논문 상세보기
Sequences of 600 comparative-tile BACs on Arabidopsis genome and their utility as seed BACs for sequencing of B. rapa chromosomes KCI 등재
Recent studies revealed that about 240 species in the tribe Brassiceae are derived through diploidization process from an ancient hexaploid after divergence with Arabidopsis. Most triplicates in Brassica genome show sequence-level co-linearity with a counterpart Arabidopsis sequence. We have obtained 91,511 BAC end sequences (BES) and high-resolution fingerprints (SNapShot) from 99,456 BAC clones originated three BAC libraries (HindIII, BamHI, and Sau3AI). All BESs were used for comparative genome analysis with the Arabidopsis. A total of 47,748 (52%) BESs show significant hit (E-6) with at least one spot of Arabidopsis chromosomes. And a total of 4,647 BAC clones (10%) are mapped on the counterpart Arabidopsis chromosomes by directional matches of both ends (9,294 BES) within 30-500 kb interval on Arabidopsis chromosome. These 4,647 clones span 92 Mb of Arabidopsis genome. We have selected a total of 629 BACs that span 86 Mb Arabidopsis genome with minimally comparative overlap (comparative-tile). Up to now, about 600 BACs are sequenced and most show co-linearity with the counterparts. Sequence-based genetic mapping of each BAC and their FPC information will be used as step-stone for walking and construction physical map of all chromosomes. Up to now, 513 BACs are sequence-based anchored on ten B. rapa genetic linkage groups that provide successful information as seed BACs for further extending to close clone gaps between the adjacent seed BACs and thus to complete sequencing of the individual chromosome. We are sequencing cytological chromosome 1 (R9) and 2 (R3), until now we finished about 50% of each chromosome. We also analyzed 130,000 ESTs from 29 cDNA libraries made with various tissues at various developing stage and treatments. The hybridization results of 24K microarray will be presented. All information will be provided to Multinational Brassica Genome Project (MBGP) members, soon, using web-based tool from our Arabidopsis-Brassica Genome Browser (www.brassica-rapa.org).
