The study, published in Genes & Development, finds disrupting the TEX11 gene located on the X chromosome in mice renders the males sterile and reduces female fecundity.

The TEX11 is also located on the human X chromosome, and the researchers say mutations may be responsible for non-measurable sperm levels in men. Like other X-linked disorders, such as color blindness, genetic mutation could be passed on from the mother. The researchers hypothesize that a screening of the TEX11 gene may provide a prebirth diagnosis for infertility in men.

This is the first meiosis-specific factor ever found on the X chromosome, the researchers say. Meiosis is the process of cell division whereby chromosomes exchange paternal and maternal genetic material to produce genetically diverse gametes -- sperm or eggs. Defects in meiosis are a leading cause of both infertility and birth defects.

The study was conducted by Jeremy Wang of the University of Pennsylvania's School of Veterinary Medicine in Philadelphia with involvement by researchers from the Massachusetts Institute of Technology, Washington State University, Karolinska Institute in Sweden and the University of Wurzburg in Germany.