title: Meichroacidin containing the membrane occupation and recognition nexus motif is essential for spermatozoa morphogenesis.
abstract: Meichroacidin (MCA) is a highly hydrophilic protein that contains the membrane occupation and recognition nexus motif. MCA is expressed during the stages of spermatogenesis from pachytene spermatocytes to mature sperm development and is localized in the male meiotic metaphase chromosome and sperm flagellum. MCA sequences are highly conserved in Ciona intestinalis, Cyprinus carpio, and mammals. To investigate the physiological role of MCA, we generated MCA-disrupted mutant mice; homozygous MCA mutant males were infertile, but females were not. Sperm was rarely observed in the caput epididymidis of MCA mutant males. However, little to no difference was seen in testis mass between wild-type and mutant mice. During sperm morphogenesis, elongated spermatids had retarded flagellum formation and might increase phagocytosis by Sertoli cells. Immunohistochemical analysis revealed that MCA interacts with proteins located on the outer dense fibers of the flagellum. The testicular sperm of MCA mutant mice was capable of fertilizing eggs successfully via intracytoplasmic sperm injection and generated healthy progeny. Our results suggest that MCA is essential for sperm flagellum formation and the production of functional sperm.
authors.affiliation: TANAKA Project, Center for Advanced Science and Innovation, Osaka University, 3-1 Yamadaoka, Suita, Osaka 565-0871, Japan.
authors.forename: Keizo
authors.initials: K
authors.lastname: Tokuhiro
authors.forename: Mika
authors.initials: M
authors.lastname: Hirose
authors.forename: Yasushi
authors.initials: Y
authors.lastname: Miyagawa
authors.forename: Akira
authors.initials: A
authors.lastname: Tsujimura
authors.forename: Shinji
authors.initials: S
authors.lastname: Irie
authors.forename: Ayako
authors.initials: A
authors.lastname: Isotani
authors.forename: Masaru
authors.initials: M
authors.lastname: Okabe
authors.forename: Yoshiro
authors.initials: Y
authors.lastname: Toyama
authors.forename: Chizuru
authors.initials: C
authors.lastname: Ito
authors.forename: Kiyotaka
authors.initials: K
authors.lastname: Toshimori
authors.forename: Ken
authors.initials: K
authors.lastname: Takeda
authors.forename: Shigeru
authors.initials: S
authors.lastname: Oshio
authors.forename: Hitoshi
authors.initials: H
authors.lastname: Tainaka
authors.forename: Junji
authors.initials: J
authors.lastname: Tsuchida
authors.forename: Akihiko
authors.initials: A
authors.lastname: Okuyama
authors.forename: Yoshitake
authors.initials: Y
authors.lastname: Nishimune
authors.forename: Hiromitsu
authors.initials: H
authors.lastname: Tanaka
mesh_terms: D020816:Amino Acid Motifs / Q000235:genetics; D000818:Animals; D002347:Carps / Q000235:genetics / Q000378:metabolism; D002462:Cell Membrane / Q000235:genetics / Q000378:metabolism*; D033481:Chromosomes, Mammalian / Q000235:genetics / Q000378:metabolism; D002938:Ciona intestinalis / Q000235:genetics / Q000378:metabolism; D004268:DNA-Binding Proteins / Q000235:genetics / Q000378:metabolism*; D004822:Epididymis / Q000378:metabolism; D005298:Fertility / Q000502:physiology*; D005786:Gene Expression Regulation / Q000502:physiology*; D008297:Male; D051379:Mice; D008817:Mice, Mutant Strains; D010587:Phagocytosis / Q000502:physiology; D012708:Sertoli Cells / Q000378:metabolism; D013082:Sperm Tail / Q000378:metabolism*; D013087:Spermatids / Q000378:metabolism; D013091:Spermatogenesis / Q000502:physiology*; D014998:Y Chromosome / Q000235:genetics / Q000378:metabolism
chemical_list: D004268:DNA-Binding Proteins; C112368:Tsga2 protein, mouse