STRUCTURE AND ORGANIZATION OF THE RBMY GENES ON THE HUMAN Y-CHROMOSOME - TRANSPOSITION AND AMPLIFICATION OF AN ANCESTRAL AUTOSOMAL HNRNPG GENE

The RBMY (RNA-binding motif, Y chromosome) gene family encodes a germ- cell-specific nuclear protein implicated in spermatogenesis, It consis ts of approximately 30 genes and pseudogenes, found on both arms of th e Y chromosome. RBMY shares high homology with an autosomal hnRNPG gen e that contains an RNA-binding motif and one of the four SRGY repeats found in RBMY. One proposal is that RBMY represents an ancestral hnRNP G gene, transposed to the Y chromosome and then amplified. We characte rized seven RBMY genes in interval 6 of the Y chromosome long arm. Fou r have the normal structure with 12 exons spanning 15 kb, whereas one lacks the first 3 exons, therefore representing a pseudogene. The rema ining two genes belong to a different subfamily, resembling the autoso mal hnRNPG gene with only one SRGY repeat, We also found that most RBM Y genes in interval 6 are arranged in tandem. The structure and organi zation of the Y-linked RBMY genes support the transposition-amplificat ion hypothesis. (C) 1998 Academic Press.