International Mammalian Genome Society

17th International Mouse Genome Conference

9-12 November 2003, Braunschweig, Germany

Plenary Presentations * Oral Presentations *
Poster Presentations: Behavioural Genetics and Genomics * Development and Stem Cells * Functional Genome Analysis * Mouse Models of Human Disease * Mouse System Biology Bioinformatics * Multigenic and Multifactorial Trait Analysis * Nutrition and Metabolic Disease * Phenotyping Methods Imaging * The Genetics and Genomics of Infectious Disease *
Verne Chapman Memorial Lecture * Table of Contents * Sponsor/Exhibitor List * Awards * Photographs

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POSTER 208 - HIGH RESOLUTION MAPPING OF QTL CONTROLLING RESISTANCE TO GASTROINTESTINAL WORMS IN MICE USING ADVANCED INTERCROSS LINES

Iraqi F A
International Livestock Research Institute (ILRI), P. O. Box 30709, Nairobi, Kenya

Co-Authors: 1) Mugambi J, 1) Nagda S, 1) Gibson J P, 2) Wakelin D, 1) Baker R L, 2) Behnke J
Institutions: 1) International Livestock Research Institute (ILRI), P. O. Box 30709, Nairobi, Kenya. 2) School of Biological Sciences, University of Nottingham, Nottingham NG7 2RD, U.K.

High resolution mapping of quantitative trait loci (QTL) to a small genomic interval that allows molecular cloning is not a trivial exercise. A number of experimental designs have been proposed to dissect a given QTL, including the use of advanced intercross lines (AIL), which was described by Darvasi and Soller (1995). Recently, we have reported the initial mapping of QTL controlling resistance to Heligmosomoides polygyrus in an F₂ crossbred population of resistant SWR and susceptible CBA inbred lines of mice. We identified 14 QTL on 12 different chromosomes affecting the parasitological and immunological traits. Five of these QTL were associated with two or more traits. The QTL were mapped within a relatively large genomic interval of 20-30cM. As a step towards fine mapping these QTL, we generated 1100 mice, which consisted of 500 F6 and 600 F7 SWR x CBA AIL populations and administered the same phenotyping protocol used for the F2 population. Microsatellite markers with an interval of 1-5cM across the previously mapped QTL were genotyped on 40% of the mice representing phenotypic extremes for total worm count at necropsy. Genetic and phenotypic data were analysed with maximum likelihood and least squares regression programmes. Preliminary results indicate that a refined mapping of 3-5 fold was achieved for the QTL on chromosomes 1 and 17 comparedto the F2 results. The QTL on chromosomes 1 and 17 probably comprise at least two loci. Some of the QTL which were previously mapped in the F2 study were not detected in this study.