Estop A M, Cieply K M, Wakim A, Feingold E
Department of Human Genetics, MCP Hahnemann Medical School, University of Pittsburgh, Pittsburgh, PA, USA.
Cytogenet Cell Genet. 1998;83(3-4):193-8. doi: 10.1159/000015177.
The sperm products of two male carriers of reciprocal translocations were studied by fluorescence in situ hybridization (FISH) using a combination of three probes for each translocation. One patient carried a t(2;18)(p21;q11.2), the other a t(8;9)(q24.2;q32). The probes selected included a centromeric marker for each chromosome involved in the translocation plus a third probe distal to the translocation breakpoint of one of the translocation chromosomes. This assay identifies alternate, adjacent 1, adjacent 2, and 3:1 types of meiotic products. It allows the identification of recombination events and also estimation of the frequency of diploidy. For the t(2;18), the frequency of normal and balanced sperm and of adjacent 1, adjacent 2, and 3:1 products was 43.6%, 29. 8%, 10.5%, and 12.8%, respectively. Similar segregation patterns had been reported for this donor by direct sperm karyotyping of sperm cells. For the t(8;9), the frequency of normal and balanced sperm and of adjacent 1, adjacent 2, and 3:1 products was 44.4%, 41%, 3.1%, and 9.4%, respectively. The frequency of complementary adjacent 1 products was statistically different in both the t(2;18) (P < 0. 0001) and the t(8;9) (P < 0.0001) carrier. When the number of adjacent 2 products with one translocation chromosome (regardless of normal or derivative) was compared to the number of adjacent 2 products with the second translocation chromosome (again, regardless of normal or derivative), no statistical difference was noted for either the t(2;18) (P = 0.32) or the t(8;9) (P = 0.69). Recombination events within the interstitial segment of chromosome 2 were statistically higher than those seen in chromosome 18 (P < 0. 0001), whereas in chromosomes 8 and 9, recombination in the interstitial segments was similar (P = 0.64). The rate of diploidy was similar in both the t(2;18) (0.5%) and the t(8;9) (0.6%). Thus, FISH provides chromosome information on the sperm products produced by translocation carriers, although it cannot provide an assessment of the full chromosome complement of the spermatozoon.
利用针对每种易位的三种探针组合，通过荧光原位杂交（FISH）技术研究了两名相互易位男性携带者的精子产物。一名患者携带t(2;18)(p21;q11.2)，另一名携带t(8;9)(q24.2;q32)。所选用的探针包括涉及易位的每条染色体的着丝粒标记，以及位于其中一条易位染色体易位断点远端的第三种探针。该检测可识别减数分裂产物的交替型、邻接1型、邻接2型和3:1型。它能够识别重组事件，并估计二倍体频率。对于t(2;18)，正常和平衡精子以及邻接1型、邻接2型和3:1产物的频率分别为43.6%、29.8%、10.5%和12.8%。通过对精子细胞进行直接精子核型分析，已报道该供体具有类似的分离模式。对于t(8;9)，正常和平衡精子以及邻接1型、邻接2型和3:1产物的频率分别为44.4%、41%、3.1%和9.4%。在t(2;18)携带者（P < 0.0001）和t(8;9)携带者（P < 0.0001）中，互补邻接1产物的频率在统计学上均有差异。当比较携带一条易位染色体的邻接2型产物数量（无论正常或衍生）与携带另一条易位染色体的邻接2型产物数量（同样无论正常或衍生）时，对于t(2;18)（P = 0.32）或t(8;9)（P = 0.69）均未发现统计学差异。2号染色体间质段内的重组事件在统计学上高于18号染色体（P < 0.0001），而在8号和9号染色体中，间质段内的重组情况相似（P = 0.64）。t(2;18)（0.5%）和t(8;9)（0.6%）的二倍体率相似。因此，FISH可提供易位携带者产生的精子产物的染色体信息，尽管它无法评估精子的完整染色体组成。
