Molecular Human Reproduction, Vol. 9, No. 5, 237-243,
May 2003
© 2003 European Society of Human Reproduction and Embryology
Article |
Molecular cloning and characterization of the human orthologue of the oppo 1 gene encoding a sperm tail protein
Submitted on December 3, 2002; accepted on January 23, 2003
1 Department of Science for Laboratory Animal Experimentation, Research Institute for Microbial Diseases, Osaka University, 3-1 Yamadaoka, Suita, Osaka 565-0871 and 2 Department of Urology, Osaka University Medical School, Osaka, Japan
3 To whom correspondence should be addressed. e-mail: nishimun{at}biken.osaka-u.ac.jp
We report here the molecular cloning and characterization of a human orthologue of oppo 1, a mouse gene encoding a male germ-cell-specific sperm tail protein, and the organization of its genomic structure. The mRNA of the human oppo 1 gene (h-oppo 1) was expressed exclusively in the testis, and the 30 kDa protein encoded by the mRNA was detected in human testis and sperm. Immunohistochemical analyses showed that human OPPO 1 protein was localized in the flagellae of ejaculated sperm. A human genomic DNA database search indicated that the h-oppo 1 gene mapped to chromosome 17. The genomic structure of h-oppo 1 showed differences in exon/intron usage, the sequence of the 5'-flanking region, and the first intron was rich in Alu repeats as compared with the mouse oppo 1 gene. Comparison of the two genomic sequences indicated that human oppo 1 has evolved independently, resulting in substantial differences in the genomic structure after the human–mouse split, whereas the sequence of the basic functional unit of the oppo 1 gene seems to have been relatively well conserved.
Key words: Alu repeat/oppo 1/outer dense fibres/sperm/spermiogenesis