Candidate genes contribute to behavioral isolation revealed by comparative genomic approach. Juan Li¹, Lan Jiang¹, Chung-I Wu^1,2, Chau-Ti Ting³, Xuemei Lu¹. 1) Beijing Institute of Genomics, Chinese Academy of Sciences, Beijing 100029, Peoples Republic of China; 2) Department of Ecology and Evolution, University of Chicago, Chicago, IL 60637; 3) Department of Life Science, Institute of Ecology and Evolutionary Biology, & Institute of Zoology, National Taiwan University, Taipei, Taiwan, ROC.

   Two behavioral races, M (for cosmopolitan) and Z (for Zimbabwe) of Drosophila melanogaster provide a great model to study the genetic basis of racial differentiation. When given a choice, females from the Zimbabwe race mate only with males from its congener whereas females from the cosmopolitan race mate readily with males from both races little discriminatorily. A series of genetic analyses showed that the Z/M behavioral isolation is mainly contributed by two major autosomes, and several fragments of the third chromosome are crucial in either male behavior or female preferences. However, very little was known about the genetic locus and the evolution of racial differentiation genes. To address this question, we have generated a reference genome of Z race by deep sequencing. By comparing to the published reference genome (M race), 0.8% of the sites have diverged between the two genomes. In addition, 104 copy number variations were identified. Of which, we narrow down to around 12 candidate regions that may contribute to the M/Z racial differentiation by analyzing a small sample from the DPGP2 genomes.These results provide a general framework on mapping behavioral genes underlying racial differentiation in D. melanogaster.