Multidimensional analysis of uncharacterized sperm proteins in Ciona intestinalis: EST-based analysis and functional immunoscreening of testis-expressed genes.
An extensive analysis of testis-expressed genes in the ascidian Ciona intestinalis explored a large number of genes of unknown function. Here we characterized these genes or gene products in a multidimensional manner. We analyzed genes both highly and uniquely expressed in the testis, as expected from the EST analysis. Immunolocalization of these proteins revealed that they are all expressed in sperm. Sperm membrane/matrix proteins play essential roles in cell responses and intracellular signaling at fertilization. By immunoscreening with antisera against the detergent-soluble and membrane fractions of sperm, we isolated 49 potential cDNA clones for membrane/matrix proteins. These included several unidentified genes, including a protein with sequence similarity to mammalian testicular cancer antigen Sp17. These data should facilitate exploration of the functions of uncharacterized sperm proteins and ultimately elucidate new molecular mechanisms in sperm physiology.
Shimoda Marine Research Center, University of Tsukuba, Shimoda, Shizuoka 415-0025, Japan.
Alu
A
Konno
Potturi
P
Padma
Yuji
Y
Ushimaru
Kazuo
K
Inaba
D000818:Animals; D002938:Ciona intestinalis; D020224:Expressed Sequence Tags / Q000378:metabolism*; D020869:Gene Expression Profiling; D005786:Gene Expression Regulation / Q000502:physiology*; D007150:Immunohistochemistry; D008297:Male; D021962:Membrane Microdomains; D008565:Membrane Proteins / Q000235:genetics / Q000378:metabolism; D017346:Protein Serine-Threonine Kinases / Q000235:genetics / Q000378:metabolism; D021381:Protein Transport; D013094:Spermatozoa; D013737:Testis / Q000378:metabolism*
D008565:Membrane Proteins; D017346:Protein Serine-Threonine Kinases