ABSTRACT
SALL4 is a homologue of the Drosophila homeotic gene spalt, a zinc finger transcription factor, required for inner cell mass proliferation in early embryonic development. It also interacts with other transcription factors to control the development of the anorectal region, kidney, heart, limbs, and brain. Truncating mutations in SALL4 cause Okihiro syndrome, manifest as Duane anomaly, radial ray defects and sensorineural and conductive deafness. We report the characterization of a novel murine Sall4 null allele created by bacterial recombineering in ES cells. Homozygous mutant mice exhibit early embryonic lethality. Heterozygous mutant mice recapitulate phenotypic features of Okihiro syndrome including deafness, lower anogenital tract abnormalities, renal hypoplasia, anencephaly, Hirschprung's disease, and skeletal defects. This phenotype shows important differences in cardiac and ear manifestations to previously characterized Sall4 mutant alleles and should prove useful for the investigation of the influence of modifier alleles and protein interactions on the transcriptional regulatory function of Sall4.
Subject(s)
DNA-Binding Proteins/physiology , Organogenesis , Transcription Factors/physiology , Animals , DNA-Binding Proteins/genetics , Duane Retraction Syndrome/embryology , Duane Retraction Syndrome/genetics , Embryonic Development , Mice , Microscopy, Electron, Scanning , Mutation , Transcription Factors/geneticsABSTRACT
The nature and the origin of de novo small marker chromosome found at prenatal diagnosis were determined by fluorescence in situ hybridization (FISH) using chromosome centromere-specific probes and by chromosome in situ suppression (CISS) using chromosome specific libraries. The small marker was characterized as being derived from chromosome 22. The fetus which exhibited a minichromosome had kidney malformations and after birth showed clinical features consistent with the Duane anomaly. One previous case with Duane anomaly and abnormalities of urogenital tract associated to a bisatellitated marker derived from chromosome 22 was reported. These findings indicate that a gene or genes located in the region of chromosome 22pter-->q11 may be associated with the Duane anomaly and the development of the urogenital tract.
