JCB logo
  Home | Help | Feedback | Subscriptions | Archive | Search | Table of Contents
This Article
Right arrow Full Text
Right arrow Full Text (PDF, 423K)
Right arrow PPT slides of all figures
Right arrow Alert me when this article is cited
Right arrow Citation Map
Services
Right arrow Email this article
Right arrow Similar articles in this journal
Right arrow Similar articles in PubMed
Right arrow Alert me to new content in the JCB
Right arrow Download to citation manager
Citing Articles
Right arrow Citing Articles via HighWire
Right arrow Citing Articles via CrossRef
Right arrow Citing Articles via Google Scholar
Google Scholar
Right arrow Articles by Kurvari, V.
Right arrow Articles by Snell, W. J.
Right arrow Search for Related Content
PubMed
Right arrow PubMed Citation
Right arrow Articles by Kurvari, V.
Right arrow Articles by Snell, W. J.
Right arrowPubmed/NCBI databases
*Gene*Protein
*UniGene
Social Bookmarking
Add to CiteULike   Add to Complore   Add to Connotea   Add to Del.icio.us   Add to Digg   Add to Facebook   Add to Reddit   Add to Technorati   Add to Twitter  
What's this?

© The Rockefeller University Press, 0021-9525/1998//1971 $5.00
The Journal of Cell Biology, Volume 143, Number 7, , 1998 1971-1980

Regular Articles

A Gamete-specific, Sex-limited Homeodomain Protein in Chlamydomonas



Venkatesh Kurvari*, Nick V. Grishin{ddagger}, and William J. Snell*

* Department of Cell Biology and Neuroscience and {ddagger} Department of Pharmacology, The University of Texas Southwestern Medical Center, Dallas, Texas 75235

During fertilization in Chlamydomonas, gametes of opposite mating types interact with each other through sex-specific adhesion molecules on their flagellar surfaces. Flagellar adhesion brings the cell bodies of the gametes into close contact and initiates a signal transduction pathway in preparation for cell–cell fusion. We have identified a cDNA, gsp1, whose transcript levels are upregulated during flagellar adhesion. The GSP1 polypeptide is a novel, gamete-specific homeodomain protein, the first to be identified in an alga. Its homeodomain shows significant identity with several higher plant homeodomain proteins. Although encoded by a single copy gene present in cells of both mating types, immunoblot analysis showed that GSP1 was expressed in mating type (mt)+ gametes, but was not detectable in mt– gametes or in vegetative cells of either mating type. Moreover, GSP1 appeared late during gametogenesis, suggesting that it may function during adhesion with mt– gametes or after zygote formation. GSP1 is expressed in imp11, mt– mutant gametes, which have a lesion in the mid gene involved in sex determination and exhibit many phenotypic characteristics of mt+ gametes. Thus, gsp1 is negatively regulated by mid and is the first molecule to be identified in Chlamydomonas that shows sex-limited expression.

Key Words: Chlamydomonas • homeodomain • sex-limited • fertilization • cell–cell adhesion

Abbreviations used in this paper: atpC1, ATP synthase subunit C; mt, mating type; ORF, open reading frame.

N.V. Grishin was supported by Welch Foundation grant I-1257 to Dr. M.A. Phillips. This work was supported by National Institutes of Health grant GM25661 to W.J. Snell.


Add to CiteULike CiteULike   Add to Complore Complore   Add to Connotea Connotea   Add to Del.icio.us Del.icio.us   Add to Digg Digg   Add to Facebook Facebook   Add to Reddit Reddit   Add to Technorati Technorati   Add to Twitter Twitter    What's this?


This article has been cited by other articles:



  Home | Help | Feedback | Subscriptions | Archive | Search | Table of Contents