Zwick M S, Islam-Faridi M N, Czeschin D G, Wing R A, Hart G E, Stelly D M, Price H J
Department of Soil and Crop Sciences, Texas A&M University, College Station 77843-2474, USA.
Genetics. 1998 Apr;148(4):1983-92. doi: 10.1093/genetics/148.4.1983.
Physical mapping of BACs by fluorescent in situ hybridization (FISH) was used to analyze the liguleless (lg-1) linkage group in sorghum and compare it to the conserved region in rice and maize. Six liguleless-associated rice restriction fragment length polymorphism (RFLP) markers were used to select 16 homeologous sorghum BACs, which were in turn used to physically map the liguleless linkage group in sorghum. Results show a basic conservation of the liguleless region in sorghum relative to the linkage map of rice. One marker which is distal in rice is more medial in sorghum, and another marker which is found within the linkage group in rice is on a different chromosome in sorghum. BACs associated with linkage group I hybridize to chromosome It, which was identified by using FISH in a sorghum cytogenetic stock trisomic for chromosome I (denoted It), and a BAC associated with linkage group E hybridized to an unidentified chromosome. Selected BACs, representing RFLP loci, were end-cloned for RFLP mapping, and the relative linkage order of these clones was in full agreement with the physical data. Similarities in locus order and the association of RFLP-selected BAC markers with two different chromosomes were found to exist between the linkage map of the liguleless region in maize and the physical map of the liguleless region in sorghum.
利用荧光原位杂交（FISH）对细菌人工染色体（BAC）进行物理图谱分析，以研究高粱的无叶舌（lg-1）连锁群，并将其与水稻和玉米的保守区域进行比较。使用六个与无叶舌相关的水稻限制性片段长度多态性（RFLP）标记来筛选16个同源高粱BAC，进而用于构建高粱无叶舌连锁群的物理图谱。结果表明，相对于水稻的连锁图谱，高粱无叶舌区域基本保守。在水稻中位于远端的一个标记在高粱中更靠近中间位置，而在水稻连锁群内发现的另一个标记在高粱中位于不同的染色体上。与连锁群I相关的BAC与染色体It杂交，这是通过在高粱细胞遗传学材料三体I（记为It）中使用FISH鉴定的，并且与连锁群E相关的一个BAC与一条未鉴定的染色体杂交。代表RFLP位点的选定BAC进行末端克隆用于RFLP图谱分析，这些克隆的相对连锁顺序与物理数据完全一致。发现玉米无叶舌区域的连锁图谱与高粱无叶舌区域的物理图谱在基因座顺序上存在相似性，并且RFLP选择的BAC标记与两条不同染色体相关。
