Poster: Evolution

Abs # 790: Organization of families of the chromosomal distal end specific satellite DNA in Silene latifolia

Presenter:	Kazama, Yusuke , kk16510@mail.ecc.u-tokyo.ac.jp
Authors	Kazama, Yusuke  (A)   Sugiyama, Ryuji  (A)   Uchida, Wakana  (A)   Matsunaga, Sachihiro  (B)   Kawano, Shigeyuki  (A)
Affiliations:	(A): Department of Integrated Biosciences, Graduate School of Frontier Sciences, University of Tokyo (B): Department of Biotechnology, Graduate School of Engineering, Osaka University

The dioecious plant, Silene latifolia has chromosomal distal end specific satellite DNA (Sl-distal-satDNA). Male and female genomic DNA of S. latifolia was digested with SacI, HaeIII, HinfI and KpnI and hybridized with the Sl-distal-satDNA as a probe. A typical ladder pattern of tandemly organized repeats was observed in all digests. Eleven BAC clones containing this satellite DNA were isolated from a partial BAC library of S. latifolia. They were digested with six restriction enzymes and hybridized with the Sl-distal-satDNA as a probe. The Southern blots showed various ladder-like patterns in all eleven BAC clones. The smaller band in the ladder-like patterns corresponded to 310-bp repeat unit, which was detected for the HaeIII digests of all BAC clones. To investigate pair-wise similarities between individual repeat units of them, a phylogenetic tree was constructed using the neighbor-joining algorithm. The repeat units derived from eleven BAC clones were classified into four clusters named as SacI, KpnI, #11F02 and #16E07 family, respectively. Multi-colored FISH with the SacI family and the KpnI family as probes demonstrated that the KpnI family is mainly localized at one end of chromosome 7. These results suggest that individual distal ends of chromosomes have various Sl-distal-satDNAs, and that chromosome 7 carries the KpnI family at only one end.