Immunosuppressive effect of infectious pancreatic necrosis virus on rainbow trout (Oncorhynchus mykiss)

The infectivity of infectious pancreatic necrosis virus (IPNV) for rainbow trout (Oncorhynchus mykiss) mononuclear leukocyte subpopulations was investigated to determine the mechanisms of immunosuppression caused by the virus. IPNV was recovered from nylon wool-adherent, surface immunoglobulin (Ig)-positive leukocytes of head kidney, spleen and peripheral blood collected from virus-inoculated fish with higher titers than non-adherent, Ig-negative cells. Non-adherent cell population showed mitogenic response to phytohemagglutinin and concanavalin A but not to lipopolysaccharide. Conversely, the responses of adherent cells to these mitogens were weak. Mitogenic response and non-specific cytotoxicity of head kidney leukocytes significantly decreased by the inoculation of fish with the virus. These results suggest that the suppression of immune responses is involved in the establishment of carrier state in fish after infection with IPNV.     

Inhibition of turkey herpesvirus replication by anti-cellular serum

Quail embryo fibroblasts were used to investigate how rabbit and chicken antisera against chicken erythrocytes carrying different B alleles of the major histocompatibility antigens affect the neutralization of herpesvirus of turkeys (HVT). Although the neutralizing activities of these antisera were rather low, the HVT propagated in chicken embryo fibroblasts (CEF) from certain genotypic embryos was neutralized more by the antisera to the corresponding erythrocytes. After absorption of these antisera with homologous erythrocytes, the neutralizing activity of the absorbed sera was reduced slightly. These results reveal that the virion antigens of HVT might be partially associated with the host cell antigens of the fibroblast infected with the virus. The virus grown in these cells might incorporate the host cell antigens, including histocompatibility antigens, into the virion envelope.     

Kazakhstani native cattle reveal highly divergent mtDNA from Bos taurus and Bos indicus lineages with an absence of Bos indicus Y chromosome

Kazakhstan is the largest landlocked country and contains two important propagation routes for livestock from the Fertile Crescent to Asia. Therefore, genetic information about Kazakhstani cattle can be important for understanding the propagation history and the genetic admixture in Central Asian cattle. In the present study, we analyzed the complete mtDNA D‐loop sequence and SRY gene polymorphism in 122 Kazakhstani native cattle. The D‐loop sequences revealed 79 mitochondrial haplotypes, with the major haplogroups T and I. The Bos taurus subhaplogroups consisted of T (3.3%), T1 (2.5%), T2 (2.5%), and T4 (0.8%) in addition to the predominant subhaplogroup T3 (86.9%), and the Bos indicus subhaplogroup of I1 (4.1%). Subsequently, we investigated the paternal lineages of Bos taurus and Bos indicus, however, all Kazakhstani cattle were shown to have Y chromosome of Bos taurus origin. While highly divergent mtDNA subhaplogroups in Kazakhstani cattle could be due to the geographical proximity of Kazakhstan with the domestication center of the Fertile Crescent, the absence of Bos indicus Y chromosomes could be explained by a decoupling of the introgression dynamics of maternal and paternal lineages. This genetic information would contribute to understanding the genetic diversity and propagation history of cattle in Central Asia.     

The Eurasian Steppe is an important goat propagation route: A phylogeographic analysis using mitochondrial DNA and Y‐chromosome sequences of Kazakhstani goats

Goats (Capra hircus) were domesticated in the Fertile Crescent and propagated all over the world. The Silk Road through the Eurasian Steppe belt is a possible propagation route for domestic goats to Central Asia. Kazakhstan is in close geographical proximity to domestication centers and covers the majority of the Eurasian Steppe belt. In this study, we examined the genetic diversity and phylogeographic structure of Kazakhstani goats. The mtDNA sequences of 141 Kazakhstani goats were categorized into haplogroups A, C, and D, of which haplogroup A was predominant (97%), whereas haplogroups C and D were detected at low frequencies (1.4% each). The Kazakhstani haplotypes C were thzen categorized into Asian mtDNA type. Sequence analysis of the SRY gene on the Y‐chromosome in 67 male Kazakhstani goats revealed two haplotypes: Y1A (64%) and Y2A (36%). Analysis of the distribution of mtDNA haplogroups and SRY haplotypes from Eurasia and Africa demonstrated genetic similarity among animals from Kazakhstan, Mongolia, and Northwest China located on the Eurasian Steppe belt. These phylogeographic results suggested that the Eurasian Steppe belt was an important propagation route for goats to Central Asia.     

