A protocol for high-throughput phenotyping, suitable for quantitative trait analysis in mice

Abstract

Whole-genome genetic association studies in outbred mouse populations represent a novel approach to identifying the molecular basis of naturally occurring genetic variants, the major source of quantitative variation between inbred strains of mice. Measuring multiple phenotypes in parallel on each mouse would make the approach cost effective, but protocols for phenotyping on a large enough scale have not been developed. In this article we describe the development and deployment of a protocol to collect measures on three models of human disease (anxiety, type II diabetes, and asthma) as well as measures of mouse blood biochemistry, immunology, and hematology. We report that the protocol delivers highly significant differences among the eight inbred strains (A/J, AKR/J, BALBc/J, CBA/J, C3H/HeJ, C57BL/6 J, DBA/2 J, and LP/J), the progenitors of a genetically heterogeneous stock (HS) of mice. We report the successful collection of multiple phenotypes from 2000 outbred HS animals. The phenotypes measured in the protocol form the basis of a large-scale investigation into the genetic basis of complex traits in mice designed to examine interactions between genes and between genes and environment, as well as the main effects of genetic variants on phenotypes.

Linkage on chromosome 14 in a genome-wide linkage study of a broad anxiety phenotype

“…42,43 The linkage studies were carried out in inbred mouse strains whose open field activity (OFA) was measured. Genome-wide association was analyzed in heterogeneous mice stocks.…”

“…Multiple complex phenotypes were investigated in the heterogeneous mice stocks and the results are freely available on http:// gscan.well.ox.ac.uk. 42,43 Unconditioned anxiety was measured with the elevated plus maze (EPM), OFA and food hyponeophagia (FN). Genome-wide significance was found in the region syntenic with our linkage signal for the open arm latency in the EPM.…”

Subtle metabolic and liver gene transcriptional changes underlie diet-induced fatty liver susceptibility in insulin-resistant mice

“…Intraperitoneal glucose tolerance test At 5 months 129S6 mice were fasted overnight and subjected to a simplified intraperitoneal glucose tolerance test (IPGTT) as previously described [15]. Mice were anaesthetised by i.p.…”

Efficiency of genomic selection using Bayesian multi-marker models for traits selected to reflect a wide range of heritabilities and frequencies of detected quantitative traits loci in mice

“…The data were freely available [28] and the care and use of animals were performed in compliance with the guidelines at the Wellcome Trust Centre for Human Genetics, University of Oxford, UK. The population has already been described and analyzed comprehensively in various papers including Solberg et al [29] and Valdar et al [11]. Therefore, only the aspects important for the present analysis will be highlighted here.…”

“…Physiological traits were hematocrit percentage in blood as part of a full blood count test (HC) and insulin level at 75 minutes after intraperitoneal injection with glucose dose as part of a test to model type 2 diabetes mellitus, at nine weeks of age (I75). For further information regarding the biology behind these traits we refer to Solberg et al [29]. These traits were normalized using the transformation given in Valdar et al [11] and subsequently multiplied or divided by appropriate factors to avoid rounding errors in the multi-marker programme.…”