1 / 10

SRY, the master switch for male development in early embryogenesis.

SRY, the master switch for male development in early embryogenesis. Sex determining region Y Gene symbol : SRY Location : Yp11.3.

daphne-riley
Download Presentation

SRY, the master switch for male development in early embryogenesis.

An Image/Link below is provided (as is) to download presentation Download Policy: Content on the Website is provided to you AS IS for your information and personal use and may not be sold / licensed / shared on other websites without getting consent from its author. Content is provided to you AS IS for your information and personal use only. Download presentation by click this link. While downloading, if for some reason you are not able to download a presentation, the publisher may have deleted the file from their server. During download, if you can't get a presentation, the file might be deleted by the publisher.

E N D

Presentation Transcript

  1. SRY, the master switch for male development in early embryogenesis.

  2. Sex determining region Y Gene symbol : SRY Location : Yp11.3 SRY encodes a 223 amino acid zinc finger transcription factor that is a member of the high mobility group (HMG)-box family of DNA binding proteins. The protein is expressed during testis development for only 2 days. Mutations in this gene give rise to XY females with gonadal dysgenesis and translocation of part of the Y chromosome containing this gene to the X chromosome in XX males.

  3. The SRY gene was discovered by 2 groups separately in 1990. Berta et al., (1990) Nature 348 448-45 Jager et al., (1990) Nature 348 452- 53 It was found by studying a human XY female. It turned out that she had a deletion in the Y chromosome that did not allow testis development.

  4. In addition to SRY, the DMRT1 gene on chromosome 9 is involved in determining testis development. And unlike the SRY gene, it has to be present in two copies to work properly. XY humans who have lost one copy of the gene fail to develop testes and show sex-reversal, despite having a functional SRY gene.

  5. Evolutionary studies have shown that the Y was once the homologous pair for X. The y chromosome contains mainly degraded copies of X linked genes and large regions of repeated sequences.

  6. Sequence alignment http://life.nthu.edu.tw/~g875406/allignment.html

  7. In females one of the X-chromosomes is inactivated in every cell. The process is called Lyonization after Mary Lyon who discovered it. Inactivation occurs during embryogenesis. The process starts at the "X inactivation center" and spreads along the chromosome. X Inactivation appears to be random in somatic cells. (mosaic pattern)

  8. XIST is located within the "X inactivation center" and only expressed by the inactive X chromosome. XIST is transcribed but not translated. It appears to act as RNA by binding to the x chromosome and promoting its movement to the nuclear periphery. Methylation of the inactive X genes maintains inactivity.

More Related