Mechanistic and Evolutionary Model for Sex-ratio Distortion (IMAGE)

PLOS

Mechanistic and Evolutionary Model for Sex-ratio Distortion

Caption

The X-linked Dox gene first evolved to target an unknown component of the Y chromosome, so that Y-bearing sperm fail to develop. This leads to an increased transmission frequency of the Dox-bearing X chromosome and a female-biased sex ratio. It remains unclear whether Dox is an RNA or protein-coding gene. Later, a transposition of Dox to Chromosome 3 created the Nmy gene. siRNAs produced from the doublestranded hairpin of Nmy target the homologous region of Dox for degradation via the RNAi pathway. As a result, Y-bearing sperm develop normally, and X-chromosome meiotic drive is suppressed. The model depicts a pre-meiotic germ cell, but the cellular manifestation of distortion occurs during nuclear condensation and maturation of sperm. Only the sex and third chromosomes are shown.

Credit

Ferree et al.

Usage Restrictions

http://creativecommons.org/licenses/by/2.5/

License

Licensed content

Disclaimer: AAAS and EurekAlert! are not responsible for the accuracy of news releases posted to EurekAlert! by contributing institutions or for the use of any information through the EurekAlert system.