RRC ID 73391
Author Otsuka K, Yamada L, Sawada H.
Title cDNA cloning, localization, and candidate binding partners of acid-extractable vitelline-coat protein Ci-v-Themis-like in the ascidian Ciona intestinalis.
Journal Mol Reprod Dev
Abstract Ascidians are hermaphrodites, although several ascidian species show self-sterility because of the occurrence of a self/nonself-recognition system called the self-incompatibility system. We previously reported that two pairs of sperm polycystin 1-like receptors, s-Themis-A and s-Themis-B, and egg fibrinogen-like ligands, v-Themis-A and v-Themis-B, are responsible for self-incompatibility in the ascidian Ciona intestinalis. Our previous results showed that v-Themis-A and v-Themis-B were hardly extracted from the vitelline coat (VC) by acid treatment, which is not in accordance with a report that an acid-extractable VC factor has the ability to distinguish self- from nonself-sperm. These results led us to explore a novel factor from acid-extractable VC proteins that could be involved in self-incompatibility. Here, we report cDNA cloning, expression, and localization of Ci-v-Themis-like, a major acid-extractable VC protein. This protein has a fibrinogen-like domain, as do v-Themis-A and v-Themis-B, but it showed no polymorphisms. Phylogenic analysis suggested that Ci-v-Themis-like is an ancestral protein of v-Themis-A and v-Themis-B. Whole mount in situ hybridization revealed that Ci-v-Themis-like mRNA is expressed in the ovary and testis. Western blotting and immunocytochemistry showed the occurrence of Ci-v-Themis-like in developing oocytes and on the VC of mature eggs. Yeast two-hybrid screenings using testis and ovary libraries revealed candidate interacting proteins; among these candidates, we succeeded in identifying several testis-specific proteins, including sperm proteases and coiled-coil-domain-containing proteins. The results suggest that Ci-v-Themis-like and its binding partners are involved in sperm binding to the VC prior to the allorecognition process during C. intestinalis fertilization.
Volume 80(10)
Pages 840-8
Published 2013-10-1
DOI 10.1002/mrd.22213
PMID 23857746
MeSH Animals Ciona intestinalis / genetics* Ciona intestinalis / metabolism Egg Proteins / biosynthesis Egg Proteins / metabolism* Female Infertility / genetics Infertility / metabolism Intracellular Signaling Peptides and Proteins / genetics Intracellular Signaling Peptides and Proteins / metabolism Male Ovary / metabolism Phylogeny Protein Structure, Tertiary / genetics Self-Fertilization / genetics Self-Fertilization / physiology* Testis / metabolism Two-Hybrid System Techniques Urochordata / genetics* Urochordata / metabolism Vitelline Membrane / metabolism Vitellins / biosynthesis Vitellins / genetics* Vitellins / metabolism
IF 2.823
C.intestinalis / (O.japonicus) Wild C. int