Genetics of fibre production in sheep and goats

Current knowledge of the genetic control of fibre production in sheep and goats is reviewed with the focus at the molecular level, particularly on the control of fibre initiation and development in mammals and birds, with the key driver being the new molecular technologies that have allowed the sequencing and identification of individual genes and their site of expression. Current theories of the biology of follicle initiation and fibre growth are discussed at the level of key developmental stages and current theories about the genetic mechanisms controlling these events are reviewed. While there is a considerable knowledge of keratin genes and proteins, the mechanisms by which such highly ordered structures are produced is still relatively unknown. The review concludes with discussion on the gaps in our knowledge with respect to the interactions between pathways underlying traits of economic importance and how this might influence the use of this knowledge in sheep and goat breeding programs.