HOME HELP FEEDBACK SUBSCRIPTIONS ARCHIVE SEARCH TABLE OF CONTENTS		QUICK SEARCH:   [advanced] Author: Keyword(s): Year:  Vol:  Page:

This Article Full Text Full Text (PDF) Alert me when this article is cited Alert me if a correction is posted Services Email this article to a friend Similar articles in this journal Similar articles in ISI Web of Science Similar articles in PubMed Alert me to new issues of the journal Download to citation manager Citing Articles Citing Articles via HighWire Citing Articles via ISI Web of Science (4) Citing Articles via Google Scholar Google Scholar Articles by Jiang, D. Articles by Smith, W. C. Search for Related Content PubMed PubMed Citation Articles by Jiang, D. Articles by Smith, W. C. Related Collections Development Reproduction Urochordates

Self- and Cross-Fertilization in the Solitary Ascidian Ciona savignyi

Department of Molecular, Cellular, and Developmental Biology, University of California Santa Barbara 93106

^* To whom correspondence should be addressed. E-mail: d_jiang{at}lifesci.ucsb.edu

Solitary ascidians are hermaphrodites that release sperm and eggs simultaneously. However, many species are self-sterile, owing to a self/non-self recognition system operating at the outer surface of the chorion during sperm-egg interaction. In Ciona intestinalis, self-incompatibility is thought to have a genetic basis. Here, we report a survey of the self-fertilization potential of a Santa Barbara, California, population of Ciona savignyi, a close relative of C. intestinalis. We found that, in contrast to reports on C. intestinalis, C. savignyi is highly self-fertile. However, using two nonlethal recessive mutant strains, aimless (aim) and immaculate (imc), and a stable transgenic strain that expresses green fluorescent protein (GFP) in the notochord to follow offspring genotype, we demonstrate that non-self sperm outcompete self-sperm in fertilization competition assays. When the chorion was removed, both self- and non-self sperm performed equally well in the competition assay. Thus the non-self/self gamete recognition in C. savignyi is not absolute but relative, and is mediated by one or more components in the chorion. We discuss the significance of this finding in the context of natural populations in the wild, where individuals of C. savignyi are typically found growing in large groups that spawn in unison and where self-fertilization would be expected to be very rare.

This article has been cited by other articles:

				Y. Harada, Y. Takagaki, M. Sunagawa, T. Saito, L. Yamada, H. Taniguchi, E. Shoguchi, and H. Sawada Mechanism of Self-Sterility in a Hermaphroditic Chordate Science, April 25, 2008; 320(5875): 548 - 550. [Abstract] [Full Text] [PDF]