Meyer zu Altenschildesche G, Heller H, Wilgenbus P, Tjia S T, Doerfler W
Institut für Genetik, Universität zu Köln, Weyertal 121, D-50931 Köln, Germany.
Chromosoma. 1996;104(5):341-4. doi: 10.1007/BF00337222.
The retrotransposon-like elements of the intracisternal A-particle (IAP) sequences occur in about 900 copies per haploid hamster cell genome. By applying the fluorescent in situ hybridization (FISH) technique and four different, cloned segments of the IAP element as hybridization probes, these elements were found to be distributed in specific patterns over many of the 44 hamster chromosomes. The hybridization patterns were very similar regardless of whether all four probes or only the IAPI probe carrying the long terminal repeat (LTR) region were used. The IAP elements were found most abundantly, though not exclusively, on the short arms of at least 12 of the autosomes. Of the sex chromosomes, the shorter Y chromosome was stained on both arms, and the X chromosome on one arm by the IAP probes. Primary Syrian hamster cells, the established Syrian hamster cell line BHK21, and the adenovirus type 12 (Ad12)-transformed BHK21 cell line T637 yielded very similar results. In Chinese hamster ovary (CHO) or 3T3 mouse cells, signals could not be elicited by FISH using the Syrian hamster IAP probes. On Southern blots, the DNAs from these cell lines hybridized very weakly, if at all, to the IAP sequences. Thus, IAP sequences were retroposed after Syrian hamster and mouse or Syrian and Chinese hamsters had diverged in evolution.
脑内A颗粒（IAP）序列中的类逆转座子元件在每个单倍体仓鼠细胞基因组中约有900个拷贝。通过应用荧光原位杂交（FISH）技术，并使用IAP元件的四个不同的克隆片段作为杂交探针，发现这些元件以特定模式分布在44条仓鼠染色体中的许多条上。无论使用所有四个探针还是仅使用携带长末端重复序列（LTR）区域的IAPI探针，杂交模式都非常相似。IAP元件在至少12条常染色体的短臂上最为丰富，但并非唯一。在性染色体中，较短的Y染色体双臂均被IAP探针染色，X染色体则有一条臂被染色。原代叙利亚仓鼠细胞、已建立的叙利亚仓鼠细胞系BHK21以及腺病毒12型（Ad12）转化的BHK21细胞系T637产生了非常相似的结果。在中国仓鼠卵巢（CHO）细胞或3T3小鼠细胞中，使用叙利亚仓鼠IAP探针进行FISH无法产生信号。在Southern印迹上，这些细胞系的DNA与IAP序列的杂交非常弱，甚至根本不杂交。因此，IAP序列是在叙利亚仓鼠与小鼠或叙利亚仓鼠与中国仓鼠在进化中分化之后逆转插入的。
