We are working with lines of cultivar tomato which have been transformed with a transgene cassette containing various markers, including a gene which expresses a fluorescent protein in mature pollen cells called TdTomato.  We are using these tomato lines which express TdTomato in mature pollen to gain insight into the mechanism and timing of tomato male gamete promotion.  Gamete promoter genes (a.k.a. pollen promoter, gamete eliminator, pollen killer) are alleles of genes that are preferentially inherited in a hemi/heterozygote (an extreme version of segregation distortion).  We can follow inheritance of a cultivar chromosome arm using a mapped FCM transgene.  We are also looking at the expression of the transgene on the cultivar chromosome arm throughout pollen development in F1 plants to determine the stage at which pollen containing the cultivar chromosome is lost.