Analysis of the Integration Site of Exogenous Gene in Transgenic Maize

doi:10.13560/j.cnki.biotech.bull.1985.2018-0756

Abstract

Abstract: Maize（Zea mays）is the largest crop in China and plays a key role in ensuring food security. Development of transgenic maize varieties with resistance to diseases and insects may effectively reduce the loss of maize yield. In the process of transgenic maize development,it is necessary to analyze the integration sites of exogenous genes,which will provide important basis for the safety evaluation of transgenic maize. In this study,the integration sites and flanking sequences of exogenous genes in a transgenic maize event IE34were analyzed using thermal asymmetric PCR（TAIL-PCR）and genetic mapping. A segment of maize genomic sequence with 776 bp was obtained using TAIL-PCR,and an event-specific PCR method for the transgenic maize was established with the specific primers in the flanking sequences and upstream sequences of exogenous genes. Sequence BLAST in MaizeGDB showed that the flanking sequence was repeat sequence and hit the locus in several chromosomes. To further confirm the integration chromosome of exogenous gene,a F₂ population was generated by crossing IE34 with maize inbred line B73. BSR-Seq analysis results demonstrated that the exogenous gene was located in the interval of 2.32-2.70 Mb on the short arm of chromosome 5. Further,fine mapping results reduced the integration sites of exogenous genes to a 260 kb region of 2.35-2.61 Mb on chromosome 5. The results of this study suggest that,for the transgenic event with complex integration site,combined TAIL-PCR and genetic mapping may effectively identify the integration sites of exogenous genes.

Key words: transgenic maize, exogenous gene, integration site, TAIL-PCR

WANG Cui-yun, LIU Yan, LIU Yun-jun. Analysis of the Integration Site of Exogenous Gene in Transgenic Maize[J]. Biotechnology Bulletin, 2019, 35(3): 1-5.

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