Notch pathway genes are expressed in mammalian ovarian follicles

Abstract

Folliculogenesis is the process of development of ovarian follicles that ultimately results in the release of fertilizable oocytes at ovulation. This is a complex program that involves the proliferation and differentiation of granulosa cells. Granulosa cells are necessary for follicle growth and support the oocyte during folliculogenesis. Genes that regulate the proliferation and differentiation of granulosa cells are beginning to be elucidated. In this study, the expression patterns of Notch receptor genes and their ligands, which have been shown to regulate cell-fate decisions in many systems during development, were examined in the mammalian ovary. In situ hybridization data showed that Notch2, Notch3, and Jagged2 were expressed in an overlapping pattern in the granulosa cells of developing follicles. Jagged1 was expressed in oocytes exclusively. Downstream target genes of Notch also were expressed in granulosa cells. These data implicate the Notch signaling pathway in the regulation of mammalian folliculogenesis.

Notch signaling as a therapeutic target in cancer: a new approach to the development of cell fate modifying agents

“…Thus, in the intestinal mucosa Notch signaling may have a classical 'lateral inhibition' function in the fate choice between the enterocyte lineage and the secretory lineage, and a prodifferentiation 'instructive' role in enterocyte development. Sequential Notch receptor activation has been suggested to occur during spermatogenesis (Mori et al, 2003) and in ovarian follicles (Johnson et al, 2001). There is strong evidence that Notch signaling participates in mammalian brain development, primarily inhibiting neuronal differentiation and allowing/ promoting glial differentiation (Morrison et al, 2000;Grandbarbe et al, 2003).…”

Notch signaling pathway in cumulus cells can be a novel marker to identify poor and normal responder IVF patients

“…Johnson et al showed differing expression levels of Notch and its ligands for different follicle sizes in an immunohistochemical study; they also emphasized that Notch2 immunopositivity was noted in all the stages of folliculogenesis and that Notch2 immunopositivity was strongly correlated with that of Notch3 [1]. They also reported that mature oocyte development can be disturbed unless Notch2 is absent; this disturbance can be a cause of infertility.…”

“…The Notch signaling pathway is initiated by interaction between the extracellular domains of Notch receptors and their ligands on the surface of adjacent cells [16]. Although there are many publications on the importance of the Notch signaling for tissue development [1,[17][18][19][20], only a few studies have been performed on the effects of Notch signaling on oocyte growth. To date, no information is available on human cumulus cells and oocyte maturation.…”

“…During the reproductive lifespan of female mammals, continuous follicle development occurs within the ovary [1]. Follicles are the functional units of the ovaries.…”

“…Notch genes are actively expressed by cumulus cells during folliculogenesis [1]. However, it is not released by oocyte and atretic follicles.…”