Germ cell-less like-2 protein is a new component of outer dense fibers in rat sperm flagella.
We have analyzed the expression profiles of ten genes in terms of testis development and organ specificity in rat, which were selected from 215 round spermatid-specific transcripts listed in a database. Out of the ten genes, we directed our attention to one gene, a germ cell-less like-2 gene (gcl-2), a homolog of Drosophila gcl gene (gcl), which is a component of the germ plasma and required for primordial germ cell formation. Rat genome contains duplicate rat gcl-2 (rgcl-2) genes, rgcl-2A and rgcl-2B, both of which are located at Xq13. RT-PCR analysis showed that the expression of the two genes was up-regulated during testis development and that they were predominantly expressed in the testis. Both rgcl-2A and rgcl-2B encode a protein of 498 amino acid residues, showing 90.56% identity at the amino acid level. Confocal laser scanning microscopy revealed that rgcl-2 protein was synthesized in the cytoplasm of elongating spermatids and at least a part of it was integrated into the middle piece of spermatozoa during spermiogenesis. Immunogold electron microscopy uncovered that rgcl-2 was localized at the abaxial (convex) surface of outer dense fibers (ODF) of rat sperm flagella. Therefore, we concluded that rgcl-2 is a new component of ODF in sperm flagella.
Laboratory of Zoology, Graduate School of Agriculture, Kyushu University, Higashiku Hakozaki 6-10-1, Fukuoka 812-8581, Japan.
Emi
E
Murayama
Michiko
M
Katoh
Akina
A
Kanebayashi
Takane
T
Kaneko
Yosaburo
Y
Shibata
Tetsuichiro
T
Inai
Hiroshi
H
Iida
D000595:Amino Acid Sequence; D000818:Animals; D001483:Base Sequence; D003593:Cytoplasm / Q000737:chemistry* / Q000648:ultrastructure; D020869:Gene Expression Profiling; D008297:Male; D018613:Microscopy, Confocal; D016253:Microscopy, Immunoelectron; D008969:Molecular Sequence Data; D020411:Oligonucleotide Array Sequence Analysis; D011506:Proteins / Q000032:analysis* / Q000235:genetics / Q000378:metabolism; D051381:Rats; D017208:Rats, Wistar; D013082:Sperm Tail / Q000737:chemistry* / Q000648:ultrastructure; D013087:Spermatids / Q000737:chemistry / Q000648:ultrastructure; D013091:Spermatogenesis / Q000502:physiology; D013737:Testis / Q000254:growth & development
D011506:Proteins; C527759:Rgcl-2A protein, rat; C527760:Rgcl-2B protein, rat