A protein known to play a role in blood clotting and other cell functions is also critical for proper sperm formation in mice, according to researchers from the University of North Carolina at Chapel Hill School of Medicine.
Male mice missing both copies of the gene that produces the protein, called CIB1, have testes about half the normal size, have smaller numbers of the cells that give rise to sperm and produce no mature sperm at all, the researchers found. Female mice missing CIB1 were fertile, as were males missing only one copy of the CIB1 gene. Mice, like humans, have two copies of every gene, one from each parent.
The serendipitous discovery occurred when lead study author Dr. Weiping Yuan, intending to study CIB1's role in blood clotting, bred mice missing the CIB1 gene. All male mice bred without both copies of the gene were infertile, said Yuan, UNC research assistant professor of pharmacology.
CIB1 joins a growing list of fertility genes discovered during the course of mice studies of diseases such as cancer, diabetes and heart disease. In 2000, UNC researchers found several genes essential for male mouse fertility while studying how cells transport chloride, sodium and potassium, Yuan notes.
The results appear online in advance of print publication in the journal Molecular and Cell Biology. The study was funded by the National Institutes of Child Health and Human Development, part of the National Institutes of Health.
Earlier work by Yuan and his colleagues showed CIB1 helps control blood clotting in humans by keeping blood platelets from sticking together, acting as a natural anti-coagulant to prevent uncontrolled clotting of blood platelets that might lead to heart attacks and strokes.