Disease relevance of CecB

• The cecropin genes were also induced when the flies were kept on food with the Drosophila pathogenic bacterium Serratia marcescens Db10 or its non-pathogenic derivative Db1140 [1].

High impact information on CecB

• CecA1 and A2 are most active in larvae and adults; CecB is preferentially active in early pupae [2].
• The genes are strongly expressed in fat body and hemocytes after injection of bacteria, the CecA genes being much more active than CecB in the fat body [2].
• The cecropin locus in Drosophila; a compact gene cluster involved in the response to infection [1].
• A small peak of constitutive cecropin expression in early pupae appears to be caused by bacteria in the food [2].
• A useful in vitro system to study the immune response has been found in Schneider's line 2 cells which respond to lipopolysaccharide and laminarin by cecropin expression [2].

Biological context of CecB

• Molecular evolution of the Cecropin multigene family in Drosophila. functional genes vs. pseudogenes [3].
• Divergence estimates indicate that the CecPsi1 and CecPsi2 pseudogenes are highly diverged, both between themselves and relative to the other three Cec genes [3].
• These features are better explained by the birth-and-death model of molecular evolution, which posits that the high instability of the Cec multigene family in Drosophila is simply determined by the duplication rate and the subsequent loss of duplicated loci [4].
• Each cDNA encoded a translation product containing a signal peptide, a pro region, and a mature cecropin peptide consistent with amino acid sequence data from chymotryptic digests [5].
• Injection of NO donors that produce NO in vivo induced the gene expression of an antibacterial peptide, cecropin B, strongly suggesting that NO produced by BmNOS following LPS stimulation is involved in signal transduction as a signalling molecule for immune gene expression [6].

Anatomical context of CecB

• An antimicrobial peptide belonging to the cecropin family was isolated from the hemolymph of bacteria-challenged adult Aedes aegypti [7].
• Through GmmRel knock-down, we could successfully block the induction of attacin and cecropin expression in the immune responsive tissues fat body and proventriculus (cardia) following microbial challenge [8].
• Cloning and expression of three cecropin cDNAs from a mosquito cell line [5].
• In vitro induction of cecropin genes--an immune response in a Drosophila blood cell line [9].
• Of the four putative novel defence proteins (DFPs) annotated by PSI-BLAST three showed similarity to extracellular matrix proteins from vertebrates implicated in innate immunity, while the fourth was similar to, yet distinct from, the anti-microbial protein cecropin [10].

Other interactions of CecB

• Andropin is less fungicidal than the cecropins, and Drosophila cecropin A is somewhat more potent than cecropin B [11].

Analytical, diagnostic and therapeutic context of CecB

• A. aegypti cecropin mRNA expression was not detected by Northern blot or reverse transcription-polymerase chain reaction analysis in any immature stage of the mosquito, nor in naïve adults, but it was observed in challenged adults 6 h after bacteria inoculation, and it continued over 7-10 days [7].
• The chromosomal regions encompassing the Cec genes were subsequently sequenced and mapped by in situ hybridization [4].
• The existence of two cecropin isoforms that differed from the previously described AalCecA was predicted by mass spectrometry and amino acid sequence analysis of peptides that eluted from reversed phase high performance liquid chromatography as a single peak just behind the previously described cecropin, AalCecA [5].

References