PARENT SESSION

(T371) EXPRESSION OF THE NOTCH REGULATORS, NUMB, NUMBLIKE, AND NEURALIZED IN MOUSE OVARY.

Beres, Brian ¹, Barton, Michael¹, McGlade, Jane ², Wilson-Rawls, Jeanne¹, ¹ Arizona State University, Tempe, AZ² University of Toronto, Hospital for Sick Children, Toronto, ON, Canada

ABSTRACT- Notch signaling pathway genes have been demonstrated to be important for folliculogenesis in mice. The function of Notch is regulated by a number of cytoplasmic proteins, among them Numb (mNb), Numblike (mNbl), and neuralized. Both mNb and mNbl are cytoplasmic proteins that have been shown to segregate asymmetrically in dividing cells. These proteins block the activation of Notch and are involved in regulation of asymmetric divisions. Neuralized is another cytoplasmic Notch regulator that has been detected in Drosophila ovary. The expression pattern of these Notch pathway components was determined by semi-quantitative RT-PCR in mouse ovary. mNb demonstrated a developmentally regulated change in isoform expression from postnatal day (p) 10 to p16, whereas mNbl was expressed at a consistent level throughout this time frame, transcripts for both genes were detected in adult ovary. Using a pan-Numb and numb and Numblike antibody these genes were detected in the granulosa cells of developing follicles, theca, oocytes of primary to early preantral follicles, corpus luteum and in the germinal epithelium. When examined in Lunatic fringe null mice, there was aberrant expression of mNb in oocytes in follicles from primary to preovulatory in size.

KEY WORDS: ovary, notch, numb, neuralized