ABSTRACT
We have isolated Kruppel-type (C2H2) zinc-finger genes, ZIM3 (zinc-finger gene 3 from imprinted domain) and ZNF264, located downstream of human and mouse USP29 genes (encoding ubiquitin-specific processing protease 29). In human, both ZIM3 and ZNF264 encode zinc-finger proteins with Kruppel-associated box (KRAB) A and B domains at the amino-terminal regions of the predicted proteins. In contrast, mouse Zim3 and Zfp264 seem to have lost protein-coding capability based on the lack of open reading frames (ORFs) in their cDNA sequences. In particular, the 3' end of the Zim3 transcript overlaps with the coding region of the adjacent gene Usp29 in an antisense orientation, indicating the conversion of mouse Zim3 into an antisense transcript gene for Usp29. The expression patterns of ZIM3 and ZNF264 have been largely conserved between human and mouse, with testis-specific expression of ZIM3 and ubiquitous expression of ZNF264, but high expression levels in adult testes in both species. Our studies also demonstrate that both mouse genes are imprinted with maternal expression of Zim3 in adult testes and paternal expression of Zfp264 in neonatal and adult brain. The reciprocal imprinting of two neighboring mouse genes, Zim3 and Zfp264, is consistent with a pattern observed frequently in other imprinted domains, and suggests that the imprinting of these two genes might be coregulated.
Subject(s)
Endopeptidases/genetics , Evolution, Molecular , Genomic Imprinting , Protein Kinases , Proteins/genetics , Transcription Factors , Zinc Fingers/genetics , Amino Acid Sequence , Animals , Blotting, Northern , Chromosomes, Human, Pair 19/genetics , DNA, Complementary/chemistry , DNA, Complementary/genetics , DNA, Complementary/isolation & purification , Embryo, Mammalian/metabolism , Exons , Female , Gene Expression , Gene Expression Regulation, Developmental , Genes/genetics , Humans , In Situ Hybridization , Introns , Kruppel-Like Transcription Factors , Male , Mice , Molecular Sequence Data , RNA/genetics , RNA/metabolism , Sequence Alignment , Sequence Analysis, DNA , Sequence Homology, Amino Acid , Tissue Distribution , Ubiquitin-Specific ProteasesABSTRACT
Draft sequence derived from the 46-Mb gene-rich euchromatic portion of human chromosome 19 (HSA19) was utilized to generate a sequence-ready physical map spanning homologous regions of mouse chromosomes. Sequence similarity searches with the human sequence identified more than 1000 individual orthologous mouse genes from which 382 overgo probes were developed for hybridization. Using human gene order and spacing as a model, these probes were used to isolate and assemble bacterial artificial chromosome (BAC) clone contigs spanning homologous mouse regions. Each contig was verified, extended, and joined to neighboring contigs by restriction enzyme fingerprinting analysis. Approximately 3000 mouse BACs were analyzed and assembled into 44 contigs with a combined length of 41.4 Mb. These BAC contigs, covering 90% of HSA19-related mouse DNA, are distributed throughout 15 homology segments derived from different regions of mouse chromosomes 7, 8, 9, 10, and 17. The alignment of the HSA19 map with the ordered mouse BAC contigs revealed a number of structural differences in several overtly conserved homologous regions and more precisely defined the borders of the known regions of HSA19-syntenic homology. Our results demonstrate that given a human draft sequence, BAC contig maps can be constructed quickly for comparative sequencing without the need for preestablished mouse-specific genetic or physical markers and indicate that similar strategies can be applied with equal success to genomes of other vertebrate species.
