Construction of a high-density reference linkage map of tea (Camellia sinensis)

A few linkage maps of tea have been constructed using pseudo-testcross theory based on dominant marker systems. However, dominant markers are not suitable as landmark markers across a wide range of materials. Therefore, we developed co-dominant SSR markers from genomic DNA and ESTs and constructed a reference map using these co-dominant markers as landmarks. A population of 54 F₁ clones derived from reciprocal crosses between ‘Sayamakaori’ and ‘Kana-Ck17’ was used for the linkage analysis. Maps of both parents were constructed from the F₁ population that was taken for BC₁ population. The order of most of the dominant markers in the parental maps was consistent. We constructed a core map by merging the linkage data for markers that detected polymorphisms in both parents. The core map contains 15 linkage groups, which corresponds to the basic chromosome number of tea. The total length of the core map is 1218 cM. Here, we present the reference map as a central core map sandwiched between the parental maps for each linkage group; the combined maps contain 441 SSRs, 7 CAPS, 2 STS and 674 RAPDs. This newly constructed linkage map can be used as a basic reference linkage map of tea.     

Enhancement of saccharification by overexpression of poplar cellulase in sengon

Lignocellulosic material from trees has great potential to form the basis of the second generation for bioethanol production because trees produce most of the biomass on the earth. We modified the wall structure of sengon (Paraserianthes falcataria) through overexpression of poplar cellulase in the cell walls. The overexpression did not decrease cellulose content but caused a decrease in xyloglucan bound to the walls. The level of saccharification and successive ethanol production was increased in the wood of the transgenic sengon overexpressing poplar cellulase compared with that of the wild type plant, and even after delignification of the wood. We propose that a xyloglucan intercalated into cellulose microfibrils could be one of the recalcitrant components in the saccharification of lignocelluloses.     

Comparison of fattening performance in Brahman grade cattle (Bos indicus) and crossbred water buffalo (Bubalus bubalis) fed on high roughage diet

The objective of this study was to compare the fattening performance in Brahman grade cattle (crossbred cattle) and crossbred water buffalo at the same young age and fed with high roughage based fattening rations in the Philippines. Ten crossbred cattle and 10 crossbred water buffalo, aged between 18 and 24 months old were used in this experiment. The animals were fed diets consisting of 85% Napier or Para grass and 15% concentrate mixture (CM) on a dry matter (DM) basis. The grass, total DM intake and bodyweight gain were significantly (P < 0.01) higher for the crossbred water buffalo than for the cattle. There was no species significant difference in the digestion coefficient and feed conversion rate between the crossbred cattle and water buffalo. The return over feed cost for fattening was significantly (P < 0.05) higher in the crossbred water buffalo than in the cattle. These results clearly indicate that under high roughage‐based fattening rations, young crossbred water buffalo are better able to utilize the roughage and they perform better in terms of feed intake and live weight gains than the crossbred cattle in the Philippines.     

Obstructive nephropathy induced with DL-potassium hydrogen tartrate in F344 rats

We experienced obstructive nephropathy in F344 rats treated with DL-potassium hydrogen tartrate (PHT) in a 13-week oral repeated dose toxicity study. Six-week-old male and female F344/DuCrj rats were fed a diet containing up to 2.0% PHT for 13 weeks. Microscopical findings including irregular dilation of the distal tubule lumen, foreign body giant cells, inflammatory cell infiltration, and regeneration of renal tubules were observed focally or multifocally in the renal cortex and/or medulla in the 0.5% and higher dosage groups of both sexes. The severity of these lesions increased in a dose-dependent manner. In the urinalysis, an increase in protein and white blood cells or the concentration of tartaric acid was detected in the 0.5% PHT and higher dosage groups of both sexes or males, respectively, though conventional blood biochemical analysis did not indicate failure of renal function. These results indicate that the PHT induces obstructive nephropathy in rats. There were no other treatment-related changes in other organs.     

Conversion of dextran to cycloisomaltooligosaccharides using an enzyme-immobilized porous hollow-fiber membrane

This paper describes a cycloisomaltooligosaccharide glucanotransferase (CITase)-multilayer-immobilized porous hollow-fiber membrane used as an enzyme bioreactor. Dextran, a substrate with an average molecular mass of 43000, is converted into seven- to nine-glucose-membered cycloisomaltooligosaccharides, effective as a preventive for dental caries, aided by convective transport of the substrate to the vicinity of the enzyme through the pores. Epoxy-group-containing graft chains were uniformly appended onto the surface of pores throughout a porous hollow-fiber membrane by radiation-induced graft polymerization. Subsequently, a diethylamino group was introduced, as an anion-exchange moiety, to the graft chains, which caused the chains to expand toward the interior of the pores due to mutual electrostatic repulsion. The expanding graft chain provided multilayer binding sites for CITase. Fifty-five milligrams of adsorbed CITase per gram of membrane is equivalent to the degree of multilayer binding of 5. Finally, 80% of the multilayer-adsorbed CITase was immobilized via enzymatic cross-linking with transglutaminase to prevent the leakage of enzymes. CITase, with a degree of multilayer immobilization of 4, produced the target cycloisomaltooligosaccharides at a conversion yield of 55% in weight at 310 K during permeation by the dextran solution at a space velocity defined as the permeation rate divided by membrane volume of 6 per hour.     

