Libbus B L, Perreault S D, Johnson L A, Pinkel D
Reproduction Laboratory, U.S. Department of Agriculture, Beltsville, MD 20705.
Mutat Res. 1987 Oct;182(5):265-74. doi: 10.1016/0165-1161(87)90011-2.
The separation of two sperm populations is possible using the technique of flow sorting, provided that a significant difference exists in the DNA content of X- and Y-bearing sperm. In order to ascertain whether or not chromosome damage was induced in sorted sperm, chromosome preparations were made from isolated sperm that had been microinjected into hamster eggs. While egg chromosomes exhibited a low frequency of chromosome aberrations, ranging from 4 to 7%, a large proportion of sperm cells exhibited chromosome damage. Between 29% of unstained and unsorted sperm and 38% of stained and unsorted sperm exhibited some type of chromosomal abnormality and this proportion increased to 50% in sorted sperm. If only damaged sperm nuclei are considered, the two unsorted sperm groups had a mean of 0.6 breaks, 0.8 triradial exchanges, and 0.2 quadriradial exchanges per nucleus. However, sorted sperm, which were stained with a fluorochrome and exposed to UV-laser irradiation, exhibited a mean of 2.9 breaks, 2.6 triradial, and 1.9 quadriradial exchanges per nucleus in which damage occurred. These observations indicate that the treatments and manipulations to which sperm nuclei are subjected during flow sorting cause chromosomal aberrations, and that exposure of the cells to UV-laser irradiation contributes substantially to the chromosome damage observed.
如果携带X和Y染色体的精子在DNA含量上存在显著差异，那么使用流式细胞分选技术分离这两种精子群体是可行的。为了确定分选后的精子是否诱导了染色体损伤，对已显微注射到仓鼠卵中的分离精子进行了染色体制备。虽然卵染色体的染色体畸变频率较低，在4%至7%之间，但很大一部分精子细胞表现出染色体损伤。在未染色和未分选的精子中，29%表现出某种类型的染色体异常，在染色和未分选的精子中这一比例为38%，而在分选后的精子中这一比例增加到了50%。如果仅考虑受损的精子细胞核，两个未分选的精子群体每个细胞核平均有0.6个断裂、0.8个三辐射交换和0.2个四辐射交换。然而，用荧光染料染色并暴露于紫外激光照射下的分选精子，每个发生损伤的细胞核平均有2.9个断裂、2.6个三辐射和1.9个四辐射交换。这些观察结果表明，精子细胞核在流式分选过程中所经历的处理和操作会导致染色体畸变，并且细胞暴露于紫外激光照射下对观察到的染色体损伤有很大影响。
