. All analyses also agree that SGD and SSD evolve independently.ConclusionsInternal dimensions of female genitalia evolve independently of female body size in nephilid spiders, and similarly, male intromittent genital size evolves independently of the male body size. The size of the male intromittent organ (the embolus) and the sizes of female internal and external genital components thus seem to respond to selection against genital size mismatches. In accord with these interpretations, we reject the validity of the existing theoretical models of genital and somatic size dimorphism in spiders.
| S-EPMC4989301 | biostudies-literature
Project description:Male to female transsexuals frequently seek feminizing vaginoplasty for "below the waist" conformation, enhancement of sexual identity, and interactive sexual function. The author shares his experience with his first 250 primary surgical procedures. Included is a brief historical background, the patient selection process, some guidelines from the World Professional Association for Transgender Health (standards of care), preoperative evaluation and instructions, surgical technique, postoperative regimen, risk factors, results, complications and management. The patients all underwent feminizing vaginoplasty at the author's ambulatory surgical facility, which includes an overnight stay. The author's results suggest that feminizing vaginoplasty when performed vigilantly on a select group of patients is feasible.
| S-EPMC3312144 | biostudies-other
Project description:Our understanding of coevolution between male genitalia and female traits remains incomplete. This is perhaps especially true for genital traits that cause internal injuries in females, such as the spiny genitalia of seed beetles where males with relatively long spines enjoy a high relative fertilization success. We report on a new set of experiments, based on extant selection lines, aimed at assessing the effects of long male spines on females in Callosobruchus maculatus. We first draw on an earlier study using microscale laser surgery, and demonstrate that genital spines have a direct negative (sexually antagonistic) effect on female fecundity. We then ask whether artificial selection for long versus short spines resulted in direct or indirect effects on female lifetime offspring production. Reference females mating with males from long-spine lines had higher offspring production, presumably due to an elevated allocation in males to those ejaculate components that are beneficial to females. Remarkably, selection for long male genital spines also resulted in an evolutionary increase in female offspring production as a correlated response. Our findings thus suggest that female traits that affect their response to male spines are both under direct selection to minimize harm but are also under indirect selection (a good genes effect), consistent with the evolution of mating and fertilization biases being affected by several simultaneous processes.
| S-EPMC8261210 | biostudies-literature
Project description:Unique compositional and functional features of the cervicovaginal microbiota have been associated with protection against and risk for sexually transmitted infections (STI). In men, our knowledge of the interaction between the penile microbiota and STI is less developed. The current state of our understanding of these microbiota and their role in select STIs is briefly reviewed, along with strategies that leverage existing findings to manipulate genital microbiota and optimize protection against STIs. Finally, we focus on major research gaps and present a framework for future studies.
| S-EPMC8206802 | biostudies-literature
Project description:Male genital morphology of animals with internal fertilization and promiscuous mating systems have been one of the most diverse and rapidly evolving morphological traits. The male genital morphology in general is known to have low phenotypic and genetic variations, but the genetic basis of the male genital variation remains unclear. Drosophila melanogaster and its closely related species are morphologically very similar, but the shapes of the posterior lobe, a cuticular projection on the male genital arch are distinct from each other, representing a model system for studying the genetic basis of male genital morphology. In this study, we used highly inbred whole genome sequenced strains of D. melanogaster to perform genome wide association analysis on posterior lobe morphology. We quantified the outline shape of posterior lobes with Fourier coefficients obtained from elliptic Fourier analysis and performed principal component analysis, and posterior lobe size. The first and second principal components (PC1 and PC2) explained approximately 88% of the total variation of the posterior lobe shape. We then examined the association between the principal component scores and posterior lobe size and 1902142 single nucleotide polymorphisms (SNPs). As a result, we obtained 15, 14 and 15 SNPs for PC1, PC2 and posterior lobe size with P-values smaller than 10(-5). Based on the location of the SNPs, 13, 13 and six protein coding genes were identified as potential candidates for PC1, PC2 and posterior lobe size, respectively. In addition to the previous findings showing that the intraspecific posterior shape variation are regulated by multiple QTL with strong effects, the present study suggests that the intraspecific variation may be under polygenic regulation with a number of loci with small effects. Further studies are required for investigating whether these candidate genes are responsible for the intraspecific posterior lobe shape variation.
| S-EPMC4504508 | biostudies-literature
Project description:BackgroundHand-to-genital contact is hypothesised to be a transmission mode of human papillomavirus (HPV) of the Alphapapillomavirus genus. We compared the relative importance of hand-to-genital and genital-to-genital HPV transmission between sexual partners.MethodsIn this prospective cohort study, we recruited and followed up female university students aged 18-24 years and their male sexual partners in Montreal, QC, Canada (2005-11). Participants were eligible if they had initiated sexual activity within the past 6 months. Women were examined at clinic visits at baseline and every 4-6 months for up to 24 months. Men had a baseline visit and a single follow-up visit approximately 4 months later. Partners provided hand and genital swab samples, which we tested for DNA of 36 HPV types using PCR. We assessed predictors of incident type-specific HPV detections using Cox proportional hazards models.FindingsParticipants were recruited between June 5, 2006, and April 4, 2013. 264 women and 291 men had valid hand samples. The hazard ratio (HR) of incident detection of HPV in genital samples from women was 5·0 (95% CI 1·5-16·4) when her partner was positive for the same HPV type on his hand versus negative, but adjustment for his genital HPV status reduced the HR to 0·5 (0·1-1·8). Similarly, the HR of incident detection of HPV on men's genitals was 17·4 (95% CI 7·9-38·5) when his partner was positive for the same HPV type on her hand versus negative, but adjustment for her genital HPV status reduced the HR to 2·3 (0·9-6·2). Conversely, the HR of type-specific incident detection of HPV in genital samples associated with partner genital HPV positivity was 19·3 (95% CI 11·8-31·8) for women and 28·4 (15·4-52·1) for men after adjustment for their hand HPV status.InterpretationClinicians can reassure their patients that HPV transmission is unlikely to occur through hand-to-genital contact. The majority of genital HPV infections are likely to be caused by genital-to-genital sexual transmission.FundingCanadian Institutes for Health Research, National Institutes of Health, Fonds de la Recherche en Santé du Québec, and Merck & Co.
| S-EPMC6404546 | biostudies-literature