Back to Search
Start Over
Sequence of a cDNA and expression of the gene encoding epidermal and gut chitinases of Manduca sexta
- Source :
- Insect Biochemistry and Molecular Biology. 23:691-701
- Publication Year :
- 1993
- Publisher :
- Elsevier BV, 1993.
-
Abstract
- Insects use chitinolytic enzymes to digest chitin in the exoskeleton during the molting process. We have isolated and sequenced a chitinase-encoding cDNA from the tobacco hornworm, Manduca sexta, compared its sequence with genes encoding chitinolytic enzymes from other sources, and studied chitinase gene expression and hormonal regulation during the larval-pupal transformation. The insert DNA in this clone is 2452 nucleotides long with an open reading frame of 1662 nucleotides that encodes a protein of 554 amino acids with a molecular weight of 62 kDa. Several regions of the amino acid sequence in this protein are similar to sequences in yeast, cucumber and bacterial endo-beta-N-acetylglucosaminidases. Hybrid-selection of mRNA and in vitro translation yielded an immunoreactive protein with an apparent molecular mass of 75 kDa, which is similar to the size of a chitinase present in pharate pupal molting fluid. Southern blot analysis indicated that one or two genes related to the cDNA clone are encoding chitinases in the Manduca genome. The major tissues expressing chitinase genes were the epidermis and gut with mRNA levels highest on c. days 5-7 during the fifth larval instar. Injection of 20-hydroxyecdysone into ligated fifth instar abdomens caused about a 10-fold increase in mRNA levels in both epidermis and gut, and topical application of the juvenile hormone mimic, fenoxycarb, suppressed the ecdysteroid-induced accumulation of chitinase RNA.
- Subjects :
- animal structures
Transcription, Genetic
Molecular Sequence Data
Gene Expression
Genes, Insect
Moths
Biochemistry
Complementary DNA
Gene expression
Animals
Amino Acid Sequence
RNA, Messenger
Cloning, Molecular
Molecular Biology
Peptide sequence
Gene
Base Sequence
biology
Chitinases
fungi
DNA
biology.organism_classification
Open reading frame
Manduca sexta
Insect Hormones
Larva
Multigene Family
Insect Science
Chitinase
biology.protein
Epidermis
Manduca
Digestive System
Subjects
Details
- ISSN :
- 09651748
- Volume :
- 23
- Database :
- OpenAIRE
- Journal :
- Insect Biochemistry and Molecular Biology
- Accession number :
- edsair.doi.dedup.....dd699d295147b18f5c62093781deff87