NSF 2010 Project

(PI: Venkatesan Sundaresan, UC-Davis; co-PI: Sheila McCormick, UC-Berkeley)

A large-scale mutant screen using Ds insertion lines resulted in the identification of about 300 lines that exhibited aberrant transmission of the linked Kanamycin resistance gene. Some lines exhibited aberrant transmission through the male parent, some through the female parent, and some through both parents. We presume that the aberrant segregation in these lines is due to disruption of a gene that is important for gametophyte development or function. The results for the lines that have aberrant transmission through the female are posted at the Sundaresan lab.

We are analyzing ~100 lines whose transmission through the male is aberrant. We plate seed on Kanamycin plates and check the pollen for obvious phenotypes, by staining with Alexander's stain (for viability), and with DAPI and decolorized aniline blue (DAB). We score at least 4 plants per line, and at least 2-3 flowers per plant. About half of the lines have an aborted pollen phenotype and about half appear normal at maturity.

We confirm the Ds insertion site by PCR or, when necessary, by TAIL-PCR. We determine the transmission ratios, and cross each line to quartet, in order to determine if the mutation is gametophytic. For those lines whose pollen appears normal at maturity, we are testing for pollen germination defects, in vitro and in vivo. For those lines that have aborted pollen, we are determining when during pollen development the arrest occurs.

This spreadsheet summarizes results to date for the lines that have confirmed Ds insertion sites and transmission defects (works best with Internet Explorer; updated 06/01/05). Lines where the Ds insertion was between two genes are in green, lines where the Ds insertion is in the same location are in red. Sequence flanking the Ds insertion for each line can be found here. For some of the genes we obtained SALK insertion lines, to see if the SALK line had similar phenotypes to the Ds insertion line; in most cases so far, there is no such match.