title: Size does matter: cre-mediated somatic deletion efficiency depends on the distance between the target lox-sites.
abstract: Cre/lox recombination in vivo has become an important tool to induce chromosomal rearrangements like deletions. Using a combination of Ds transposition and Cre/lox recombination in two independent experiments on chromosomes 6 and 7 of tomato, two sets of somatic deletions up to a size of 200 kb were obtained. The efficiency of somatic deletion decreased with increasing deletion size. The largest germinally transmitted deletion had a size of only 55 kb. The results show that Cre-mediated deletion in somatic cells is less efficient when the lox sites are separated over larger distances. A further drop of the deletion efficiency after germinal transmission of the larger deletions can be explained by the probable loss of genes that are of vital importance to gametophyte function. Plasmid rescue of an 8.4 kb circularised deleted DNA showed that the Cre-mediated deletion takes place in tomato as expected. Since the circular Cre-deleted DNA could only be PCR amplified in plant cells where the deletion was not complete, the double-stranded DNA circle is assumed to be instable.
authors.affiliation: Department of Genetics, Faculty of Earth and Life Sciences, Institute for Molecular Cell Biology, Experimental, Vrije Universiteit, De Boelelaan 1087, 1081, HV Amsterdam, The Netherlands. eric.coppoolse@wur.nl
authors.forename: Eric R
authors.initials: ER
authors.lastname: Coppoolse
authors.forename: Marianne J
authors.initials: MJ
authors.lastname: de Vroomen
authors.forename: Femke
authors.initials: F
authors.lastname: van Gennip
authors.forename: Bart J M
authors.initials: BJ
authors.lastname: Hersmus
authors.forename: Mark J J
authors.initials: MJ
authors.lastname: van Haaren
mesh_terms: D001665:Binding Sites / Q000235:genetics; D002872:Chromosome Deletion; D002874:Chromosome Mapping; D032461:Chromosomes, Plant / Q000235:genetics*; D003433:Crosses, Genetic; D004251:DNA Transposable Elements / Q000235:genetics; D018744:DNA, Plant / Q000737:chemistry / Q000235:genetics; D019426:Integrases / Q000235:genetics* / Q000378:metabolism; D018551:Solanum lycopersicum / Q000235:genetics / Q000254:growth & development; D009690:Nucleic Acid Conformation; D011995:Recombination, Genetic / Q000235:genetics; D014764:Viral Proteins / Q000235:genetics* / Q000378:metabolism
chemical_list: D004251:DNA Transposable Elements; D018744:DNA, Plant; D014764:Viral Proteins; C045073:Cre recombinase; D019426:Integrases