小麦体细胞无性系的DNA突变

采用mRNA差异显示和SSR（微卫星）技术,比较了小麦品种丰抗8号及其幼胚培养突变系第R8代株系的基因编码区和非编码区的核苷酸序列,证明突变系的DNA序列存在大量的突变,突变类型为：嘌呤与嘧啶相互转换、核苷酸片段缺失、增加核苷酸片段.DNA序列的突变揭示了突变系农艺性状和生理生化方面变异的分子基础.     

Defect of the mitochondrial DNA hypervariable region as a risk factor for canine mammary tumour

The aim of this study was to identify mutations in the hypervariable region of mitochondrial DNA in canine mammary tumours and to determine their association with the process of neoplastic transformation. A total of 93 biological samples, including blood as well as normal and neoplastic tissue samples from 31 dogs with diagnosed malignant canine mammary tumours were analysed. DNA extraction, amplification and sequencing of the D‐loop as well as bioinformatic and statistical analyses were performed. In the mitochondrial D‐loop sequence, 26 polymorphic loci and 5 mutations were identified. For the first time, D‐loop length heteroplasmy was detected in dogs with mammary tumours. The malignancy grade exerted no effect on the presence of nucleotide changes. A statistically significant association between the presence of mutations and polymorphisms and the size of dogs was demonstrated. The 100% frequency of length heteroplasmy may imply that this is a hotspot mutation of canine mammary tumour.     

Intergenerational differences of color sensation and preference for naturally dyed fabrics

This study was performed in order to evaluate subjective color sensation and preference for yellowish and reddish natural dye fabrics and to provide meaningful objective colorimetric properties which can quantify the sensation and preference focused on intergenerational differences. Among lots of natural dye silk fabrics, four differently dyed fabrics for each hue were used as specimens by cluster analysis. College students as younger generation and high school teachers as middle-aged evaluated them subjectively in terms of eight aspects color sensation such as clearness, lightness, depth, warmth, strength, brightness, hardness, and fragrance. Intergenerational differences appeared more frequently as for the lightest and the most saturated yellowish fabrics dyed with amur cork than any other fabrics. All of sensation and preference were significantly explained by some colorimetric properties for each generation. Color lightness, L* was the only positive predictor for color preference of younger generation’s preference whereas color saturation, C* illustrated negatively for that of middle-aged.     

Fluorescence detection of a new photosensitizer, PAD-S31, in tumour tissues and its use as a photodynamic treatment for skin tumours in dogs and a cat: a preliminary report

We describe here the detection by fluorescence of a new photosensitizer, PAD-S31, in tumours in dogs and cats and the effect of photodynamic therapy (PDT) by using PAD-S31 for skin tumours in two dogs and one cat. PAD-S31 is a hydrophilic photosensitizer that has two peaks at absorption wavelengths 406 and 665 nm in distilled water. In a preliminary experiment in mice transplanted with SCCVII and colon 26, PAD-S31 was retained in tumour tissues rather than in other organs. The tumours resected from dogs and cats after intravenous administration of PAD-S31 at a dose of 15 mg/kg emitted strong red fluorescence under light illumination of 402 nm wavelength. Animals given PAD-S31 showed no cutaneous photosensitivity under room light illumination. Irradiation at laser light 670 nm wavelength (fluence rate 150 mW/cm2 and total light dosage 150 J/cm2) on cutaneous mast cell tumours in dogs ( n=2 ) and a cutaneous basal cell tumour in a cat induced complete remission. These results suggest PAD-S31 could be a promising photosensitizer for use in a small animal veterinary practice.     

Effects of previous forest types and site conditions on species composition and abundance of naturally regenerated trees in young <Emphasis Type="Italic">Cryptomeria japonica</Emphasis> plantations in northern Japan

Naturally regenerated trees in young Cryptomeria japonica plantations were investigated in 141 quadrats of 10 × 50 m within a watershed of 1,000 ha, and factors affecting their composition and abundance were examined. The species composition of naturally regenerated trees was classified into four types. Dominant species were Swida controversa, Magnolia hypoleuca and Pterocarya rhoifolia in Type A1, Betula maximowicziana, M. hypoleuca, Quercus crispula and Castanea crenata in Type A2, Q. serrata and C. crenata in Type B1, and Pinus densiflora in Type B2. The results of path analysis showed significant influences of previous forest type and geology among the factors that correlated with the species composition of naturally regenerated trees; previous forest type in particular showed a higher absolute path coefficient value. Species composition types of naturally regenerated trees corresponded to the previous forest types: Types (A1 and A2) corresponded to the natural forests composed of Thujopsis dolabrata var. hondai, Fagus crenata, Aesculus turbinata, etc., Type B1 corresponded to the secondary Q. crispula and Q. serrata forest, and Type B2 corresponded to the secondary P. densiflora forest, respectively. The abundance of naturally regenerated trees was strongly affected by geology; i.e., plantations on soft-sedimentary dacitic tuff contained great amounts of colonizing P. densiflora trees.     

