This action funds an NSF Postdoctoral Research Fellowship for FY 2010. The fellowship supports a research and training plan entitled "Why are chromosomes from our maternal grandparents more thoroughly mixed than chromosomes from our paternal grandparents?" for Yaniv Brandvain. The host institution for this research is the University of California - Davis, and the sponsoring scientist is Graham Coop.
Recombination plays an important role "mixing" up genetic information, and is one mechanism that produces differences among individuals in a population. Although scientists have observed that males and females mix their chromosomes to different extents, the underlying cause(s) and consequences of this observation are unclear. This research uses bioinformatics tools, modeling approaches, and a newly-constructed database to determine which parameters (ecological, evolutionary, life-history, etc.) best predict sex-differences in recombination rates across a broad range of species - from humans and other mammals, to birds and plants. Public data are also being incorporated into the final analysis to gain an even broader view of recombination across a wider number of species.
Training goals for this fellowship include use of genomics and informatics tools and complex statistical analysis for basic biology research. The results of this work are being disseminated to the public through scientific publication, presentation at national meetings, and communication with media and journalists. In addition to presenting and testing multiple hypothesis, the proposed research also contributes to a better understanding of the molecular mechanisms, and their implications both for basic problems in human health and fertility.
Because a sufficient number and appropriate genomic placement of recombination events is critical to a successful meiosis and abnormalities during meiosis are associated with numerous developmental diseases, understanding the sex-difference in the placement and frequency of recombination events is a basic question in reproductive biology. As proposed, Brandvain investigated how alleles that distort female meiosis [hereafter, meiotic drivers] in their favor can play a fundamental role in shaping female recombination. This work highlighted that elevated rates of female recombination near centromeres can evolve as a mechanisms of meiotic drive suppression – a view corresponding to empirical patterns in humans and many other species. More broadly, this work highlighted the diversity of ways in which meiotic drive can influence female meiosis, depending on how and when meiotic drive occurs and the relative genomic location of meiotic drivers and allelic modifiers of the recombination rate, and ultimately how genetic conflict may play a major role in shaping basic biological processes. This work resulted in a publication in the journal, Genetics, and a lasting scientific resource – a publicly available database documenting cases of sex-differences in the recombination rate across the tree of life. This work provided training essential for Brandvain’s future research – developing his strengths in mathematical techniques for theoretical population genetics, database construction, and computer programing. Additionally, in this work Brandvain mentored one undergraduate student and one post baccalaureate student, strengthening their preparedness for a career in mathematical and computational approaches to biology.
