Unexpected factors affecting the sex of the child
Last reviewed: 16.10.2021
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Researchers from the University of Geneva tried to shed light on this complex process by identifying the decisive role of insulin and insulin-like growth factors IGF1 and IGF2, a family of hormones known for their direct involvement in human metabolism and growth.
Researchers from the University of Geneva tried to shed light on this complex process by identifying the decisive role of insulin and insulin-like growth factors IGF1 and IGF2, a family of hormones known for their direct involvement in human metabolism and growth.
The absence of these factors at the time of sex determination does not make it possible to determine whether the embryo belongs to either the male or female sex.
Insulin-like growth factors IGF1 and IGF2 are the most important representatives of the family of insulin-like growth factors. This family carries out autocrine, endocrine and paracrine regulation of growth processes, development and differentiation of cells and tissues of the body.
The results of this study, published in the scientific journal PLoS Genetics, allow a better understanding of the sexual development process and ultimately improve the diagnosis and practice of genetic counseling for people with sexual dysfunction.
In mammals, sexual development is a long process that begins at conception, when the transmission of X chromosomes and Y chromosomes through sperm determines the sex of the embryo.
Researchers were interested in the role of the family of insulin-like growth factors and their receptors in cells.
These factors are known to participate in the regulation of metabolism and growth, and also play a key role in regulating the reproductive capacity of man, whether male or female. Reproductive function, in fact, is closely related to metabolism and growth.
In fact, it is quite logical: a person can not develop normally without sufficient energy consumption and there is no sense in reproduction if the intake of calories is inadequate. This may explain why some women with anorexia have anovulatory cycles and may suffer from infertility.
People with obesity have significant impairments of fertility. Despite the fact that it is now known that the interaction between metabolism, growth and reproductive capacity is regulated by common factors, such as insulin and insulin-like growth factors, the researches of the professor of the Department of Genetic Medicine Serge Nef show that these interactions are even more important than was considered earlier, since insulin and insulin-like growth factors are also important for the primary determination of sex in mammals.
To analyze the impact of these factors on the definition of sex, Professor Nef's group used genetically modified mice. Scientists genetically inactivated receptors for insulin and insulin-like growth factors in mouse embryos.
They found that, due to the lack of these factors at the time of sex determination, a violation of gonad colonization in these mutant mice prevented the development of testicles or ovaries in embryos. Thus, the embryo and its gonads remained undifferentiated for several days, which demonstrates the essential role of these hormones and growth factors in sexual differentiation.