家蚕肾脏形卵(ki)的荧光差异显示研究

为了探明家蚕（Bombyx mori)肾脏形卵的胚子不能正常发育的原因。使用FDD（flourescent different display)法对ki(kidney)基因同质型与异质型的母蛾所产未受精卵及受精24h卵的mRNA进行了差异显示研究。通过137组引物组合进行FDD差异显示，结果检出8254条扩增带。其中未受精卵与受精后24h卵之间的差异片段为206条，占总片段数的2．5％，而ki同质型与ki异质型的差异片段为141条，占总片段数的1．7％，其余的95．8％的扩增片段为4方共有，并且约60％的差异带是比较清晰的。回收了较明显的差异片段计199条，占总扩增带数的2．4％，并对其中部分差异片段进行序列分析表明，其中5个克隆序列分析为：small heat shock proteins,proprotein convertase,cancer antigen like protein fusion RNA-binding protein及receptor like protein kinase同源序列，其余5个克隆序列未发现同源性，可能是新基因。     

Nitrous oxide (N<Subscript>2</Subscript>O)-reducing denitrifier-inoculated organic fertilizer mitigates N<Subscript>2</Subscript>O emissions from agricultural soils

The only known sink for nitrous oxide (N₂O) is biochemical reduction to dinitrogen (N₂) by N₂O reductase (N₂OR). We hypothesized that the application of N₂O-reducing denitrifier-inoculated organic fertilizer could enhance soil N₂O consumption while the disruption of nosZ genes could result in inactivation of N₂O consumption. To test such hypotheses, a denitrifier-inoculated granular organic fertilizer was applied to both soil microcosms and fields. Of 41 denitrifier strains, 38 generated ³⁰N₂ in the end products of denitrification (³⁰N₂ and ⁴⁶N₂O) after the addition of Na¹⁵NO₃ in culture condition, indicating their high N₂O reductase activities. Of these 41 strains, 18 were screened in soil microcosms after their inoculation into the organic fertilizer, most of which were affiliated with Azospirillum and Herbaspirillum. These 18 strains were nutritionally starved to improve their survival in soil, and 14 starved and/or non-starved strains significantly decreased N₂O emissions in soil microcosms. However, the N₂O emission had not been decreased in soil microcosms after inoculating with a nosZ gene-disruptive strain, suggesting that N₂O reductase activity might be essential for N₂O consumption. Although the decrease of N₂O was not significant at field scales, the application of organic fertilizer inoculated with Azospirillum sp. TSH100 and Herbaspirillum sp. UKPF54 had decreased the N₂O emissions by 36.7% in Fluvisol and 23.4% in Andosol in 2014, but by 21.6% in Andosol in 2015 (H. sp. UKPF54 only). These results suggest that the application of N₂O-reducing denitrifier-inoculated organic fertilizer may enhance N₂O consumption or decrease N₂O emissions in agricultural soils.     

Peroxide Concentrations in Fog Water at Mountainous Sites in Japan

Measurements of peroxide concentrations in fog water were conducted near the summit of Mt. Norikura (altitude, 2770m) in central Japan, and at the midslope of Mt. Oyama (altitude, 680m), southwest of the Kanto Plain. The concentrations of peroxide at Mt. Norikura, far from industrial regions, ranged from 3 to 120 µ M during the summer and early autumn in 1993. The potential capacity for SO₂ oxidation appears to be very high near the summit of Mt. Norikura. Analysis of the chemical composition of three-stage size-fractionated fog water samples collected at Mt. Norikura showed that the concentrations of peroxide were apparently independent of droplet size, whereas the concentrations of chemical constituents mainly derived from secondary aerosols and the acidity were higher in smaller droplets. Peroxide concentrations in fog water were low (< 5 µ M) at Mt. Oyama, located near heavy industrial areas, and lower than those in rain water sampled simultaneously (0.2–33 µ M). Especially, peroxide was scarcely detected in strongly acidic fogs (< 0.2 µ M). Peroxide might have been decomposed by SO₂ (S(IV)) oxidation in the aqueous-phase.     

Principal soil types (Great soil groups) in Japan

Classified into three types, zonal, intra-zonal, and azonal, Japanese soil type may be explained as follows (see “General map of principal soil types”).     

The Presence of a New S-RNase Allele (S10) in Asian Pear (Pyrus pyrifolia (Burm; Nakai))

A PCR (polymerase chain reaction) amplification method using newly designed S-RNase primers was carried out in five Korean-bred pear cultivars and ten Japanese-bred pear cultivars. A new S-RNase allele, designated as S₁₀, was discovered from ‘Chengsilri’, containing a 1513 bp and two exons (213 bp in total) that coded for a peptide of 71 amino acids. The S₁₀-RNase allele contained the three conserved cysteine residues peculiar to S-RNase in Japanese pear and one histidine residue essential for RNase activity. We compared nucleotide sequence similarity of the exon regions of ten pear S-RNase alleles. The nucleotide sequence of S₁ showed a high similarity to S₄ (97.4%) and the new S₁₀ shows 77.8% (S₅) to 84.4% (S₄) similarity with the other pear S-RNase alleles. S₁₀ had a unique restriction endonuclease site for ‘HhaI’, with digests yielding fragments of 1235 and 491 bp. The S-genotype of pear cultivar (‘Chengsilri’) was determined to be S₅S₁₀ by PCR–RFLP (restriction fragment length polymorphism). Cluster analysis of 49 known S-RNase alleles of the Rosaceae separated into two divergent groups are as follows: group I: pear and apple, group II: almond, sweet cherry and mume.     

