The mysteries of why some men can’t produce sperm are now closer to being solved by scientists. The inability to make sperm is one of many reasons why men may be unable to conceive, making up around 10 percent of infertile men....CONTINUE READING
Now, scientists have shed light on what might be going wrong in the process of sperm generation, according to a new study published in the journal Science Advances.
Experimenting on mice, researchers found that the process of meiosis, which is how the body produces haploid sex cells—containing a single set of chromosomes, rather than two as usual—which develop into sperm.
“A significant contributor to infertility is defects in meiosis,” Katherine Billmyre, a meiotic chromosome biology researcher at the University of Georgia, former postdoctoral fellow at the Stowers Institute for Medical Research, and co-author of the paper, said in a statement.
“To understand how chromosomes separate into reproductive cells correctly, we are really interested in what happens right before that when the synaptonemal complex forms between them.”
The synaptonemal complex is a protein structure formed in meiosis, which forms a bridge of sorts between pairs of chromosomes, allowing genes to be swapped around and the chromosomes to successfully split off into haploid cells.
Previous research suggested that mutations in the proteins that make up the synaptonemal complex may contribute to an inability to create sperm, which this study confirms.
The researchers—hailing from the Stowers Institute for Medical Research, in collaboration with the Wellcome Centre for Cell Biology at the University of Edinburgh—used a gene editing technique to mutate specific proteins in the synaptonemal complex protein in mice, and found that a single mutation was enough to cause infertility in the rodents.
“We’re talking about pinpoint surgery here,” Scott Hawley, an investigator at the Stowers Institute for Medical Research, a professor of cell biology and physiology at the University of Kansas School of Medicine, and co-author of the paper, said in the statement.
“We focused on a tiny little region of one protein in this gigantic structure that we were pretty sure could be a significant cause of infertility.”
Mice are often used as a model species for human conditions, and although they are separate species, the researchers also modeled human protein sequences and found that as the synaptonemal complex is very similar between species, the same mutated protein likely leads to infertility in humans, too.
“What is really exciting to me is that our research can help us understand this really basic process that is necessary for life,” said Billmyre.
The researchers hope that these findings will help them to develop ways to treat infertility in men, especially those who do not make enough sperm.
“A significant cause of infertility in males is that they just cannot make sperm,” Hawley said. “If you know exactly what is wrong, there are technologies emerging right now that might give you a way to fix it…CONTINUE READING>>
