IDENTIFICATION OF HUMAN MURR1, THE HOMOLOGUE OF MOUSE IMPRINTED Murr1 GENE

Different fromthe biallelic expression mannerof most common autosomal genes,i mprinting is aspecial genomic expression phenomenon,of whichthe i mprinted genes show parental-specific expres-sion only according to their parental origin[1].Cor-rect i mprintingis i mportant inthe nor mal embryon-ic development,postnatal growth,as well as behav-ior of ani mals.Dysregulation of i mprinting hasbeen i mplicated in the pathogenesis of congenitaldiseases and cancer[2-3].To date,78kinds of mousei mprinte…

IDENTIFICATION OF HUMAN MURR1, THE HOMOLOGUE OF MOUSE IMPRINTED Murr1 GENE

Objective To identify the mRNA sequence, genetic construction, imprinting status, and expression profile of human MURR1 gene, the homologue of mouse imprinted Murr1 gene. Methods The MURR1 mRNA sequence was identified by colony hybridization screening of human cDNA library and the 5-RACE analyses; Absence of U2AF1-RS1 gene within MURR1 was confirmed by Southern Blotting; Expression profile of MURR1 was examined by Northern Blotting; The imprinting status of MURR1 were revealed by SNP investigation and RT-PCR followed by scquencings and RFLP analyses. Results The full-length mRNA sequence of MURR1 spans 711 bp, transcribed from 3 exons, encodes predicted MURR1 protein of 190 amino acids. The gene was expressed in all the 12 kinds of human adult tissues and 6 kinds of fetal tissues. It showed biallelic expression in all 32 investigated samples including 6 kinds of human fetal tissues and 8 adult brains. Unlike mouse imprinted U2af1-rs1 gene existing in the intron of Murr1, the human U2AF1-RS1 gene was not located in the MURR1 locus. Conclusion Human MURR1 gene is not imprinted and the non-imprinting is possible due to the absence of human homologue of mouse U2af1-rs1 within MURR1 locus.