Midgut-specific immune molecules are produced by the blood-sucking insect Stomoxys calcitrans
AUTOR(ES)
Lehane, Michael J.
FONTE
The National Academy of Sciences of the USA
RESUMO
We have cloned and sequenced two defensins, Smd1 and Smd2, from anterior midgut tissue of the blood-sucking fly Stomoxys calcitrans. The DNA and N-terminal protein sequences suggest both are produced as prepropeptides. Smd1 differs from the classic defensin pattern in having an unusual six-amino acid-long N-terminal sequence. Both Smd1 and Smd2 have lower pI points and charge than insect defensins derived from fat body/hemocytes. Northern analysis shows both of these defensin molecules are tissue specific; both are produced by the anterior midgut tissue and, unlike the other insect defensins reported to date, neither appears to be expressed in fat body or hemocytes. Northern analysis also shows that mRNAs for both defensins are constitutively produced in the anterior midgut tissues and that these transcripts are up-regulated in response to sterile as well as a lipopolysaccharide-containing blood meal. However, anti-Gram-negative biological activity in the midgut is substantially enhanced by lipopolysaccharide. These findings suggest that the insect midgut has its own tissue-specific immune mechanisms and that this invertebrate epithelium is, like several vertebrate epithelia, protected by specific antibacterial peptides.
ACESSO AO ARTIGO
http://www.pubmedcentral.nih.gov/articlerender.fcgi?artid=23519Documentos Relacionados
- Unconsidered Factors in Disease Transmission by Blood-Sucking Insects. Frederick Knab
- Conserved function of anopheles gambiae midgut-specific promoters in the fruitfly.
- Cultivation of Rickettsia-like Microörganisms from Certain Blood-sucking Pupipara
- Effect of sequential heat and cold shocks on nuclear phenotypes of the blood-sucking insect, Panstrongylus megistus (Burmeister) (Hemiptera, Reduviidae)
- Isolation of Bartonella schoenbuchensis from Lipoptena cervi, a Blood-Sucking Arthropod Causing Deer Ked Dermatitis