Structural differences between myofibrillar protein,paratropomyosin, and tropomyosin as revealed by high‐performance liquid chromatography

Paratropomyosin (PTM) composes myofibril functions to weaken the rigor linkages formed between actin and myosin during postmortem aging of muscles. PTM has the similar physico‐chemical properties as tropomyosin (TM) that is a regulatory protein of myofibrils. So far, it is unclear whether PTM is definitely different from TM, because the primary structure of PTM has not been determined yet. The aim of this study was to clarify structural difference of PTM from TM. PTM was prepared by column chromatography immediately after slaughter from broiler breast muscle, and purified by high‐performance liquid chromatography (HPLC). Purified PTM was successfully separated from TM, and the recovered PTM molecule was reduced with dithiothreitol to separate again by HPLC. Two subunits were obtained and peptides from each digested subunit by V8 protease were recovered by HPLC, and then amino acid sequences of the peptides were analyzed by protein sequencing. As a result, some amino acid residues were replaced from that of TMα1 isoform which is the major isoform of TM, and also was different between the two subunits. Therefore, it is concluded that PTM clearly differs from TM and it is suggested that functional difference in PTM from TM is attributed to amino acid replacements in subunits composing PTM.     

Effect of increased concentrate allotment before evening grazing on herbage intake,nitrogen utilization and rumen fermentation in dairy cows grazed on perennial ryegrass pasture

Two experiments were conducted to elucidate the effect of increased concentrate allotment before evening grazing on herbage intake, nitrogen utilization and rumen fermentation in dairy cows. In experiment 1, nine lactating cows were grazed in the morning and evening sessions (2.5 h each). The cows were allocated to treatments of three concentrate allotment levels before the evening grazing session by altering proportions to daily total offered; 25%, 50% and 75%. Daily herbage dry matter intake quadratically decreased with increasing the concentrate allotment levels (P < 0.05). Nitrogen utilization was similar among treatments. To investigate diurnal changes in rumen fermentation, a second experiment was conducted where six ruminally cannulated non‐lactating dairy cows grazed in the morning and evening sessions (3 h each) were subjected to the same treatments as experiment 1. Total volatile fatty acid concentration in the rumen linearly increased with increasing the concentrate allotment levels throughout the pre‐evening grazing session to the post‐morning grazing session (P < 0.01). The results indicate that dairy cows reduce daily herbage intake but do not alter nitrogen utilization with increasing concentrate allotment before evening grazing. © 2016 Japanese Society of Animal Science     

Estrous cycle based on blood progesterone profiles and changes in vulvar appearance of Malayan tapirs (Tapirus indicus)

The progesterone (P(4)) profiles and macroscopic vulvar changes of female Malayan tapirs were investigated in order to understand their fundamental reproductive physiology and to search for visual indicators of estrus. Blood was collected once or twice a week from seven female Malayan tapirs kept at four zoos. Serum or plasma P(4) concentrations were determined by radioimmunoassay. The P(4) concentrations changed cyclically throughout the years, and a total of 56 cycles was confirmed in the seven females. The length of the estrous cycle based on the P(4) profiles was 43.6+/-2.0 days; however, this mean includes great variation in length, from 21 to 84 days. Mucous discharge from the vulva and vulvar swelling were seen when the P(4) concentrations were low before the beginning of a rise in most cases. In conclusion, captive female Malayan tapirs have variations of approximately 1 to 3 months in estrous cycle length, and visual changes in the vulva are helpful in estimating estrus in female Malayan tapirs.     

农杆菌感染桑幼苗的研究

农杆菌A-208接种桑幼苗以其致瘤基因作标记,调查接种部位冠瘿瘤的有无和大小,以此为桑苗对农杆菌敏感性的参考指标;用不同菌体对桑幼苗进行接种试验,探明了菌液接种的效果好于菌体;用农杆菌A-110株(L=BA4404／pIG121-Hm)菌液对桑幼苗子叶腋隙进行剌伤接种,由接种部位长出的桑芽表型异常。取处理株叶片基因组DNA进行分子生物学鉴定。结果显示：以处理株基因组DNA为模板,经PCR反应后得到特异性扩增片段,该片段用SalI酶解,酶切产物与预计大小完全相符;用GUS基因作探针进行Southem杂交和用Kan基因作探针对基因组DNA进行Southem杂交,均获得较强的杂交信号;取畸形株扦插后,用组织化学染色法对扦插苗幼根进行显色反应,幼根出现深兰色区段,这一结果表明GUS基因在桑苗中得到部分表达。     

Five New Diterpenoids from an Okinawan Soft Coral,Cespitularia sp.

Five new diterpenoids 1–5 were isolated from an Okinawan soft coral, Cespitularia sp., together with the known diterpenoid, alcyonolide (6). New diterpenoid structures were elucidated by spectroscopic methods and by comparison of their NMR data with those of related compounds. Alcyonolide (6) was cytotoxic against HCT 116 cells (IC₅₀ 5.85 μM), while these new diterpenoids 1–5 were much less active (IC₅₀ 28.2–91.4 μM).     

Temporal fluctuation in the abundance of alginate‐degrading bacteria in the gut of abalone Haliotis gigantea over 1 year

In this study, we identified and enumerated alginate‐degrading bacteria in the gut of abalone over 1‐year period. From a total of 360 colonies growing on agar medium enriched with alginate, 251 isolates (70%) had the ability to degrade alginate. In addition, a high number of viable alginate‐degrading bacteria were detected throughout the survey period. Alginate‐degrading bacteria were more abundant in the cold season relative to the summer season (10⁷ vs. 10⁴ CFU g^?1, respectively). Strong positive correlation was also observed between the number of alginate‐degrading bacteria and feed intake (R = 0.854; P < 0.01). The identified alginate‐degrading bacteria comprised of 35 species grouped into 11 genera including Algibacter, Formosa, Polarybacter, Tamlana, Tenacibaculum (CFB group), Roseobacter, Ruegeria, Silicibacter (α‐proteobacteria), Agarivorans, Shewanella and Vibrio (γ‐proteobacteria) respectively. More than 80% of the isolated alginate‐degrading bacteria belonged to the genus Vibrio, showing high homology to Vibrio cyclotorophicus, Vibrio splendidus, Vibrio halioticoli and Vibrio neonatus. Based on the results, it was suggested that algal‐polysaccharide (alginate) degrading bacteria (mainly Vibrio) commonly exist in the gut of abalone and may play an important role in the degradation and digestion of the host's feed.     

Changes in fructooligosaccaride composition and related enzyme activities of burdock root during low-temperature storage

Changes in the composition of fructooligosaccarides (FOSs) and related enzyme activities of burdock root during low-temperature storage (1 °C) were measured. Burdock root is composed of monosaccharides, such as glucose and fructose, disaccharides, such as sucrose, and FOS in the extracted carbohydrates. The composition was the highest in fructose, followed by sucrose, FOS, and glucose. The FOS composition was the highest in 1-kestose, followed by nystose and 1-fructofuranosyl nystose. The fructose and glucose contents in burdock root during storage at 1 °C decreased significantly, whereas the sucrose content increased sharply. In contrast, the 1-kestose, nystose, and 1-fructofuranosyl nystose contents significantly increased. The activities of sucrose:sucrose 1-fructosyl transferase (1-SST) and fructan:fructan 1-fructosyl transferase (1-FFT) increased sharply and then gradually decreased, and they were closely related to the changes in FOS content. However, the activity of fructan 1-exohydrolase (1-FEH) was constant. These results indicate that changes in the FOS composition and related enzyme activities of burdock root might be related to low temperature during long term storage.