Trophodynamic structure of a swampy bog at the clymax stage of limnological succssion I. Prmary production dynamics

Effect of emergent vegetation on the population dynamics of phytoplankton community in Matsumi-ike Bog, a typical bog at the climax stage of limnological succession, was studied. The emergent vegetation grew until August and then withered and collapsed mainly during December and January, supplying the debris of emergent plants into the water column. Population density of the predominant phytoplankton showed sinusoidal fluctuation affected primarily by the water temperature, with various lag phases due to the function of other environmental factors. Shading by the emergent vegetation shifted the initiation of phytoplankton fluctuation earlier. This fluctuation patterns was most obvious among those phytoplankton contain chlorophyll-a and -b, but non -a and-c. The population dynamics were also compared with that of Matsumi-ike Bog at premature stages without (8 yr ago) or with littoral vegetations (3 yr ago). The population density of phytoplankton with chlorophyll-b decreased but those with chlorophyll-c increased, due to the shading effect of the emergent vegetation with the limnological succession of the bog. At the climax of succession, the dynamic state of phytoplankton community has become more stable.     

Neuromuscular and vascular hamartoma of the small intestine in an F344 rat

An intestinal mass was found in the border area of the jejunum and ileum of a 110-week-old male F344 rat. Histopathologically, the mass protruded into the lumen and was covered with intestinal epithelium, exhibiting a normal architecture. The lesion was located in the submucosa and consisted of loose connective tissue, smooth muscle, scattered ganglion cells, and blood vessels of various sizes. Although these components showed an irregular and disordered structure, no cellular atypia, increased proliferation activity, or invasive growth to adjacent tissues were detected. Immunohistochemical analyses revealed that smooth muscle, ganglion, and endothelial cells were positive for α-smooth muscle actin and vimentin, S-100, and CD34 and von Willebrand factor, respectively, indicating maturation of these cells. Thus, the mass was diagnosed as a neuromuscular and vascular hamartoma of the small intestine. To the best of our knowledge, this is the first report of this type of lesion in rodents.     

Impact of short-term high-fat feeding on lipid droplet content in mouse oocytes

Mature mammalian oocytes contain lipid droplets (LDs), which are neutral lipid storage organelles critically important for energy metabolism. In mice, maternal obesity, induced by long-term (> 3 months) high-fat feeding, contributes to the accumulation of LDs in mature oocytes. However, few studies have investigated the influence of short-term high-fat feeding on LD content. In this study, we demonstrated that 3 weeks of high-fat feeding is sufficient to increase LD content and intracellular triacylglycerol levels. Using a two-step centrifugation technique to release LDs into the perivitelline space, we found that short-term high-fat feeding increased the level of LDs in MII oocytes and that 3 days of high-fat feeding were sufficient to increase efficiency of LD release. Collectively, our study suggests that short-term high fat feeding can have a higher impact on lipid metabolism during oocyte maturation.     

Development of enzyme immunoassay for chromogranin A (CgA) and profiling of plasma CgA concentrations in the cow

The objectives of this study were to establish and characterize a homologous immunoassay for bovine chromogranin A (bCgA) and to profile plasma bCgA concentrations during early pregnancies. We synthesized oligopeptide corresponding to the amino acid sequence 341–355 of bCgA for immunizing rabbits and peptide corresponding to the amino acid sequence 336–365 of bCgA for both a biotinylated tracer and reference standards. Recombinant bCgA protein was also generated in Escherichia coli lysate. Dose-dependent displacement curves were obtained from 1 to 1,000 nM of the reference standards. The displacement curves showed a good relationship between the reference standards of the synthetic peptide and the serially diluted plasma sample or recombinant bCgA protein generated in the present study. The assay sensitivity defined as the value of two standard deviations below the zero standard was calculated as 0.46 nM. The intraassay and interassay coefficients of variation were 6.48% and 13.4%, respectively. Changes in the plasma bCgA concentrations in early pregnancies undulated in nonpregnant animals. The results of the present study suggest that assaying plasma bCgA concentrations could be utilized as measures to evaluate the physiological status of cattle.