scholarly journals Fine-scale genital morphology affects male ejaculation success: an experimental test

2020 ◽  
Vol 16 (6) ◽  
pp. 20200251
Author(s):  
Meng-Han Joseph Chung ◽  
Rebecca J. Fox ◽  
Michael D. Jennions
Keyword(s):  
Potential Role ◽  
Detectable Effect ◽  
Gambusia Holbrooki ◽  
Fine Scale ◽  
Sperm Production ◽  
Internal Fertilization ◽  
Sperm Release ◽  
Selection For ◽  
Male Genital

The evolution of male genital traits is usually ascribed to advantages that arise when there is sperm competition, cryptic female choice or sexual conflict. However, when male–female contact is brief and sperm production is costly, genital structures that ensure the appropriate timing of sperm release should also be under intense selection. Few studies have examined the role of individual structures in triggering ejaculation. We therefore conducted a series of anatomical manipulations of fine-scale features of the complex intromittent organ (gonopodium) of a freshwater fish with internal fertilization ( Gambusia holbrooki ) to determine their effects on sperm release. Mating in G. holbrooki is fleeting (less than 50 ms), so there should be strong selection for control over the timing of sperm release. We surgically removed three features at the tip of the gonopodium (claws, spines, awl-shape) to test for their potential role in triggering ejaculation. We show that the ‘awl-shape' of the tip affects sperm release when a male makes contact with a female, but neither gonopodial claws nor spines had a detectable effect. We suggest that the claws and spines may instead function to increase the precision of sperm deposition (facilitating anchorage and contact time with the female's gonopore), rather than the initiation of ejaculation.

scholarly journals Maternal effects alter the severity of inbreeding depression in the offspring

2016 ◽  
Vol 283 (1838) ◽  
pp. 20161023 ◽  
Author(s):  
Natalie Pilakouta ◽  
Per T. Smiseth
Keyword(s):  
Maternal Effects ◽  
Inbreeding Depression ◽  
Potential Role ◽  
Causal Effect ◽  
Natural Populations ◽  
Larval Survival ◽  
Burying Beetle ◽  
Nicrophorus Vespilloides ◽  
Selection For

A maternal effect is a causal influence of the maternal phenotype on the offspring phenotype over and above any direct effects of genes. There is abundant evidence that maternal effects can have a major impact on offspring fitness. Yet, no previous study has investigated the potential role of maternal effects in influencing the severity of inbreeding depression in the offspring. Inbreeding depression is a reduction in the fitness of inbred offspring relative to outbred offspring. Here, we tested whether maternal effects due to body size alter the magnitude of inbreeding depression in the burying beetle Nicrophorus vespilloides . We found that inbreeding depression in larval survival was more severe for offspring of large females than offspring of small females. This might be due to differences in how small and large females invest in an inbred brood because of their different prospects for future breeding opportunities. To our knowledge, this is the first evidence for a causal effect of the maternal phenotype on the severity of inbreeding depression in the offspring. In natural populations that are subject to inbreeding, maternal effects may drive variation in inbreeding depression and therefore contribute to variation in the strength and direction of selection for inbreeding avoidance.

Male terminalia morphology of sixteen species of the Drosophila saltans group Sturtevant (Diptera, Drosophilidae)

Zootaxa ◽  
2021 ◽  
Vol 5061 (3) ◽  
pp. 523-544
Author(s):  
BRUNA EMILIA ROMAN ◽  
LILIAN MADI-RAVAZZI
Keyword(s):  
Sexual Selection ◽  
Sibling Species ◽  
Potential Role ◽  
Rapid Evolution ◽  
Variable Structure ◽  
Diagnostic Feature ◽  
Internal Fertilization ◽  
Saltans Group

Male terminalia in insects with internal fertilization evolve more rapidly than other structures. The aedeagus is the most variable structure, making it a valuable diagnostic feature to distinguish species. The saltans group Sturtevant of Drosophila Fallén contains sibling species, that can be distinguished by their aedeagi. Here, we revised and illustrated the morphology of the male terminalia of the following species: Drosophila prosaltans Duda, 1927; D. saltans Sturtevant, 1916; D. lusaltans Magalhães, 1962; D. austrosaltans Spassky, 1957; D. septentriosaltans Magalhães, 1962; D. nigrosaltans Magalhães, 1962; D. pseudosaltans Magalhães, 1956; D. sturtevanti Duda, 1927; D. lehrmanae Madi-Ravazzi et al., 2021; D. dacunhai Mourão & Bicudo, 1967; D. milleri Magalhães, 1962; D. parasaltans Magalhães, 1956; D. emarginata Sturtevant, 1942; D. neoelliptica Pavan & Magalhães in Pavan, 1950; D. neosaltans Pavan & Magalhães in Pavan, 1950 and D. neocordata Magalhães, 1956. We found that phallic structures (e.g., the aedeagus) evolve more rapidly than periphallic structures (e.g., epandrium), being completely different among the subgroups and within them. This rapid evolution may be due to the action of sexual selection or to the potential role of those structures in speciation.  