Immunohistochemical analysis for G protein in the olfactory organs of soft-shelled turtle, Pelodiscus sinensis

In turtles, the epithelia lining the upper and lower chambers of the nasal cavity project axons to the ventral and dorsal parts of the olfactory bulbs, respectively. In a semi-aquatic soft-shelled turtle, Pelodiscus sinensis, more than 1,000 odorant receptor genes have been found, but it is not known where they are expressed. In this study, we aimed to clarify the distribution of cells expressing these genes in the olfactory organs of soft-shelled turtles. Immunoreactions for the Gαolf, the α subunit of G protein coupled to the odorant receptors, were detected on the surface of epithelia lining both the upper and lower chambers of the nasal cavity. The receptor cells in the epithelium of both chambers possessed cilia on the tip of their dendrites, whereas microvillous, non-ciliated, receptor cells were not found. These data suggest that the odorant receptor genes are expressed by the ciliated receptor cells in the upper and lower chamber epithelia. Precise location of the vomeronasal epithelium is not known at present.     

5α-Reductase inhibitory compounds produced by polymerization of resveratrol with horseradish peroxidase

To produce 5-reductase inhibitory compounds, resveratrol was enzymatically oxidized in a horseradish peroxidase (HRP)/H₂O₂ system. Ethyl acetate extract of the oxidation products showed strong 5-reductase inhibitory activity with 10%–15% organic solvents in the system, whereas without organic solvent little inhibitory activity was exhibited. The optimum pH of enzymatic oxidation for acquisition of the inhibitory activity was 4.5. The inhibitory compounds were isolated and identified as resveratroltrans-dehydrodimer and resveratrolcis-dehydrodimer by comparing with published nuclear magnetic resonance data. The two resveratrol dehydrodimers have stronger inhibitory activity than natural resveratrol dimers and trimers found inShorea species.     

Predicting chronosequential changes in carbon stocks of pachymorph bamboo communities in slash-and-burn agricultural fallow,northern Lao People’s Democratic Republic

In northern Lao People’s Democratic Republic, rising human population has drastically reduced the fallow period of slash-and-burn agriculture which has led to a considerable decrease in the carbon stock in these communities. We estimated chronosequential changes in the communities' carbon stocks, and established the relationship between the fallow period and fallow-period-average carbon stocks in three carbon pools of bamboo-dominated communities in hilly areas of the Luang Prabang Province, northern Lao People’s Democratic Republic. Based on measurements by destructive sampling, we devised a model and root-to-shoot ratios for estimating bamboo biomass. In six secondary plant communities established after slash-and-burn cropping, we estimated community biomass using the above model and others, and measured deadwood and litter stocks. The communities’ biomass and deadwood significantly increased with time after the last cropping and the former reached about 100 Mg ha⁻¹ after 15 years, whereas litter stocks did not show significant trends over time. Extending the fallow period from 2 to 5 years would increase fallow-period-average carbon stock from 14.2 to 25.1 Mg C ha⁻¹. The overstory height was significantly correlated with biomass, deadwood, and litter carbon stocks of these communities. Based on our findings, changes in a community’s carbon stocks can be estimated using the changes in overstory height, which should be taken into account in future studies to reduce uncertainty in estimating carbon stocks in tropical ecosystems.     

Antioxidant mechanism studies on ferulic acid: identification of oxidative coupling products from methyl ferulate and linoleate

In our studies of the chain-breaking antioxidant mechanism of natural phenols in food components, ferulic acid, a phenolic acid widely distributed in edible plants, especially grain, was investigated. The radical oxidation reaction of a large amount of ethyl linoleate in the presence of the methyl ester of ferulic acid produced four types of peroxides as radical termination products. The isolation and structure determination of the peroxides revealed that they had tricyclic structures which consisted of ethyl linoleate, methyl ferulate, and molecular oxygen. Based on the formation pathway of the products, a radical scavenging reaction occurred at the 3'-position of the ferulate radical with the four types of peroxyl radicals of ethyl linoleate. The produced peroxides subsequently underwent intramolecular Diels-Alder reaction to afford stable tricyclic peroxides.