AZFb and candidate genes:
AZFb locus spans about 1.5 Mb of the Y chromosome.
Two important candidate gene families that have been mapped on the AZFb locus are EIF1AY (translation initiation factor 1 A, Y isoform) and RBMY (
EIF1AY encodes a ubiquitously expressed translation initiation factor. However it also possesses abundant testis-specific transcripts.
RBMY is a multicopy