Location: Southern Insect Management Research Unit
2011 Annual Report
Objective 2: Determine gene flow and migration patterns by analyzing tobacco budworm and bollworm populations in temporal and spatial scales using genetic and/or empirical/mathematical approaches.
Objective 3: Identify possible mechanisms of resistance to Bt toxins by profiling gene expression patterns and develop a marker based genetic linkage map.
Transcriptome of tobacco budworm was assembled using over 20 million nucleotide sequence reads. All nucleotide reads and assemblies were submitted to public databases. Glass slide microarrays containing 44,000 features were developed using curated transcriptome sequences. BW transcriptome sequencing using Roche 454 and Illumina platforms was completed. Assembly and bioinformatic analyses were performed to identify expressed genes in the transcriptome assembly. Nucleotide sequence reads were re-assembled (overlaid) using curated reference gene sequences to identify single nucleotide polymorphisms. Nucleotide reads and assemblies of tobacco budworm and bollworm were submitted to public databases. Primary cell cultures generated from susceptible YDK strain and resistant KCB and CXC strains of tobacco budworm were treated with Cry1Ac and Cry2Ab toxins. Treated and control cells were harvested and total RNA and proteins were extracted. RNA extractions are being used in RNA-Seq based gene expression profiling experiments. Protein fractions were subjected to two-dimensional differential gel electrophoresis to identify differentially expressed proteins. The protein spots identified were excised from the genes and were submitted to a core facility for mass spectrometry based determination of amino acid sequences. Laboratory screening of bollworm larvae collected from transgenic corn plants was initiated to select a bollworm line resistant to Cry1Ac. Bollworm larvae collected from various field sites were used to establish laboratory strains to obtain genetic material for mapping studies.
Jurat-Fuentes, J., Karumbahiah, L., Jakka, S.K., Ning, C., Liu, C., Wu, K., Jackson, J., Gould, F., Blanco, C., Portilla, M., Perera, O.P., Adang, M.J. 2011. Reduced levels of membrane-bound alkaline phosphatase are common to lepidopteran strains resistant to Cry toxins from Bacillus thuringiensis. PLoS One. 6:e17606.
Hardke, J., Leonard, R., Huang, F., Jackson, R.E. 2011. Damage and survivorship of fall armyworm (Lepidoptera: Noctuidae) on transgenic field corn expressing Bacillus thuringiensis cry proteins. Crop Protection Journal. 30(2):168-172.
Blanco, C., Portilla, M., Jurat-Fuentes, J., Sanchez, J.F., Viteri, D., Vega-Aquin, P., Teran-Vargas, A.P., Azuara-Dominguez, A., Lopez, J., Arias De Ares, R.S., Zhu, Y., Barrera, D., Jackson, R.E. 2010. Susceptibility of Spodoptera frugiperda (Lepidoptera: noctuidae) isofamilies to Cry1Ac and Cry1F proteins of Bacillus thuringiensis. Southwestern Entomologist. 35(3):409-415.