Weighted co-expression networks shed light on the molecular mechanism of action of metyrapone on wool follicle development

Abstract

The density of Merino wool follicles is established early in fetal development. This commercially important trait dictates wool fibre diameter which is the key driver of the price paid for wool. Merino lambs exposed to metyrapone (an inhibitor of cortisol synthesis) in utero show a lifetime alteration in wool growth parameters. Microarray data from a metyrapone treatment experiment were analysed within a systems biology framework using Weighted Gene Co-expression Network Analysis (WGCNA). Four networks were created to determine those genes involved in metyrapone mediated improvement of wool growth parameters. Using the WGCNA approach, we were able to detect co-expressed gene modules associated with metyrapone treatment. Gene ontology enrichment analysis of the genes comprising these modules identified a Bone Morphogenetic Protein (BMP4), a ligand known to be involved in hair/wool follicle development and expressed at the time of branching of secondary-derived follicles in Merino sheep.