Event Title

Locating a Novel Mutation Responsible For Two Mutant Phenotypes in Arbidopsis thaliana

Mentor 1

Dr. Heather Owen

Location

Union Wisconsin Room

Start Date

29-4-2016 1:30 PM

End Date

29-4-2016 3:30 PM

Description

With one of the smallest known genomes for a diploid flowering plant and conservation of genetic code across species, mutations are induced in Arabidopsis thaliana using Agrobacterium tumefaciens in order to identify individual gene function. In our laboratory we study mutant plant lines that do not make normal pollen. The current study addresses a novel mutation that effects normal pollen wall patterning, however the specific gene responsible remains unknown. Past work using plasmid rescue identified that a non-canonical T-DNA insertion occurred with Ti plasmid overrun. Using positional cloning, a previous student found decreased recombination frequencies at the top of chromosome 3 as well as at the bottom of chromosome 4 in sterile plants from the mapping population, a cross between Wassilewskija (Ws) and Colombia ecotypes (Col). It was later determined that not all sterile plants in the population had abnormal pollen wall patterning. In addition to the pollen wall mutation, a population of sterile plants were found to have normal wall patterning. However, these plants appeared to have a problem during meiosis, leading to production of large and small pollen grains. The mutant line has a lineage associated with the ecotype Wassilewskija (Ws). As the location of the mutation has narrowed to the top of chromosome 3, electrophoresis bands representing DNA segment lengths matched that of Ws wildtype with greater frequency, as opposed to Col, in the plants with the wall mutation. Interestingly, the same procedure with plants appearing to have a meiotic defect show both Col and Ws bands at the same location. Such analysis suggests the presence of the T-DNA insertion is responsible for both mutant phenotypes at the same location on the chromosome. Understanding gene function in an area such as pollen development confers the ability to manipulate sterility and virility, an important aspect in agricultural production.

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Apr 29th, 1:30 PM Apr 29th, 3:30 PM

Locating a Novel Mutation Responsible For Two Mutant Phenotypes in Arbidopsis thaliana

Union Wisconsin Room

With one of the smallest known genomes for a diploid flowering plant and conservation of genetic code across species, mutations are induced in Arabidopsis thaliana using Agrobacterium tumefaciens in order to identify individual gene function. In our laboratory we study mutant plant lines that do not make normal pollen. The current study addresses a novel mutation that effects normal pollen wall patterning, however the specific gene responsible remains unknown. Past work using plasmid rescue identified that a non-canonical T-DNA insertion occurred with Ti plasmid overrun. Using positional cloning, a previous student found decreased recombination frequencies at the top of chromosome 3 as well as at the bottom of chromosome 4 in sterile plants from the mapping population, a cross between Wassilewskija (Ws) and Colombia ecotypes (Col). It was later determined that not all sterile plants in the population had abnormal pollen wall patterning. In addition to the pollen wall mutation, a population of sterile plants were found to have normal wall patterning. However, these plants appeared to have a problem during meiosis, leading to production of large and small pollen grains. The mutant line has a lineage associated with the ecotype Wassilewskija (Ws). As the location of the mutation has narrowed to the top of chromosome 3, electrophoresis bands representing DNA segment lengths matched that of Ws wildtype with greater frequency, as opposed to Col, in the plants with the wall mutation. Interestingly, the same procedure with plants appearing to have a meiotic defect show both Col and Ws bands at the same location. Such analysis suggests the presence of the T-DNA insertion is responsible for both mutant phenotypes at the same location on the chromosome. Understanding gene function in an area such as pollen development confers the ability to manipulate sterility and virility, an important aspect in agricultural production.