Desert hedgehog ( @entity12544 ) is a cell-signaling molecule that was first discovered in @entity238 . A unique testicular phenotype has been described in neonatal and adult @entity12544 -null animals that includes anastomotic seminiferous tubules, pertitubular cell abnormalities, and absence of adult-type Leydig cells. In the present study, we addressed the developmental basis for the abnormalities previously described for the adult @entity12544 -null phenotype. The source of @entity12544 is the Sertoli cell, and receptors are localized on peritubular cells and possibly Leydig cells. The development of testes from @entity12544 -null @entity19 embryos was studied using light and electron microscopy at 11.5, 12.5, 13.5, and 16.5 days postcoitum (dpc) and was compared with that in control @entity12544 heterozygous and wild-type embryos. @entity12544 -null and control testes were generally similar during the period of early cord formation (11.5-12.5 dpc). By 13.5 dpc, the basal lamina delimiting the cords was lacking in some regions and disorganized in @entity12544 -null testes, and occasional germ cells were seen outside cords. At 16.5 dpc, these defects were more prominent and cord organization was less well defined than in controls. In addition, there were numerous extracordal germ cells, some of which were partially enclosed by a somatic cell of unknown identity. Numerous fibroblast-like cells, apparently secreting collagen and basal lamina, characterized the interstitium of the @entity12544 -null testis. These defects likely stem from abnormal peritubular stimulation due to the lack of @entity12544 , leading to the abnormalities seen in the developmental stages studied here and in the adult testis.

A developmental study of the Desert hedgehog-null XXXX testis.

@entity238 :: ('7227', 'Species') :: ['Drosophila'] @entity19 :: ('10090', 'Species') :: ['mouse'] @entity12544 :: ('13363(Tax:10090)', 'Gene') :: ['Dhh']
@entity19 :: (10090,Species) :: ['mouse']
