Influence of ? Particular Genes on Sex Determination Влияние отдельных генов на детерминацию пола Head of foreign languages department: Mogilyova I. I. Scientific supervisor: Senior Lecturer L. M. Tyumina Author: D. O. Akhmedov, 2 nd year
Investigated issues: n. Influence of some genes on genotype and phenotype n. Consequences of these genes mutations
The issue of diseases genesis is very important for modern branches of science, such as neogenetics.
If gender depends on genes, then it`s easy to study the process of sex determination.
But if sex depends on external conditions, it`s more complicated to find the sex-determining genes.
Gene SRY is the most promising.
Gene SRY is located on Y-chromosome and has an important role in development of male gender.
Mutations in gene SRY lead to development of a female organism with genotype XY (Swyer syndrome). Translocation of Ychromosome`s part, containing this gene, to Xchromosome, leads to development of de la Chapelle syndrome.
n People with one X-chromosome and several Y-chromosomes are usually male. n There are people with male phenotype and female genotype.
Gene SRY is expressed in gender ridge during induction of differentiation. If there are mutations in gene SRY, testis don`t differentiate.
Apart from gene SRY, several autosomic genes play a role in primarial gender differentiation. One of them is gene-supressor of Wilm`s tumor.
Another gene of same type is SOX 9.
Mutations in gene SOX 9 are followed by campomelic displasia, during which an 46, XY-individual has female phenotype.
Steroidogene factor 1 (SF 1) is a transcriptionary factor regulating expression of various genes which take part in production of steroid hormones and male gender differentiation.
Gene DAX 1 (dosage-sensitive sex reversal - adrenal hypoplasia congenita)
DAX 1 determines development of ovary and is normally repressed in males.
Another well-known example is gene Doublesex
Its product is a transcriptionary factor. It regulates activity of genes, responsible for gender specific characteristics` development.
Recently, Japanese scientists discovered two subspecies of Dsx Dapma. Dsx 1 и Dapma Dsx 2.
To find out which of these subspecies is more important for sex determination scientists tried to block each of them.
Thanks for your attention!