Sex chromosome drive

Sex chromosomes are especially prone to be invaded by meiotic drive elements, resulting in strong selection for suppressors due to distortion of population sex ratio. A genomic signature of cryptic sex chromosome drive may be co-amplification of genes on the X and Y chromosomes.

Sex chromosome drive can lead to co-amplification of genes the X and Y that are targeted by small RNA’s.

Our analysis on the neo-Y of D. miranda has revealed rampant co-amplification of genes involved in meiosis or RNAi as expected under drive models.

Co-amplified X/Y genes on D. miranda neo-sex chromosomes have meiosis-related or RNAi functions

We found that co-amplified X and Y genes are common in Drosophila species with neo-sex chromosomes.

Current work focuses on characterizing putative cryptic sex chromosome drive using transgenic and molecular approaches. This is combined with population studies, to infer the evolutionary dynamics of recurrent sex chromosome drive. In addition to flies from the obscura group, we have also started to carefully characterize sex chromosomes in species belonging to the melanica and robusta groups. 

Relevant publications:
Bachtrog D, Mahajan S & Bracewell R (submitted). Massive gene amplification on a recently formed Drosophila Y chromosome. 
Ellison CE & D Bachtrog (2019) Recurrent gene co-amplification on Drosophila X and Y chromosomes. PLoS Genetics, in press. 

%d bloggers like this: