Follicular development in vitro

There has been tremendous interest in recent years in the culture of oocyte s and follicles. Although much of the research using follicle culture aims to increase understanding of the regulation of follicle development, an imp ortant goal has been to develop a method that will eventually allow maturat ion of human oocytes from the primordial follicle to the mature Graafian st age. We are still some way from this at present, although it has now been a chieved in the mouse. In this article, we consider various methods of folli cle culture for primordial, preantral, and antral follicles. In vitro devel opment of primordial follicles has used primarily whole ovaries or ovarian fragments as a source of follicles. Culture of later stages of follicle dev elopment uses mainly isolated follicular units, either whole (with an intac t basement membrane and, in some cases, attached thecal cells) or nonintact (oocyte-somatic cell complexes, which may or may not have remnants of base ment membranes and/or thecal cells attached).