Isolation of novel mouse genes that were differentially expressed in W/W(V) mouse fundus

Using cDNA microarray analysis that displays a total of 8734 mouse genes, we have identified 21 known and novel transcripts, including mouse expressed sequence tags (ESTs) that were consistently up- or downregulated in the fundus of wild-type mice and W/W(V) mice, where intramuscular interstitial cells of Cajal (ICC; IC-IM) are lost.

By using these tags as part of the full-length mRNA sequence of the murine genes, we screened a mouse-brain cDNA library and the FASTA database (http://www.ebi.ac.uk/fasta33/).

Three of the queries were identified as novel mouse genes, whereas six transcripts had their human counterparts that were known to encode functional proteins. Four transcripts, DRIM (downregulated in metastasis), SLP8 (tumor antigen), PTK7/CCK4 (receptor protein tyrosine kinase-like molecule-7/colon carcinoma kinase-4), and a novel gene AWMS2 were increased in W/W(V) mice. Expression of another five genes was decreased in W/W(V) mice: BB1 (overexpressed in bladder and breast carcinoma), HTATIP/CPLA2 (HIV-1 TAT interactive protein/cytosolic phospholipase A2), Tenascin-receptor like (Hexabrachion, Cytotactin, Neuronectin, Myotendinous antigen), and two novel transcripts: DRWMS1 and DRWMS2. Molecular profiling generated by cDNA microarray analysis from the fundus of W/W(V) mice and its complete list of full-length cDNAs will be shown on our web site (http://www.yamanashi.ac.jp/).

Differential gene comparisons between control and mutant animals with losses in specific populations of ICCs will contribute significantly to our understanding of motility disorders associated with the loss of these cells and electrical slow waves in the gastrointestinal tract.