海南岛1961～2011年气候变化特征分析

应用线性倾向估计、M-K突变检验和Morlet小波函数变换分析了海南岛1961~2011年的年平均和四季平均气温、年平均最高气温、年平均最低气温、年平均和四季降水量、年降水日数、年强降水日数、年降水强度等气象要素的时间序列变化特征。结果表明:(1)近51 a来海南岛气候变暖趋势明显,通过信度为0.05的显著性水平检验,其中,年平均最低气温和冬季平均气温的上升趋势最为显著,气候倾向率分别为0.28℃/10 a和0.29℃/10 a;各气温要素均在20世纪80年代后期发生突变,并存在3~4 a和12 a时间尺度的周期变化。(2)年平均和四季降水量呈微弱的线性增加趋势,而达到暴雨等级的年强降水日数和年降水强度线性增加趋势明显,分别通过了信度为0.05和0.01的显著性水平检验。(3)四季降水量和年降水日数存在12~14 a时间尺度的周期变化,年降水量、年强降水日数和年降水强度存在8~10 a时间尺度的周期变化,同时,各个要素均叠加有周期较小的高频振荡。     

梅山猪氨肽酶基因N(pAPN)cDNA克隆、序列分析及重要变异位点的筛选

氨肽酶N(aminopeptidase N,APN)蛋白是猪(Sus scrofa)传染性胃肠炎病毒(Transmissible gastroenteritis virus,TGEV)和猪的流行性腹泻病毒(Porcine epidemic diarrhea virus,PEDV)等一系列冠状病毒的受体蛋白。为探讨梅山猪APN基因的分子结构特征以及重要的变异位点,本研究通过PCR扩增和测序技术,结合生物信息学分析梅山猪APN基因功能区域和重要变异位点,对其蛋白质结构进行预测和分析。结果表明,梅山猪APN基因cDNA全长2 886 bp(GenBank登录号:KF280271),含有20个外显子,编码961个氨基酸。与GenBank数据库公布的标准序列(登录号:NM_214277.1)相比,梅山猪APN基因编码区变异共引起10处氨基酸突变与2处氨基酸缺失,其中Phe82Asn、Leu107Phe、Leu108 Ile、Ser330Pro、Trp399Arg和Glu465 Gly等6处突变位于APN酶催化活性区域,Gln747His突变、748Tyr和749Ser缺失突变位于APN病毒结合区域。蛋白结构和编码产物功能分析发现,pAPN为不稳定的亲水性蛋白,无信号肽,具有1个跨膜螺旋(跨膜区位于12~34氨基酸,二级结构元件以α螺旋和β折叠为主,编码产物主要参与细胞被膜(cell envelope)、中央中间代谢(central intermediary metabolism)、辅酶因子生物合成(biosynthesis of cofactors)等功能。Gln747His、748Tyr和749Ser缺失突变可能与氨肽酶N结合病毒能力有关。本研究对梅山猪pAPN基因功能的分析及变异位点的筛选,为今后筛选猪抗病毒性腹泻的有效遗传标记提供理论基础。     

1961～2013年天峻地区降水变化特征分析

利用青海省天峻县1961~2013年月降水数据,采用线性倾向估计和Mann-Kendall突变检验等方法,对天峻县53a来降水量的年、季、汛期和月变化趋势进行了分析。结果表明:天峻县降水的年和季节变化特征明显;夏季、汛期和年降水量呈显著的上升趋势,主要是7月份降水量变化造成的;冬季降水波动较大,夏季降水相对稳定;进入21世纪00年代后期,年、夏季和汛期降水量增加趋势明显,突变时间均发生在90年代中期。     

Occurrence of weak mutators among avian pathogenic Escherichia coli (APEC) isolates causing salpingitis and peritonitis in broiler breeders

