- 期刊
Early-Stage Evolution of the Neo-Y Chromosome in Drosophila albomicans
並列摘要
Numerous theories have specified that an originally autosomal neo-Y chromosome arm is expected to undergo degenerative evolution. Neo-sex chromosomes of Drosophila albomicans originated from 2 Robertsonian translocation events, one for X and the other for Y, between ancestral Drosophila sex chromosomes and a pair of autosomes homologous to the 3rd chromosomes of its sibling species D. nasuta. Since the neo-sex chromosome in D. albomicans is still evolutionarily young, we used genetic approaches to reveal changes in the entire neo-Y chromosome. Non-disjunction is an indicator used to investigate differences between homologous chromosomes. In this study, we first confirmed that no male recombination had occurred in hybrid males of these 2 sibling species. With the aid of molecular marker genotyping and direct karyotyping of aneuploid offspring produced through specially designed crosses and backcrosses of fertile hybrids, we found that the non-disjunction rate was significantly higher in hybrid males with the neo-Y chromosome than in hybrids without it. The high non-disjunction rate made it possible to generate 3, X, X/neo-Y F2 females and X, neo-Y/neo-Y F3 male offspring which can reveal recessive effects of the homozygous 3rd chromosome arm. Results of this aneuploid study revealed severe recessive inviability of the neo-Y chromosome. Our results further suggested that increased non-disjunction in hybrid males with the neo-Y chromosome is likely due to changes that occurred on the Y arm, whereas recessive deleterious alleles might be located on the 3rd arm of the neo-Y chromosome. Taken together, the elevated non-disjunction rate and severe recessive inviability revealed significant changes in the neo-Y chromosome at this early stage of chromosome evolution in D. albomicans.
延伸閱讀
- Chang, H. Y., & Lin, F. J. (1995). The Interaction between Chromosomal Inversion and Recessive Lethals in Drosophila albomicans. Zoological Studies, 34(1), 47-54. https://www.airitilibrary.com/Article/Detail?DocID=10215506-199501-201308200016-201308200016-47-54
- Tsai, T. H. (2008). Chromosome evolution of Drosophila albomicans [master's thesis, National Taiwan University]. Airiti Library. https://doi.org/10.6342/NTU.2008.02633
- Yang, Y. Y., Lee, C. Y., Yang, Y. H., Huang, S. P., Chang, T. P., & Chang, H. Y. (2008). The Fate of Neo-Sex Chromosomes in Drosophila albomicans-nasuta Hybrid Populations. Zoological Studies, 47(1), 84-95. https://www.airitilibrary.com/Article/Detail?DocID=10215506-200801-47-1-84-95-a
- Chang, H. Y., & Kung, T. Y. (2008). Evolutionary Changes in a Y-Like Chromosome in Hybrids of Drosophila albomicans and D. nasuta. Zoological Studies, 47(4), 455-465. https://www.airitilibrary.com/Article/Detail?DocID=10215506-200807-47-4-455-465-a
- 張德斌（2008）。Evolution of neo-sex chromosomes in Drosophila albomicans〔博士論文，國立臺灣大學〕。華藝線上圖書館。https://doi.org/10.6342/NTU.2008.10406