Buising C M, Benbow R M
Department of Zoology and Genetics, Iowa State University, Ames 50011-3223.
Mol Gen Genet. 1994 Apr;243(1):71-81. doi: 10.1007/BF00283878.
Supercoiled plasmid expression vectors containing the petunia transformation booster sequence (TBS) were introduced by microprojectile bombardment into dicotyledenous (tobacco) and monocotyledonous (maize) cells. TBS effected a 7.8- to 16-fold increase in transformation frequencies in tobacco, and a 1.7- to 2.4-fold increase in maize. Although TBS contains a well-defined transcription enhancer element, no increases in plasmid gene expression were observed. TBS did not alter integration patterns in transformants, and did not affect segregation of linkage in R1 progeny. Computer analyses of the TBS sequence revealed numerous modular elements previously shown to be associated with putative chromosomal replication origin regions in eukaryotes, including DNA unwinding elements, scaffold-associated regions and pyrimidine tracts.
含有矮牵牛转化增强序列（TBS）的超螺旋质粒表达载体通过微粒轰击法导入双子叶植物（烟草）和单子叶植物（玉米）细胞中。TBS使烟草的转化频率提高了7.8至16倍，使玉米的转化频率提高了1.7至2.4倍。尽管TBS含有一个明确的转录增强元件，但未观察到质粒基因表达增加。TBS未改变转化体中的整合模式，也不影响R1后代中连锁的分离。对TBS序列的计算机分析揭示了许多先前显示与真核生物中假定的染色体复制起始区域相关的模块化元件，包括DNA解旋元件、支架相关区域和嘧啶序列。