A collection of 46 avian pathogenic Escherichia coli (APEC) isolates was examined for the presence of mutators by determining the rate of mutation to rifampicin resistance. The collection included 34 E. coli isolates obtained in pure culture from chronic lesions of salpingitis and peritonitis in 34 broiler breeders, of which 12 were associated with the development of secondary septicemia. Twelve additional isolates were obtained from a clonal outbreak (ST95) of E. coli peritonitis syndrome (EPS), the lesions of which changed gradually over time into a subacute/chronic form. The hypothesis of the present study was that mutation rates would be higher for chronic infection isolates than for isolates from acute infections/exacerbations. The distribution of mutation rates followed a pattern similar to that found for other clinical isolates of E. coli, with a modal/median value of 1.47 × 10⁻⁸. Of the 46 isolates, 24% (n = 11) were weakly hypermutable (2.00 × 10⁻⁸ ≤ μ < 2.00 × 10⁻⁷), however, no strong mutators were detected (μ ≥ 2.00 × 10⁻⁷). Chronic salpingitis isolates had the highest proportion (45%, P = 0.001) of weak mutators and also, significantly higher mutation rates (P = 0.003) compared to isolates that caused septicemia (4%). In addition, mutation rates were significantly lower among ST95 isolates (P < 0.0005), and among isolates from the same clonal group as ST95 (P = 0.027), when compared to isolates from other groups. Although a clear association with the time phase of infection (as lesions of EPS became more chronic) could not be observed (ρ = 0.523, P = 0.081), a higher frequency of weak mutators among chronic infection isolates suggests that increased mutation rates play a role in adaptation of APEC to long-term persistence in an infected host environment.     

Ehlers-Danlos Syndrome in a Quarter Horse Gelding: A Case Report of PPIB-Independent Hereditary Equine Regional Dermal Asthenia

A Quarter Horse gelding presented with pathology consistent with hereditary equine regional dermal asthenia (HERDA) but without the familial association typically present with this disease. Grossly, lesions exhibited either a firm, scar-like appearance or a potential space between the superficial and deep dermis. Both lesioned and non-lesioned skin showed evidence of edema and collagen fragmentation, whereas lesions were also characterized by hemorrhage and inflammation. Genetic testing was performed by three independent laboratories, each using different methods to detect the mutation described in the PPIB gene, previously shown to be associated with HERDA. No mutations in the PPIB gene were revealed by genetic testing, either at the known location of the point mutation or at any other location in the coding sequence. These findings are suggestive of a diagnosis of HERDA or hyperelastosis cutis in the absence of the well-described, putatively causative mutation in the PPIB gene. We propose that, whereas HERDA refers specifically to a familial disease caused by a mutation in the PPIB gene, similar symptoms may in fact be caused by a syndrome resulting from either inherited or spontaneous mutations in any of a number of collagen-processing genes. We conclude that Ehlers-Danlos syndrome be diagnosed in horses of any breed with HERDA-like pathology without the causative mutation.     

家蚕心形眼纹(ces)的遗传与基因定位研究

通过对家蚕基因资源库保存品系的性状调查,发现一种幼虫眼状纹变异——心形眼纹(cordiform eye-spot,ces),其特征是:幼虫眼纹呈倒心型,相当于正常型眼纹的中间部分,色浅。与正常型进行杂交试验,表明该突变为隐性遗传,外显率稍低;与各染色体标记基因进行连锁分析,确认突变基因ces属于第14染色体;育成青熟油蚕(oa)与ces的双隐性系统后,通过ces与oa和Nd-s(丝胶茧)的三点测验,初步将ces基因定位于家蚕连锁图谱第14连锁群的50.7 cM位点,表示为ces(14-50.7)。     

植物诱变育种研究进展

简述了诱变育种的发展现状,系统介绍了辐射诱变、化学诱变和航天诱变的特点、诱变机理、生物学效应及其在植物育种中的应用。     

离子注入诱变改良农业微生物的研究进展及应用前景

离子注入生物体诱变是人工诱变的新方法,利用其可以获得较高的突变率,扩大突变谱,从而为筛选优良的突变菌株提供了更广阔的空间。该研究综述了离子注入诱变微生物的机理、生物学效应和近年来该技术应用于农业微生物诱变改良的实例,同时分析了今后离子注入在农业微生物诱变育种工作中的发展前景。     

氮离子注入五叶茄子诱变育种遗传规律研究

以35keV的氮离子辐照五叶茄种子,M1代的生长势明显增强,出现了早熟大果变异株.M2代出现了大量分离,分离率高达97.7%,M3代分离率小于10%,早熟变异果和大果性状稳定,变异率小,已初步形成两个新品系.     

氮离子注入番茄M1代的生物学效应

对番茄 N+离子注入诱变效应进行了研究。结果表明 ,番茄单果重、座果数等性状变幅大、变异率高 ;而对发芽率和果实的品质性状影响较小。并以 4× 10 1 6N+/cm2 、6× 10 1 6N+/cm2 剂量处理 ,产量提高明显。但不同品系 ,不同性状的最佳诱变剂量略有不同。