Related Experiment Videos
Genomic structure and expression analysis of the gene encoding a silkworm basic Kunitz-type chymotrypsin inhibitor
Ningjia He1, Masatoshi Yakiyama, Hiroshi Fujii
1Institute of Insect Genetic Resources, Graduate School of Bioresource and Bioenvironmental Science, Kyushu University, 6-10-1, Hakozaki, Fukuoka 812-8581, Higashi, Japan.
Biochimica Et Biophysica Acta
|July 10, 2003
Summary
The silkworm Bombyx mori CIb1 gene, encoding a chymotrypsin inhibitor, is regulated transcriptionally. Its expression is tissue-specific and responds to immune challenges, suggesting a role in insect immunity.
Area of Science:
- Molecular Biology
- Insect Genetics
- Biochemistry
Background:
- The Kunitz-type chymotrypsin inhibitor CIb1 in Bombyx mori is a 62-amino acid peptide.
- Understanding the transcriptional regulation of CIb1 gene expression is crucial.
Purpose of the Study:
- To clone and analyze the genomic structure of the CIb1 gene.
- To identify regulatory elements in the 5'-flanking region.
- To investigate the transcriptional regulation and tissue-specific expression of CIb1.
Main Methods:
- Cloning of the CIb1 gene using BAC sub-library screening.
- DNA sequencing to determine gene structure and identify regulatory motifs.
- Southern and Northern blot analyses to assess gene copy number and expression patterns.
- Analysis of gene expression in response to immune stimuli (LPS and E. coli).
Main Results:
- The CIb1 gene comprises three exons separated by two introns.
- Consensus TATA and CCAAT boxes, along with binding sites for various transcription factors (NF-kappaB, GATA, C/EBP, etc.), were identified in the 5'-flanking region.
- Southern blot indicated a single CIb1 gene copy.
- Northern blot revealed tissue-specific expression in fat body, ovary, trachea, and skin, and demonstrated transcriptional regulation during development.
- CIb1 transcript levels fluctuated upon LPS and E. coli injection, confirming its role as an immune-responsive gene.
Conclusions:
- The CIb1 gene structure and regulatory elements suggest complex transcriptional control.
- CIb1 exhibits developmental and tissue-specific expression patterns.
- The gene's response to immune challenges highlights its significance in the silkworm's immune system.
- Further investigation into the identified transcription factors is warranted to elucidate CIb1's physiological role in hemolymph.