title: [Mutant gene expression in mouse aggregation chimeras. I. The white gene].
abstract: Miwh gene expression was studied on newborn and 20 day old chimaeric mice Miwh/Miwh--57BR in equilibrium +/+ (CBA). The newborn chimaeras were characterized by mosaicism of retinal pigment epithelium (RPE) consisting of normal pigmented and hyperplased unpigmented patches, the number and size of abnormal RPE regions being greater in the dorsal eye part than in its ventral part. The same character of RPE mosaicism was observed in 20 day old chimaeras but hyperplasia of its unpigmented patches was expressed stronger: the cells had cubic shape and used to form a few layers. These chimaeras were also characterized by disturbance of the photoreceptor layer differentiation and by the absence of choroid pigmentation in the regions adjacent to the hyperplased RPE patches. The eye size of chimaeras did not, however, differ from that in the normal mice. Hence, in the mouse chimaeras Miwh/Miwh---+/+ the hyperplasia of certain RPE patches is due to the action of defective Miwh/Miwh ectomesenchyme which leads, in turn, to disturbance of the photoreceptor retinal layer differentiation. A high correlation in the percentage of pigmented and unpigmented RPE patches was established between the right and left eye of chimaeric mice (r = 0.90), thus suggesting the equal participation of the ectomesenchyme cell clones in the development of both eyes. A strict dependence was observed between the number of unpigmented patches in skin and hair of the chimaeras and the degree of disturbance of RPE patches.
mesh_terms: D000483:Alleles; D000818:Animals; D000831:Animals, Newborn; D002678:Chimera; D005260:Female; D005786:Gene Expression Regulation; D005796:Genes; D006720:Homozygote; D006965:Hyperplasia / Q000473:pathology; D008297:Male; D051379:Mice; D008810:Mice, Inbred C57BL / Q000235:genetics*; D008808:Mice, Inbred CBA / Q000235:genetics*; D009030:Mosaicism; D009154:Mutation; D010857:Pigment Epithelium of Eye / Q000473:pathology; D011247:Pregnancy
vernacular_title: Izuchenie ékspressii mutantnykh genov u agregatsionnykh khimer myshi. 1. Gen white.