Genetic population structure of the deep-sea whelk Buccinum tsubai in the Japan Sea

ABSTRACT:   The purpose of the present paper was to examine the genetic population structure of Buccinum tsubai in the Japan Sea. Mitochondrial 16SrRNA gene sequence analysis was performed with specimens from various stations in the Japan Sea. Mitochondrial lineages were clearly patterned geographically in four separate areas: the Hokkaido area, the Yamagata–Toyama area, the Yamato Bank area, and the San'in area. The main distribution depth range of B. tsubai is between 200 m and 1000 m isodepths, and the horizontal distance between the 200 m and 1000 m isodepth lines represents the specific spatial scale of the habitat (SSSH). These four areas were separated either by the complete discontinuity of the SSSH area or by its narrow spatial extension. Genetic distances between the main haplotypes of each area were calculated as Jukes–Cantor distances, the value of which ranged between 0.012 and 0.017. This value seemed to be unrelated to the geographic distance. There was no tendency for clustering according to depth. In future, the morphological characters of the four lineages of B. tsubai should be compared in detail in order to elucidate significant genetic differences among them.     

Leptin inhibits hepatocyte growth factor-induced ductal morphogenesis of bovine mammary epithelial cells

We examined the effect of stroma-derived factors, hepatocyte growth factor (HGF) and leptin, on morphological differentiation of bovine mammary epithelial cells (BMEC) in collagen gel three-dimensional culture in vitro. BMEC treated with HGF, but not leptin, formed duct-like organoids. The formation of organoids by HGF was enhanced by treatment with a mixture of insulin, cortisol and prolactin, while BMEC treated with the mixture alone did not produce the organoid. In contrast, the formation of organoids by HGF was dose-dependently inhibited by simultaneous addition of leptin, regardless of the presence or absence of the hormone mixture. These results suggest that stroma-derived factors intricately regulate mammary epithelial morphogenesis.     

Performance of a new carbon dioxide absorbent,Yabashi lime? as compared to conventional carbon dioxide absorbent during sevoflurane anesthesia in dogs

In the present study, we compare a new carbon dioxide (CO₂) absorbent, Yabashi lime^® with a conventional CO₂ absorbent, Sodasorb^® as a control CO₂ absorbent for Compound A (CA) and Carbon monoxide (CO) productions. Four dogs were anesthetized with sevoflurane. Each dog was anesthetized with four preparations, Yabashi lime^® with high or low-flow rate of oxygen and control CO₂ absorbent with high or low-flow rate. CA and CO concentrations in the anesthetic circuit, canister temperature and carbooxyhemoglobin (COHb) concentration in the blood were measured. Yabashi lime^® did not produce CA. Control CO₂ absorbent generated CA, and its concentration was significantly higher in low-flow rate than a high-flow rate. CO was generated only in low-flow rate groups, but there was no significance between Yabashi lime^® groups and control CO₂ absorbent groups. However, the CO concentration in the circuit could not be detected (≤5ppm), and no change was found in COHb level. Canister temperature was significantly higher in low-flow rate groups than high-flow rate groups. Furthermore, in low-flow rate groups, the lower layer of canister temperature in control CO₂ absorbent group was significantly higher than Yabashi lime^® group. CA and CO productions are thought to be related to the composition of CO₂ absorbent, flow rate and canister temperature. Though CO concentration is equal, it might be safer to use Yabashi lime^® with sevoflurane anesthesia in dogs than conventional CO₂ absorbent at the point of CA production.     

Bioactive Alkaloids from the Sea: A Review

In our ongoing search for bioactive substances from marine organisms, novel alkaloids have been isolated. Pinnatoxins and pinnamine, potent shellfish poisons, were purified from the Okinawan bivalve Pinna muricata. Pinnatoxins activate Ca²⁺ channels. Halichlorine was isolated from the marine sponge Halichondria okadai. This compound inhibits the induction of VCAM-1. Drugs that block VCAM-1 may be useful for treating coronary artery diseases, angina, and noncardiovascular inflammatory diseases. Pinnaic acids, which are cPLA₂ inhibitors, were also obtained from P. muricata. Interestingly, the structures of pinnaic acids are closely related to that of halichlorine. Norzoanthamine hydrochloride, isolated from the colonial zoanthid Zoanthus sp., suppresses decreases in bone weight and strength in ovariectomized mice, and could be a good candidate for an osteoporotic drug. Ircinamine, purified from the marine sponge Ircinia sp., has a reactive thioester. Aburatubolactams, inhibitors of superoxide anion generation, were isolated from Streptomyces sp. This article covers the bioactive marine alkaloids that have been recently isolated by this research group.     

