Scientists in Shanghai have discovered that amutation at a specific location in a gene —mainlyactive inmale reproductive cells — leads tomale infertility. And they’ve figured out how it works, which is likely to bring new insights into treatment.
The scientists discovered that infertility results when a key step in the development of spermcells is obstructed by themutation at a domain called “Dbox”on the gene Hiwi. Their findings were published recently on the website of the scientific journal Cell, which is based in theUnited States.
Before a sperm cell matures, the histones in genomic DNA must transform into another form automatically, so that the geneticmaterials fromthemale are stored in the spermhead in a safer and more condensed way, explained LiuMofang, the lead researcher on the team at the Institute of Biochemistry and Cell Biology,abranchof the Chinese Academy of Sciences’Shanghai Institutes for Biological Sciences.
“But the mutation hindered the transformation fromtaking place during the late stages of spermformation,which results in a drastic decrease in the number of sperm, abnormal structureof thespermheadand spermviability loss,”Liu said.
There are many types of gene mutations that appear to correlate with human male infertility. However, only a handful of such mutations have been scientifically proved to result in infertility, Liu said.
In their lab experiments, the researchers successfully overrode the obstruction by inserting a certain part of a protein into the spermcell of mice with themutation.
“The sperm will thus restore normal structure and activity,”Liu said.
According to one scientific reviewer of the research, “The observation of human Hiwi mutations in azoospermia is extremely exciting and provides a clear context for disease relevance”.
WangJian, deputy director of the Shanghai Institute of Planned Parenthood Research, said it’s widely acknowledged in medical circles that problems in males are a factor in half the infertility cases around the world.
“A lownumber of sperm, low activity of sperm and malformation of spermare important reasons that causemale infertility, but thestrategies fordiagnosis and treatment are quite limited so far,”Wang said. “This
discovery will provide a potential solution for certain types of humanmale infertility.”
Liu said the mutation is either acquired from the male subject’s mother or happens for unknown reasons before he is born.
原载于Chinadaily 2017年6月6日
