Activation for cell fusion in Chlamydomonas: analysis of wild-type gametes and nonfusing mutants

doi:10.1083/jcb.92.2.378

This Article

	Full Text (PDF, 1136K)
	Alert me when this article is cited
	Citation Map

Services

	Email this article
	Similar articles in this journal
	Similar articles in PubMed
	Alert me to new content in the JCB
	Download to citation manager

Citing Articles

	Citing Articles via HighWire
	Citing Articles via CrossRef
	Citing Articles via Google Scholar

Google Scholar

	Articles by Goodenough, U. W.
	Articles by Hwang, C.
	Search for Related Content

PubMed

	PubMed Citation
	Articles by Goodenough, U. W.
	Articles by Hwang, C.


Social Bookmarking

	What's this?

ARTICLES

Activation for cell fusion in Chlamydomonas: analysis of wild-type gametes and nonfusing mutants

UW Goodenough, PA Detmers and C Hwang

Gametes of Chlamydomonas reinhardi become activated for cell fusion as the consequence of sexual adhesion between membranes of mating-type plus and minus flagella. By using tannic acid plus en bloc uranyl acetate staining, and by fixing at very early stages in the mating reaction, we have demonstrated the following. (a) Activation of the minus mating structure entails major modifications in the structure of the organelle, causing it to double in size and to concentrate surface coat material, termed fringe, into a central zone. (b) The unactivated plus mating structure is endowed with fringe that moves with the tip of the actin-filled fertilization tubule during activation. Pre-fusion images suggest the occurrence of a specific recognition event between the plus and minus fringes. (c) Gametes carrying the imp-1 mutation fail to form a fringe and are unable to fuse. The imp-1 mutation is linked to the mating-type plus (mt+) locus, suggesting that the gene specifying the synthesis or insertion of fringe is encoded in this sector of the genome. (d) Gametes carrying the imp-11 mutation fail to form both a normal fringe and a normal submembranous density beneath the fringe, and are also unable to fuse. The imp-11 mutation converted a wild-type minus cell into a pseudo-plus strain; a model to explain this conversion proposes that the normal imp-11 gene product represses plus-specific genes concerned with Chlamydomonas gametogenesis.
Add to CiteULike CiteULike Add to Complore Complore Add to Connotea Connotea Add to Del.icio.us Del.icio.us Add to Digg Digg Facebook Add to Reddit Reddit Add to Technorati Technorati Twitter What's this?

This article has been cited by other articles:

Liu, Y., Tewari, R., Ning, J., Blagborough, A. M., Garbom, S., Pei, J., Grishin, N. V., Steele, R. E., Sinden, R. E., Snell, W. J., Billker, O. (2008). The conserved plant sterility gene HAP2 functions after attachment of fusogenic membranes in Chlamydomonas and Plasmodium gametes. Genes Dev. 22: 1051-1068 [Abstract] [Full Text]
Hamaji, T., Ferris, P. J., Coleman, A. W., Waffenschmidt, S., Takahashi, F., Nishii, I., Nozaki, H. (2008). Identification of the Minus-Dominance Gene Ortholog in the Mating-Type Locus of Gonium pectorale. Genetics 178: 283-294 [Abstract] [Full Text]
Abe, J., Kubo, T., Saito, T., Matsuda, Y. (2005). The Regulatory Networks of Gene Expression during the Sexual Differentiation of Chlamydomonas reinhardtii, as Analyzed by Mutants for Gametogenesis. Plant Cell Physiol 46: 312-316 [Abstract] [Full Text]
Misamore, M. J., Gupta, S., Snell, W. J. (2003). The Chlamydomonas Fus1 Protein Is Present on the Mating Type plus Fusion Organelle and Required for a Critical Membrane Adhesion Event during Fusion with minus Gametes. Mol. Biol. Cell 14: 2530-2542 [Abstract] [Full Text]
Ferris, P. J., Armbrust, E. V., Goodenough, U. W. (2002). Genetic Structure of the Mating-Type Locus of Chlamydomonas reinhardtii. Genetics 160: 181-200 [Abstract] [Full Text]
Wilson, N. F., O'Connell, J. S., Lu, M., Snell, W. J. (1999). Flagellar Adhesion between mt+ and mt- Chlamydomonas Gametes Regulates Phosphorylation of the mt+-specific Homeodomain Protein GSP1. J. Biol. Chem. 274: 34383-34388 [Abstract] [Full Text]
(1998). The Chlamydomonas Zygospore: Mutant Strains of Chlamydomonas monoica Blocked in Zygospore Morphogenesis Comprise 46 Complementation Groups. Genetics 148: 131-138
Ferris, P. J., Pavlovic, C., Fabry, S., Goodenough, U. W. (1997). Rapid evolution of sex-related genes in�Chlamydomonas. Proc. Natl. Acad. Sci. USA 94: 8634-8639 [Abstract] [Full Text]
Wilson, N. F., Foglesong, M. J., Snell, W. J. (1997). The Chlamydomonas Mating Type Plus Fertilization Tubule, a Prototypic Cell Fusion Organelle: Isolation, Characterization, and In Vitro Adhesion to Mating Type Minus Gametes. JCB 137: 1537-1553 [Abstract] [Full Text]
Pan, J., Snell, W. J. (2002). Kinesin-II Is Required for Flagellar Sensory Transduction during Fertilization in Chlamydomonas. Mol. Biol. Cell 13: 1417-1426 [Abstract] [Full Text]