Programmed cell death in the ovary: Insights and future prospects using genetic technologies

Programmed cell death (PCD) plays a prominent role in development of the fe tal ovaries and in the postnatal ovarian cycle. As is the case with other m ajor organ systems, an evolutionarily conserved framework of genes and sign aling pathways has been implicated in determining whether or not ovarian ge rm cells and somatic cells will die in response to either developmental cue s or pathological insults. However, the identification of increasing number s of potential ovarian cell death regulatory factors over the past several years has underscored the need for studies to now separate correlation (e.g . endogenous gene expression) from function (e.g. requirement of the gene p roduct for the execution of PCD). In this regard, genetic technologies have recently been used to examine the functional significance of specific prot eins and signaling molecules to the regulation of PCD in the female gonad i n vivo. In addition to the more classic approaches, such as the use of gene tic null and transgenic mice, methods that achieve cell lineage-selective a nd/or developmentally timed gene targeting are on the horizon for use by re productive biologists to more accurately dissect the mechanisms by which PC D is controlled in the ovary. This minireview will highlight some of the ad vances that have already been made using gene knockout and transgenic mice, as well as provide an overview of the current and future status of cell li neage-selective gene disruption, in the context of PCD and ovarian function .