Evolutionary Rate Covariation Identifies New Members of a Protein Network Required for Drosophila melanogaster Female Post-Mating Responses

Seminal fluid proteins transferred from males to females during copulation are required for full fertility and can exert dramatic effects on female physiology and behavior. In Drosophila melanogaster, the seminal protein sex peptide (SP) affects mated females by increasing egg production and decreasing receptivity to courtship. These behavioral changes persist for several days because SP binds to sperm that are stored in the female. SP is then gradually released, allowing it to interact with its female-expressed receptor. The binding of SP to sperm requires five additional seminal proteins, which act together in a network. Hundreds of uncharacterized male and female proteins have been identified in this species, but individually screening each protein for network function would present a logistical challenge. To prioritize the screening of these proteins for involvement in the SP network, we used a comparative genomic method to identify candidate proteins whose evolutionary rates across the Drosophila phylogeny co-vary with those of the SP network proteins. Subsequent functional testing of 18 co-varying candidates by RNA interference identified three male seminal proteins and three female reproductive tract proteins that are each required for the long-term persistence of SP responses in females. Molecular genetic analysis showed the three new male proteins are required for the transfer of other network proteins to females and for SP to become bound to sperm that are stored in mated females. The three female proteins, in contrast, act downstream of SP binding and sperm storage. These findings expand the number of seminal proteins required for SP's actions in the female and show that multiple female proteins are necessary for the SP response. Furthermore, our functional analyses demonstrate that evolutionary rate covariation is a valuable predictive tool for identifying candidate members of interacting protein networks. © 2014 Findlay et al

The Drosophila melanogaster Seminal Fluid Protease “Seminase” Regulates Proteolytic and Post-Mating Reproductive Processes

Proteases and protease inhibitors have been identified in the ejaculates of animal taxa ranging from invertebrates to mammals and form a major protein class among Drosophila melanogaster seminal fluid proteins (SFPs). Other than a single protease cascade in mammals that regulates seminal clot liquefaction, no proteolytic cascades (i.e. pathways with at least two proteases acting in sequence) have been identified in seminal fluids. In Drosophila, SFPs are transferred to females during mating and, together with sperm, are necessary for the many post-mating responses elicited in females. Though several SFPs are proteolytically cleaved either during or after mating, virtually nothing is known about the proteases involved in these cleavage events or the physiological consequences of proteolytic activity in the seminal fluid on the female. Here, we present evidence that a protease cascade acts in the seminal fluid of Drosophila during and after mating. Using RNAi to knock down expression of the SFP CG10586, a predicted serine protease, we show that it acts upstream of the SFP CG11864, a predicted astacin protease, to process SFPs involved in ovulation and sperm entry into storage. We also show that knockdown of CG10586 leads to lower levels of egg laying, higher rates of sexual receptivity to subsequent males, and abnormal sperm usage patterns, processes that are independent of CG11864. The long-term phenotypes of females mated to CG10586 knockdown males are similar to those of females that fail to store sex peptide, an important elicitor of long-term post-mating responses, and indicate a role for CG10586 in regulating sex peptide. These results point to an important role for proteolysis among insect SFPs and suggest that protease cascades may be a mechanism for precise temporal regulation of multiple post-mating responses in females

Estimating the number of children exposed to parental psychiatric disorders through a national health survey

