Successive microsporogenesis affects pollen aperture pattern in the tam mutant of Arabidopsis thaliana

Aperture Pattern and Microsporogenesis in Asparagales

The aperture pattern of pollen grains is a character defined as the number, shape, and position of apertures. Although this character is highly variable in angiosperms, two states are particularly widespread. Pollen grains with one polar aperture occur frequently in basal angiosperms and monocots while tricolpate pollen is a synapomorphy of the eudicots. Many morphological characters are the re...

Formation of unreduced pollen in Arabidopsis thaliana.

Sexual polyploidization, as a result of 2n gamete formation, is thought to be the main process involved in the origin of polyploid plants (Bretagnolle & Thompson, 1995). These gametes, possessing the somatic rather than the gametophytic chromosome number, can be formed either during microsporogenesis (2n pollen, big pollen, diplandroidy) or megasporogenesis (2n eggs, diplogynoecy). In general, ...

sidecar pollen, an Arabidopsis thaliana male gametophytic mutant with aberrant cell divisions during pollen development.

During pollen development each product of meiosis undergoes a stereotypical pattern of cell divisions to give rise to a three-celled gametophyte, the pollen grain. First an asymmetric mitosis generates a larger vegetative cell and a smaller generative cell, then the generative cell undergoes a second mitosis to give rise to two sperm cells. It is unknown how this pattern of cell divisions is co...

Arabinogalactan Proteins in Arabidopsis thaliana Pollen Development

The Pattern of Polymorphism in Arabidopsis thaliana

We resequenced 876 short fragments in a sample of 96 individuals of Arabidopsis thaliana that included stock center accessions as well as a hierarchical sample from natural populations. Although A. thaliana is a selfing weed, the pattern of polymorphism in general agrees with what is expected for a widely distributed, sexually reproducing species. Linkage disequilibrium decays rapidly, within 5...