Preliminary system of rapid analysis of blood retinol level in cattle

Control of blood retinol levels in cattle during fattening is important in the production of marbled beef. However, it is difficult to easily measure the blood retinol concentration in the field. In this study, we attempted to develop an analysis method that does not require blood cell separation and uses a compact fluorescence analyzer that can be carried around as a preliminary system for measuring blood retinol concentration in the field. This system was used to monitor blood retinol levels in 12 fattening cattle (14 to 27 months old) and demonstrated a strong correlation (r = 0.78) with the results obtained by the standard high-performance liquid chromatography (HPLC) method. Stronger correlations (r = 0.87) were obtained until the cattle were 24 months of age. These results suggest that higher correlations can be expected to be obtained by improving the robustness of the extraction system. Refinements for practical use need to be considered, but whole blood extraction and the vitamin A analyzer that was developed show potential to be used for on-farm monitoring of retinol levels.     

Molecular cloning, tissue expression, and subcellular localization of porcine peptidoglycan recognition proteins 3 and 4

Peptidoglycan recognition proteins (PGRPs) are innate immune molecules that are present in most invertebrates and vertebrates. Mammals have four PGRPs, PGLYRP1-4. In the present study, we cloned the cDNAs encoding porcine PGLYRP3 and 4 from the esophagus of adult swine. The length of the complete open reading frames of porcine PGLYRP3 and 4 are identical and contain 1125bp encoding 374 amino acid residues. The amino acid sequences of these two proteins were more similar to their human orthologs (78.9% [PGLYRP3] and 73.9% [PGLYRP4]) than to their mouse orthologs (71.3% [PGLYRP3] and 67.9% [PGLYRP4]). Expression analysis revealed that both PGLYRP3 and 4 were more strongly expressed in digestive tract, especially the esophagus, than in immune organs such as spleen or mesenteric lymph nodes in both newborn and adult swine. To analyze the subcellular distribution of porcine PGLYRP1-4, we constructed transfectant cell lines. Western blot and flow cytometric analyses revealed that porcine PGLYRP3 and 4 are not only secreted, but also expressed on the cell surface, unlike PGLYRP1 and 2. These results should help contribute to the understanding of PGLYRP3- and 4-mediated immune responses via their recognition of intestinal microorganisms in newborn and adult swine.     

Correlation between skeletal muscle fiber type and free amino acid levels in Japanese Black steers

Free amino acids are important components of tastants and flavor precursors in meat. To clarify the correlation between muscle fiber type and free amino acids, we determined the concentrations of various free amino acids and dipeptides in samples of different muscle tissues (n = 21), collected from 26‐month‐old Japanese Black steers (n = 3) at 2 days postmortem. The proportions of the myosin heavy chain (MyHC), slow (MyHC1) and fast (MyHC2) isoforms were determined by sodium dodecyl sulfate–polyacrylamide gel electrophoresis (SDS–PAGE). The contents of free amino acids and dipeptides were measured by high performance liquid chromatography (HPLC). The MyHC isoform composition varied among the tissue samples. The MyHC1 proportion ranged from 6.9% ± 3.9% to 83.3% ± 16.7%. We confirmed that there was a strong positive correlation between MyHC1 composition and total free amino acid concentrations, including those for two dipeptides. Among the 31 measured free amino acids and dipeptides, 11 showed significant positive correlations and five showed significant negative correlations with MyHC1 composition. These results suggest that a high MyHC1 content induces high free amino acid contents in bovine muscles possibly because of greater oxidative metabolism. This high level of free amino acids could contribute to the intense flavor of meat that is rich in slow‐twitch fibers.     

Lingual squamous cell carcinoma in a California sea lion (Zalophus californianus).

A 28-yr-old female California sea lion (Zalophus californianus) in a commercial aquarium developed an ulcerated lingual tumor and died. Necropsy revealed a moderately differentiated squamous cell carcinoma. Immunohistochemical staining and electron microscopic studies revealed that the tumor cells were strongly positive with anti-keratin-cytokeratin antibody and had abundant tonofibrils and desmosomes. The neoplasm had metastasized to a mandibular lymph node.     

Large-scale molecular dynamics simulations of self-assembling systems

Relentless increases in the size and performance of multiprocessor computers, coupled with new algorithms and methods, have led to novel applications of simulations across chemistry. This Perspective focuses on the use of classical molecular dynamics and so-called coarse-grain models to explore phenomena involving self-assembly in complex fluids and biological systems.     

Fine Mapping of HWC2, a Complementary Hybrid Weakness Gene, and Haplotype Analysis Around the Locus in Rice

Hybrid weakness is a reproductive barrier. In rice, the hybrid weakness caused by two complementary genes––HWC1 and HWC2––has been surveyed extensively. However, their gene products and the molecular mechanism that causes hybrid weakness have remained unknown. We first performed fine mapping of HWC2, narrowing down the area of interest to 19 kb. We thereby identified five candidate genes. Second, we performed haplotype analysis around the HWC2 locus of 33 cultivars. With 15 DNA markers examined, all the 13 Hwc2-1 carriers share the same haplotype for consecutive 14 DNA markers. As for hwc2-2 carriers, five out of 20 have the haplotypes relatively similar to those of Hwc2-1 carriers. However, the other haplotypes differ remarkably from them. These results are useful to identify the HWC2 gene and to study rice varietal differentiation.     

Plant regeneration in <Emphasis Type="Italic">Actinidia polygama</Emphasis> Miq. by leaf,stem, and petiole culture with zeatin,and from stem-derived calli on low-sucrose medium

We examined the effect of zeatin on the formation of shoot buds from explants and callus tissues derived from stem segments of Actinidia polygama Miq. (matatabi or silver vine). Stem and petiole segments cultured on combined broad-leaved tree medium and woody plant medium (BW medium) supplemented with zeatin for 40 days formed many shoot buds. Callus tissues derived from the stem segments and subcultured on BW medium supplemented with 6-benzyladenine and 1-naphthaleneacetic acid formed shoot buds when the medium contained 13.7µM zeatin. BW medium containing low concentrations of sucrose strongly induced the formation of shoot buds from the callus.     

Time‐coordinated prevalence of extracellular HGF,FGF2 and TGF‐β3 in crush‐injured skeletal muscle

Successful regeneration and remodeling of neuromuscular junctions are critical for restoring functional capacities and properties of skeletal muscle after damage, and axon‐guidance molecules may be involved in the signaling that regulates such restoration. Recently, we found that early‐differentiated satellite cells up‐regulate a secreted neural chemorepellent Sema3A upon in vivo muscle‐crush injury. The study also revealed that Sema3A expression is up‐regulated in primary satellite‐cell cultures in response to hepatocyte growth factor (HGF) and basic fibroblast growth factor (FGF2) and is prevented by transforming growth factor (TGF)‐β2, 3. In order to verify the physiological significance of this regulation in vitro, the present study was designed to estimate the time‐course of extracellular HGF, FGF2 and TGF‐β3 concentrations after crush‐injury of Gastrocnemius muscle in the rat lower hind‐limb, using a combination of a non‐homogenization/non‐spin extraction of extracellular wound fluids and enhanced chemiluminescence–Western blotting analyses. Results clearly demonstrated that active HGF and FGF2 are prevalent in 2–8 days post‐crush, whereas active TGF‐β3 increases after 12 days, providing a better understanding of the time‐coordinated levels of HGF, FGF2 and TGF‐β3 that drive regulation of Sema3A expression during regenerative intramuscular moto‐neuritogenesis.