The cumulus oophorus also called discus proligerus, is a cluster of cells (called cumulus cells) that surround the oocyte

Oocyte

An oocyte, ovocyte, or rarely ocyte, is a female gametocyte or germ cell involved in reproduction. In other words, it is an immature ovum, or egg cell. An oocyte is produced in the ovary during female gametogenesis. The female germ cells produce a primordial germ cell which undergoes a mitotic...

 both in the ovarian follicle

Ovarian follicle

Ovarian follicles are the basic units of female reproductive biology, each of which is composed of roughly spherical aggregations of cells found in the ovary. They contain a single oocyte . These structures are periodically initiated to grow and develop, culminating in ovulation of usually a single...

 and after ovulation

Ovulation

Ovulation is the process in a female's menstrual cycle by which a mature ovarian follicle ruptures and discharges an ovum . Ovulation also occurs in the estrous cycle of other female mammals, which differs in many fundamental ways from the menstrual cycle...

. In the antral follicle

Antral follicle

An antral follicle is an ovarian follicle during a certain latter stage of folliculogenesis.Definitions differ in where the shift into an antral follicle occurs in the staging of folliculogenesis, with some stating that it occurs when entering the secondary stage, and others stating that it occurs...

, it may be regarded as an extension of the membrana granulosa

Membrana granulosa

The larger ovarian follicles consist of an external fibrovascular coat, connected with the surrounding stroma of the ovary by a network of bloodvessels; and an internal coat, which consists of several layers of nucleated cells, called the membrana granulosa...

.

This layer of cells must be penetrated by the spermatocyte in order for fertilization to occur.

Functions

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.

It also provides energy substrates for oocyte meiotic resumption and promotes glycolysis.

In addition, it provides protection for the oocyte.

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

Aneuploidy

Aneuploidy is an abnormal number of chromosomes, and is a type of chromosome abnormality. An extra or missing chromosome is a common cause of genetic disorders . Some cancer cells also have abnormal numbers of chromosomes. Aneuploidy occurs during cell division when the chromosomes do not separate...

, 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

HAS2

Hyaluronan synthase 2 is an enzyme that in humans is encoded by the HAS2 gene.-Further reading:...

, GREM1 and PTGS2

PTGS2

Prostaglandin-endoperoxide synthase 2, also known as cyclooxygenase-2 or simply COX-2, is an enzyme that in humans is encoded by the PTGS2 gene.- History :...

.

In contrast, genes where increased expression is correlated with lower oocyte competence or worse pregnancy outcomes include: BDNF, CCND2, CXCR4

CXCR4

C-X-C chemokine receptor type 4 also known as fusin or CD184 is a protein that in humans is encoded by the CXCR4 gene.- Function :...

, GPX3

GPX3

Glutathione peroxidase 3 , also known as plasma glutathione peroxidase or extracellular glutathione peroxidase is an enzyme that in humans is encoded by the GPX3 gene....

, HSPB1, DVL3

DVL3

Segment polarity protein dishevelled homolog DVL-3 is a protein that in humans is encoded by the DVL3 gene.-Interactions:DVL3 has been shown to interact with DAB2, DVL1 and PRPF3.-Further reading:...

, DHCR7, CTNND1

CTNND1

Catenin delta-1 is a protein that in humans is encoded by the CTNND1 gene.-Interactions:CTNND1 has been shown to interact with Beta-catenin, FYN, Collagen, type XVII, alpha 1, PTPN6, YES1, PTPRJ, VE-cadherin, MUC1, CDH1, CDH2, PTPRM, Cortactin, Nephrin, ZBTB33 and PSEN1.-Further reading:...

, TRIM28

TRIM28

Tripartite motif-containing 28 also known as transcriptional intermediary factor 1β is a protein that in humans is encoded by the TRIM24 gene.- Function :...

, STAR

Steroidogenic acute regulatory protein

The steroidogenic acute regulatory protein, commonly referred to as StAR , is a transport protein that regulates cholesterol transfer within the mitochondria, which is the rate-limiting step in the production of steroid hormones...

, AREG

Areg

Areg is a town in the Aragatsotn Province of Armenia.- References :*Kiesling, Rediscoving Armenia, p. 20, available online at the...

, CX43, PTGS2

PTGS2

Prostaglandin-endoperoxide synthase 2, also known as cyclooxygenase-2 or simply COX-2, is an enzyme that in humans is encoded by the PTGS2 gene.- History :...

, SCD1

Scd1

Scd1 can refer to:* Stearoyl-CoA desaturase-1, an enzyme involved in fatty acid metabolism*/dev/scd1, SCSI audio-oriented optical disk drives...

 and SCD5.

External links

- "Mammal, bovine ovary (LM, Medium)" - "Female Reproductive System: ovary, cumulus oophorus"