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United States Department of Agriculture

Agricultural Research Service

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2011 Annual Report

1a. Objectives (from AD-416)
Sequencing and profiling of functional transcripts constructed in expressed sequence tags (ESTs) of Coptotermes formosanus to fulfill the following objectives: a) Identifying and annotating of genes specifically associated with post-embryonic polyphenism (caste differentiation and development); b) Discovering of genes specifically responding to environmental cues and internal signals (pesticides, food sources, juvenile hormones, etc.); and c) Characterizing of genes uniquely involved in critical physiological pathways (digestion, molting, immunity, etc.). The fulfillment of these objectives would directly lead to achieving the following goals: a) providing biochemical/physiological/molecular bases for disruption of colony formation, development and survival; b) Discovering novel target site(s) that would be developed into new control strategies that could be incorporated into effective area-wide integrated management of Formosan subterranean termites. The overall objectives of this cooperative research are to determine genes that are unique to termites - specifically reproductive and development associated genes e.g. nymph or soldier formation mechanisms with specific emphasis on Coptotermes formosanus while also examining cellulosic material hydrolyzing enzymes for agriculture and industry. We will also concentrate on private and public database and website development strategies.

1b. Approach (from AD-416)
A cDNA library representing expressed genes in each different developmental stage of Coptotermes formosanus has been constructed. To facilitate transcriptome analysis and rare gene discovery, repeated transcripts were proportionally removed from the cDNA library using the procedure of cDNA normalization. The cDNA library would contain approximately 400,000 independent clones, an estimate of at least 16X coverage of the entire expressed genes, provided that the protein-coding capacity of invertebrate genomes is in the range of 16,000 to 25,000 genes. The sequencing and gene data assembly of the cDNA library will be cooperatively conducted in JCVI. We will continue Sanger sequencing of EST clones and perform SoLID sequencing to determine differential gene expression. EST sequences will be compared against existing databases and annotated using the Basic Local Alignment Search Tool (BLAST). Batches of sequences will be sequentially released to GenBank for public access. Unique genes and singletons would be selected and gene expression analysis. Differentially-expressed genes or development-stage specific genes will be preferentially analyzed quantitatively (such as real-time PCR) or qualitatively (such as gene silencing by RNA interference).

3. Progress Report
In 2010, J. Craig Venter Institute (JCVI) completed determining the sequence of a portion of the genetic material from the Formosan Subterranean Termite (FST), Coptotermes formosanus. The 132,000 cDNA (complementary deoxyribonucleic acid) sequencing reads were determined to represent 25,000 unique sequences corresponding to individual genes from the termites and microorganisms living in the termite gut. Furthermore, JCVI initiated next generation sequencing of the genome of the FST. Thus far, 18-fold coverage has been thus far obtained and 80-fold coverage of the genome is expected by the end of July 2011. We expect to annotate the termite genome and compare it with that of the native subterranean termite Reticulitermes flavipes in order to further understand caste differentiation and development and provide information on cellulose digestion useful in cellulosic biofuel production. Our planned strategy is to characterize all individual stages of the termite to perform analysis of 7 individual termite stages and identify genes that may regulate processes associated with differentiation in order to determine possible biologically-based control measures for the termite. Progress in this project is monitored through Annual FST Technical Committee Meetings, reports, regular meetings with cooperators, routine phone calls, and e-mail correspondence.

4. Accomplishments

Last Modified: 07/25/2017
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