Robinson T J, Wittekindt O, Pasantes J J, Modi W S, Schempp W, Morris-Rosendahl D J
Department of Zoology, University of Stellenbosch, Matieland, South Africa.
Chromosome Res. 2000;8(7):635-43. doi: 10.1023/a:1009294226213.
Conflicting data has recently appeared concerning altered methylation patterns in interspecific mammalian hybrids and the potential this may hold for driving karyotypic evolution. We report no detectable methylation difference in the genomic DNA of different interspecific F1 antelope hybrids (family Bovidae) and their parent species using the methylation-sensitive enzyme HpaII and its methylation insensitive isoschizomer MspI. However, both enzymes released a tandemly repeated satellite array. Characterization of the repeat using Southern blotting and a combination of sequencing, fluorescence in-situ hybridization (FISH) and C-banding, shows some similarity in the family of repeats between the hybridizing antelope species groups, and that the satellite is localized in the centromeric C-band positive regions of the chromosomes. Moreover, although there is little meaningful sequence homology with the well characterized bovine 1.715 satellite DNA, there is 86% sequence similarity with the sheep/goat satellite I, suggesting that they are related and are likely to have originated and evolved separately from the bovine unit.
最近出现了相互矛盾的数据,涉及种间哺乳动物杂交种中甲基化模式的改变以及这可能对驱动核型进化具有的潜力。我们报告称,使用甲基化敏感酶HpaII及其甲基化不敏感的同裂酶MspI,在不同种间F1羚羊杂交种(牛科)及其亲本物种的基因组DNA中未检测到甲基化差异。然而,两种酶都释放出一个串联重复的卫星阵列。使用Southern印迹法以及测序、荧光原位杂交(FISH)和C带技术相结合对该重复序列进行表征,结果表明杂交羚羊物种组之间的重复序列家族存在一些相似性,并且该卫星定位于染色体的着丝粒C带阳性区域。此外,尽管与特征明确的牛1.715卫星DNA几乎没有有意义的序列同源性,但与绵羊/山羊卫星I有86%的序列相似性,这表明它们相关,并且可能是从牛的卫星单元中分别起源和进化而来的。