Genetic Architecture of Hybrid Male Sterility in Drosophila: Analysis of Intraspecies Variation for Interspecies Isolation

Background: The genetic basis of postzygotic isolation is a central puzzle in evolutionary biology. Evolutionary forces causing hybrid sterility or inviability act on the responsible genes while they still are polymorphic, thus we have to study these traits as they arise, before isolation is complete. Methodology/Principal Findings: Isofemale strains of D. mojavensis vary significantly in their production of sterile F 1 sons when females are crossed to D. arizonae males. We took advantage of the intraspecific polymorphism, in a novel design, to perform quantitative trait locus (QTL) mapping analyses directly on F1 hybrid male sterility itself. We found that the genetic architecture of the polymorphism for hybrid male sterility (HMS) in the F1 is complex, involving multiple QTL, epistasis, and cytoplasmic effects. Conclusions/Significance: The role of extensive intraspecific polymorphism, multiple QTL, and epistatic interactions in HMS in this young species pair shows that HMS is arising as a complex trait in this system. Directional selection alone would be unlikely to maintain polymorphism at multiple loci, thus we hypothesize that directional selection is unlikely to be the only evolutionary force influencing postzygotic isolation

Promotora de Salud: Promoting Folic Acid Use Among Hispanic Women

BACKGROUND: The U.S. Public Health Service recommends that all women in the United States capable of becoming pregnant consume 400 μg of folic acid daily to reduce their risk of having a pregnancy affected by a neural tube defect (NTD). However, disparities exist in the consumption of folic acid, with Hispanic women having lower rates of folic acid consumption than non-Hispanic white women. METHODS: A community-based feasibility study was designed to assess the utility of the promotora de salud model to promote consumption of multivitamins containing folic acid for the prevention of NTDs among Spanish-speaking Hispanic women in North Carolina. The study consisted of an educational intervention given by a promotora (a lay, community health worker), with data collection occurring at baseline and four months post-intervention to measure changes in knowledge and behavior. Overall, 52% (n = 303) of participants completed all components of the study. RESULTS: Self-reported daily multivitamin consumption increased from 24% at baseline to 71% four months post-intervention. During the same time frame, awareness of folic acid increased from 78% to 98% and knowledge of the role of folic acid in the prevention of birth defects increased from 82% to 92%. CONCLUSIONS: The results of this study indicate that the promotora de salud model may be effective in reaching a subpopulation of women with the folic acid message. Additional studies with larger population sizes are warranted to validate these findings