Effectiveness of recombinant soybean cysteine proteinase inhibitors against selected crop pests

Three recombinant soybean cysteine proteinase inhibitors (rSCPIs), L1, R1 and N2, were assessed for their potential to inhibit the growth and development of three major agricultural crop pests known to utilize digestive cysteine proteinases: Western corn rootworm (Diabrotica virgifera virgifera, WCR), Colorado potato beetle (Leptinotarsa decemlineata, CPB) and cowpea weevil (Callosobruchus maculatus, CW). In vitro experiments showed that cysteine proteinase activities in the crude gut extracts of the WCR, CPB, and CW were inhibited to various degrees by the three rSCPIs. Of the three rSCPIs tested, N2 was most effective in inhibiting the crude gut extract of WCR, CPB, and CW (50% inhibition at 5 x 10(-8), 5 x 10(-8), and 3 x 10(-7) M, respectively). The L1 was the least potent of the three CPIs tested, with 50% inhibition at 5 x 10(-6) M of the crude gut extracts of WCR. Results of in vivo experiments conducted to assess the effect of the three rSCPIs on the vital growth parameters of WCR, CPB and CW were consistent with results of the in vitro experiments.     

A meta-analysis of changes in bacterial and archaeal communities with time

Ecologists have long studied the temporal dynamics of plant and animal communities with much less attention paid to the temporal dynamics exhibited by microbial communities. As a result, we do not know if overarching temporal trends exist for microbial communities or if changes in microbial communities are generally predictable with time. Using microbial time series assessed via high-throughput sequencing, we conducted a meta-analysis of temporal dynamics in microbial communities, including 76 sites representing air, aquatic, soil, brewery wastewater treatment, human- and plant-associated microbial biomes. We found that temporal variability in both within- and between-community diversity was consistent among microbial communities from similar environments. Community structure changed systematically with time in less than half of the cases, and the highest rates of change were observed within ranges of 1 day to 1 month for all communities examined. Microbial communities exhibited species–time relationships (STRs), which describe the accumulation of new taxa to a community, similar to those observed previously for plant and animal communities, suggesting that STRs are remarkably consistent across a broad range of taxa. These results highlight that a continued integration of microbial ecology into the broader field of ecology will provide new insight into the temporal patterns of microbial and ‘macro''-bial communities alike.     

The effect of nutrient availability and temperature on chain length of the diatom, Skeletonema costatum

We determined the effects of temperature and nutrients on thechain length of a diatom, Skeletonema costatum, in batch cultureand enclosure experiments with estuarine water from San FranciscoBay, USA, using the recently developed CytoBuoy flow cytometer.Determination of the number of cells per diatom chain by CytoBuoyflow cytometer and associated software correlated well withbut was much more precise and time efficient than microscopicquantification. Increasing temperatures (from 6, 8 to 17°C)and nutrient concentrations induced high growth rates and dominanceby longer chains in a cultured S. costatum strain that was originallyacclimatized to a temperature range of 11–30°C. Similarly,a positive correlation between growth rate and chain lengthwas observed in S. costatum in batch culture and natural communitiesin enclosure experiments. Maximal chain lengths of S. costatumwere greater in natural populations than in the batch culture.Longer chains affect sinking rates and thus likely help thediatom remain suspended in the upper part of the water columnwhere physical and chemical parameters are more favorable forgrowth.     

Comparison of primer sets for use in automated ribosomal intergenic spacer analysis of aquatic bacterial communities: an ecological perspective

Two primer sets for automated ribosomal intergenic spacer analysis (ARISA) were used to assess the bacterial community composition (BCC) in Lake Mendota, Wisconsin, over 3 years. Correspondence analysis revealed differences in community profiles generated by different primer sets, but overall ecological patterns were conserved in each case. ARISA is a powerful tool for evaluating BCC change through space and time, regardless of the specific primer set used.     

