File:Mouse model of ovarian cord formation 01.jpg

Model of intact ovarian cord formation and maturation promoting oocyte survival and development in follicles

E12.5 - germ cells located in cysts in the female genital ridge are not yet competent to survive and form follicles when re-aggregated (re-agg).

E13.5 - ovary maturation and development of intact ovarian cord structures containing oocyte and somatic granulosa cell clusters are sufficient to permit some oocyte survival and follicle formation upon re-aggregation.

E16.5 - intact ovarian cord-enclosed meiotic oocyte clusters and granulosa somatic cells are now primed to undergo robust follicle formation and oocyte development in follicles when re-aggregated. The percentage of surviving re-aggregated oocytes was calculated in comparison to intact transplant controls.

• Oocyte (green) and granulosa cell (blue) contacts and paracrine signaling factors may promote oocyte survival (+) and possibly facilitate programmed ovarian germ cell cyst break down into follicles.
• The cord and/or oocyte-mediated recruitment of granulosa cell clusters during ovary differentiation may also provide somatic cell signaling factors such as WNT4, R-spondin1, and Follistatin that promote oocyte survival and maturation.
• Intact ovarian cords may facilitate the protection of oocytes from re-aggregation induced inhibitory signaling from somatic cells in the genital ridge.
• Model defines a critical window from e13.5 to e16.5 of oocyte enclosure in intact fetal ovarian cord structures for the intrinsic programming of oocytes with competence to survive and undergo further development.

Links: Oocyte Development | Mouse Development

Reference

<pubmed>20064216</pubmed>| PMC2830955 | [http://www.biomedcentral.com/1471-213X/10/2

Copyright

© 2010 Nicholas et al; licensee BioMed Central Ltd. This is an Open Access article distributed under the terms of the Creative Commons Attribution License (http://creativecommons.org/licenses/by/2.0), which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited.

Nicholas et al. BMC Developmental Biology 2010 10:2 doi:10.1186/1471-213X-10-2