Deciphering neo-sex and B chromosome evolution by the draft genome of Drosophila albomicans

BMC Genomics

Research Article

Hong-mei Zhu¹  Chen Ye¹  Quan-fei Huang¹  Zhao-lin Xuan¹  Xiu-qing Zhang¹  Jun Wang¹  Ruo-ping Zhao²  Li Zhao²  Yue Zhang²  Wen Wang²  Guo-jie Zhang³  Qi Zhou⁴  Scott W Roy⁵  Doris Bachtrog⁶  Jue Ruan⁶  Beatriz Vicoso⁶ 

[1] Beijing Genomics Institute-Shenzhen, 518083, Shenzhen, China;CAS-Max Planck Junior Research Group, State Key Laboratory of Genetic Resources and Evolution, Kunming Institute of Zoology, Chinese Academy of Sciences, 650223, Kunming, Yunnan, China;CAS-Max Planck Junior Research Group, State Key Laboratory of Genetic Resources and Evolution, Kunming Institute of Zoology, Chinese Academy of Sciences, 650223, Kunming, Yunnan, China;Beijing Genomics Institute-Shenzhen, 518083, Shenzhen, China;CAS-Max Planck Junior Research Group, State Key Laboratory of Genetic Resources and Evolution, Kunming Institute of Zoology, Chinese Academy of Sciences, 650223, Kunming, Yunnan, China;Department of Integrative Biology, University of California, 94720, Berkeley, CA, USA;Department of Biology, Stanford University, 94305, Palo Alto, CA, USA;Department of Integrative Biology, University of California, 94720, Berkeley, CA, USA;

关键词: Drosophila albomicans;    neo-sex chromosome;    B chromosome;   

DOI  :  10.1186/1471-2164-13-109

 received in 2011-10-25, accepted in 2012-03-22,  发布年份 2012

来源: Springer

【 摘 要 】

BackgroundDrosophila albomicans is a unique model organism for studying both sex chromosome and B chromosome evolution. A pair of its autosomes comprising roughly 40% of the whole genome has fused to the ancient X and Y chromosomes only about 0.12 million years ago, thereby creating the youngest and most gene-rich neo-sex system reported to date. This species also possesses recently derived B chromosomes that show non-Mendelian inheritance and significantly influence fertility.MethodsWe sequenced male flies with B chromosomes at 124.5-fold genome coverage using next-generation sequencing. To characterize neo-Y specific changes and B chromosome sequences, we also sequenced inbred female flies derived from the same strain but without B's at 28.5-fold.ResultsWe assembled a female genome and placed 53% of the sequence and 85% of the annotated proteins into specific chromosomes, by comparison with the 12 Drosophila genomes. Despite its very recent origin, the non-recombining neo-Y chromosome shows various signs of degeneration, including a significant enrichment of non-functional genes compared to the neo-X, and an excess of tandem duplications relative to other chromosomes. We also characterized a B-chromosome linked scaffold that contains an actively transcribed unit and shows sequence similarity to the subcentromeric regions of both the ancient X and the neo-X chromosome.ConclusionsOur results provide novel insights into the very early stages of sex chromosome evolution and B chromosome origination, and suggest an unprecedented connection between the births of these two systems in D. albomicans.

【 授权许可】

Unknown   
© Zhou et al; licensee BioMed Central Ltd. 2012. This article is published under license to BioMed Central Ltd. This is an Open Access article distributed under the terms of the Creative Commons Attribution License (http://creativecommons.org/licenses/by/2.0), which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited.