Movement of retinal along the visual transduction path

Movement of the ligand/receptor complex in rhodopsin (Rh) has been traced. Bleaching of diazoketo rhodopsin (DK-Rh) containing 11-cis-3-diazo-4-oxo-retinal yields batho-, lumi-, meta-I-, and meta-II-Rh intermediates corresponding to those of native Rh but at lower temperatures. Photoaffinity labeling of DK-Rh and these bleaching intermediates shows that the ionone ring cross-links to tryptophan-265 on helix F in DK-Rh and batho-Rh, and to alanine-169 on helix D in lumi-, meta-I-, and meta-II-Rh intermediates. It is likely that these movements involving a flip-over of the chromophoric ring trigger changes in cytoplasmic membrane loops resulting in heterotrimeric guanine nucleotide-binding protein (G protein) activation.     

A spontaneous thymic carcinosarcoma in a young Sprague Dawley rat

We encountered a case of spontaneous thymic carcinosarcoma in a young Crl:CD (Sprague Dawley) rat. Grossly, a white multinodular mass replaced the thymus in the thoracic cavity. Histologically, multiple nodules were separated by fibrous stroma, and each nodule included isolated regions that were composed of epithelial or non-epithelial tumor cells. The epithelial tumor cells were relatively large and round to polygonal cells with large nuclei and weakly eosinophilic cytoplasm. These cells were cytokeratin-positive and vimentin-negative. These cells infiltrated the lungs. The non-epithelial tumor cells were poorly differentiated, small, round to spindle-shaped cells with small nuclei and basophilic cytoplasm. These cells were vimentin-positive and mostly cytokeratin-negative. Many islands of cartilage were observed near non-epithelial cells. Based on these findings, the tumor was diagnosed as a primary thymic carcinosarcoma consisting of a malignant thymoma composed of epithelial tumor cells and a mesenchymal chondrosarcoma composed of non-epithelial tumor cells.     

Ant nestmate and non-nestmate discrimination by a chemosensory sensillum

In animal societies, chemical communication plays an important role in conflict and cooperation. For ants, cuticular hydrocarbon (CHC) blends produced by non-nestmates elicit overt aggression. We describe a sensory sensillum on the antennae of the carpenter ant Camponotus japonicus that functions in nestmate discrimination. This sensillum is multiporous and responds only to non-nestmate CHC blends. This suggests a role for a peripheral recognition mechanism in detecting colony-specific chemical signals.     

Experimental transmission of ovine herpesvirus-2 in sheep

Transmission of ovine herpesvirus-2 (OvHV-2) in sheep via natural contact and nasal secretions was examined. OvHV-2-free lambs were produced by separating newborn lambs from their mothers within 5 days of birth and raising them in an isolation facility. Transmission experiments via natural contact were conducted by keeping OvHV-2-free lambs with OvHV-2-infected sheep of different ages. Six of the infected ewes in this experiment were pregnant and gave birth during the experimental period. OvHV-2 was not transmitted from the adult sheep, though viral DNA was consistently detected in their peripheral blood leukocytes (PBL). On the other hand, OvHV-2 was transmitted from recently infected lambs to sheep at 10 or 12 weeks after the onset of contact. In addition, we attempted the experimental transmission of OvHV-2 via nasal secretions, by transferring nasal washings from infected sheep to the nostrils of uninfected sheep. Sheep receiving the nasal washings from infected adult sheep maintained their negative status for 15 months, whereas sheep receiving nasal washings from recently infected lambs acquired OvHV-2 by 8 months. The results of these experiments support that OvHV-2 is more easily transmitted to negative sheep by recently infected lambs than by adult sheep. Further, it is supposed that the nasal cavity is a portal for entry and shedding of infectious OvHV-2 in sheep.     

Regulatory effect of amino acids on the pasting behavior of potato starch is attributable to its binding to the starch chain

The binding of an amino acid, glycine (Gly), alanine (Ala), epsilon-aminocaproic acid (-AC), monosodium glutamate (GluNa), or lysine (Lys), to starch was examined by a biomolecular interaction analyzer (IAsys). A starch sample (ATS) hydrolyzed to an extent of 1% hydrolysis rate with 15% sulfuric acid was used as a model starch for the binding examination. The reducing end of ATS was oxidized by the Somogyi reagent, and the conversion of the reducing end to the carboxyl group of ATS was confirmed by a carboxylic acid fluorescence labeling reagent. The oxidized ATS was immobilized to the amino group of a sensor cuvette by using water-soluble carbodiimide and N-hydroxysuccinimide through an amide bond. The IAsys examination showed that Gly, Ala, and epsilon-AC scarcely bound to the immobilized starch chains but that GluNa and Lys favorably bound with their increasing concentrations. The relative binding index (RBI) of each amino acid was defined by the ratio of the slope of the linear regression equation between the binding response and the concentration for each amino acid to that for Gly. Because the relationships between the RBI and the pasting characteristics (pasting temperature, peak viscosity, breakdown, and swelling index) could each be expressed by a linear regression equation with a high correlation coefficient, it is concluded that the regulation of the pasting behavior of starch with an amino acid is caused by binding of the amino acid to the starch chains.     

Front Cover Image

The cover image is based on the Research Article Nonanal, a new fall armyworm sex pheromone component, significantly increases the efficacy of pheromone lures by Ahmed M. Saveer et al., https://doi.org/10.1002/ps.7460 . Image Credit: Matt Bertone.

     

Study of Internal Structure of Waxy Wheat Starch Granules by KI/I2 Solution

Wheat starch granules were separated from waxy wheat flour by the acetic acid (pH 3.5) fractionation technique. Waxy wheat starch samples were stained red‐brown using KI/I₂ solution. Subsequently, the concentration of the KI/I₂ solution was increased to >2.5% KI and 1.0% I₂. Then the appearance of the waxy wheat starch granules quickly became ghostlike. The internal structure of the ghost could be observed. This structure consisted of two parts with different colors: a red‐brown central part and a slightly pinkish surrounding part. Sonication of the ghost at 20 kHz for 20 sec separated the central part from the surrounding part. Each of the separated parts were subjected to gel‐filtration chromatography, and their chromatography profiles indicated only amylopectin and no amylose. The central and surrounding parts had molecular weights of 54.3 × 10⁵ and 23.8 × 10⁶ from Berry plots, respectively.