How Partially Redundant Genes Compensate for the Loss of their Partner: Examination of the Partially Redundant Roles of the Tbx8 and Tbx9 Genes in Embryonic Nematode Development

Gene duplication is common in evolution, but we know little about the degree to which a duplicate gene can compensate for the loss of its counterpart. To study this we are looking at a duplicated gene found in C. elegans. The Tbx-8 and Tbx-9 genes encode Tbox transcription factors which affect embryonic development. Tbx-8 and Tbx-9 are are thought to be a result of a recent genetic duplication, because they reside in close proximity to one another in the genome, they encode proteins with 64% amino acid identity, they are largely redundant, and they are both expressed in precursor cells of the hypodermis and bodywall muscle. We hypothesize that tbx-8 can compensate for the loss of Tbx-9 by activating the expression of Tbx-8 in cells that normally express Tbx-9.To test this hypothesis, we generated a strain of C. elegans with a Tbx-8 promoter fusion to mCherry such that we can test whether tbx-8 promoter activity is altered in a tbx-9 or tbx-8 deletion background. By using confocal microscopy to image mCherry fluorescence during embryonic development, we anticipate that our studies will reveal how the expression of a partially redundant gene can change to compensate for loss of its counterpart.