Cumulus oophorus consists of a cluster of granulosa cells that surround and support the oocyte (a female germ cell involved in reproduction) in an antral follicle (a developmental stage of a follicle, with a single fluid-filled cavity in the center, Pic. 1). These cells serve three primary functions:
Cumulus oophorus consists of a group of cells that are tightly packed together around the maturing oocyte. They originate from the cell population known as membrana granulosa, or granulosa cells, which form a solid layer around the oocyte in the early stages of follicle maturation (Pic. 2). As the follicle matures, small spaces start to appear among the granulosa cells. These spaces gradually fuse together until they form a single cavity in the center of the follicle, which is filled with fluid and is called a follicle antrum. One part of the granulosa cells then forms a layer lining the antrum, and the rest forms a cluster of cells that bulges into the antrum and contains a mature oocyte, which is called the cumulus oophorus (Pic. 3). The part that connects the cumulus itself to the rest of granulosa cells is sometimes called discus prodigerus. Furthermore, the innermost layer of the cumulus, that directly surrounds the oocyte, is called corona radiata, and it has important roles in protecting the oocyte during ovulation.
Gene expression profiling
Gene expression profiling is a procedure used to estimate oocyte quality in laboratory conditions. It can give hints whether the gene information contained in the oocyte have suffered mutations or hints about the embryo development and pregnancy outcomes. Such information is used to describe the competence of an oocyte. It is possible to determinate the competence of an oocyte according to the level of gene expression of specific genes of cumulus cells.
The exact role of cumulus cells in fertility and its disorders is still not fully understood. However, studies show that proteins produced by cumulus cells are indispensable for a healthy oocyte development and normal ovulation. Therefore, disorders of the cumulus oophorus functions may account for a portion of cases of unexplained infertility and ovulatory disorders.
Failure of the ovaries to release an oocyte over a period of time generally exceeding 3 months.
The absence of implantation after three or more transfers of high quality embryos or after placement of 10 or more embryos in multiple transfers.
The loss of function of the ovaries before age 40.
The time in most women's lives when menstrual periods stop permanently, and the woman is no longer able to have children.
Surgical removal of one or both ovaries.
The ovum-producing organs of the internal female reproductive system
The process of the maturation of the female gametes through the meiotic division.