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Abstract Detail


Genomics / Proteomics

Brown, Jennifer [1], Lappin, Fiona [2], Weingartner, Laura [3], Hawkins, Kevin [2], McDermott, Ross [2], Harkess, Alex [2], Moore, Richard [4].

Expanding our understanding of the evolution of the Carica papaya X and Y chromosomes.

The sex chromosomes of the tropical crop papaya (Carica papaya) are young and consequently allow for the examination of evolutionary forces that affect early sex chromosome formation. Previously, we found striking differences in the patterns of polymorphism and divergence of the papaya X and Y chromosome. Specifically, from a survey of four X/Y gene pairs from regions that span the sex-determining region, we found evidence of selective sweeps driving reduced diversity on the X while the Y has significantly elevated polymorphism. We have expanded our study to include over 20 X/Y gene pairs spanning ~250 kb intervals across the gene enriched regions of the X and Y. We also have increase our survey of autosomal diversity to include over 30 loci, with a particular focus on pericentromeric loci, as the papaya sex determining region spans a centromere. We will present our analysis of polymorphism and divergence in these loci in order to test whether the patterns of selection we observed previously are restricted to specific regions of the sex-determining region or,whether they are diagnostic of the sex chromosomes as a whole. We predict that these patterns will be distributed broadly across the X and Y, given the unique pericentromeric location the low recombination rates that characterize this region.

Broader Impacts:


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1 - Miami University, Botany, 316 Pearson Hall, Oxford, OH, 45056, USA
2 -
3 - Indiana University, Jordan Hall, 1001 E Third St., Bloomington, IN, 47405, USA
4 - Miami University, Botany, 316 Pearson, Oxford, OH, 45056, USA

Keywords:
Sex chromosome
Molecular evolution
Genome evolution.

Presentation Type: Oral Paper:Papers for Topics
Session: 44
Location: Union B/Hyatt
Date: Wednesday, July 11th, 2012
Time: 8:00 AM
Number: 44001
Abstract ID:375


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