Replacing one nucleotide increases fertility
The discovery of American geneticists who conducted research in an isolated religious sectarian community of Hutterites was reported by the online publication The Scientist. The actual results were presented at the beginning of April at the Colloquium on Evolution in Health and Medicine named after the American researcher and philanthropist Arthur M. Sackler (The Arthur M. Sackler Colloquia on Evolution in Health and Medicine) in Washington.
By now, many genes that predestine infertility have been known. But the discovery of a gene that increases fertility in humans was an outstanding event, because in modern society there are various kinds of cultural, social and economic restrictions on family size, which naturally complicates the statistical analysis necessary for medical and genetic research.
The Hutterites are not just an isolated community living on the prairies of South Dakota, they are a sect of Anabaptists, i.e. supporters of the community of property and wives, who, moreover, completely reject birth control. Thus, Hatterite couples can have 10 or more children, no more than two years pass between the birth of each of them. Moreover, they rarely marry or get married outside the community, which minimizes the level of "noise", i.e. errors introduced into the results of genetic research by environmental factors or "alien" gene pool.
Carole Ober from the University of Chicago has been studying fertility in South Dakota hutterite populations for more than 20 years. Two years ago, she saw a certain hereditary component in the reproductive success of both male and female hatterites, after which she began genomic research to identify fertility-related genes.
According to the researcher, polymorphism, i.e. a variety of variants of the gene encoding the channel of transport of chlorine ions through the cell membrane, turned out to be a great success. This is a well-known polymorphism involved in the development of both cystic fibrosis and infertility. Cystic fibrosis is a hereditary disease caused by a mutation of this particular transport gene (transmembrane regulator of cystic fibrosis), in which the glands of external secretion are affected, the functions of the respiratory and gastrointestinal tract are disrupted.
One of the polymorphisms of the cystic fibrosis gene is a single substitution in the DNA sequence, as a result of which alternative amino acids - either valine or methionine – appear in a certain position in the synthesized protein. Having studied this polymorphism in 207 male hatterites, none of whom suffered from infertility, the researcher found that the presence of valine correlates with a relatively larger number of children in the owner of this polymorphism than the average population. The difference, according to her data, is 4.3%. Currently, she is studying the sperm of 100 Hutterite volunteers - carriers of "valine polymorphism" in order to try to understand how valine ensures their success in producing offspring.
Portal "Eternal youth" www.vechnayamolodost.ru15.04.2009