ANALYSIS OF SATELLITE DNA SEQUENCE OF SUNCUSU MURINUS.

点击翻译按钮获取中文摘要

We have cloned six satellite DNA fragments (pSBs) from the BamHI digested genomic DNA of Suncus murinus. These clones were all mapped to the subcentromeric regions coinsistent with the locations of heterochromatic C-banded regions. Sequence analysis of these clones showed that approximately 3000 copies of the (TTC) repeat were clustered in the satellite DNA.FISH analysis using oligonucleotide (TTC)6 as a probe revealed that (TTC)6 was preferentially hybridized to only one of the two sister chromatids. Such asymmetric hybridization on the sister chromatids has not yet been reported in any probes used in the past. To elucidate the biological significance of the asymmetric hybridization of the (TTC)n repeat, we proposed the "Sister chromatid printing hypothesis" which suggest that each of the sister chromatids might be differentially modified to distinguish chromatids by the unknown genetic mechanisms. This machinary may control the selective segregation of the sister chromatids, resulting in the allocation of a definite set of sister chromatids to the daughter cells.