Genetic transfer and linkage mapping in bacteria: Transduction

Question 1

Transduction

Answer 1

Movement of genetic material via a viral intermediate

Question 2

Bacteriophage (or ‘phage’)

Answer 2

Bacterial viruses

Question 3

Generalised transduction

Answer 3

Movement of genes from anywhere in chromosome of donor in a recipient strain

• Integrated into chromosomes by homologous recombination

Question 4

P1 vir

Answer 4

Lytic mutant of phage P1
- when it replicates - inserts DNA into chromosome
- Most of P1 phage capsids produced during replication of phage

Question 5

Transducing particles

Answer 5

P1 packing machinery is sloppy and can package some of host chromosome
- These cannot make new phage
- Process is almost random
- 1 in 100 bacteriophage P1 virions

Question 6

How many base pairs can a P1 capsid fit?

Answer 6

90-100 kbp (~2’) of E.coli

Question 7

Transducing particle

Answer 7

• Can infect a new host can recombine to host chromosome
• Genes that are < 2’ apart can cotransduced in same transducing particle
• Frequency is based on distance