There are currently 402 studies in the GENERA database.

Advanced Search

General Information

Document type
  • Peer-reviewed journal article
GE organism
  • cotton
GE trait
  • marker
Country
  • Singapore, China

Transgene integration and organization in cotton (Gossypium hirsutum L.) genome

Zhang, J; Cai, L; Cheng, J; Mao, H; Fan, X; Meng, Z; Chan, KM; Zhang, H; Qi, J; Ji, L; Hong, Y
Transgenic Research. 2008 April. 17(2):293-306

Link to full text (journal may charge for access)

PMID: 17549600 DOI: 10.1007/s11248-007-9101-3 ISSN: 0962-8819

Abstract

While genetically modified upland cotton (Gossypium hirsutum L.) varieties are ranked among the most successful genetically modified organisms (GMO), there is little knowledge on transgene integration in the cotton genome, partly because of the difficulty in obtaining large numbers of transgenic plants. In this study, we analyzed 139 independently derived T0 transgenic cotton plants transformed by Agrobacterium tumefaciens strain AGL1 carrying a binary plasmid pPZP-GFP. It was found by PCR that as many as 31% of the plants had integration of vector backbone sequences. Of the 110 plants with good genomic Southern blot results, 37% had integration of a single T-DNA, 24% had two T-DNA copies and 39% had three or more copies. Multiple copies of the T-DNA existed either as repeats in complex loci or unlinked loci. Our further analysis of two T1 populations showed that segregants with a single T-DNA and no vector sequence could be obtained from T0 plants having multiple T-DNA copies and vector sequence. Out of the 57 T-DNA/T-DNA junctions cloned from complex loci, 27 had canonical T-DNA tandem repeats, the rest (30) had deletions to T-DNAs or had inclusion of vector sequences. Overlapping micro-homology was present for most of the T-DNA/T-DNA junctions (38/57). Right border (RB) ends of the T-DNA were precise while most left border (LB) ends (64%) had truncations to internal border sequences. Sequencing of collinear vector integration outside LB in 33 plants gave evidence that collinear vector sequence was determined in agrobacterium culture. Among the 130 plants with characterized flanking sequences, 12% had the transgene integrated into coding sequences, 12% into repetitive sequences, 7% into rDNAs. Interestingly, 7% had the transgene integrated into chloroplast derived sequences. Nucleotide sequence comparison of target sites in cotton genome before and after T-DNA integration revealed overlapping microhomology between target sites and the T-DNA (8/8), deletions to cotton genome in most cases studied (7/8) and some also had filler sequences (3/8). This information on T-DNA integration in cotton will facilitate functional genomic studies and further crop improvement.

Keywords

Transgene, Cotton (Gossypium hirsutum L.), Agrobacterium-mediated transformation, Transgene/plant genome junctions, Transgene repeats, Vector backbone integration

Funding

Funding source
  • Temasek Life Sciences Laboratory, Singapore
Funding country
  • China
Funding type
  • NGO: independent

Links to outside analysis of this resource

Please contact us if you know of an independent summary or analysis of this resource.

Cite this study

MLA

Zhang, J, L Cai, J Cheng, H Mao, X Fan, Z Meng, KM Chan, H Zhang, J Qi, L Ji, Y Hong. "Transgene integration and organization in cotton (Gossypium hirsutum L.) genome." Transgenic Research 17.2 (2008): 293-306. Web. 11 Dec. 2018.

APA

Zhang, J., Cai, L., Cheng, J., Mao, H., Fan, X., Meng, Z., Chan, KM., Zhang, H., Qi, J., Ji, L., & Hong, Y. (2008). Transgene integration and organization in cotton (Gossypium hirsutum L.) genome. Transgenic Research, 17(2), 293-306. doi:10.1007/s11248-007-9101-3

Please verify citations before use, citations are automatically generated based on information stored within the GENERA database and therefore may or may not be correct.