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

oocyte An oocyte (, ), oöcyte, or ovocyte 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 a female fetus in the ovary during female gametogenesis. The femal ...

both in the

ovarian follicle An ovarian follicle is a roughly spheroid cellular aggregation set found in the ovaries. It secretes hormones that influence stages of the menstrual cycle. At the time of puberty, women have approximately 200,000 to 300,000 follicles, each with t ...

and after

ovulation Ovulation is the release of eggs from the ovaries. In women, this event occurs when the ovarian follicles rupture and release the secondary oocyte ovarian cells. After ovulation, during the luteal phase, the egg will be available to be fertilize ...

. 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 In neuroanatomy, the corona radiata is a white matter sheet that continues inferiorly as the internal capsule and superiorly as the centrum semiovale. This sheet of both ascending and descending axons carries most of the neural traffic from and ...

. This layer of cells must be penetrated by

spermatozoa A spermatozoon (; also spelled spermatozoön; ; ) is a motile sperm cell, or moving form of the haploid cell that is the male gamete. A spermatozoon joins an ovum to form a zygote. (A zygote is a single cell, with a complete set of chromos ...

for

fertilization Fertilisation or fertilization (see spelling differences), also known as generative fertilisation, syngamy and impregnation, is the fusion of gametes to give rise to a new individual organism or offspring and initiate its development. Proce ...

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 Transcription is the process of copying a segment of DNA into RNA. The segments of DNA transcribed into RNA molecules that can encode proteins are said to produce messenger RNA (mRNA). Other segments of DNA are copied into RNA molecules called ...

. It also provides energy substrates for oocyte meiotic resumption and promotes glycolysis. 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 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 In vitro fertilisation (IVF) is a process of fertilisation where an egg is combined with sperm in vitro ("in glass"). The process involves monitoring and stimulating an individual's ovulatory process, removing an ovum or ova (egg or eggs) f ...

gene expression profiling In the field of molecular biology, gene expression profiling is the measurement of the activity (the expression) of thousands of genes at once, to create a global picture of cellular function. These profiles can, for example, distinguish between c ...

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 is the presence of an abnormal number of chromosomes in a cell, for example a human cell having 45 or 47 chromosomes instead of the usual 46. It does not include a difference of one or more complete sets of chromosomes. A cell with any ...

, embryo development and pregnancy outcomes. Increased knowledge in these aspects is useful in, for example, embryo selection. In gene

expression profiling In the field of molecular biology, gene expression profiling is the measurement of the activity (the expression) of thousands of genes at once, to create a global picture of cellular function. These profiles can, for example, distinguish between c ...

of cumulus cells, genes where increased expression is correlated with higher oocyte competence or better pregnancy outcomes, include: HAS2,

GREM1 Gremlin is an inhibitor in the TGF beta signaling pathway. It primarily inhibits bone morphogenesis and is implicated in disorders of increased bone formation and several cancers. Structure Gremlin1, previously known as Drm, is a highly con ...

and

PTGS2 Prostaglandin-endoperoxide synthase 2 (prostaglandin G/H synthase and cyclooxygenase) (The HUGO official symbol is PTGS2; HGNC ID, HGNC:9605), also known as cyclooxygenase-2 or COX-2, is an enzyme that in humans is encoded by the ''PTGS2'' gene ...

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

BDNF Brain-derived neurotrophic factor (BDNF), or abrineurin, is a protein found in the and the periphery. that, in humans, is encoded by the ''BDNF'' gene. BDNF is a member of the neurotrophin family of growth factors, which are related to the canon ...

, CCND2,

CXCR4 C-X-C chemokine receptor type 4 (CXCR-4) also known as fusin or CD184 (cluster of differentiation 184) is a protein that in humans is encoded by the ''CXCR4'' gene. The protein is a CXC chemokine receptor. Function CXCR-4 is an alpha-chemokin ...

GPX3 Glutathione peroxidase 3 (GPx-3), also known as plasma glutathione peroxidase (GPx-P) or extracellular glutathione peroxidase is an enzyme that in humans is encoded by the ''GPX3'' gene. GPx-3 belongs to the glutathione peroxidase family, which f ...

HSPB1 Heat shock protein 27 (Hsp27) also known as heat shock protein beta-1 (HSPB1) is a protein that in humans is encoded by the ''HSPB1'' gene. Hsp27 is a chaperone of the sHsp (small heat shock protein) group among α-crystallin, Hsp20, and others. ...

DVL3 Segment polarity protein dishevelled homolog DVL-3 is a protein that in humans is encoded by the ''DVL3'' gene. This gene is a member of a multi-gene family which shares strong similarity with the Drosophila dishevelled gene, dsh. The Drosophila d ...

DHCR7 7-Dehydrocholesterol reductase, also known as DHCR7, is a protein that in humans is encoded by the ''DHCR7'' gene. Function The protein encoded by this gene is an enzyme catalyzing the production of cholesterol from 7-Dehydrocholesterol usi ...

CTNND1 p120, and called catenin delta-1 is a protein that in humans is encoded by the CTNND1 gene. Function This gene encodes a member of the Armadillo protein family, which function in adhesion between cells and signal transduction. Multiple transla ...

TRIM28 Tripartite motif-containing 28 (TRIM28), also known as transcriptional intermediary factor 1β (TIF1β) and KAP1 (KRAB-associated protein-1), is a protein that in humans is encoded by the ''TRIM28'' gene. Function The protein encoded by this ge ...

, STAR, AREG,

CX43 Gap junction alpha-1 protein (GJA1), also known as connexin 43 (Cx43), is a protein that in humans is encoded by the ''GJA1'' gene on chromosome 6. As a connexin, GJA1 is a component of gap junctions, which allow for gap junction intercellular co ...

, SCD1 and SCD5.

References

External links

* - "Mammal, bovine ovary (LM, Medium)" * * * - "Female Reproductive System: ovary, cumulus oophorus" {{DEFAULTSORT:Cumulus Oophorus Mammal female reproductive system