The benefits of polled beef animals in the value chain have become well known and provides an impetus to beef cattle breeders to select for the POLLED gene. Animal welfare is a major concern and polled animals do not need to be subjected to painful dehorning; additional advantages include lower injury risks during transport and improved safety during handling of the animals. The polled condition has been studied over many decades suggesting various modes of inheritance for polled and scur. Since the completion of the bovine reference genome and the advancement of bovine genomics, developments in molecular technology provided additional tools for investigating the genetic basis of the polled and scurs phenotypes. Even though four causal mutations of the POLLED locus have been identified, the molecular basis governing polled/horned condition and the underlying genetics for scurs remains unclear. In this review, a brief overview is provided on the growth and development of horns followed by a discussion on the molecular advancements made over the past two decades in identifying the POLLED gene and associated variants. The identification of the SCURS locus is complicated by the lack of accurate recording of phenotypes for scurs on-farm.

价值链中被轮询的牛肉动物的好处已广为人知，并为肉牛育种者选择POLLED基因提供了动力。动物福利是一个主要问题，不需要对被轮询的动物进行痛苦的除角处理。其他优点包括降低运输过程中的受伤风险，并提高了动物处理过程中的安全性。已经对投票条件进行了数十年的研究，提出了针对投票和垃圾的各种继承模式。由于牛参考基因组的完成和牛基因组学的发展，分子技术的发展为调查民意调查表和杂乱表型的遗传基础提供了额外的工具。即使POLLED有四个因果突变已经确定了基因座，尚不清楚控制轮询/有角条件的分子基础和杂种的潜在遗传学。在这篇综述中，对角的生长和发育进行了简要概述，然后讨论了过去二十年来在鉴定POLLED基因和相关变体方面的分子进展。SCURS基因座的鉴定由于缺乏准确记录农场潮虫的表型而变得复杂。