Potential for mating disruption of Sparganothis sulfureana (Lepidoptera: Tortricidae) in cranberries.

The feasibility of disrupting mating of Sparganothis fruitworm with a sprayable microencapsulated formulation of (E)-11-tetradecenyl acetate (E11-14:Ac), the major pheromone component, was evaluated in New Jersey during 1996 and 1997 seasons. In both years, application of encapsulated E11-14:Ac, at 25-187.5 g (AI)/ha, reduced the incidence of mating of virgin females placed in treated plots relative to those placed in control plots. Pheromone trap catches were lower in pheromone treated plots, indicating that fewer male moths were able to locate the traps in treated plots. Larval density and fruit damage were significantly lower in plots treated with 62.5,125, or 187.5 g (AI)/ha of pheromone than in the untreated control. Air and foliage samples were collected to determine the air titers and foliage residuals of E11-14:Ac throughout the adult flight during 1996 and 1997. E11-14:Ac levels in air and foliage samples, declined sharply one wk after the pheromone application. However, detectable levels of E11-14:Ac were present in both air and foliage samples throughout the 3- to 4-wk period after the pheromone application. Multiple applications of pheromone at lower rates may be more effective in maintaining pheromone levels than a single dose at higher rates. These results suggest that mating disruption is a promising strategy to manage Sparganothis fruitworm in cranberries.     

A possible second role for calmodulin in biological clock-controlled processes of euglena

The response of the Euglena gracilis (Klebs strain Z) photosynthesis circadian rhythm to three calmodulin antagonists was examined. In the presence of an antagonist, the photosynthetic reactions were uncoupled from the biological clock. Instead of the highly predictable rhythmic pattern characteristic of a biological clock-controlled circadian rhythm, the photosynthetic rate appears to be influenced by the light/dark cycle. The rate of O₂ evolution increases throughout the light portion of the cycle and does not decrease until the cells are exposed to darkness. Shortterm exposure to a calmodulin antagonist (2 hour pulses) failed to cause phase shifts in the timing of the rhythm. This suggests that calmodulin is not part of the clock controlling photosynthesis and that it has a clock-related role different from that reported for the cell division rhythm in Euglena.     

The use of digital image segmentation to quantify an aminoanthraquinone dye biotransformation by white-rot fungi

Summary Three methods are presented for the objective, digital evaluation of Remazol Brilliant Blue R dye biotransformation by the white rot fungi, Pycnoporus cinnabarinus and Phanerochaete chrysosporium. This screening technique uses computerized image analysis and a binary logical and function to provide a rapid (2 min per analysis), quantitative, digital densitometry interpretation of enzyme induced chromophore conversion by fungi. A kinetic measure of metabolic activity (enzyme activity coefficient, ) may also be determined. It is shown that chromophore conversion is more rapid and extensive by P. cinnabarinus.     

Regulation of the Photosynthesis Rhythm in Euglena gracilis: I. Carbonic Anhydrase and Glyceraldehyde-3-Phosphate Dehydrogenase Do Not Regulate the Photosynthesis Rhythm

A circadian rhythm of O₂ evolution has been found in Euglena gracilis, Klebs strain Z. The rhythm persists for at least 5 days in constant dim light and temperature, but damps out in constant bright light. The phase of this rhythm can be shifted by a pulse of bright light and the period length is not changed over a 10 C span of growth temperature.

The O₂ evolution rhythm is found in both logarithmic and stationary phase cultures, but CO₂ uptake is clearly rhythmic only in stationary phase cultures.

The activity of glyceraldehyde-3-phosphate dehydrogenase was not rhythmic as previously reported (Walther and Edmunds [1973] Plant Physiol. 51: 250-258). Carbonic anhydrase activity was rhythmic when the cultures were maintained under a light-dark cycle with the highest enzyme activity coinciding with the fastest rate of O₂ evolution. However, the rhythm in carbonic anhydrase activity disappeared under constant conditions. Changes in the activities of these two enzymes are therefore not responsible for the rhythmic changes in photosynthetic capacity.

