International Mammalian Genome Society

The 16th International Mouse Genome Conference (2002)

Plenary Presentations * Oral Presentations *
Poster Presentations: Complex Genetics and Disease Modifiers * Developmental Genetics * Functional Genomics * Gene Discovery * Genetic Manipulations to Alter Gene Function * Mouse Models: Human Disease and Pharmacogenetics * Sequence Annotation and Comparative Analysis of Genomes *
Attendees * Sponsors * Table of Contents * Photographs * Awards

POSTER 81 - IDENTIFICATION OF LOCI CONTROLLING HYPOTHALAMIC GENE EXPRESSION AND PHENOTYPIC TRAITS RELATED TO ENERGY BALANCE

S.R. Wesolowski
University of Nebraska

Elo KT, Nielsen MK Pomp D
Department of Animal Science, University of Nebraska

In the mouse, many genes with known physiological relevance to energy regulating pathways have been discovered, while several predisposition genes (QTL) are being identified.  Given that few relevant mutations have been identified within these “physiological genes” that explain variation in segregating populations, it is interesting to speculatively hypothesize that predisposition and physiological genes represent different loci.  To test this theory, we are conducting experiments to identify QTL regulating the expression of genes with physiological relevance to energy balance. In the present study, we conducted a QTL scan using an F2 population (n = 636) derived from two mouse lines divergently selected for heat loss.  The inbred high (IH) heat loss mice have ~50% greater heat loss, ~35% less body fat, ~20% greater feed intake, and two-fold greater activity levels compared to the inbred low (IL) heat loss mice.  Yet, both lines are similar in body weight.  Previously, we have shown differential mRNA expression of hypothalamic oxytocin (Oxt), tissue inhibitor of metalloproteinase 2 (Timp-2), and ribosomal protein L3 (Rpl3) between the IH and IL lines.  Evidence for QTL controlling Oxt and Rpl3 expression were detected on chromosome 6 and 3, respectively.  QTL influencing heat loss (Chr. 5 and 14), 12-week body weight (Chr. 2, 9, 11, 12, and X), gonadal fat (Chr. 3, 6, and 12), and total body fat (Chr. 3, 12, and 17) were also identified.  Identification of QTL for these traits improves our understanding of the complex genetic architecture of polygenic traits and correlation between predisposition and physiology.