Identification and characterization of Mlr1,2: Two mouse homologues of Mblk-1, a transcription factor from the honeybee brain

We previously identified the Mblk-1 gene in the honeybee brain, which encodes a transcription factor containing two DNA binding motifs, termed RHF1 and 2 (Takeuchi et al. (2001) Insect Mol. Biol. 121, 134-140). Here, we identified two mouse Mblk1 homologues, Mlr1 and Mlr2. Both encode proteins containing a single DNA-binding motif highly conserved with RHF2 and activate transcription mediated by a DNA element recognized by honeybee Mblk-1. Mlr1 was expressed predominantly in the spermatocytes of the testis, while Mlr2 was expressed in various tissues other than testis. Mlr1 transcripts were lost in the testis of W/W^v mutant mice, suggesting a role in spermatogenesis.