molecular phenotyping screen

We use a highly efficient gene expression-profiling approach to molecularly phenotype tissues of mouse models in the German Mouse Clinic (GMC). For systemic analysis in the primary screen, 12 distinct organs (testis, liver, kidney, spleen, lung, heart, thymus, skeletal muscle and brain) of each submitted mutant mouse line (MML) are collected. Samples for gene expression-profiling are selected based on conspicuous phenotypes in other GMC screens or based on previous knowledge of gene functions.

Statistical analysis is performed for identification of significant changes in gene expression levels in each single organ of a MML. The subsequent analysis includes the assessment of the regulated genes and their functional annotation. Commercial and public software tools are available for cluster analyses and mining of the scientific literature, for example, in order to identify frequent co-citations of co-expressed genes and over-representation of GeneOntology (GO) functional annotations in the set of regulated genes.

In the secondary screen tissues are analysed that are not included in the routine set of organs of the primary screen (e.g. eye, bone, intestine, blood, spinal cord, adrenal glands, pancreas, salivary gland, bulbourethral glands, activated T-cells, yolk sac, seminal vesicles, white adipose tissue, brown adipose tissue, tyroid gland, skin and cartilage (auricle). We offer to collect these organs at an age different from that in the primary screen, or from female mice, or after environmental challenges (e.g. nutrition, physical exercise, air pollution or stress). For most of these organs optimised protocols for isolation of total RNA are established. Due to insufficient amounts of RNA from some organs (e.g. eye, bone, yolk sac, and activated T-cells) for cDNA-chip hybridisations, amplification of RNA is required.

In the secondary screen all other procedures like organ collection, hybridisation or data analysis are performed following our standardised protocols of the primary screen.