<p>Abstract</p> <p>Objective</p> <p>Children whose parents have psychiatric disorders experience an increased risk of developing psychiatric disorders, and have higher rates of developmental problems and mortality. Assessing the size of this population is important for planning of preventive strategies which target these children.</p> <p>Methods</p> <p>National survey data (CCHS 1.2) was used to estimate the number of children exposed to parental psychiatric disorders. Disorders were diagnosed using the World Psychiatric Health Composite International Diagnostic Interview (WMH-CIDI) (12 month prevalence). Data on the number of children below 12 years of age in the home, and the relationship of the respondents with the children, was used to estimate exposure. Parent-child relations were identified, as was single parenthood. Using a design-based analysis, the number of children exposed to parental psychiatric disorders was calculated.</p> <p>Results</p> <p>Almost 570,000 children under 12 live in households where the survey respondent met criteria for one or more mood, anxiety or substance use disorders in the previous 12 months, corresponding to 12.1% of Canadian children under the age of 12. Almost 3/4 of these children have parents that report receiving no mental health care in the 12 months preceding the survey. For 17% of all Canadian children under age 12, the individual experiencing a psychiatric disorder is the only parent in the household.</p> <p>Conclusion</p> <p>The high number of children exposed causes major concern and has important implications. Although these children will not necessarily experience adversities, they possess an elevated risk of accidents, mortality, and of developing psychiatric disorders. We expect these estimates will promote further research and stimulate discussion at both health policy and planning tables.</p

The Consequences of Genetic Variation in Sex Peptide Expression Levels for Egg Laying and Retention in Females

The accessory gland proteins (Acps) that male Drosophila melanogaster produce and transfer to females during copulation are key to male and female fitness. One Acp, the sex peptide (SP), is largely responsible for a dramatic increase in female egg laying and decrease in female receptivity after copulation. While genetic variation in male SP expression levels correlate with refractory period duration in females, it is unknown whether male SP expression influences female egg laying or if any effect of SP is mediated by SP retention in the female reproductive tract. Here we measured the amount of SP retained in the female reproductive tract after mating and female egg laying after copulating with virgin males. We found no correlation between male SP expression levels and egg laying, or the amount of SP in the female reproductive tract after mating. Additionally, the amount of SP retained in the female did not influence egg laying. These finding suggests that additional factors, such as variation in other Acps, are important for the retention of SP in females and its quantitative effects on egg laying. It also shows that egg laying and refractory period response to SP is at least partially uncoupled. © 2012 Macmillan Publishers Limited All rights reserved

Prevalência de abuso físico na infância e exposição à violência parental em uma amostra brasileira Prevalence of physical abuse in childhood and exposure to parental violence in a Brazilian sample

O estudo objetivou avaliar a prevalência de abuso físico e exposição à violência parental na infância, segundo características sócio-demográficas. Um procedimento de amostragem de múltiplos estágios foi usado para selecionar 3.007 indivíduos de 14 anos de idade ou mais, entre 2005/2006, incluindo sujeitos de todas as regiões do país, assim, os resultados são nacionalmente representativos. Foram acessadas experiências de abuso físico (bater, bater com alguma coisa, queimar/escaldar, ameaçar/usar faca ou arma) e exposição à violência parental (testemunhou ameaça e/ou agressão física parental) na infância. Realizaram-se as análises através do teste qui-quadrado de Pearson. A prevalência de história de abuso físico na infância foi de 44,1%, sendo que 33,8% relataram história de abuso físico moderado e 10,3% abuso físico severo. A prevalência de exposição à violência parental foi de 26,1%, sendo que 7,5% testemunharam violência parental moderada e 18,6% testemunharam violência parental severa na infância. Análises combinadas entre estes dois tipos de violência demonstraram significativas associações entre elas. Estes resultados podem ajudar na implementação de estratégias de intervenção alertando profissionais de saúde para alta prevalência deste tipo de violência na população.<br>The aim of this study was to investigate the prevalence of physical abuse and exposure to parental violence during childhood, in relation to socio-demographic characteristics. Multi-stage sampling was used to select 3,007 individuals 14 years or older in 2005-2006, from all regions of the country. The study detected cases of physical abuse (beating, striking with objects, burning or scalding, threatening and/or using knives or firearms) and exposure to parental violence (witnessing parental threats and/or actual physical aggression) during childhood. Analyses were performed with the Pearson chi-square test. Prevalence of history of physical abuse in childhood was 44.1% (33.8% moderate, 10.3% severe). Prevalence of exposure to parental violence was 26.1% (7.5% witnessed moderate parental violence and 18.6% severe). Combined analyses of these two types of violence showed significant associations between them. The findings may help implement intervention strategies to call the attention of health professionals to the high prevalence of this type of violence