Nucleic Acids Research Advance Access published online on June 19, 2009
Nucleic Acids Research, doi:10.1093/nar/gkp528
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Methods Online |
A genome-wide library of CB4856/N2 introgression lines of Caenorhabditis elegans
Laboratory of Nematology, Wageningen University, Droevendaalsesteeg 1, 6708PB Wageningen, The Netherlands
*To whom correspondence should be addressed. Tel: +31 317 482998/482197; Fax: +31 317 484254; Email: Jan.Kammenga{at}wur.nl
Received April 20, 2009. Revised June 4, 2009. Accepted June 4, 2009.
Recombinant inbred lines (RILs) derived from Caenorhabditis elegans wild-type N2 and CB4856 are increasingly being used for mapping genes underlying complex traits. To speed up mapping and gene discovery, introgression lines (ILs) offer a powerful tool for more efficient QTL identification. We constructed a library of 90 ILs, each carrying a single homozygous CB4856 genomic segment introgressed into the genetic background of N2. The ILs were genotyped by 123 single-nucleotide polymorphism (SNP) markers. The proportion of the CB4856 segments in most lines does not exceed 3%, and together the introgressions cover 96% of the CB4856 genome. The value of the IL library was demonstrated by identifying novel loci underlying natural variation in two ageing-related traits, i.e. lifespan and pharyngeal pumping rate. Bin mapping of lifespan resulted in six QTLs, which all have a lifespan-shortening effect on the CB4856 allele. We found five QTLs for the decrease in pumping rate, of which four colocated with QTLs found for average lifespan. This suggests pleiotropic or closely linked QTL associated with lifespan and pumping rate. Overall, the presented IL library provides a versatile resource toward easier and efficient fine mapping and functional analyses of loci and genes underlying complex traits in C. elegans.
Present address: Agnieszka Doroszuk, Evolutionary Biology, Leiden University, Kaiserstraat 63, 2311 GP Leiden, The Netherlands.