Approaches to half-tetrad analysis in bacteria: Recombination between repeated, inverse-order chromosomal sequences

A. M. Segall, J. R. Roth

Research output: Contribution to journalArticle

26 Citations (Scopus)

Abstract

In standard bacterial recombination assays, a linear fragment of DNA is transferred to a recipient cell and, at most, a single selected recombinant type is recovered from each merozygote. This contrasts with fungal systems, for which tetrads allow recovery of all meiotic products, including both ultimate recombinant products of an apparent single act of recombination. We have developed a bacterial recombination system in which two recombining sequences are placed in inverse order at widely separated sites in the circular chromosome of Salmonella typhimurium. Recombination can reassort markers between these repeated sequences (double recombination and apparent gene conversion), or can exchange flanking sequences, leading to inversion of the chromosome segment between the recombining sequences. Since two recombinant products remain in the chromosome of a recombinant with an inversion, one can, in principle, approach the capability of tetrad analysis. Using this system, the following observations have been made. (a) When long sequences (40 kb) recombine, conversion frequently accompanies exchange of flanking sequences. (b) When short sequences (5 kb) recombine, conversion rarely accompanies exchange of flanks. (c) Both recA and recB mutations eliminate inversion formation. (d) The frequency of exchanges between short repeats is more sensitive to the distance separating the recombining sequences in the chromosome. The results are presented with the assumption that inversions occur by simple interaction of two sequences in the same circular chromosome. In an appendix we discuss mechanistically more complex possibilities, some of which could also apply to standard fungal systems.

Original languageEnglish (US)
Pages (from-to)27-39
Number of pages13
JournalGenetics
Volume136
Issue number1
StatePublished - 1994
Externally publishedYes

Fingerprint

Genetic Recombination
Bacteria
Chromosomes
Gene Conversion
Salmonella typhimurium
Mutation
DNA

ASJC Scopus subject areas

  • Genetics
  • Genetics(clinical)

Cite this

Approaches to half-tetrad analysis in bacteria : Recombination between repeated, inverse-order chromosomal sequences. / Segall, A. M.; Roth, J. R.

In: Genetics, Vol. 136, No. 1, 1994, p. 27-39.

Research output: Contribution to journalArticle

@article{0c37f8f57fa040bcb7de202b939b2430,
title = "Approaches to half-tetrad analysis in bacteria: Recombination between repeated, inverse-order chromosomal sequences",
abstract = "In standard bacterial recombination assays, a linear fragment of DNA is transferred to a recipient cell and, at most, a single selected recombinant type is recovered from each merozygote. This contrasts with fungal systems, for which tetrads allow recovery of all meiotic products, including both ultimate recombinant products of an apparent single act of recombination. We have developed a bacterial recombination system in which two recombining sequences are placed in inverse order at widely separated sites in the circular chromosome of Salmonella typhimurium. Recombination can reassort markers between these repeated sequences (double recombination and apparent gene conversion), or can exchange flanking sequences, leading to inversion of the chromosome segment between the recombining sequences. Since two recombinant products remain in the chromosome of a recombinant with an inversion, one can, in principle, approach the capability of tetrad analysis. Using this system, the following observations have been made. (a) When long sequences (40 kb) recombine, conversion frequently accompanies exchange of flanking sequences. (b) When short sequences (5 kb) recombine, conversion rarely accompanies exchange of flanks. (c) Both recA and recB mutations eliminate inversion formation. (d) The frequency of exchanges between short repeats is more sensitive to the distance separating the recombining sequences in the chromosome. The results are presented with the assumption that inversions occur by simple interaction of two sequences in the same circular chromosome. In an appendix we discuss mechanistically more complex possibilities, some of which could also apply to standard fungal systems.",
author = "Segall, {A. M.} and Roth, {J. R.}",
year = "1994",
language = "English (US)",
volume = "136",
pages = "27--39",
journal = "Genetics",
issn = "0016-6731",
publisher = "Genetics Society of America",
number = "1",

}

TY - JOUR

T1 - Approaches to half-tetrad analysis in bacteria

T2 - Recombination between repeated, inverse-order chromosomal sequences

AU - Segall, A. M.

AU - Roth, J. R.

PY - 1994

Y1 - 1994

N2 - In standard bacterial recombination assays, a linear fragment of DNA is transferred to a recipient cell and, at most, a single selected recombinant type is recovered from each merozygote. This contrasts with fungal systems, for which tetrads allow recovery of all meiotic products, including both ultimate recombinant products of an apparent single act of recombination. We have developed a bacterial recombination system in which two recombining sequences are placed in inverse order at widely separated sites in the circular chromosome of Salmonella typhimurium. Recombination can reassort markers between these repeated sequences (double recombination and apparent gene conversion), or can exchange flanking sequences, leading to inversion of the chromosome segment between the recombining sequences. Since two recombinant products remain in the chromosome of a recombinant with an inversion, one can, in principle, approach the capability of tetrad analysis. Using this system, the following observations have been made. (a) When long sequences (40 kb) recombine, conversion frequently accompanies exchange of flanking sequences. (b) When short sequences (5 kb) recombine, conversion rarely accompanies exchange of flanks. (c) Both recA and recB mutations eliminate inversion formation. (d) The frequency of exchanges between short repeats is more sensitive to the distance separating the recombining sequences in the chromosome. The results are presented with the assumption that inversions occur by simple interaction of two sequences in the same circular chromosome. In an appendix we discuss mechanistically more complex possibilities, some of which could also apply to standard fungal systems.

AB - In standard bacterial recombination assays, a linear fragment of DNA is transferred to a recipient cell and, at most, a single selected recombinant type is recovered from each merozygote. This contrasts with fungal systems, for which tetrads allow recovery of all meiotic products, including both ultimate recombinant products of an apparent single act of recombination. We have developed a bacterial recombination system in which two recombining sequences are placed in inverse order at widely separated sites in the circular chromosome of Salmonella typhimurium. Recombination can reassort markers between these repeated sequences (double recombination and apparent gene conversion), or can exchange flanking sequences, leading to inversion of the chromosome segment between the recombining sequences. Since two recombinant products remain in the chromosome of a recombinant with an inversion, one can, in principle, approach the capability of tetrad analysis. Using this system, the following observations have been made. (a) When long sequences (40 kb) recombine, conversion frequently accompanies exchange of flanking sequences. (b) When short sequences (5 kb) recombine, conversion rarely accompanies exchange of flanks. (c) Both recA and recB mutations eliminate inversion formation. (d) The frequency of exchanges between short repeats is more sensitive to the distance separating the recombining sequences in the chromosome. The results are presented with the assumption that inversions occur by simple interaction of two sequences in the same circular chromosome. In an appendix we discuss mechanistically more complex possibilities, some of which could also apply to standard fungal systems.

UR - http://www.scopus.com/inward/record.url?scp=0028010718&partnerID=8YFLogxK

UR - http://www.scopus.com/inward/citedby.url?scp=0028010718&partnerID=8YFLogxK

M3 - Article

C2 - 8138164

AN - SCOPUS:0028010718

VL - 136

SP - 27

EP - 39

JO - Genetics

JF - Genetics

SN - 0016-6731

IS - 1

ER -