低分子量热激蛋白Bmhsp19.9基因的表达

利用RT-PCR技术，对家蚕(Bombyx moil)低分子量热激蛋白Bmhsp19．9基因进行了定量表达分析。Bmhsp19．9在各组织中均有一定量的表达，但不同组织间的表达差异达10多倍，表达量丰富的组织是生长发育旺盛的组织，如精巢和卵巢，然后是丝腺、蛹等组织。其应激表达模式可分为3类，以其在精巢、后部丝腺和脂肪体中的强应激表达模式为主，经热刺激处理后其表达量有显著增加。经刺激诱导2h后其表达量达到最高，随后逐渐降低，在热刺激诱导12h后是未刺激的2～3倍，而此时Bmhsp19．9在脂肪体中的应激表达是其对照的10多倍。根据Bmhsp19．9在不同组织中的基本表达量、应激表达量和应激表达的持续时间各不相同，显示其与细胞分裂与分化等生命活动有一定联系。并认为其在后部丝腺、脂肪体、精巢、卵巢与血液中作用方式不一样，推测其作为分子伴侣在组织间的作用对象与作用效应也应有所差异。     

自动化机械发酵食醋过程中品质变化规律

为全面了解转鼓式反应器固态发酵食醋过程中主要成分和风味物质的动态变化规律,该文对反应器发酵食醋过程进行跟踪取样,利用高效液相色谱、固相微萃取技术、气相色谱-质谱联用技术,对酒精、总酸、还原糖、氨基态氮、有机酸、挥发性风味物质含量变化进行实时监测,结合主成分分析方法,探究食醋不同发酵阶段的风味物质差异。结果表明,酒精含量在发酵0～4 d内迅速增加,随后逐渐下降至零;总酸含量呈现先快速上升后缓慢上升的趋势;还原糖含量呈先快速下降后逐渐上升,最后逐渐下降的趋势;氨基态氮呈现先快速上升后缓慢上升的趋势;乙酸和乳酸是主要的有机酸,整个发酵过程中,乙酸含量持续增加,乳酸含量呈先上升后下降趋势,其他有机酸含量较少,发酵期间变化波动相对较小;共检测出64种挥发性风味物质,包括酯类25种,醇类12种,酸类6种,酚类5种,醛类5种,酮类6种,杂环类5种;发酵前、中、后期的重要挥发性物质分别是醇类化合物、酯类和醛类化合物、酸类化合物。该结果为推进转鼓式固态发酵食醋反应器的实际生产应用提供了理论基础和数据参考。     

The antiproliferative effect of bovine lactoferrin on canine mammary gland tumor cells

Lactoferrin has several biological activities, including antitumor activities in some human and animal tumor cells. Clinical trials have been carried out in human medicine based on these effects. However, the antitumor effects of lactoferrin in veterinary medicine remain unknown. In this in vitro study, we demonstrated that co-incubation of canine mammary gland tumor cells (CIPp and CHMp) and bovine lactoferrin induced growth arrest of tumor cells. This growth arrest was associated with induction of G1 arrest. Furthermore, this effect was stronger in tumor cells than in normal cells. These findings demonstrate that bovine lactoferrin has anti-tumor activity in canine mammary tumors and has the potential for use in tumor-bearing dogs.     

Partial characterization of phylogeny,ecology and function of the fibrolytic bacterium Ruminococcus flavefaciens OS14, newly isolated from the rumen of swamp buffalo

The fibrolytic rumen bacterium Ruminococcus flavefaciensOS14 was isolated from swamp buffalo and its phylogenetic, ecological and digestive properties were partially characterized. Isolates from rumen contents of four swamp buffalo were screened for fibrolytic bacteria; one of the 40 isolates showed a distinctive feature of solubilizing cellulose powder in liquid culture and was identified as R. flavefaciens based on its 16S ribosomal DNA sequence. This isolate, OS14, was employed for detection and digestion studies, for which a quantitative PCR assay was developed and defined cultures were tested with representative forages in Thailand. OS14 was phylogenetically distant from other isolated and uncultured R. flavefaciens and showed limited distribution among Thai ruminants but was absent in Japanese cattle. OS14 digested rice straw and other tropical forage to a greater extent than the type strain C94 of R. flavefaciens. OS14 produced more lactate than C94, and digested para grass to produce propionate more extensively in co‐culture with lactate‐utilizing Selenomonas ruminantium S137 than a co‐culture of C94 with S137. These results indicate that phylogenetically distinct OS14 could digest Thai local forage more efficiently than the type strain, possibly forming a symbiotic cross‐feeding relationship with lactate‐utilizing bacteria. This strain might be useful for future animal and other industrial applications.     

Prevalence and risk factors associated with Cryptosporidium oocysts shedding in pigs in Central Vietnam

We investigated the prevalence and risk factors associated with Cryptosporidium oocysts shedding in pigs in Central Vietnam. A total of 740 single fecal samples collected from diarrheic and non-diarrheic pigs on 89 farms were screened by the modified Ziehl-Neelsen staining method. Prevalence at the animal and the farm levels were 18.1% (134/740) and 71.9% (64/89), respectively. Risk factors for the infection were identified using univariate and multivariate logistic regression analysis. The results revealed that age, sanitary condition and topography were significantly associated with oocyst shedding (P<0.05). Pre-weaned piglets were at the highest risk for infection, followed by post-weaners, sows and finishing pigs. Good sanitary conditions showed positive effects in decreasing oocysts shedding. Topographically, Cryptosporidium was more common in mountainous zone than that in coastal delta zone. There was an association between the occurrence of diarrhea and the level of Cryptosporidium oocyst excretion within infected pigs. This is the first epidemiological investigation of prevalence and risk factors of Cryptosporidium in pigs in Vietnam.