Phylogeny of Six Genera of the Subclass Haptoria (Ciliophora,Litostomatea) Inferred from Sequences of the Gene Coding for Small Subunit Ribosomal RNA

ABSTRACT. The small subunit ribosomal RNA genes of nine species belonging to six genera of litostome ciliates, namely Amphileptus aeschtae, Chaenea teres, Chaenea vorax, Lacrymaria marina, Litonotus paracygnus, Loxophyllum sp.‐GD‐070419, Loxophyllum jini, Loxophyllum rostratum, and Phialina salinarum, were sequenced for the first time. Phylogenetic trees were constructed using different methods to assess the inter‐ and intra‐generic relationships of haptorians, of which Chaenea, Lacrymaria, Litonotus, and Phialina were analyzed for the first time based on molecular data. Monophyly of the order Pleurostomatida was strongly confirmed, and the two existing families of pleurostomatids, created on the basis of morphology, were confirmed by molecular evidence. Within the Pleurostomatida, Siroloxophyllum utriculariae occupied a well‐supported position basal to the Loxophyllum clade, supporting the separation of these genera from one another. Both the subclass Haptoria and the order Haptorida were partially unresolved, possibly paraphyletic assemblages of taxa in all analyses, creating doubts about the traditional placement of some haptorid taxa. The existing sequence of L. rostratum in GenBank (DQ411864) was conspicuously different from that of the isolate from Qingdao, China sequenced in the present work, indicating that they are different species. The isolate from Qingdao was verified as L. rostratum by morphological analysis, and the published morphology of existing GenBank record of L. rostratum is different from it. Based on both morphological and molecular evidence, the latter may be congeneric with an undescribed species of Loxophyllum from Guangdong Province, China.     

Possible contribution of brain angiotensin III to ingestive behaviors in baboons

Recent experiments with specific aminopeptidase inhibitors in rats have strengthened earlier proposals that ANG III may be an important regulatory peptide in the brain. Central mechanisms regulating blood pressure, ingestive behaviors, and vasopressin release could be involved. Arguments in favor of a role for ANG III depend, in part, on the efficacy of ANG III as an agonist. These first studies in primates tested whether ANG III stimulates ingestive behaviors in baboons. Intracerebroventricular (ICV) infusions of ANG III were as potent as ANG II in stimulating water drinking and intake of NaCl solution. On the basis of this criterion and consistent with findings in rats, ANG III could be a main effector peptide in the regulation of ingestive behaviors in a primate.     

Assessing the effects of social environment on blood pressure and heart rates of baboons

The objective of this publication is to report on the feasibility of using a tether system for obtaining data on blood pressure and heart rates of socially housed primates and to evaluate the extent to which housing environment alters cardiovascular responses (mean arterial blood pressure and heart rate). Blood pressure and heart rates of adult male baboons (Papio cynocephalus hamadryas) were evaluated over a 6 week period under three different housing conditions: social companion, individual, and socially unfamiliar. Social environment was manipulated in a specially designed cage that incorporated removable panels of either woven wire or solid sheet metal. The design of the cage permitted nonhuman primates to engage in species-typical social behaviors such as grooming and aggression. Using a tether and catheter system, we monitored cardiovascular physiology. We tested the hypothesis that individual housing, housing with social companions, and housing with social strangers would produce different mean arterial blood pressure and heart rate responses. Individual housing and housing with strangers produced resting mean arterial blood pressures that were elevated relative to blood pressure responses with social companions. Individual housing and housing with social strangers produced different patterns of cardiovascular response. Individual housing resulted in lowered heart rates and elevated blood pressures relative to the social companion condition. Housing with social strangers resulted in both elevated blood pressure and elevated heart rate, relative to the social companion condition. Responses observed during this study demonstrated the sensitivity of blood pressure and heart rates to differences in social environment.     

The use of restriction endonucleases to measure mitochondrial DNA sequence relatedness in natural populations

Summary Restriction endonucleases and agarose gel electrophoresis have been used to demonstrate extensive nucleotide sequence diversity in mitochondrial DNA (mtDNA) within and between conspecific populations of rodents and other mammals. Cleavage of mtDNA samples with a relatively small number of endonucleases provides information concerning the phylogenetic relatedness of individual organisms which cannot now be readily obtained by any other type of molecular analysis. This information is qualitatively different from that available from the study of nuclear genes or gene products because the mitochondrial genome is inherited intact from the female parent and is not altered by recombination or meiotic segregation.The requirements for large tissue samples and laborious DNA purification procedures have imposed severe limitations on the kinds of population surveys in which this technique could be utilized. Here, we show that these difficulties can be overcome by using DNA-DNA hybridization to detect minute amounts of mtDNA in crude tissue fractions which can be more easily and rapidly prepared from very small amounts of tissue without the use of expensive and immobile laboratory equipment. The techniques are described in detail in an effort to make restriction analysis of mtDNA available to biologists who may be unfamiliar with current DNA technology.