MAP3Kε1 and MAP3Kε2 are a pair of Arabidopsis thaliana genes that encode protein kinases related to cdc7p from Saccharomyces cerevisiae. We have previously shown that the map3kε1;map3kε2 double-mutant combination causes pollen lethality. In this study, we have used an ethanol-inducible promoter construct to rescue this lethal phenotype and create map3kε1(-/-);map3kε2(-/-) double-mutant plants i...

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 mutation...

The monotypic fern genus Dryopolystichum Copel. combines a unique assortment of characters that obscures its relationship to other ferns. Its thin-walled sporangium with a vertical and interrupted annulus, round sorus with peltate indusium, and petiole with several vascular bundles place it in suborder Polypodiineae, but more precise placement has eluded previous authors. Here we investigate it...

Haploid Ceratopteris gametophytes are either hermaphroditic or male. The determinate of sex type is the pheromone antheridiogen (ACE) which is secreted by the meristic hermaphrodite and promotes ameristic male development of sexually undetermined gametophytes. Several mutations effecting the sex of the haploid gametophyte have been isolated and are described. The hermaphroditic (her) mutants ar...

Reproductive traits in plants tend to evolve rapidly due to various causes that include plant-pollinator coevolution and pollen competition, but the genomic basis of reproductive trait evolution is still largely unknown. To characterize evolutionary patterns of genome wide gene expression in reproductive tissues in the gametophyte and to compare them to developmental stages of the sporophyte, w...

—Because of the fragmentary preservation of the earliest Cooksonia-like terrestrial plant macrofossils, younger Devonian fossils with complete anatomical preservation and documented gametophytes often have received greater attention concerning the early evolution of vascular plants and the alternation of generations. Despite preservational deficits, however, possible physiologies of Cooksonia-l...

Sundberg, S. 2000. The ecological significance of sexual reproduction in peat mosses (Sphagnum). Acta Universitatis Upsaliensis. Comprehensive Summaries of Uppsala Dissertations from the Faculty of Science and Technology 581. 37 pp. Uppsala. ISBN 91-554-4847-X. Peat mosses (Sphagnum) are widely distributed and are a major component of mire vegetation and peat throughout the boreal and temperate...

Background: Analyses of complete genomes and large collections of gene transcripts have shown that most, if not all seed plants have undergone one or more genome duplications in their evolutionary past. Results: In this study, based on a large collection of EST sequences, we provide evidence that the haploid moss Physcomitrella patens is a paleopolyploid as well. Based on the construction of li...

1 Albrecht-von-Haller-Institut f r Pflanzenwissenschaften, Abteilung Systematische Botanik, Georg-August-Universit t G ttingen, Untere Karsp le 2, 37073 G ttingen, Germany 2 Department of Botany, The Field Museum, 1400 South Lake Shore Drive, Chicago, IL, U.S.A. 3 Nachtigallenweg 9, 29342 Wienhausen, Germany 4 Courant Research Centre Geobiology, Georg-August-Universit t G ttingen, Goldschmidtst...