Regulation of Notch 1 Expression in Neonatal Mice Spermatogonia
There are many cells and proteins involved in the process of spermatogenesis and the loss of any of these cells or proteins can lead to infertility. Mice lacking the gene coding for the Ets related molecule (ERM) (knockout mice) have smaller testes and are infertile. Based on this finding, it is believed that ERM regulates the Notch signaling pathway that promotes spermatogonia differentiation. It is thought that Notch 1 binds to Jagged 1 and presenilin activates Notch 1 by cleaving it, producing a soluble domain known as Notch Intracellular Domain (NICD). This intracellular domain moves to the nucleus and acts there as a transcription factor, leading to the proliferation and differentiation of spermatogonial stem cells. Our hypothesis was that ERM regulates the expression of presenilin and that this enzyme should be absent in ERM knockouts mice. As a consequence, NICD should not be expressed in the nucleus of spermatogonial stem cells. Using immunohistochemistry, we investigated the presence of presenilin and NICD in the spermatogonial stem cells of the ERM -/- testes and compared it with their expression in the wild type testes (WT). Our results indicate that NICD is down regulated. However, the expression of presenilin is not affected in the ERM -/- mice.
School:
University of Puerto Rico at Bayamón
Department:
Biology
Research Advisor:
Marie-Claude Hofmann
Department of Research Advisor:
Reproductive Biology
Year of Publication:
2007