INTERNATIONAL JOURNAL OF NOVEL RESEARCH AND DEVELOPMENT International Peer Reviewed & Refereed Journals, Open Access Journal ISSN Approved Journal No: 2456-4184 | Impact factor: 8.76 | ESTD Year: 2016
Scholarly open access journals, Peer-reviewed, and Refereed Journals, Impact factor 8.76 (Calculate by google scholar and Semantic Scholar | AI-Powered Research Tool) , Multidisciplinary, Monthly, Indexing in all major database & Metadata, Citation Generator, Digital Object Identifier(DOI)
The finding that sex chromosomes in one lineage may be homologous to autosomes in other lineages are consistent with the hypothesis that sex chromosomes evolved independently from autosomes that have acquired a sex determining allele. Therian mammals (marsupials and placental) have an XX female: XY male sex chromosome system, which is homologous to autosomes in other vertebrates. The testis-determining gene, SRY, is conserved on the Y throughout therians but is absent in other vertebrates, suggesting that the mammal system evolved about 310 million years ago (MYA). The profoundly different journeys of male and female life are thus decided by a genetic coin toss. Male bipotential gonad develops into testes containing type A spermatogonia with influences from SRY, SOX-9, SF-1. SF-1 acts on sertoli cells, which secretes Mullerian Inhibiting Substance. It also acts on Leydig cell too to exert testosterone secretion. This male specific hormone influences the Wolffian duct to structure internal genitalia (seminal vesicle, epididymis, vas deferens). In the absence of SRY, the female foetus results in decreased expression of SF -1. Granulosa & thecal cells of ovary secrete oestrogen under the influence of RSOP -1 & WNT-4. Mullerian duct will be going to form female internal genitals. Genital tubercles form external genitals.
Keywords:
Sex determination, SRY, SOX9, Wnt, Testis determination , Ovary determination
Cite Article:
"Sex Determination in Mammals: In Startling Evolutionary Approaches", International Journal of Novel Research and Development (www.ijnrd.org), ISSN:2456-4184, Vol.9, Issue 1, page no.c154-c161, January-2024, Available :http://www.ijnrd.org/papers/IJNRD2401220.pdf
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ISSN:
2456-4184 | IMPACT FACTOR: 8.76 Calculated By Google Scholar| ESTD YEAR: 2016
An International Scholarly Open Access Journal, Peer-Reviewed, Refereed Journal Impact Factor 8.76 Calculate by Google Scholar and Semantic Scholar | AI-Powered Research Tool, Multidisciplinary, Monthly, Multilanguage Journal Indexing in All Major Database & Metadata, Citation Generator
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