细菌可以通过结合作用获得抗性,致病性和改变代谢途径。通过应用荧光蛋白融合技术SeqA-YFP,这一过程可在大肠杆菌中实时展现出来。性菌毛作为DNA媒介使之可在细胞间传递,大约96%的DNA可在受体菌中重组;其余的在细胞中被核酸酶降解。获得的完整DNA通过连续复制留下足迹,偶然情况会断裂或被染色体分隔开来,所以,不同的基因可以在细胞中复制遗传。这一技术使基因横向转移全过程展现在我们面前。(生物谷)
生物谷推荐原始出处:
Science 14 March 2008:
Vol. 319. no. 5869, pp. 1533 - 1536
DOI: 10.1126/science.1153498
Direct Visualization of Horizontal Gene Transfer
Ana Babi,1,2* Ariel B. Lindner,1,2 Marin Vuli,1,2 Eric J. Stewart,1,2 Miroslav Radman1,2,3
Conjugation allows bacteria to acquire genes for antibiotic resistance, novel virulence attributes, and alternative metabolic pathways. Using a fluorescent protein fusion, SeqA-YFP, we have visualized this process in real time and in single cells of Escherichia coli. We found that the F pilus mediates DNA transfer at considerable cell-to-cell distances. Integration of transferred DNA by recombination occurred in up to 96% of recipients; in the remaining cells, the transferred DNA was fully degraded by the RecBCD helicase/nuclease. The acquired integrated DNA was tracked through successive replication rounds and was found to occasionally split and segregate with different chromosomes, leading to the inheritance of different gene clusters within the cell lineage. The incidence of DNA splitting corresponds to about one crossover per cell generation.
1 INSERM U571, Paris F-75015, France.
2 Université Paris Descartes Faculté de Médecine, Paris F-75015, France.
3 Mediterranean Institute for Life Sciences, Metrovievo etalite bb, 21000 Split, Croatia.