Y Chromosome: Difference between revisions

Revision as of 18:51, 9 November 2010

Introduction

Human Y chromosome

Humans have 23 pairs of chromosomes, 22 autosomes and a pair of sex chromosomes. Males have one X and one Y chromosomes (46, XY) and females have a pair of X chromosomes (46, XX).

contains approximately 200+ genes
50 million base pairs

Historic Embryology - Genital
General: 1901 Urinogenital Tract \| 1902 The Uro-Genital System \| 1904 Ovary and Testis \| 1912 Urinogenital Organ Development \| 1914 External Genitalia \| 1921 Urogenital Development \| 1921 External Genital \| 1942 Sex Cords \| 1953 Germ Cells \| Historic Embryology Papers \| Historic Disclaimer
Female: 1904 Ovary and Testis \| 1904 Hymen \| 1912 Urinogenital Organ Development \| 1914 External Genitalia \| 1914 Female \| 1921 External Genital \| 1927 Female Foetus 15 cm \| 1927 Vagina \| 1932 Postnatal Ovary
Male: 1887-88 Testis \| 1904 Ovary and Testis \| 1904 Leydig Cells \| 1906 Testis vascular \| 1909 Prostate \| 1912 Prostate \| 1914 External Genitalia \| 1915 Cowper’s and Bartholin’s Glands \| 1920 Wolffian tubules \| 1935 Prepuce \| 1935 Wolffian Duct \| 1942 Sex Cords \| 1943 Testes Descent \| Historic Embryology Papers \| Historic Disclaimer

Some Recent Findings

Dual nuclear import mechanisms of sex determining factor SRY: intracellular Ca2+ as a switch PMID21051653 "The sex-determining region on the Y chromosome (SRY) has 2 nuclear localization signals (NLSs) that flank the DNA binding high mobility group (HMG) domain; the β-NLS and the CaM-NLS, which mediate nuclear transport through importin β1 (Impβ1) and the calcium-binding protein calmodulin (CaM), respectively. ...The results imply mutual exclusivity of nuclear transport via the 2 NLSs with intracellular Ca(2+) as the switch between the 2.-Kaur, G. Jans, D. A. Dual nuclear import mechanisms of sex determining factor SRY: intracellular Ca(2+) as a switch."

Male Sex Determination

Sry gene, found in 1990 on the Y chromosome, the sry gene encodes a "testis-determining factor" a 204aa protein (Mr 23884 Da).

Sry acts as a transcriptional activator (HMG type-high mobility group) binding to DNA and initiating male sex determination then regulating male development. The protein sequence is shown on this current page and the full genebank entry can also be seen. The sry protein has a HMG box that binds DNA by intercalating in the minor groove. Read about the mapping of the testis determining factor which is SRY.

The actual gene targets of SRY are still being determined but at least one downstream gene Sox9 has been identified. Another gene Dax1 (nuclear hormone-receptor superfamily member) when expressed as a transgene will antagonize Sry and also force dosage-sensitive sex reversal.

References

Online Textbooks

Developmental Biology (6th ed) Gilbert, Scott F. Sunderland (MA): Sinauer Associates, Inc.; c2000. The Digestive Tube and Its Derivatives | Endodermal development of a human embryo

Search NLM Online Textbooks "Y chromosome" : Developmental Biology | Endocrinology | Molecular Biology of the Cell | The Cell- A molecular Approach

Reviews

Articles

Search PubMed

Search November 2010 "Y Chromosome" - All (11590) Review (1052) Free Full Text (2688)

Search Pubmed: Y Chromosome

Carnegie Stages: 1 | 2 | 3 | 4 | 5 | 6 | 7 | 8 | 9 | 10 | 11 | 12 | 13 | 14 | 15 | 16 | 17 | 18 | 19 | 20 | 21 | 22 | 23 | About Stages | Timeline

Cite this page: Hill, M.A. (2024, May 2) Embryology Y Chromosome. Retrieved from https://embryology.med.unsw.edu.au/embryology/index.php/Y_Chromosome

What Links Here?

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-* '''Dual nuclear import mechanisms of sex determining factor SRY: intracellular Ca2+ as a switch''' PMID21051653 "The sex-determining region on the Y chromosome (SRY) has 2 nuclear localization signals (NLSs) that flank the DNA binding high mobility group (HMG) domain; the β-NLS and the CaM-NLS, which mediate nuclear transport through importin β1 (Impβ1) and the calcium-binding protein calmodulin (CaM), respectively. ...The results imply mutual exclusivity of nuclear transport via the 2 NLSs with intracellular Ca(2+) as the switch between the 2.-Kaur, G. Jans, D. A. Dual nuclear import mechanisms of sex determining factor SRY: intracellular Ca(2+) as a switch."
+* '''Dual nuclear import mechanisms of sex determining factor SRY: intracellular Ca2+ as a switch''' [http://www.ncbi.nlm.nih.gov/pubmed/21051653 PMID21051653] "The sex-determining region on the Y chromosome (SRY) has 2 nuclear localization signals (NLSs) that flank the DNA binding high mobility group (HMG) domain; the β-NLS and the CaM-NLS, which mediate nuclear transport through importin β1 (Impβ1) and the calcium-binding protein calmodulin (CaM), respectively. ...The results imply mutual exclusivity of nuclear transport via the 2 NLSs with intracellular Ca(2+) as the switch between the 2.-Kaur, G. Jans, D. A. Dual nuclear import mechanisms of sex determining factor SRY: intracellular Ca(2+) as a switch."
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 ==Male Sex Determination==