PAIRING COMPETITION BETWEEN IDENTICAL AND HOMOLOGOUS CHROMOSOMES IN AUTOTETRAPLOID RYE HETEROZYGOUS FOR INTERSTITIAL C-BANDS
PAIRING COMPETITION BETWEEN IDENTICAL AND HOMOLOGOUS CHROMOSOMES IN AUTOTETRAPLOID RYE HETEROZYGOUS FOR INTERSTITIAL C-BANDS
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DOI：
10.1007/bf00329687
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发表时间：
1989-09-01
期刊：
影响因子：
1.6
通讯作者：
ORELLANA, J
中科院分区：
文献类型：
--
作者：
BENAVENTE, E;ORELLANA, J
在黑麦同源四倍体中期I细胞中，分析了同源和同源不同染色体之间的配对竞争，其中一对完全相同的配对在6R染色体的长臂上有一条间隙C-带，而另一对完全相同的配对没有这样的C-带。这使得研究同一染色体臂上两个不同区域的配对偏好成为可能。涉及同源伙伴的关联在近端片段(从着丝粒到C带)总是观察到显著过剩，而在远端片段(从C带到端粒)发现与预期的随机比率或完全相同的配对偏好。6RL中配对和交叉形成过程的差异，和/或由于同源不完全相同的配对而导致的间质C-带杂合性导致交叉分布模式的重新调整，可能是在标记臂的两个区域检测到的不同行为的原因。
Pairing competition beween identical and homologous non-identical chromosomes is analysed in autotetraploid metaphase I cells of rye where one pair of identical partners bears an interstitial C-band in the long arm of chromosome 6R whereas the other pair of identical partners lacks such a C-band. This makes it possible to study pairing preferences in two distinct regions of the same chromosome arm. A significant excess of associations involving homologous partners is always observed in the proximal segment (from the centromere to the C-band), whereas a good fit with the expected random ratio, or else identical pairing preferences, is found in the distal segment (from the C-band to the telomere). Differences in the processes of pairing and chiasma formation in 6RL, and/or a readjustment in the pattern of chiasma distribution due to heterozygosity for the interstitial c-band as a result of homologous non-identical pairing, may be responsible for the different behaviour detected in the two regions of the marked arm.