Zhang Y, Ma C, Delohery T, Nasipak B, Foat BC, Bounoutas A, Bussemaker HJ, Kim SK, Chalfie M.
Identification of genes expressed in C. elegans touch receptor neurons. Nature. 2002;418 :331-5.
AbstractThe extent of gene regulation in cell differentiation is poorly understood. We previously used saturation mutagenesis to identify 18 genes that are needed for the development and function of a single type of sensory neuron--the touch receptor neuron for gentle touch in Caenorhabditis elegans. One of these genes, mec-3, encodes a transcription factor that controls touch receptor differentiation. By culturing and isolating wild-type and mec-3 mutant cells from embryos and applying their amplified RNA to DNA microarrays, here we have identified genes that are known to be expressed in touch receptors, a previously uncloned gene (mec-17) that is needed for maintaining touch receptor differentiation, and more than 50 previously unknown mec-3-dependent genes. These genes are randomly distributed in the genome and under-represented both for genes that are co-expressed in operons and for multiple members of gene families. Using regions 5' of the start codon of the first 20 genes, we have also identified an over-represented heptanucleotide, AATGCAT, that is needed for the expression of touch receptor genes.
Zhang Y, Chalfie M.
MTD-1, a touch-cell-specific membrane protein with a subtle effect on touch sensitivity. Mech Dev. 2002;119 :3-7.
AbstractWe have used representational difference analysis (RDA) applied to cDNA to isolate transcripts regulated by MEC-3, a transcription factor needed for the differentiation of the six touch receptor neurons in Caenorhabditis elegans. Six percent of 595 cDNAs isolated by cDNA RDA were mec-3-dependent. These cDNAs represented mRNA from two previously known genes, mec-18 and mec-7, and one new gene, mtd-1 (mec-three-dependent). mtd-1 encodes a novel transmembrane protein that is exclusively expressed in the six touch cells throughout development. mtd-1 loss results in a subtle defect in the touch receptor neurons. Neither mtd-1 RNAi nor a putative mtd-1 loss-of-function mutation resulted in touch insensitivity, but both enhanced the touch insensitivity of mec-6(u247), a temperature sensitive allele, at the permissive temperature.