@entity1 ovarian development is characterized by a sequential pattern of mitotic proliferation of oogonia, initiation then arrest of meiosis, and primordial follicle formation. The factors regulating these processes are poorly understood. The neurotropins are survival and differentiation factors in the nervous system, acting via high affinity receptors of the @entity2250 protooncogene family and the low affinity p75 nerve growth factor receptor, and have also been described in the rodent ovary, where changes in @entity19563 / @entity12715 gene expression have been detected at the time of primordial follicle formation. There are no data on neurotropin expression in the normal @entity1 ovary. We have investigated the expression and localization of neurotropins and their receptors in the midtrimester @entity1 fetal ovary (13-21 wk gestation). Expression of mRNA for neurotropins and their receptors was detected by RT-PCR. Clusters of oogonia were found to be the predominant site of @entity19563 mRNA expression using in situ hybridization. However, at later gestations granulosa cells of primordial follicles showed increased expression, with lesser expression in the enclosed oocytes. @entity19563 protein was also localized to the granulosa cells by immunohistochemistry and at earlier developmental stages to epithelioid cells, which were mingled with clusters of oogonia not expressing @entity19563 . @entity12715 receptor protein was localized by immunohistochemistry to germ cells at all gestations examined. The p75 nerve growth factor receptor protein was exclusively expressed in the @entity43 . These data demonstrate the expression of neurotropins and their receptors within the @entity1 fetal ovary. Developmental changes in the pattern of expression of @entity19563 around the time of primordial follicle formation suggest that neurotropins may be involved in signaling between somatic cells and germ cells at this crucial stage of ovarian development.

Neurotropins and their receptors are expressed in the XXXX fetal ovary.

@entity1 :: ('9606', 'Species') :: ['human', 'Mammalian'] @entity43 :: ('MESH:D010051', 'Disease') :: ['ovarian stroma'] @entity19563 :: ('4909', 'Gene') :: ['NT4'] @entity2250 :: ('4914', 'Gene') :: ['trk'] @entity12715 :: ('4915', 'Gene') :: ['TrkB']
@entity1 :: (9606,Species) :: ['human']
