Sex-ratio meiotic drive is found in diverse groups of metazoans including arthropods, mammals and plants. Drive occurs because a selfish sex chromosome, usually the X chromosome, is able to debilitate the opposite sex chromosome. The result is that males carrying the driving X chromosome produce almost all daughters. Understanding the genetics of sex-ratio meiotic drive has been hindered by the association of drive loci with large inversions. The Drosophila affinis sex-ratio system has an additional level o complexity: males lacking a Y chromosome are fertile. In fact, a male with a driving X chromosome and no Y produces mostly sons - the driving X appears to be suicidal in the absence of a Y chromosome. I propose a strategy using next generation sequencing for genomic analysis of sex-ratio meiotic drive in Drosophila affinis. Using a combination of comparative genomics of the driving and non-driving X chromosomes and transcriptomic analysis of both chromosomes in males testes, I hope to identify candidate genes involved in the drive phenotype. Subsequent analysis will help identify specific genes. The approach is novel in that I will be attempting to map genes within inversions in a non-model species, and the methods I develop will facilitate similar analysis in other systems. The biological insight obtaine from our analysis may shed light on the genetics of sex-ratio meiotic drive and sex chromosome evolution, both of which have implications for fertility.

Public Health Relevance

Drosophila melanogaster has long been used as a model for understanding a wide range of biological principles ranging from metabolism to disease to aging. Branching out to related Drosophila species allows for the exploration of equally important questions, specific to a particular species'biology. Understanding the genomics of sex-ratio meiotic drive and sex chromosome evolution may help us understand the basis of fertility problems in humans (reviewed in Burt and Trivers 2006).

National Institute of Health (NIH)
Eunice Kennedy Shriver National Institute of Child Health & Human Development (NICHD)
Postdoctoral Individual National Research Service Award (F32)
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Special Emphasis Panel (ZRG1-F08-E (20))
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Taymans, Susan
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Cornell University
Schools of Arts and Sciences
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Unckless, Robert L; Howick, Virginia M; Lazzaro, Brian P (2016) Convergent Balancing Selection on an Antimicrobial Peptide in Drosophila. Curr Biol 26:257-262
Unckless, Robert L; Rottschaefer, Susan M; Lazzaro, Brian P (2015) A genome-wide association study for nutritional indices in Drosophila. G3 (Bethesda) 5:417-25
Unckless, Robert L; Rottschaefer, Susan M; Lazzaro, Brian P (2015) The complex contributions of genetics and nutrition to immunity in Drosophila melanogaster. PLoS Genet 11:e1005030
Unckless, Robert L; Messer, Philipp W; Connallon, Tim et al. (2015) Modeling the Manipulation of Natural Populations by the Mutagenic Chain Reaction. Genetics 201:425-31
Unckless, Robert L; Larracuente, Amanda M; Clark, Andrew G (2015) Sex-ratio meiotic drive and Y-linked resistance in Drosophila affinis. Genetics 199:831-40
Unckless, R L; Clark, A G (2014) Sex-ratio meiotic drive and interspecific competition. J Evol Biol 27:1513-21
Orr, H Allen; Unckless, Robert L (2014) The population genetics of evolutionary rescue. PLoS Genet 10:e1004551