Work

Complex Evolutionary History of the Y Chromosome in Flies of the Drosophila obscura Species Group

Year: 2020

Type: article

Abstract: The Drosophila obscura species group shows dramatic variation in karyotype, including transitions among sex chromosomes. Members of the affinis and pseudoobscura subgroups contain a neo-X chromosome (a fusion of the X with an autosome), and ancestral Y genes have become autosomal in species harboring the neo-X. Detailed analysis of species in the pseudoobscura subgroup revealed that ancestral Y genes became autosomal through a translocation to the small dot chromosome. Here, we show that the Y-dot translocation is restricted to the pseudoobscura subgroup, and translocation of ancestral Y genes in the affinis subgroup likely followed a different route. We find that most ancestral Y genes have translocated to unique autosomal or X-linked locations in different taxa of the affinis subgroup, and we propose a dynamic model of sex chromosome formation and turnover in the obscura species group. Our results suggest that Y genes can find unique paths to escape unfavorable genomic environments that form after sex chromosome-autosome fusions.

Source: Genome Biology and Evolution

DOI: 10.1093/gbe/evaa051

Authors: Ryan Bracewell, Doris Bachtrog

Institution: University of California, Berkeley

Language: English

Topic: Genetic and Clinical Aspects of Sex Determination and Chromosomal Abnormalities

Subfield: Genetics

Field: Biochemistry, Genetics and Molecular Biology

Domain: Life Sciences

Open Access status: gold

Estimated APC paid: $2,850

Funders: National Institutes of Health, National Institute of General Medical Sciences