Impact of fresh and aged palm shell biochar on N2O emissions,soil properties,nutrient content and yield of Komatsuna (Brassica rapa var. perviridis) under sandy soil conditions

ABSTRACT

Biochar can reduce N₂O emissions and it can be added to the soil once, whereas fertilizers are often applied every cultivation season. The aging of biochar in soil affects its functioning but it is unclear whether palm shell biochar (PSB) could still mitigate N₂O emissions even when additional basal N fertilizers are applied 1 year after the initial biochar application. We studied the impact of fresh and aged PSB (0%, 6%, 12%, and 18% w/w of dry soil) on N₂O emissions, soil properties, nutrient content and yield of Komatsuna (Brassica rapa var. perviridis) under sandy soil conditions. The aged PSB non-significantly reduced N₂O emissions but significantly offset soil acidification, and maintained a high soil nutrient status. Biochar application with fertilizer significantly increased plant tissue K and Ca content but decreased N, P and Mg content compared to the treatments without biochar. At higher application rates, biochar had negative effects on crop yield but as it aged, the negative effects were offset as a result of the similar variation in plant N uptake. Since seasonal N fertilizer application seems to be inevitable in Komatsuna cultivation, addition of biochar could be a possible way of counteracting the effects of excessive fertilizer use. Further research is needed to assess the feasible biochar application rates for Komatsuna fields in various soil types under field conditions.     

Studies on inter-relationship of various ions in absorption by tobacco plants IV

The foliar symptoms of magnesium deficiency occur not only by the decrease in the contents of exchangeable magnesium in soil, but the antagonistic interaction among the nutrient elements in absorption. The relationship between phosphorus and magnesium in absorption was reported previously (1). In this paper influence of potassium and calcium on the magnesium absorption of tobacco plant was investigated.     

Effect of chloropicrin fumigation on microbial communities evaluated by community-level physiological profile and the resistance against fusarium wilt

Different microbial communities characterized by the Biolog pattern were developed in the rhizosphere of radish grown on a rockwool hydroponic system treated with chloropicrinfumigated and non-fumigated soil suspensions although no differences were observed in their viable counts. Different microbial communities also were developed in the rhizosphere and non-rhizosphere. After the development of microbial communities in the rhizosphere, bud cells of Fusarium oxysporum that causes vascular wilt of radish plants were inoculated, and disease symptoms were examined. Treatment with the non-fumigated soil suspension was much more effective than that with the fumigated one in controlling the disease, indicating that the Biolog method might be applicable to characterize microbial communities that control the disease caused by F. oxysporum.     

Studies on interrelationship of various ions in absorption by tobacco plants (Part 1) relation of nitrogen forms and cation levels in culture solution

The nutrient absorption by tobacco plants is sensitve to the condition of culture media, as a close absorbing relationship is kept among various nutrient elements. Tobacco plant, comparing with other plants, contains inorganic bases in its tissue in especially large amounts as against other inorganic elements. The reciprocal proportion of various bases has a great influence upon the growth and the quality of the leaf.     

Relationships between the translocation of photosynthetic products and the nicotine synthesis in tobacco plants

Nicotine in the tobacco plant is synthesized in the root using the carbon source translcated from the shoot (1). The incorporation of ¹⁴C assimilated from CO₂ into nicotine (2,3) and the translocation of ¹⁴C in the tobacco plant (4,5) have been well studied by many workers. It seems, however, that there has been no report on the relationships between the translocation of ¹⁴C, especially into the root, and the incorporation of ¹⁴C into the nicotine.     

Translocation of serine from leaves to roots in tobacco plants

It has been reported that nitrogen in the leaves of tobacco plant was translocated to the stem and root during the ripening period (1). Free amino acids in the leaves would play an important role in the translocation of nitrogen. It was also reported that the amino acids injected into the tobacco leaves were translocated to the roots (2,3). It seems probable that the translocation of amino acids would be characteristic among the individual amino acid. As reported previously, ¹⁴C assimilated in the leaves is translocated rapidly to the roots (2). Although it has been well known that the photosynthetic product was translocated mainly in the form of sugar, possibility that a part of photosynthetic products is translocated in the form of amino acid would be expected, because the carbon is incorporated rapidly into some of the amino acids, such as glycine, serine and alanine (4).