Serial polygyny in the primitively eusocial wasp Ropalidia marginata: implications for the evolution of sociality

Social insects usually live in colonies comprising one or a small number of reproductive individuals and a few or large number of sterile individuals. In termites only, both sexes are represented among the reproductives as well as among the sterile workers. In other social insects, namely ants, bees, and wasps, males do not participate significantly in the social life of colonies, which involves primarily the fertile queens and sterile female workers (Wilson 1971). The haplodiploid genetic system found universally in the Hymenoptera creates an asymmetry in genetic relatedness such that a female is more closely related to her full sister (coefficient of genetic relatedness, r = 0.75) than to her offspring (r = 0.5). This makes inclusive fitness theory (Hamilton, 19640, b) particularly applicable to the evolution of sterile worker castes in the social hymenoptera (Wilson 1971; Hamilton 1972)

Antimicrobial peptides from the Asian harvester ants of the genus <i>Monomorium</i>: <i>In vitro</i> screening for antimicrobial activity

50-55Insect antimicrobial peptides (AMPs) have received considerable attention in the last two decades as potential scaffolds for synthetic antimicrobial compounds with wide ranging applications. Among insects, the hymenopterans comprising of ants, wasps and bees are well known for their extraordinary diversity of chemical defenses. In the present study, three species of ants of the genus Monomorium (Hymenoptera: Formicidae) were screened for their antimicrobial peptides. The whole body extracts of worker ants were prepared using polar solvents and screened for antimicrobial activity against standard bacterial strains. Active crude extracts were subjected to fractionation using RP-HPLC to generate the peptide profile of the extracts. Peptides ranging in mass from 500 Da to 3500 Da were identified using MALDI-TOF analysis. The three species of ants used in this study were found to be a promising source for bioprospecting antimicrobial peptides

Combined Electron Transfer Dissociation-Collision-Induced Dissociation Fragmentation in the Mass Spectrometric Distinction of Leucine, Isoleucine, and Hydroxyproline Residues in Peptide Natural Products

Distinctions between isobaric residues have been a major challenge in mass spectrometric peptide sequencing. Here, we propose a methodology for distinction among isobaric leucine, isoleucine, and hydroxyproline, a commonly found post-translationally modified amino acid with a nominal mass of 113 Da, through a combined electron transfer dissociation-collision-induced dissociation approach. While the absence of c and z(center dot) ions, corresponding to the Yyy-Xxx (Xxx = Leu, Ile, or Hyp) segment, is indicative of the presence of hydroxyproline, loss of isopropyl (Delta m = 43 Da) or ethyl radicals (Delta m = 29 Da), through collisional activation of z(center dot) radical ions, are characteristic of leucine or isoleucine, respectively. Radical migration processes permit distinctions even in cases where the specific e ions, corresponding to the Yyy-Leu or -Ile segments, are absent or of low intensity. This tandem mass spectrometric (MSn) method has been successfully implemented in a liquid chromatography MSn platform to determine the identity of 23 different isobaric residues from a mixture of five different peptides. The approach is convenient for distinction of isobaric residues from any crude peptide mixture, typically encountered in natural peptide libraries or proteomic analysis

Combined Electron Transfer Dissociation–Collision-Induced Dissociation Fragmentation in the Mass Spectrometric Distinction of Leucine, Isoleucine, and Hydroxyproline Residues in Peptide Natural Products

Distinctions between isobaric residues have been a major challenge in mass spectrometric peptide sequencing. Here, we propose a methodology for distinction among isobaric leucine, isoleucine, and hydroxyproline, a commonly found post-translationally modified amino acid with a nominal mass of 113 Da, through a combined electron transfer dissociation–collision-induced dissociation approach. While the absence of <i>c</i> and <i>z</i>^<i>•</i> ions, corresponding to the Yyy-Xxx (Xxx = Leu, Ile, or Hyp) segment, is indicative of the presence of hydroxyproline, loss of isopropyl (Δ<i>m</i> = 43 Da) or ethyl radicals (Δ<i>m</i> = 29 Da), through collisional activation of <i>z</i> radical ions, are characteristic of leucine or isoleucine, respectively. Radical migration processes permit distinctions even in cases where the specific <i>z</i>^<i>•</i> ions, corresponding to the Yyy–Leu or −Ile segments, are absent or of low intensity. This tandem mass spectrometric (MS^<i>n</i>) method has been successfully implemented in a liquid chromatography–MS^<i>n</i> platform to determine the identity of 23 different isobaric residues from a mixture of five different peptides. The approach is convenient for distinction of isobaric residues from any crude peptide mixture, typically encountered in natural peptide libraries or proteomic analysis