Localization of jointless-2 gene in the centromeric region of tomato chromosome 12 based on high resolution genetic and physical mapping
Localization of jointless-2 gene in the centromeric region of tomato chromosome 12 based on high resolution genetic and physical mapping
复制标题
DOI：
10.1007/s00122-003-1429-3
复制
发表时间：
2004-01-01
影响因子：
5.4
通讯作者：
Wing, RA
中科院分区：
文献类型：
--
作者：
Budiman, MA;Chang, SB;Wing, RA
脱落是植物脱落器官（如花、果实和叶子）的普遍过程。在番茄中，已发现非等位基因突变jointless和jointless-2是隐性突变，可完全抑制花梗脱落区的形成。使用 1,122 株无接缝 F-2 植物构建了无接缝-2 的高分辨率遗传图谱。限制性片段长度多态性 (RFLP) 标记 RPD140 与 Jointless-2 基因座完全共分离，并定位在 RFLP 标记 CD22 和 TG618 之间 2.4 cM 的间隔中。为了染色体行走至 Jointless-2，所有三个标记均用于筛选细菌人工染色体 (BAC) 文库并开发了重叠群。由于每个重叠群远端的高度重复的序列内容，大量努力扩展和合并 BAC 重叠群并未成功。为了确定三个重叠群之间的物理距离和方向，我们使用高分辨率粗线期荧光原位杂交 (FISH) 作图。 RPD140 重叠群位于 12 号染色体的着丝粒区域，位于两个大的着丝粒周围异染色质块之间，距离短臂上的 TG618 重叠群约 50 Mb，距离长臂上的 CD22 重叠群约 10 Mb。基于高分辨率遗传和物理图谱，我们得出结论，jointless-2 基因位于 12 号染色体着丝粒内或附近，其中 1 cM 的长度约为 25 Mb。
Abscission is a universal process whereby plants shed their organs, such as flowers, fruit and leaves. In tomato, the non-allelic mutations jointless and jointless-2 have been discovered as recessive mutations that completely suppress the formation of pedicel abscission zones. A high resolution genetic map of jointless-2 was constructed using 1,122 jointless F-2 plants. Restriction fragment length polymorphism (RFLP) marker RPD140 completely co-segregated with the jointless-2 locus and mapped in a 2.4 cM interval between RFLP markers CD22 and TG618. To chromosome walk to jointless-2, all three markers were used to screen a bacterial artificial chromosome (BAC) library and contigs were developed. Intensive efforts to expand and merge the BAC contigs were unsuccessful because of the highly repetitive sequence content on the distal ends of each contig. To determine the physical distance between and the orientation of the three contigs, we used high resolution pachytene fluorescence in situ hybridization (FISH) mapping. The RPD140 contig was positioned in the centromeric region of chromosome 12 between two large pericentric heterochromatin blocks, about 50 Mb from the TG618 contig on the short arm and 10 Mb from the CD22 contig on the long arm, respectively. Based on high resolution genetic and physical mapping, we conclude that the jointless-2 gene is located within or near the chromosome 12 centromere where 1 cM is approximately 25 Mb in length.