Clulow J R, Evans G, Morris L H A, Maxwell W M C
University of Sydney, Sydney, NSW 2006, Australia.
Anim Reprod Sci. 2009 Jul;113(1-4):220-8. doi: 10.1016/j.anireprosci.2008.08.019. Epub 2008 Aug 20.
Intrinsic differences between stallions exist for semen traits such as motility, morphology fertility and the ability of spermatozoa to survive cryopreservation processes. Ejaculates from 11 stallions were used to test the differences between stallions when selecting X- and Y-chromosome bearing spermatozoa using a modified flow cytometer. Data on orientation and viability of spermatozoa were collected during sex-sorting, and motility characteristics of sex-sorted and non-sorted (control) spermatozoa were assessed before and after cryopreservation. An index was created to rank each stallion in order of their suitability for sex-sorting using the data generated by the flow cytometry software. Motility of spermatozoa was higher after sorting and cooling than in the fresh ejaculates, but was significantly lower after thawing in comparison to fresh semen for both sex-sorted and non-sorted spermatozoa. Semen samples with a high percentage of food dye positive, defined as dead, spermatozoa had a low sortability index and ranking. Thus, percentage of dead spermatozoa in the semen sample was identified as the most important factor determining sortability. We conclude that variation between stallions exists for the sortability of their spermatozoa and that the sortability index is a useful tool for the selection of suitable stallions for a sex-sorting program.
种马在精液特征方面存在内在差异，如活力、形态、生育能力以及精子在冷冻保存过程中的存活能力。使用改良的流式细胞仪，从11匹种马的射精样本中选取携带X和Y染色体的精子，以测试种马之间的差异。在性别分选过程中收集精子的取向和活力数据，并在冷冻保存前后评估性别分选和未分选（对照）精子的活力特征。利用流式细胞仪软件生成的数据创建一个指数，对每匹种马进行排序，以确定它们在性别分选方面的适宜程度。分选和冷却后精子的活力高于新鲜射精样本，但解冻后，性别分选和未分选精子的活力均显著低于新鲜精液。精液样本中，被定义为死亡精子的食物染料阳性比例较高的，其分选指数和排名较低。因此，精液样本中死精的比例被确定为决定分选能力的最重要因素。我们得出结论，种马精子的分选能力存在差异，分选指数是为性别分选计划选择合适种马的有用工具。
