Characterization of Mutations That Feminize Gametophytes of the Fern Ceratopteris

Corresponding author: Jo Ann Banks, Department of Botany and Plant Pathology, Whistler Bldg., Purdue University, West Lafayette, IN 47907., banks{at}btny.purdue.edu (E-mail)

Communicating editor: T. W. CLINE

Gametophytes of the fern Ceratopteris are either male or hermaphroditic. Their sex is epigenetically determined by the pheromone antheridiogen, which is secreted by the hermaphrodite and induces male and represses female development in other young, sexually undetermined gametophytes. To understand how antheridiogen represses the development of female traits at the genetic level, 16 new mutations that feminize the gametophyte in the presence of antheridiogen were identified and characterized. Seven are very tightly linked to the FEM1 locus previously described. Nine others define another locus named NOTCHLESS1 (NOT1), as several of the not1 mutants lack a meristem notch. Some not1 mutations also affect sporophyte development only when homozygous, indicating that the not1 mutations are recessive and that NOT1 is also required for normal sporophyte development. The epistatic interactions among FEM1, NOT1, and other sex-determining genes are described. This information was used to expand the genetic model of the sex-determining pathway in Ceratopteris. On the basis of this model, we can say that the presence of antheridiogen leads to the activation of the FEM1 gene, which not only promotes the differentiation of male traits, but also represses female development by activating the NOT1 gene. NOT1 represses the TRA genes necessary for the development of female traits in the gametophyte.

This article has been cited by other articles:

				L. G. Quintanilla, L. d. Soto, A. Jimenez, and M. Mendez Do antheridiogens act via gametophyte size? A study of Woodwardia radicans (Blechnaceae) Am. J. Botany, June 1, 2007; 94(6): 986 - 990. [Abstract] [Full Text] [PDF]

				L. Gumaelius, B. Lahner, D. E. Salt, and J. A. Banks Arsenic Hyperaccumulation in Gametophytes of Pteris vittata. A New Model System for Analysis of Arsenic Hyperaccumulation Plant Physiology, October 1, 2004; 136(2): 3198 - 3208. [Abstract] [Full Text] [PDF]

				M. Tanurdzic and J. A. Banks Sex-Determining Mechanisms in Land Plants PLANT CELL, June 1, 2004; 16(suppl_1): S61 - S71. [Full Text] [PDF]