Cloning and mapping of a testis-specific gene with sequence similarity to a sperm-coating glycoprotein gene.
A testis-specific gene Tpx-1, located between Pgk-2 and Mep-1 on mouse chromosome 17, was isolated from a cosmid clone, and its cDNA sequences were determined. The predicted coding sequence of Tpx-1 isolated from BALB/c mice showed 64.2% nucleotide and 55.1% amino acid sequence similarity with that of a rat sperm-coating glycoprotein gene, the protein product of which is secreted by the epididymis. To examine the evolutionary relationship between Tpx-1 and a sperm-coating glycoprotein gene, the cDNA sequence of TPX1, the human counterpart of Tpx-1, was determined. The comparison of the predicted coding sequences of Tpx-1 and TPX1 showed 77.8% nucleotide and 70% amino acid sequence similarity. Since Tpx-1 (from mouse) is more similar to TPX1 (from man) than it is to a rat sperm-coating glycoprotein gene, we conclude that Tpx-1 (TPX1) and a sperm-coating glycoprotein gene are closely related, but distinct, genes belonging to the same gene family. The predicted Tpx-1 protein of a t mutant mouse CRO437 differs from that of BALB/c mice by one amino acid insertion in the putative signal peptide. TPX1 was mapped to 6p21-qter by Southern blot analysis of interspecies somatic hybrid cell lines.
Kasahara
M
M
Department of Microbiology and Immunology, University of Miami School of Medicine, Florida 33101.
Gutknecht
J
J
Brew
K
K
Spurr
N
N
Goodfellow
P N
PN
D000595:Amino Acid Sequence; D000818:Animals; D001483:Base Sequence; D015139:Blotting, Southern; D015815:Cell Adhesion Molecules; D002896:Chromosomes, Human, Pair 6; D003001:Cloning, Molecular; D004247:DNA / Q000235:genetics / Q000302:isolation & purification; D006023:Glycoproteins / Q000235:genetics*; D006801:Humans; D008297:Male; D008565:Membrane Proteins; D051379:Mice; D008807:Mice, Inbred BALB C; D008969:Molecular Sequence Data; D051381:Rats; D012689:Sequence Homology, Nucleic Acid; D013737:Testis / Q000378:metabolism*
C062621:CRISP2 protein, human; C062790:CRISP2 protein, rat; D015815:Cell Adhesion Molecules; C483816:Crisp2 protein, mouse; D006023:Glycoproteins; D008565:Membrane Proteins; D004247:DNA