     

Labelling the blueberry leaftier, Croesia curvalana with foliar sprays of rubidium chloride

The feasibility of labelling blueberry leaftier by rearing the larvae on blueberry plants treated with foliar sprays of rubidium chloride (RbCl) at concentrations of 1000, 5000, 10 000 and 20 000 ppm were assessed. RbCl sprays above 5000 ppm significantly reduced survivorship to adult stage. The adult longevity, fecundity and mating were not affected when the larvae were reared on foliage treated with 5000 ppm RbCl solution. Reciprocal matings of 5000 ppm treated moths with untreated moths revealed transfer of label above the 0.1 µg Rb/insect threshold level from treated males to untreated females (in 8 out of 13 pairs) and vice versa (in 1 out of 9 pairs). Considerable loss of Rb (56–64%) occurred from the leaves over a 15 day period. All of the moths and pupae collected from the RbCl treated plots in 1989 and 1990 respectively, had a Rb content higher than the threshold level. In a preliminary dispersal study, marked male and female moths were found in sweepnet samples collected 20 and 60 m from the centre of the treated field. Labelled male moths were also captured in pheromone traps arranged in a circle, 40 m from the treated plot.     

RS‐1 enhances CRISPR‐mediated targeted knock‐in in bovine embryos

Targeted knock‐in (KI) can be achieved in embryos by clustered regularly interspaced short palindromic repeats (CRISPR)‐assisted homology directed repair (HDR). However, HDR efficiency is constrained by the competition of nonhomologous end joining. The objective of this study was to explore whether CRISPR‐assisted targeted KI rates can be improved in bovine embryos by exposure to the HDR enhancer RS‐1. In vitro produced zygotes were injected with CRISPR components (300 ng/µl Cas9 messenger RNA and 100 ng/µl single guide RNA against a noncoding region) and a single‐stranded DNA (ssDNA) repair template (100 ng/µl). ssDNA template contained a 6 bp XbaI site insert, allowing targeted KI detection by restriction analysis, flanked by 50 bp homology arms. Following microinjection, zygotes were exposed to 0, 3.75, or 7.5 µM RS‐1 for 24 hr. No differences were noted between groups in terms of development or genome edition rates. However, targeted KI rates were doubled in the group exposed to 7.5 µM RS‐1 compared to the others (52.8% vs. 25% and 23.1%, for 7.5, 0, and 3.75 µM, respectively). In conclusion, transient exposure to 7.5 µM RS‐1 enhances targeted KI rates resulting in approximately half of the embryos containing the intended mutation, hence allowing direct KI generation in embryos.     

An Acinetobacter baumannii,Zinc-Regulated Peptidase Maintains Cell Wall Integrity during Immune-Mediated Nutrient Sequestration

1. Download high-res image (209KB)
2. Download full-size image

     

Mitochondria in stem cells

The current status of knowledge about mitochondrial properties in mouse, monkey and human embryonic, adult and precursor stem cells is discussed. Topics include mitochondrial localization patterns, oxygen consumption and ATP content in cells as they relate to the maintenance of stem cell properties and subsequent differentiation of stem cells into specific cell types. The significance of the perinuclear arrangement of mitochondria, which may be a characteristic feature of stem cells, as well as the expression of mitochondrial DNA regulatory proteins and mutations in the mitochondrial stem cell genome is also discussed.     

Viral vectors as tools for studies of central cardiovascular control

During the last few years physiological genomics has been the most rapidly developing area of physiology. Given the current ease of obtaining information about nucleotide sequences found in genomes and the vast amount of readily available clones, one of the most pertinent tasks is to find out about the roles of the individual genes and their families under normal and pathological conditions. Viral gene delivery into the brain is a powerful tool, which can be used to address a wide range of questions posed by physiological genomics including central nervous mechanisms regulating the cardio-vascular system. In this paper, we will give a short overview of current data obtained in this field using viral vectors and then look critically at the technology of viral gene transfer.