ABE-induced PDGFD start codon silencing unveils new insights into the genetic architecture of sheep fat tails.

Sheep is an important livestock species raised globally to pro-duce meat,milk,wool,and other by-products.During the Neolithic Revolution,sheep were domesticated in the Fertile Crescent of Southwest Asia around 10,000 years ago(Chessa et al.,2009).Nat-ural and artificial selection has been driving the development of various sheep breeds/ecotypes adapted to different climatic and production conditions.Sheep breeds often differ in coat color,pres-ence or absence of horns,tail shape,etc.Sheep tails can be divided into five main patterns,including fat-long tail,fat-short tail,thin-long tail,thin-short tail,and fat rump(i.e.,'tailless'),which are determined by the length and number of caudal vertebrae as well as the amount of fat deposition.In modern breeding programs,the thin-short tail is considered preferable since other tail patterns have specific issues of concern.For example,fat tails are indicated to be associated with low mating success,animal locomotion,excessive fat deposition,increased production costs,and reduced consumer preference.Similarly,thin long-tailed sheep require tail docking as part of the an-imal management practice,which is a concern for animal welfare.