Sertoli cells under the influence of Follicle Stimulating Hormone are known to provide a microenvironment for the growth and differentiation of germ cells. Follicle Stimulating Hormone regulates proliferation of Sertoli cells only during the early neonatal period and during adult period it regulates functional parameters like Transferrin, Androgen binding protein and other factors needed for ge...

Long-term adult stem cells sustain tissue regeneration throughout the lifetime of an organism. They were hypothesized to originate from embryonic progenitor cells that acquire long-term self-renewal ability and multipotency at the end of organogenesis. The process through which this is achieved often remains unclear. Here, we discovered that long-term hair follicle stem cells arise from embryon...

During Drosophila oogenesis, asymmetrically localized Gurken activates the EGF receptor (Egfr) and determines dorsal follicle cell fates. Using a mosaic follicle cell system we have identified a mutation in the D-cbl gene which causes hyperactivation of the Egfr pathway. Cbl proteins are known to downregulate activated receptors. We find that the abnormal Egfr activation is ligand dependent. Ou...

Two different protocols for ovulation induction used in phase I of the in vitro fertilization (IVF) programme at Tygerberg Hospital are presented. Previous experience with gonadotrophins and clomiphene citrate was applied in the development of the protocols. By means of experience gained during ovulation induction it was possible to establish critical values for the parameters of follicle matur...

The mammalian oocyte develops within a complex of somatic cells known as a follicle, within which signals from the somatic cells regulate the oocyte, and signals from the oocyte regulate the somatic cells. Because isolation of the oocyte from the follicle disrupts these communication pathways, oocyte physiology is best studied within an intact follicle. Here we describe methods for quantitative...

Hair follicle stem cells in the hair follicle bulge area of mice are nestinand CD34-positive, and keratin 15 (K15)negative. The mouse hair follicle stem cells are multipotent and can differentiate into neurons, glial cells, keratinocytes, smooth muscle cells, and melanocytes (Proc. Natl. Acad. Sci. USA 102, 5530-5534, 2005). Recently, pluripotent stem cells have been identified in human hair fo...

Complex patterns of morphogenesis require intricate coordination of multiple, regulatory processes that control cellular identities, shapes, and behaviors, both locally and over vast distances in the developing organism or tissue. Studying Drosophila oogenesis as a model for tissue morphogenesis, we have discovered extraovarian regulation of follicle formation. Clonal analysis and ovary transpl...

The ovarian follicle has a three-dimensional (3D) structure in which the oocyte is surrounded by tightly connected follicle cells that mediate the action of external signals and nourish the gamete during its maturation. Thus, the maintenance of follicle organization during the whole growth process is crucial for the correct acquisition of developmental competence. In recent years, much attentio...

The occurrence of more than two ova from the same follicle (polyovular follicle) in humans has been observed. In this case report there was a high frequency of conjoined oocytes retrieved with individual zona pellucida (40% of oocytes retrieved, 4.3% of mature follicles) from women with polycystic ovary syndrome (PCOS). We may have to be more aware of the risk of multiple pregnancies in inferti...

Porokeratotic eccrine and hair follicle nevus is a very rare non-hereditary disorder of keratinization with eccrine and hair follicle involvement with only 9 cases described in the literature. In 2009 the term porokeratotic anexial ostial nevus was proposed to comprehend porokeratotic eccrine and hair follicle nevus and a related and more common process without follicular involvement: porokerat...