Researchers at the Weizmann Institute for the first time fully described the sex characteristics of gene expression common to women and men.
Studying how different genes are expressed in men and women is important for understanding human evolution and developing new therapeutic strategies. An example of such specificity is sexual dimorphism: for example, it is expressed in the features of anatomy, structure and work of the brain, behavior and mortality. In 2012, an international team of scientists (QTLs). Pr that only in B-lymphocytes about 15 percent of quantitative trait loci (QTLs) influence the expression with regard to sex. At the same time, the carriers of most of these genes are assumed to be representatives of both sexes, and although mutations in them often accumulate along one line, selection restrictions can lead to the spread of the anomaly to the other sex, increasing the population risk.
In a new work, Israeli scientists have completely described the expression of genes dependent on sex in 45 universal tissues. To do this, they studied the results of RNA sequencing of the Genotype-Tissue Expression (GTEx) project using 8555 samples from 357 men and 187 women. The authors assessed the sex characteristics of expression by comparing the individual index of 18 670 out of 19 644 genes encoding proteins for each tissue. Further comparison between the sexes made it possible to isolate over 6500 genes with high sex specificity, the expression of 650 of which was significantly different in two tissues, and 22 in nine or more. The most pronounced specificity was demonstrated by 6123 genes in the mammary glands.
Assessment of gender-specific gene expression (a) and their number in 45 tissues of men and women (b) / Moran Gershoni et al., BMC Biology, 2017
Specific expression of more than one hundred genes was found in skeletal muscles, skin, subcutaneous fatty tissue, anterior cingulate cortex (in total, in seven out of 13 brain tissues) and the left ventricle of the heart. In particular, in men, the MUCL1 gene was overexpressed in the skin, while in women, in the mammary glands. Similar differences were characteristic of liver tissue. Additionally, scientists assessed the relationship of genes with the risk of various diseases and the characteristics of the work of internal organs. The analysis showed that "female" genes are positively correlated with glucose metabolism, obesity, muscle disease and cardiomyopathy. In turn, “male” genes, in addition to glucose metabolism (also specific), were associated with a different molecular mechanism of muscle contraction.
Among genes, the expression of which was stronger (by no more than 10 percentage points) was manifested only in one sex, the authors attributed 1559 DNA regions. Most of them (82.6 percent) turned out to be "male" and were overexpressed in the testes. Also, many of these genes have been associated with the prostate gland and skin. In women, such genes have been found in the reproductive system and brain tissues. According to scientists, the results confirm the evolutionary importance of differences in the structure and function of the genitals of men and women. In this sense, it is noteworthy that dozens of genes were specifically expressed in men in skin tissues not directly related to the function of procreation. The findings clarify the genetic differences between the sexes.
Details of the work are presented in the journal BMC Biology.
Denis Strigun
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