The use of bioacoustic characters for distinguishing between cryptic species in insects: Potentials,restrictions, and prospects

Differences in acoustic signal patterns between closely related species often form the main precopulatory reproductive barrier in insects. For this reason, discrimination between similar forms based on their signal patterns allows one to recognize reproductively isolated species. A calling signal produced by a mature male for attracting a conspecific female is a “species ID” testifying to the fact that it belongs to the same species. This is the reason why the use of the calling signal analysis for discriminating between cryptic species or elucidating the taxonomic rank of dubious forms is highly efficient. In certain species, courtship signals also show species-specific patterns. In insect taxonomy, the study of acoustic signals is most promising in morphologically or/and ecologically heterogeneous groups. Chances that any morphologically homogeneous form will actually appear to be a complex of cryptic species are low. The degree of signal variability differs in different orders, families and even congeneric species. Therefore, in every taxon investigated for the first time, it is necessary to evaluate the limits of intraspecific variability of signals before using the acoustic characters in taxonomy. Species not involved in acoustic interactions due to allopatry, different host specialization, etc. can produce calling signals with identical patterns. Consequently, similarity in the signal structure in such species is by no means evidence of their synonymy.     

The effect of toxin-producing Fusarium fungi on behavior of the rice weevil Sitophilus oryzae (Coleoptera,Dryophthoridae)

The paper describes laboratory tests in which the behavior response of adult rice weevils Sitophilus oryzae L. to the presence of seven species of micromycetes of the genus Fusarium (F. graminearum, F. culmorum, F. cerealis, F. poae, F. sporotrichioides, F. langsethiae, and F. sibiricum; 3 strains for each species) infecting cereals was characterized. The chemicals of unkown structure, released by the fungi, can have both attractive and repellent effects on the weevils; in some cases a neutral response was observed. The strains of Fusarium species characterized as weak pathogens (F. langsethiae, F. poae, and F. sibiricum) in most cases stimulated attractive and neutral responses. Relatively strong pathogens (F. cerealis, F. culmorum, F. graminearum, and F. sporotrichioides) generally had a repellent effect. The results obtained are discussed in the context of possible relationships between Fusarium fungi and the rice weevil during their utilization of cereals as a shared food substrate.     

(2-Hydroxypropyl)-β-Cyclodextrin Is a New Angiogenic Molecule for Therapeutic Angiogenesis

BackgroundPeripheral artery disease (PAD), which is caused by atherosclerosis, results in progressive narrowing and occlusion of the peripheral arteries and inhibits blood flow to the lower extremities. Therapeutic angiogenesis is a promising strategy for treating ischemia caused by PAD. Nitric oxide (NO) has been shown to be a key mediator of angiogenesis. It has been demonstrated that β-cyclodextrincan stimulate vessel growth in rabbit corneas. In this study, we assessed the mechanism of action and therapeutic potential of a new angiogenic molecule, (2-hydroxypropyl)-β-cyclodextrin (2HP-β-CD).ConclusionsTherapeutic angiogenesis by 2HP-β-CD may be beneficial to patients with PAD.     

Splenic gene expression profiling in White Leghorn layer inoculated with the Salmonella enterica serovar Enteritidis

Salmonella enterica serovar Enteritidis (SE) is a foodborne pathogen that can threaten human health through contaminated poultry products. Live poultry, chicken eggs and meat are primary sources of human salmonellosis. To understand the genetic resistance of egg‐type chickens in response to SE inoculation, global gene expression in the spleen of 20‐week‐old White Leghorn was measured using the Agilent 4 × 44 K chicken microarray at 7 and 14 days following SE inoculation (dpi). Results showed that there were 1363 genes significantly differentially expressed between inoculated and non‐inoculated groups at 7 dpi (I7/N7), of which 682 were up‐regulated and 681 were down‐regulated genes. By contrast, 688 differentially expressed genes were observed at 14 dpi (I14/N14), of which 371 were up‐regulated genes and 317 were down‐regulated genes. There were 33 and 28 immune‐related genes significantly differentially expressed in the comparisons of I7/N7 and I14/N14 respectively. Functional annotation revealed that several Gene Ontology (GO) terms related to immunity were significantly enriched between the inoculated and non‐inoculated groups at 14 dpi but not at 7 dpi, despite a similar number of immune‐related genes identified between I7/N7 and I14/N14. The immune response to SE inoculation changes with different time points following SE inoculation. The complicated interaction between the immune system and metabolism contributes to the immune responses to SE inoculation of egg‐type chickens at 14 dpi at the onset of lay. GC, TNFSF8, CD86, CD274, BLB1 and BLB2 play important roles in response to SE inoculation. The results from this study will deepen the current understanding of the genetic response of the egg‐type chicken to SE inoculation at the onset of egg laying.     

Subunit IV (Mr = 14,384) of the cytochrome b-c1 complex from Rhodobacter sphaeroides. Cloning, DNA sequencing, and ubiquinone binding domain.

The Rhodobacter sphaeroides gene encoding subunit IV of the cytochrome b-c1 complex (fbcQ) was cloned and sequenced. The fbcQ cistron is 372 base pairs long and encodes 124 amino acid residues. The molecular mass of subunit IV, deduced from the nucleotide sequence, is 14,384 Da. A hydropathy plot of the predicted amino acid sequence revealed only one transmembrane helix; it is near the C-terminal end. The 3-azido-2-methyl-5-methoxy-6-(3,7-dimethyl[3H]octyl)-1,4-benzoquinone ([3H]azido-Q)-labeled subunit IV was isolated from the [3H]-azido-Q-treated cytochrome b-c1 complex. A ubiquinone-binding peptide was obtained by digesting the labeled subunit IV with V8 protease followed by high performance liquid chromatography separation. Amino acid analysis and partial N-terminal sequencing of this ubiquinone-binding peptide revealed that it corresponded to residues 77-124 of subunit IV. Based on the hydropathy profile and predicted tendency to form alpha-helices and beta-sheets, we propose a structural model for subunit IV. In this model the ubiquinone-binding domain is located near the surface of the membrane.