The cumulus oophorus, also called discus proligerus, is a cluster of cells (called cumulus cells) that surround the oocyte both in the ovarian follicle and after ovulation. In the antral follicle, it may be regarded as an extension of the membrana granulosa. The innermost layer of these cells is the corona radiata.
Section of vesicular ovarian follicle of cat. X 50. (Discus proligerus labeled at lower left.)
This layer of cells must be penetrated by spermatozoa in order for fertilization to occur.
Functions of the cumulus oophorus include coordination of follicular development and oocyte maturation. Mechanisms of the latter include stimulation of amino acid transport and sterol biosynthesis and regulation of oocyte gene transcription.
...regulation of oocyte gene transcription. < In addition, it provides protection for the oocyte. Also used in cloning procedures Cumulus oophorus cells contribute heavily to the maturation and eventual fertilization of an oocyte. As a follicle grows in size and the antrum develops, more layers of cumulus oophorus cells accumulate around the oocyte to aid in the acrosome reaction and sperm penetration into the oocyte. The close proximity between the cumulus oophorus cells and the oocyte favors bidirectional communication, which is vital for oocyte development.
Gene expression profiling
As a part of the process of in vitro fertilization, gene expression profiling of cumulus cells can be performed to estimate oocyte quality and the efficiency of an ovarian hyperstimulation protocol, and may indirectly predict oocyte aneuploidy, embryo development and pregnancy outcomes.</> Increased knowledge in these aspects is useful in, for example, embryo selection.<
In gene expression profiling of cumulus cells, genes where increased expression is correlated with higher oocyte competence or better pregnancy outcomes include: HAS2, GREM1 and PTGS2.<ref
In contrast, genes where increased expression is correlated with lower oocyte competence or worse pregnancy outcomes include: BDNF, CCND2, CXCR4, GPX3, HSPB1, DVL3, DHCR7, CTNND1, TRIM28, STAR, AREG, CX43, PTGS2, SCD1 and SCD5.
- Gilbert, Scott F. Developmental Biology (Ninth ed.). Sinauer Associates, Inc. p. 126. ISBN 978-0878933846.
- The Evian Annual Reproduction (EVAR) Workshop Group 2010; Fauser, B. C. J. M.; Diedrich, K.; Bouchard, P.; Domínguez, F.; Matzuk, M.; Franks, S.; Hamamah, S.; Simón, C.; Devroey, P.; Ezcurra, D.; Howles, C. M. (2011). "Contemporary genetic technologies and female reproduction". Human Reproduction Update. 17 (6): 829–847. doi:10.1093/humupd/dmr033. PMC 3191938. PMID 21896560.
Biase, Fernando H. & Kimble, Katelyn M. Functional signaling and gene regulatory networks between the oocyte and the surrounding cumulus cells. BMC Genomics. 2018; 19(1):351. doi:10.1186/s12864-018-4738-2.
- Anatomy photo: Reproductive/mammal/ovary5/ovary3 - Comparative Organology at University of California, Davis - "Mammal, bovine ovary (LM, Medium)"
- Swiss embryology (from UL, UB, and UF) dbefruchtung/objectbefru01
- UIUC Histology Subject 366
- Histology image: 18404loa – Histology Learning System at Boston University - "Female Reproductive System: ovary, cumulus oophorus"