EFFECTS OF B-CHROMOSOMES ON THE ACTIVITY OF NUCLEOLAR ORGANIZER REGIONS IN THE GRASSHOPPER EYPREPOCNEMIS-PLORANS - ACTIVATION OF A LATENT NUCLEOLAR ORGANIZER REGION ON A B-CHROMOSOME FUSED TO AN AUTOSOME
EFFECTS OF B-CHROMOSOMES ON THE ACTIVITY OF NUCLEOLAR ORGANIZER REGIONS IN THE GRASSHOPPER EYPREPOCNEMIS-PLORANS - ACTIVATION OF A LATENT NUCLEOLAR ORGANIZER REGION ON A B-CHROMOSOME FUSED TO AN AUTOSOME
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DOI：
10.1139/g87-020
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发表时间：
1987-02-01
期刊：
影响因子：
3.1
通讯作者：
CAMACHO, JPM
中科院分区：
文献类型：
--
作者：
CABRERO, J;ALCHE, JD;CAMACHO, JPM
四个核仁组织区（NORs）在标准雄性蚱蜢（Eyprepocnemis plorans）中活跃。它们位于S9、S10、S11和X染色体的着丝粒区附近。在存在B2型多余染色体的情况下，NOR活性模式发生了变化。由于NORs在S11和x上的活性显著增加，具有1个B的雄性比无B的雄性在每个细胞中显示出更高的活性NORs的平均数量。然而，无B和1个B的胚胎显示出相似的活性模式。在男性之间的着丝粒融合B和L1的染色体,激活潜伏的也出席了端粒的长臂B,和活动的平行明显降低在S9 / S10现象源于不同古称之间的竞争的存在B。因此,虽然S10 0 B男性活动的也不影响的古称X和S9或是从一个消极的角度,在一个B男性做不到这一点,尽管在B-L1融合的雄性中观察到这种影响，其中S10 NOR的活性再次显著降低。另一方面，S9和S11上的NOR活性在零B和一B雄性中都显示出显著的正相互依赖关系，其中S11 NOR活性增加，但在B- l1融合雄性中没有增加，这表明S9 NOR活性显著降低。
Four nucleolar organizer regions (NORs) are active in standard males of the grasshopper Eyprepocnemis plorans. They are located near the centromeric regions of the S9, S10, S11, and X chromosomes. Changes in the pattern of NOR activity have been observed in the presence of a B2 type supernumerary chromosome. Males with one B show a higher mean number of active NORs per cell than do zero B males owing to significant increases in the activity of the NORs on the S11 and the X. Zero B and one B embryos, however, showed similar patterns of activity. In a male carrying a centric fusion between a B and one of the L1 chromosomes, the activation of a latent NOR, present at the telomere of the long arm of the B, parallelled a significant decrease of NOR activity on the S9 and S10 bivalents stemming from a competition between different NORs in the presence of the B. Thus, while in zero B males the activity of the S10 NOR influences that of the NORs on the X and S9 in a negative way, in one B males it does not do so, although such an influence is observed in the B-L1 fusion male where the activity of the S10 NOR again decreases significantly. On the other hand, the activities of the NORs on the S9 and S11 show a significant positive interdependence in both zero B and one B males where S11 NOR activity is increased but do not do so in the B-L1 fusion male, which shows a significant decrease in the S9 NOR activity.