FIGURE 2

Positional cloning of mutant^cas7. (A) Genetic mapping of the cas7 region on chromosome 20. Bulk segregation analysis positioned cas7 mutation to Chr. 20. Fine mapping using SSLPs narrowed down the region between markers SNP1 and SNP4, including tprb and two other genes as indicated. (B) There is a C-to-G missense mutation in tprb gene in mutant^cas7, which leads to leucine to valine (L9V) at ninth amino acid in Tpr protein. (C) The ninth amino acid leucine of Tpr is highly conserved from human to fruit fly (* marked). (D) Comparison of the gene syntenic relationship between zebrafish tprb and human TPR loci. Seven genes, including TPR, are located within a genomic region on human chromosome 1. (Right) Seven zebrafish homologs of these genes are listed according to their map positions on chromosome 20 (Ensembl website). Mb, mega base. (E) Western blotting images of Tpr protein in whole embryo lysates of sibling and mutant^cas7 embryos at the indicated time. All embryos were extracted for genomic DNA and genotyped by sequencing.