Premating Reproductive Barriers between Hybridising Cricket Species Differing in Their Degree of Polyandry

Understanding speciation hinges on understanding how reproductive barriers arise between incompletely isolated populations. Despite their crucial role in speciation, prezygotic barriers are relatively poorly understood and hard to predict. We use two closely related cricket species, Gryllus bimaculatus and G. campestris, to experimentally investigate premating barriers during three sequential mate choice steps. Furthermore, we experimentally show a significant difference in polyandry levels between the two species and subsequently test the hypothesis that females of the more polyandrous species, G. bimaculatus, will be less discriminating against heterospecific males and hence hybridise more readily. During close-range mating behaviour experiments, males showed relatively weak species discrimination but females discriminated very strongly. In line with our predictions, this discrimination is asymmetric, with the more polyandrous G. bimaculatus mating heterospecifically and G. campestris females never mating heterospecifically. Our study shows clear differences in the strength of reproductive isolation during the mate choice process depending on sex and species, which may have important consequences for the evolution of reproductive barriers

Assessing the Consultation and Relational Empathy (CARE) Measure in sexual health nurses' consultations

Background: Increasingly healthcare policies emphasise the importance of person-centred, empathic care. Consequently, healthcare professionals are expected to demonstrate the ‘human’ aspects of care in training and in practice. The Consultation and Relational Empathy (CARE) Measure is a patient-rated measure of the interpersonal skills of healthcare practitioners. It has been widely validated for use by healthcare professionals in both primary and secondary care. This paper reports on the validity and reliability of the CARE Measure with sexual health nurses. Methods: Patient questionnaires were collected for 943 consultations with 20 sexual health nurses. Participating patients self-completed the questionnaire immediately after the encounter with the nurse. The questionnaire included the ten item CARE Measure, the Patient Enablement Index, and overall satisfaction instruments. Construct validity was assessed through Spearman’s correlation and principal component analysis. Internal consistence was assessed through Cronbach’s alpha and the inter-rater reliability through Generalisability Theory. Data were collected in 2013 in Scotland. Results: Female patients completed 68% of the questionnaires. The mean patient age was 28.8 years (standard deviation 9.8 years). Two of the 20 participating nurses withdrew from the study. Most patients (71.7%) regarded the CARE Measure items as very important to their consultation and the number of ‘not applicable’ and missing responses’ were low (2.6% and 0.1% respectively). The participating nurses had high CARE Measure scores; out of a maximum possible score of 50, the overall mean CARE measure score was 47.8 (standard deviation 4.4). The scores were moderately correlated with patient enablement (rho = 0.232, p = 0.001) and overall satisfaction (rho = 0.377, p = 0.001. Cronbach’s alpha showed the measure’s high internal consistency (Cronbach’s alpha coefficient = 0.95), but the inter-rater reliability could not be calculated due to the high achieved CARE Measure scores that varied little between nurses. Conclusions: Within this clinical context the CARE Measure has high perceived relevance and face validity. The findings support construct validity and some evidence of reliability. The high CARE Measure scores may have been due to sample bias. A future study which ensures a representative sample of patients on a larger group of nurses is required to determine whether the measure can discriminate between nurses

Identification of ejaculated proteins in the house mouse (Mus domesticus) via isotopic labeling

<p>Abstract</p> <p>Background</p> <p>Seminal fluid plays an important role in successful fertilization, but knowledge of the full suite of proteins transferred from males to females during copulation is incomplete. The list of ejaculated proteins remains particularly scant in one of the best-studied mammalian systems, the house mouse (<it>Mus domesticus</it>), where artificial ejaculation techniques have proven inadequate. Here we investigate an alternative method for identifying ejaculated proteins, by isotopically labeling females with ¹⁵N and then mating them to unlabeled, vasectomized males. Proteins were then isolated from mated females and identified using mass spectrometry. In addition to gaining insights into possible functions and fates of ejaculated proteins, our study serves as proof of concept that isotopic labeling is a powerful means to study reproductive proteins.</p> <p>Results</p> <p>We identified 69 male-derived proteins from the female reproductive tract following copulation. More than a third of all spectra detected mapped to just seven genes known to be structurally important in the formation of the copulatory plug, a hard coagulum that forms shortly after mating. Seminal fluid is significantly enriched for proteins that function in protection from oxidative stress and endopeptidase inhibition. Females, on the other hand, produce endopeptidases in response to mating. The 69 ejaculated proteins evolve significantly more rapidly than other proteins that we previously identified directly from dissection of the male reproductive tract.</p> <p>Conclusion</p> <p>Our study attempts to comprehensively identify the proteins transferred from males to females during mating, expanding the application of isotopic labeling to mammalian reproductive genomics. This technique opens the way to the targeted monitoring of the fate of ejaculated proteins as they incubate in the female reproductive tract.</p

