Background and Aims: In a previous study, the authors of the present study cloned mouse meichroacidin (MCA), which is expressed in stages of spermatogenesis from pachytene spermatocytes through round spermatid germ cells. MCA protein contains the membrane occupation and recognition nexus (MORN) motif and localizes to a male meiotic metaphase chromosome. Recently, a MCA homolog of carp (Cyprinus carpio), MORN motif-containing sperm-specific axonemal protein (MSAP), was reportedly identified and localized in sperm flagella. Present knowledge of human spermiogenesis requires the identification of proteins in human sperm. The present study identified the human orthologue of MCA. Methods: Colony hybridization using a human testis plasmid cDNA library was carried out to clone human MCA (h-MCA) cDNA. Northern blot, Western blot, and immunohistochemical analyses were carried out. Results: h-MCA was found to be specifically expressed in the testes. The h-MCA amino acid sequence shared 79.8% identity with mouse MCA and contained MORN motifs. h-MCA localized in the sperm flagellum and basal body, as does MSAP in carp. Conclusion: Expression and localization analyses showed that h-MCA is a component of the sperm flagellum and basal body and might play an important role in the development of the sperm flagellum in humans. (Reprod Med Biol 2005; 4: 213-219).
Background and Aims: In a previous study, the authors of the present study cloned mousemeichroacidin (MCA), which is expressed in stages of spermatogenesis from pachytene spermatocytes through round spermatid germ cells. MCA protein contains the membrane occupation and recognition nexus (MORN) motif and localizes to a male meiotic metaphase chromosome. Recently, a MCA homolog of carp (Cyprinus carpio), MORN motif-containing sperm-specific axonemal protein (MSAP), was reportedly identified and localized in sperm flagella. Present knowledge of human spermiogenesis requires the identification of proteins in human sperm. The present study identified the human orthologue of MCA. Methods: Colony hybridization using a human testis plasmid cDNA library was carried out to clone humanMCA (h-MCA) cDNA. Northern blot, Western blot, and immunohistochemical analyses were carried out. Results: h-MCA was found to be specifically expressed in the testes. The h-MCA amino acid sequence shared 79.8% identity with mouseMCA and contained MORN motifs. h-MCA localized in the sperm flagellum and basal body, as does MSAP in carp. Conclusion: Expression and localization analyses showed that h-MCA is a component of the sperm flagellum and basal body and might play an important role in the development of the sperm flagellum in humans. (Reprod Med Biol 2005; 4: 213-219).
Authors: M M Taketo; Y Araki; A Matsunaga; A Yokoi; J Tsuchida; Y Nishina; M Nozaki; H Tanaka; M Koga; K Uchida; K Matsumiya; A Okuyama; J M Rochelle; Y Nishimune; M Matsui; M F Seldin Journal: Genomics Date: 1997-11-15 Impact factor: 5.736