ISHS Acta Horticulturae 459: International Symposium Brassica 97, Xth Crucifer Genetics Workshop
SCREENING FOR GAMETOPHYTIC MUTATIONS IN THE VERSAILLES COLLECTION OF ARABIDOPSIS THALIANA TRANSFORMANTS : FIRST RESULTS FOR TWO PUTATIVE MALE GAMETOPHYTIC MUTANTS |
| Authors: | S. Bonhomme, C. Horlow, A. Guyon, M. Férault, D. Vezon, M. Marchand, S. de Laissardière, N. Bechtold, G. Pelletier |
| Abstract:
The search for mutations affecting sexual reproduction is one of the possible strategies for establishing the molecular steps of this process, and the species Arabidopsis thaliana is an attractive model for such a project. Among reproduction mutants, gametophytic mutants affected in genes active in the pollen and/or embryo sac, are rare, much less easy to screen than sterile mutants, but should allow the isolation of new genes essential for gametogenesis. We have screened the Versailles collection of Arabidopsis thaliana transformants, in the aim of isolating T-DNA tagged gametophytic mutations. The transforming T-DNA carries the nptII gene, allowing the identification of segregation distortions in the progeny of selfed transformants. On the basis of a 1: 1 segregation of seedlings for kanamycin resistance after T2 generation selfing, 56 putative gametophytic mutants were retained out of 6000 transformants. 19 possibly tagged genotypes, leading to a transmission defect of male, female or both types of gametes, were isolated. For two putative male gametophytic mutants, the first cytological studies showed failure in pollen tube growth for one of them, while no obvious abnormality was observed for the second. Both mutations are thought to be tagged and incompletely penetrant. Molecular analysis of the first putative mutant suggests that a single copy of the T-DNA has been inserted in a region presenting no obvious homology with known sequences. | |
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