The Y chromosome contains 50 to 60 genes that encode specific proteins. A large chunk of this chromosome contains non-coding parts that produce tiny non-coding RNA molecules.
In a mouse study, researchers have now found that a region of non-coding parts of the Y chromosome, when deleted, leads to sperm abnormalities and male sterility1.
The researchers have discovered that such deletion disrupts the activities of several sperm proteins associated with sperm motility.
To date, the roles of the non-coding parts of Y chromosome have remained unclear. The scientists, including researchers from the Centre for Cellular and Molecular Biology in Hyderabad, India, deleted a region of the non-coding parts on the Y chromosome that produce small non-coding RNAs in mice.
The researchers, led by Rachel A. Jesudasan, found that the deletion led to the deregulation of at least eight sperm proteins. These proteins have roles in the sperms’ motility, structural integrity and eventually its ability to fertilise an ovum.
Surprisingly, genes related to the deregulated proteins localised to other chromosomes (autosomes) and not to the deleted region of the Y chromosome.
They detected that the deleted portion of Y chromosome form the non-coding RNAs. Such non-coding RNAs bind to the Piwi proteins in germ cells and form complexes that regulate specific genes located on chromosomes other than the Y chromosome.
