An evolutionarily conserved germ cell-specific hnRNP is encoded by a retrotransposed gene.
The gene encoding heterogeneous ribonucleoprotein (hnRNP) G recently has been mapped to the X chromosome. All mammals have a Y chromosome-encoded homologue of HNRNP G called RBMY, which is implicated with a role in male fertility and is a candidate for the azoospermia factor gene. We have identified a new member of this gene family, HNRNP G-T, and have mapped it as a single-copy gene on chromosome 11. This gene contains an uninterrupted open reading frame and no introns, consistent with derivation from a retroposon. However, unlike many retroposon-derived genes, HNRNP G-T is not a pseudogene. An antiserum raised to the conceptual reading frame of HNRNP G-T showed that it encodes a protein that is highly expressed in germ cells and in particular in the nuclei of meiotic spermatocytes. Surprisingly, although this antiserum was raised against human hnRNP G-T protein, it can also detect a similar protein in the testis of several mammals. This suggests that the protein is highly conserved and that the retrotransposition event generating the HNRNP G-T gene pre-dated at least the common ancestor of mouse and man. The existence of an additional testis-specific hnRNP G family member provides evidence for the importance of these proteins in normal germ cell development.
Elliott
D J
DJ
MRC Human Genetics Unit, Western General Hospital, Crewe Road, Edinburgh EH4 2XU, UK. davide@hgu.mrc.ac.uk
Venables
J P
JP
Newton
C S
CS
Lawson
D
D
Boyle
S
S
Eperon
I C
IC
Cooke
H J
HJ
D000595:Amino Acid Sequence; D000818:Animals; D015139:Blotting, Southern; D002417:Cattle; D002467:Cell Nucleus; D002880:Chromosomes, Human, Pair 11; D003001:Cloning, Molecular; D017124:Conserved Sequence; D018076:DNA, Complementary / Q000378:metabolism; D004591:Electrophoresis, Polyacrylamide Gel; D019143:Evolution, Molecular; D015723:Gene Library; D008040:Genetic Linkage; D034441:Heterogeneous-Nuclear Ribonucleoproteins; D006801:Humans; D017404:In Situ Hybridization, Fluorescence; D007438:Introns; D008297:Male; D008540:Meiosis / Q000235:genetics; D051379:Mice; D008969:Molecular Sequence Data; D016366:Open Reading Frames; D020161:Physical Chromosome Mapping; D051381:Rats; D018626:Retroelements / Q000235:genetics*; D012261:Ribonucleoproteins / Q000096:biosynthesis* / Q000235:genetics*; D017386:Sequence Homology, Amino Acid; D013090:Spermatocytes / Q000378:metabolism*; D013737:Testis / Q000378:metabolism; D020798:Two-Hybrid System Techniques; D014960:X Chromosome
D018076:DNA, Complementary; D034441:Heterogeneous-Nuclear Ribonucleoproteins; C415905:RBMXL2 protein, human; D018626:Retroelements; D012261:Ribonucleoproteins