Complex genetic nature of sex-independent transmission ratio distortion in Asian rice species: the involvement of unlinked modifiers and sex-specific mechanisms

Transmission ratio distortion (TRD), in which one allele is transmitted more frequently than the opposite allele, is presumed to act as a driving force in the emergence of a reproductive barrier. TRD acting in a sex-specific manner has been frequently observed in interspecific and intraspecific hybrids across a broad range of organisms. In contrast, sex-independent transmission ratio distortion (siTRD), which results from preferential transmission of one of the two alleles in the heterozygote through both sexes, has been detected in only a few plant species. We previously reported S6 locus-mediated siTRD, in which the S6 allele from an Asian wild rice strain (Oryza rufipogon) was transmitted more frequently than the S6^[a] allele from an Asian cultivated rice strain (O. sativa) through both male and female gametes in heterozygous plants. Here, we report on the effect of a difference in genetic background on S6 locus-mediated siTRD based on the analysis using near-isogenic lines and the original wild strain as a parental strain for crossing. We found that the degree of TRD through the male gametes varied depending on the genetic background of the female (pistil) plants. Despite the occurrence of TRD through both male and female gametes, abnormality was detected in ovules, but not in pollen grains, in the heterozygote. These results suggest the involvement of unlinked modifiers and developmentally distinct, sex-specific genetic mechanisms in S6 locus-mediated siTRD, raising the possibility that siTRD driven by a single locus may be affected by multiple genetic factors harbored in natural populations

Hybridization and adaptive mate choice in flycatchers.

Hybridization in natural populations is strongly selected against when hybrid offspring have reduced fitness. Here we show that, paradoxically, pairing with another species may offer the best fitness return for an individual, despite reduced fitness of hybrid offspring. Two mechanisms reduce the costs to female collared flycatchers of pairing with male pied flycatchers. A large proportion of young are sired by conspecific male collared flycatchers through extra-pair copulations, and there is a bias in favour of male offspring (which, unlike females, are fertile) within hybrid pairs. In combination with temporal variation in breeding success, these cost-reducing mechanisms yield quantitative predictions about when female collared flycatchers should accept a male pied flycatcher as a mate; empirical data agree with these predictions. Apparent hybridization may thus represent adaptive mate choice under some circumstances

Decoding the Ascaris suum Genome using Massively Parallel Sequencing and Advanced Bioinformatic Methods - Unprecedented Prospects for Fundamental and Applied Research

Parasitic nematodes cause substantial morbidity and mortality in animals and people globally and major losses to food production annually. Ascaris is among the commonest geohelminths of swine and people worldwide, and causes major disease and socioeconomic losses, particularly in developing countries. The control of ascariasis has become a global health and welfare priority, but current treatment programs carry a significant risk of inducing anthelmintic resistance. Therefore, there is a need to work toward the sustainable control of Ascaris/ascariasis, built on a solid understanding of its molecular biology and genetics. Recently, we reported the 273 megabase (Mb) draft genome of Ascaris suum (sequenced from the reproductive tract of a single adult female worm) and explored transcription in different organs, stages, and both sexes of this nematode using advanced sequencing and computer technologies. We characterized key genes and biological pathways linked to the parasite's migration in the host, and its immunobiology, reproduction, and development. We also predicted and prioritized drug targets in A. suum, providing a basis for discovering new groups of nematocides. The present chapter provides an account of these recent advances, describes new methodologies established, and emphasizes prospects for profound investigations into the comparative genomics, genetics, evolution, immunobiology, epidemiology, and ecology of Ascaris from both pig and human hosts as well as for the development of new interventions against ascariasis and other helminthiases. © 2013 Copyrigh