title: The discovery and analysis of a diverged family of novel antifungal moricin-like peptides in the wax moth Galleria mellonella.
abstract: Screening for components with antifungal activity in the hemolymph of immune-stimulated Galleria mellonella larvae led to the identification of four novel moricin-like peptides (A, B, C3 and D). Subsequently, eight moricin-like peptide genes (A, B, C1-5 and D) were isolated and shown to code for seven unique peptides (mature C4 and C5 are identical). These genes contained single introns which varied from 180 to 1090bp. The moricin-like peptides were particularly active against filamentous fungi, preventing the growth of Fusarium graminearum at 3 microg/ml, and were also active against yeasts, gram positive bacteria and gram negative bacteria. Searches of the databases identified 30 moricin-like peptide genes which code for 23 unique mature peptides, all belonging to the Lepidoptera (moths and butterflies). The first comprehensive phylogenetic analysis of the moricin-like peptides suggested that they fall into two basic classes which diverged a long time ago. The peptides have since diversified extensively through a high level of gene duplication within species, as seen in G. mellonella and Bombyx mori. The restriction of moricin-like peptides to the Lepidoptera combined with their potent antifungal activity suggests that this diverse peptide family may play a role in the defence response of moths and butterflies.
authors.affiliation: CSIRO Entomology, GPO Box 1700, Acton, ACT 2601, Australia. sue.brown@csiro.au
authors.forename: Susan E
authors.initials: SE
authors.lastname: Brown
authors.forename: Antoinette
authors.initials: A
authors.lastname: Howard
authors.forename: Annette B
authors.initials: AB
authors.lastname: Kasprzak
authors.forename: Karl H
authors.initials: KH
authors.lastname: Gordon
authors.forename: Peter D
authors.initials: PD
authors.lastname: East
mesh_terms: D000595:Amino Acid Sequence; D000818:Animals; D000935:Antifungal Agents / Q000302:isolation & purification*; D023181:Antimicrobial Cationic Peptides / Q000235:genetics / Q000302:isolation & purification*; D019143:Evolution, Molecular; D006458:Hemolymph / Q000737:chemistry; D054884:Host-Pathogen Interactions / Q000235:genetics / Q000276:immunology; D008826:Microbial Sensitivity Tests; D008969:Molecular Sequence Data; D009036:Moths / Q000737:chemistry* / Q000235:genetics / Q000276:immunology; D005810:Multigene Family; D017386:Sequence Homology, Amino Acid
chemical_list: D000935:Antifungal Agents; D023181:Antimicrobial Cationic Peptides