Wheeler Matthew B, Rutledge Jack J, Fischer-Brown Amy, VanEtten Tara, Malusky Samantha, Beebe David J
Department of Animal Sciences, University of Illinois at Urbana-Champaign, Urbana, IL 61801, USA.
Theriogenology. 2006 Jan 7;65(1):219-27. doi: 10.1016/j.theriogenology.2005.09.032. Epub 2005 Nov 2.
Use of sexed semen in conjunction with in vitro embryo production is a potentially efficient means of obtaining offspring of predetermined sex. For thousands of years, livestock owners have desired a methodology to predetermine the sex of offspring for their herds. The ability to sort individual sperm cells into viable X- and Y-chromosome-bearing fractions made producers' sex selection dreams reality in the 1990s and now semen can be sexed with greater than 90% accuracy with use of a flow cytometric cell sorter. Several concerns regarding the implementation of sexed semen technology include the apparent lower fertility of sorted sperm, the lower survival of sorted sperm after cryopreservation and the reduced number of sperm that could be separated in a specified time period. These issues are discussed in this review. There are also a number of issues that appear to influence the success rates of using sexed semen to produce bovine embryos in vitro. These issues include reductions in fertilization rates, lower cleavage rates, blastocyst rates and pregnancy rates, partial capacitation of the sperm, dilute sperm samples and sire variation. These subjects are also addressed in this paper. Finally, we will describe a recent field trial in which female Holstein embryos produced using the combined technologies of sex-selected semen and microfluidics were transferred either as single or bilateral twin embryos into beef cattle recipients, demonstrating these technologies' contributions to viable embryo production. The results indicate that large-scale transfer of in vitro produced, Holstein heifer embryos to beef recipients is a feasible production scheme.
将性别分选精液与体外胚胎生产相结合是一种获得预定性别的后代的潜在有效方法。数千年来，家畜饲养者一直渴望有一种方法来预先确定其畜群后代的性别。在20世纪90年代，能够将单个精子细胞分选成携带X和Y染色体的有活力部分，使生产者的性别选择梦想成为现实，现在使用流式细胞仪细胞分选仪可以以超过90%的准确率对精液进行性别分选。关于性别分选精液技术实施的几个问题包括分选精子明显较低的受精率、冷冻保存后分选精子较低的存活率以及在特定时间段内可分离的精子数量减少。本综述将讨论这些问题。还有一些问题似乎会影响使用性别分选精液体外生产牛胚胎的成功率。这些问题包括受精率降低、卵裂率、囊胚率和妊娠率降低、精子部分获能、精子样本稀释以及种公牛差异。本文也将探讨这些主题。最后，我们将描述一项最近的田间试验，在该试验中，使用性别选择精液和微流控技术联合生产的雌性荷斯坦胚胎作为单胚或双侧双胚移植到肉牛受体中，展示了这些技术对可行胚胎生产的贡献。结果表明，将体外生产的荷斯坦小母牛胚胎大规模移植到肉牛受体中是一种可行的生产方案。
