Effect Of Copy Numbers Of Insect-Resistant Gene On Protein Expression And Inheritance In Trangegic Cotton

The introduction of transgenic insect-resistant cotton is expected to reduce environmental pollution from synthetic insecticides, and improve economic benefits for cotton producing. However widespread adoption of insect-resistant varieties will impose strong selection on insect population for more adapted genotypes and may eventually lead to insect population resistant to the Cry1A protein. Once insect pruduce resistance, the insect-resistant cotton wouldn't be continued to adopt. The birth of transgenic cotton harboring double-gene (cry1A+cpti) provides a new way for settling the problem and decrease the possibility insect resistant to the Cry1A insecticidal proteins, extend using time. but it was found that segregation in the progenies derived from several transgenic plants. The question was been discussed in many references. What's the cause? Do the two insecticidal genes express synchronously? Aimed at the questions, it was studied. The content and results as follow: PCR was used to analyze the first group material of R7 divided from different lines of transgenic cotton harboring double-gene. It was demonstrated that the two foreign genes of cry1A and cpti by the way of pollen-tube pathway mediated have been inserted to the genome of cotton. At the same time, Southern blotting was used to detect the copy numbers of the two genes and their proteins concentration in different lines was measured by the way of ELISA. As a result, the two genes of cry1A and cpti can't express synchronously and variation from the mole numbers was instability apparently. However, their expression kept uniform in different stages. It was high before bloom but declined rapidly when blooming and increased after bloom. It could be concluded that the environment factors influenced the gene expression. The report about the result hasn't been seen by far and the studies on the content also were few. PCR was used to analyze the second group of material from different selfed generation of the transgenic "SGK zhong 23"line. It was demonstrated that the foreign genes of cry1A by the way of pollen-tube pathway mediated have been inserted to the genome of cotton. At the same time, Southern blotting was used to detect the copy numbers of the different generations. It was concluded that there was at least one copy of 4.7kb can be inherited stably in the line. The resistant of insect was observed in field. As a result, segregation in most of the...