scholarly journals The Influence of Applicant and Reviewer Gender on Resident Selection for Internal Medicine

2021 ◽  
Vol 8 ◽  
pp. 238212052110165
Author(s):  
Steven J Katz
Keyword(s):  
Internal Medicine ◽  
Gender Bias ◽  
Potential Role ◽  
Selection Process ◽  
Expected Number ◽  
Internal Medicine Residency Program ◽  
Selection For ◽  
Resident Selection ◽  
Component Scores

Background: While gender bias in medicine, including physician training, has been well described, less is known about gender bias in the selection process for post graduate residency training programs. This analysis reviews the potential role of gender on resident selection for an internal medicine residency program. Methods: File review and interview overall and component scores were analyzed based on the gender of the applicant. File review scores were further analyzed based on the reviewer’s gender. Results: Women applicants scored higher than men applicants on their file review. There were no differences in any one component score except for leadership in art. Women file reviewers scored applicants higher than men file reviewers, but there was no difference between gender scores. There was no difference in overall or component interview scores between men or women applicants. Scoring did not impact the expected rank performance of applicants based on gender at any stage of the selection process. Conclusions: While higher scores were observed in women applicants upon their file review, and women reviewers provided higher file review scores, this did not appear to impact the expected number of women and men applicants at each stage of the applicant process. This suggests a potential lack of gender bias at these stages of applicant selection.

scholarly journals Potential Role of Convolutional Neural Network Based Algorithm in Patient Selection for DCIS Observation Trials Using a Mammogram Dataset

2020 ◽  
Vol 27 (6) ◽  
pp. 774-779
Author(s):  
Simukayi Mutasa ◽  
Peter Chang ◽  
Eduardo P. Van Sant ◽  
John Nemer ◽  
Michael Liu ◽  
...  
Keyword(s):  
Neural Network ◽  
Convolutional Neural Network ◽  
Patient Selection ◽  
Potential Role ◽  
Selection For

scholarly journals Light environment influences mating behaviours during the early stages of divergence in tropical butterflies

2020 ◽  
Author(s):  
Alexander E. Hausmann ◽  
Chi-Yun Kuo ◽  
Marília Freire ◽  
Nicol Rueda-M ◽  
Mauricio Linares ◽  
...  
Keyword(s):  
Close Relative ◽  
Putative Hybrid ◽  
Fine Scale ◽  
Hybrid Species ◽  
Video Footage ◽  
Signal Perception ◽  
Visual Attraction ◽  
Selection For ◽  
Mating Cues

ABSTRACTSpecies divergence is facilitated when traits under divergent selection also act as mating cues. Fluctuations in sensory conditions can alter signal perception independently of adaptation to contrasting sensory environments, but how this fine scale variation affects behavioural isolation has received less attention, especially in terrestrial organisms. The warning patterns of Heliconius butterflies are under selection for aposematism and act as mating cues. Using computer vision, we extracted behavioural data from 1481 hours of video footage for 387 individuals. We show that the putative hybrid species H. heurippa and its close relative H. timareta linaresi differ in their response to divergent warning patterns, and that these differences are strengthened with increased local illuminance. Trials with live individuals reveal low-level assortative mating that are sufficiently explained by differences in visual attraction. Finally, results from hybrid butterflies are consistent with linkage between a major warning pattern gene and the corresponding behaviour, though the differences in behaviour we observe are unlikely to cause rapid reproductive isolation as predicted under a model of hybrid trait speciation. Overall, our results highlight that the role of ecological mating cues for behavioural isolation may depend on the immediate sensory conditions during which they are displayed to conspecifics.

POPDC proteins and cardiac function

2019 ◽  
Vol 47 (5) ◽  
pp. 1393-1404 ◽  
Author(s):  
Thomas Brand
Keyword(s):  
Potential Role ◽  
Striated Muscle ◽  
Short Review ◽  
Effector Proteins ◽  
Muscle Disease ◽  
Disease Genes ◽  
Protein Protein Interaction ◽  
Interaction Partners ◽  
And Function

Abstract The Popeye domain-containing gene family encodes a novel class of cAMP effector proteins in striated muscle tissue. In this short review, we first introduce the protein family and discuss their structure and function with an emphasis on their role in cyclic AMP signalling. Another focus of this review is the recently discovered role of POPDC genes as striated muscle disease genes, which have been associated with cardiac arrhythmia and muscular dystrophy. The pathological phenotypes observed in patients will be compared with phenotypes present in null and knockin mutations in zebrafish and mouse. A number of protein–protein interaction partners have been discovered and the potential role of POPDC proteins to control the subcellular localization and function of these interacting proteins will be discussed. Finally, we outline several areas, where research is urgently needed.

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