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1.
Phytochemistry ; 68(4): 521-35, 2007 Feb.
Article in English | MEDLINE | ID: mdl-17222873

ABSTRACT

Pea albumin 1b (PA1b) is a small sulphur-rich peptide from pea seeds, also named leginsulin because of the binding characteristics of its soybean orthologue. Its insecticidal properties were discovered more recently. By using a combination of molecular, biochemical and specific insect bioassays on seed extracts, we characterised genes from numerous Papilionoideae, but not from Caesalpinioideae or Mimosoideae, although the last group harboured species with partially positive cues (homologous biological activities). The A1b defence peptide family, therefore, appears to have evolved relatively late in the legume lineage, maybe from the sophoroid group (e.g. Styphnolobium japonicum). However, unambiguous sequence information is restricted to a group of tribes within the subfamily Papilionoideae (Psoraleae, Millettieae, Desmodieae, Hedysareae, Phaseoleae, Vicieae, and the now clearly polyphyletic "Trifolieae" and "Galegeae"). Recent diversification by gene duplications has occurred in many species, or longer ago in some lineages (Medicago truncatula), as well as probable gene or expression losses at different taxonomic levels (Loteae, Vigna subterranea).


Subject(s)
Fabaceae/genetics , Genetic Variation , Plant Proteins/toxicity , Seeds/physiology , Amino Acid Sequence , Biological Assay , Cloning, Molecular , Fabaceae/classification , Insecticides , Molecular Sequence Data , Pisum sativum/genetics , Phylogeny , Plant Proteins/chemistry , Plant Proteins/genetics
2.
Oecologia ; 149(3): 428-43, 2006 Sep.
Article in English | MEDLINE | ID: mdl-16794834

ABSTRACT

Because of their particular biology, seed beetles exhibit a strong relationship with their larval host plants. In Europe, however, field data have long been scarce and unreliable. The results of Legume seed collections of nearly 1,000 samples belonging to 292 species from various locations in Europe are summarized. The status of current Bruchidius species groups is amended on morphological and phylogenetic bases. Recent advances in the knowledge of phylogenetic structures of both Fabaceae and Bruchinae provide a new picture of Bruchinae-Fabaceae interactions. It reveals a certain level of host conservatism. The hypothesis of radiative adaptation seems the most compatible with observed data.


Subject(s)
Adaptation, Physiological , Coleoptera/physiology , Diet , Feeding Behavior , Animals , Coleoptera/anatomy & histology , Coleoptera/classification , Europe , Genetic Speciation , Genitalia, Male/anatomy & histology , Larva/classification , Larva/physiology , Male , Phylogeny , Plants/classification , Seeds/classification , Species Specificity
3.
Arch Insect Biochem Physiol ; 60(2): 84-92, 2005 Oct.
Article in English | MEDLINE | ID: mdl-16175535

ABSTRACT

Improvement of an existing meat-based diet has been obtained for rearing the generalist predator Dicyphus tamaninii (Heteroptera: Miridae). The approach followed, different from the classical addition/deletion method, was performing biochemical analysis of adult carcasses in order to have information about the nutritional status of the predator. Comparison of total, free amino acids and lipid composition of meat-reared and conventionally reared females allowed detecting some nutritional deficiencies. A reformulated diet with new sources of proteins and lipids was tested again with the predator. Some biological parameters of bugs that were inferior in the initial meat diet when compared with those of the conventionally reared insects, such as nymphal development time and fresh weight, have been improved with the reformulated diet.


Subject(s)
Animal Feed , Diet/veterinary , Heteroptera/anatomy & histology , Heteroptera/chemistry , Meat , Amino Acids/analysis , Animals , Eggs , Fatty Acids/analysis , Female , Lepidoptera , Nymph/physiology , Predatory Behavior , Nicotiana
4.
Mol Biol Evol ; 21(6): 965-73, 2004 Jun.
Article in English | MEDLINE | ID: mdl-14739242

ABSTRACT

Intracellular symbiosis is widespread in the insect world where it plays an important role in evolution and adaptation. The weevil family Dryophthoridae (Curculionoidea) is of particular interest in intracellular symbiosis evolution with regard to the great economical and ecological features of these invasive insects, and the potential for comparative studies across a wide range of host plants and environments. Here, we have analyzed the intracellular symbiotic bacteria of 19 Dryophthoridae species collected worldwide, representing a wide range of plant species and tissues. All except one (Sitophilus linearis) harbor symbiotic bacteria within specialized cells (the bacteriocytes) assembled as an organ, the bacteriome. Phylogenetic analysis of the 16S rDNA gene sequence of the Dryophthoridae endosymbionts revealed three endosymbiotic clades belonging to gamma3-Proteobacteria and characterized by different GC contents and evolutionary rate. The genus name Candidatus Nardonella was proposed for the ancestral clade infesting Dryophthoridae 100 MYA and represented by five of nine bacterial genera studied. For this clade showing low GC content (40.5% GC) and high evolutionary rate (0.128 substitutions/site per 100 Myr), a single infection and subsequent cospeciation of the host and the endosymbionts was observed. In the two other insect lineage endosymbionts, with relatively high GC content (53.4% and 53.8% GC), competition with ancestral pathogenic bacteria might have occurred, leading to endosymbiont replacement in present-day last insects.


Subject(s)
Gammaproteobacteria/genetics , Phylogeny , Symbiosis , Weevils/microbiology , Animals , Base Composition , Base Sequence , DNA Primers , DNA, Ribosomal/genetics , Evolution, Molecular , In Situ Hybridization, Fluorescence , Likelihood Functions , Models, Genetic , Molecular Sequence Data , Sequence Analysis, DNA , Species Specificity
5.
Arch Insect Biochem Physiol ; 52(2): 81-91, 2003 Feb.
Article in English | MEDLINE | ID: mdl-12529863

ABSTRACT

The predatory coccinellid Harmonia axyridis is a polyphagous species, efficient at controlling certain aphid species and already commercialized in Europe for that purpose. The complete development of this predator can be accomplished using the aphid Acyrthosiphon pisum or Ephestia kuehniella eggs as substitution prey. Biochemical analyses were conducted on the proteins, lipids, and carbohydrates of these two different prey species. E. kuehniella eggs were 2 times richer in amino acids than A. pisum adults (12% of the fresh weight vs. 6%). E. kuehniella eggs were 3 times richer in lipids than the aphids but, on the contrary, the aphids were 1.5 times richer in glycogen. The impact of these two kinds of food on the body composition of the coccinellid was evaluated to appreciate the degree of nutritional plasticity of the coccinellid. The composition of the coccinellids feeding either on E. kuehniella eggs or on aphids was compared for amino acid, fatty acid and glycogen contents, revealing a good capability of H. axyridis to develop on foods that are very different in their biochemical composition. Nevertheless, when fed on aphids, the crude protein content of the predator was reduced and the lipid content decreased by a factor of two, with a change in amino and fatty acid patterns. Some biological parameters, such as larval mortality, adult weight, and fecundity, were modified according to the food eaten.


Subject(s)
Animal Nutritional Physiological Phenomena , Coleoptera/physiology , Predatory Behavior , Adaptation, Physiological , Amino Acids/metabolism , Animals , Aphids , Coleoptera/metabolism , Female , Fertility , Glycogen/metabolism , Lipid Metabolism , Molting , Moths , Ovum , Species Specificity
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