Male infertility related to gene composition

A recent study saw scientists trying to explain the importance of a gene in regulating the production of fully-functioning sperm.

For the first time, experts have identified the role of the gene, RBMXL2, which is very similar to a possible infertility gene found on the Y chromosome found only in men. This provided a model for the team to manipulate as the Y chromosome itself is very difficult to analyse.

The study, published today in the Journal of eLife, sheds light on why some men may be infertile as RBMXL2 has been shown to be essential to make sperm.
Scientists found that deleting the RBMXL2 gene from chromosome 11 blocked sperm production and this paves the way for further exciting research in this area.

"Male infertility is a poorly understood topic, and this study helps us to understand why some men might become infertile. This is important since many couples suffer from infertility and it can cause psychological stress, and also have economic consequences in some countries as it can affect care in later life," said David Elliott, lead author of the study.

Making sperm and eggs, and then eventually the next generation depends upon a special kind of cell division known as meiosis.
Meiosis is a hotspot for gene expression and sperm development, which involves copying long stretches of DNA into RNA.

Without the important RBMXL2 gene, other genes are not expressed properly - they still make RNA, but this process does not replicate accurately, leading to mistakes which eventually block the production of sperm.

The research found that the block occurred while the cells were dividing in the testes to make sperm, under the process of meiosis. This block meant that none of the cells developed into sperm cells were able to swim and fertilise eggs.