Impact of genomics on the study of plant nutrition. 7. Practical use of naturally occurring genomic variation in plant nutrition

(Jpn. J. Soil Sci.Plant Nutr., 77, 343–349, 2006)     

沙门氏菌耐药株gyrA基因和parC基因突变特征分析

提取沙门氏菌染色体DNA，设计引物扩增gyrA基因和parC基因片段，克隆测序寻找耐药菌株的突变位点，通过系统的比较，分析氟喹诺酮类药物（以环丙沙星为代表）对各沙门氏菌MIC和耐药突变位点之间的关系。通过对耐药突变位点的研究，可以为下一步研究耐药性监测的快速方法提供理论基础。     

养蟹稻田稻飞虱发生规律研究

通过系统调查和大田普查相结合的方法，研究明确了养蟹稻田稻飞虱的发生规律。养蟹田和非养蟹田稻飞虱的发生期基本一致。由于螃蟹对稻飞虱的控制作用，养蟹稻田稻飞虱的发生量比不施药对照田明显偏低，一般发生年份，不用药防治，即可控制稻飞虱的为害。养蟹田稻飞虱的分布与距养殖沟的距离呈显著的正相关。距养殖沟越远，虫量越高，防治时应注意区别对待。     

Myostatin基因及其与动物双肌性状间关系的研究进展

肌肉生长抑制素（myostatin,MSTN）又称生长分化因子8（growth differentiation factor 8,GDF-8）,属于转化生长因子β（transforming growth factor β,TGF-β）超家族成员,由McPherron等在1997年筛选小鼠肌肉cDNA文库时首次发现。目前已研究过的不同哺乳物种间的MSTN基因结构均含３个外显子和２个内含子,且成熟肽氨基酸序列的差异均在3个以内。MSTN在多个组织中表达,包括心肌、脂肪、胎盘、乳腺、子宫、嗅觉神经细胞、肝、脾、肺和肾等,主要在骨骼肌中高水平表达。MSTN的成熟包括由信号肽酶、前蛋白转化酶Furin和金属蛋白酶BMP-1/tolloid家族的酶解和加工,成熟的MSTN为同质二聚体化。MSTN的最显著作用是作为骨骼肌的强有力的负调控因子,可通过自分泌或旁分泌的方式激活TGF-β、p38 MAPK、ERK1/2、和JNK等信号途径及抑制IGF-AKT和Wnt信号途径,协同抑制成肌细胞的增殖和分化。MSTN基因敲除小鼠的肌肉重量显著增加而表现为双肌性状,并可通过增强肌肉再生和降低纤维化的方式提高肌肉愈伤能力;糖的消耗和糖摄入加强,且对胰岛素的敏感性加强;心脏增大且压力应激增强;脂肪重量减轻,脂肪发生受到抑制,且白色脂肪组织的黄化加强而能够促进生热作用;骨密度和骨矿物质含量增强,并可增加骨折骨痂的尺寸和强度而促进骨折的愈合。MSTN还可通过调控胎盘的建立和葡萄糖的摄入、调控子宫平滑肌细胞和内膜上皮细胞的增殖及乳腺的发育,参与雌性哺乳动物的生殖调控。自然发生的MSTN基因功能缺失型纯合突变也能够引起动物表现双肌性状,已知的这些突变包括牛的p.D273RfsX13(也称nt821(del11))、p.C313Y、p.F140X(也称nt419(del7ins10))、p.Q204X、p.E226X和p.E291X突变, 绵羊的c.960delG(也称p.K320NfsX39)和c.120insA（也称p.N40MfsX9）突变,狗的c.939-940delTG突变和人类的c.373+5G＞A突变;此外在绵羊中还存在一个靶向MSTN基因的miRNA功能获得型纯合突变c.2360G＞A(也称g.6223G＞A)也可引起双肌性状。双肌动物在19世纪初就已记载,不仅表现有更多的肌肉,而且有更少的骨骼和脂肪,然而双肌性状也会带来一些缺点,包括产奶率下降、雌性繁殖力下降、难产增加和幼畜死亡率增加,因此运用基因工程技术合理优化MSTN功能的发挥且又降低双肌性状副作用的方法来培育优质肉用家畜品种一直是研究热点。在牛中还存１个保守性错义突变p.F94L,并不会改变MSTN的功能,所以不会发生双肌表型的副作用,但可引起肌肉重量增加,并降低肌内和肌外的脂肪含量,且不会影响肉嫩度,因此目前p.F94L突变已较理想地用于肉牛的分子标记育种。本文综述了哺乳动物MSTN基因的结构、表达、信号转导、生理功能、突变体、双肌表型和在家畜育种中的最新研究进展,旨在为更深入理解哺乳动物MSTN作用机理及为肉用家畜品种的培育提供参考。     

Detection of resistance-associated point mutations of organophosphate-insensitive acetylcholinesterase in the olive fruit fly, Bactrocera oleae (Gmelin)

We have recently identified two resistance-associated point mutations of organophosphate (OP)-insensitive acetylcholinesterase in the olive fruit fly Bactrocera oleae, the most important olive orchard pest world-wide. We have developed simple PCR-restriction fragment length polymorphism assays for each mutation, utilising an AccI restriction site created by Ile214Val, and a BssHII restriction site destroyed by a neutral change always accompanying the second mutation Gly488Ser. Samples from Greece homozygous for both mutations proved the most insensitive to dimethoate. The frequencies of these mutations in field-collected samples from several countries were investigated. Ninety-three percent of samples from Greece and Albania, where OPs have been extensively used in B. oleae control, were homozygous for both mutations. Resistance-associated alleles were detected at lower frequencies, but still with both mutations in conjunction in the majority of cases, in western Mediterranean countries with limited use of OPs. Samples from South Africa, however, did not have either of the resistance-associated mutations. The double mutation haplotype clearly confers a strong selective advantage in field populations of B. oleae exposed to OPs.