The nature of selection of the dominant follicle is reviewed by comparing research results between cattle and horses. In both species, emergence of a follicular wave is stimulated by an FSH surge. The surge reaches a peak by the time the follicles attain 4 mm in diameter in cattle and 13 mm in mares. In cattle, all of the growing follicles >/=5 mm contribute to the decline in FSH concentrations...

There are many cell types in the hair follicle, including hair matrix cells which form the hair shaft and stem cells which can initiate the hair shaft during early anagen, the growth phase of the hair cycle, as well as pluripotent stem cells that play a role in hair follicle growth but have the potential to differentiate to non-follicle cells such as neurons. These properties of the hair follic...

Ultrastructural studies of oocyte degeneration in the oocyte, and the functions of follicle cells during oocyte degeneration are described to clarify the reproductive mechanism on oocyte degeneration of Mactra chinensis using cytological methods. Commonly, the follicle cells are attached to the oocyte. Follicle cells play an important role in oocyte degeneration. In particular, the functions of...

In the brachiopod Terebratalia transversa, each ovarian follicle consists of (i) a prophase-arrested oocyte with an enlarged nucleus (= the germinal vesicle, or GV), and (ii) a surrounding sheath of follicle cells that attach to the oocyte by means of junctional complexes. Within about 80 min after removing a follicle from the ovary, the follicular sheath undergoes a microfilament-mediated retr...

stem cells are generally defined as clonogenic cells capable of both self-renewal and differentiation. probably the best method for long-term preservation of spermatogonial stem cells is cryopreservation. in this study, effects of follicle stimulating hormone and testosterone on viability rate of cryopreserved spermatogonial stem cell after thawing were investigated. sertoli and spermatogonial ...

The extracellular matrix (ECM) provides a three-dimensional structure that promotes and regulates cell adhesion and provides signals that direct the cellular processes leading to tissue development. In this report, synthetic matrices that present defined ECM components were employed to investigate these signaling effects on tissue formation using ovarian follicle maturation as a model system. I...

The developmental requirements of ovarian follicles are dependent on the maturation stage of the follicle; in particular, elegant studies with genetic models have indicated that FSH is required for antral, but not preantral, follicle growth and maturation. To elucidate further the role of FSH and other regulatory molecules in preantral follicle development, in vitro culture systems are needed. ...

background: there is a fundamental correlation between follicles and endometrium in intracytoplasmic sperm injection (icsi) cycles. objective: to assess the relation between perifollicular perfusion and sub endometrial parameters in doppler ultrasonography and outcome of in icsi cycles. materials and methods: in this prospective deh1ive pilot study 10 patients were enrolled. strict inclusion cr...

The hair follicle is a skin appendage with a complex structure containing many cell types that produce highly specialised proteins. The hair follicle is in a continuous cycle: anagen is the hair growth phase, catagen the involution phase and telogen is the resting phase. The follicle offers many potential therapeutic targets. Hoffman and colleagues have pioneered hair-follicle-specific targetin...

Wnt proteins are secreted molecules that play multiple roles during hair follicle development and postnatal hair cycling. Wntless (Wls) is a cargo protein required for the secretion of various Wnt ligands. However, its role during hair follicle development and hair cycling remains unclear. Here, we examined the expression of Wls during hair follicle induction and postnatal hair cycling. We also...