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【目的】植物的几丁质酶与其抗病能力、防御反应和生长发育密切相关,本文通过生物信息学方法来研究柑橘几丁质酶基因家族成员的性质。【方法】通过检索柑橘全基因组序列,发现了32个几丁质酶基因,使用生物信息学软件对这些基因进行分子量、等电点、信号肽、细胞定位、转录谱、保守结构域、系统发育树等方面进行研究。【结果】该家族基因中有26个成员定位在染色体上,其余6个位置尚未确定。这些几丁质酶基因家族成员的蛋白分子量、氨基酸残基和等电点分别位于14.8～72.7KDa、134～636个和4.53～9.21之间。。除3个预测蛋白不含信号肽外,其余均含有信号肽,其中23个蛋白定位在细胞外,6个蛋白横跨细胞膜。对这些基因在花、叶、果实和愈伤等组织的转录组测序数据进行分析,发现它们的转录水平相差巨大,有的在几种组织中转录水平都很高,有的在不同组织中转录水平相差很大,有的在所有组织中表达量都很低。用最大似然法对蛋白序列构建系统发育树,结合保守结构域的分析结果,可将这些几丁质酶基因分为4类。第1类有信号肽且定位在细胞外,有GH18几丁质酶结构域,同时具有糖基水解酶的功能;第2类大部分是带信号肽的跨膜蛋白,也有GH18几丁质酶结构域,还有一个丝氨酸/苏氨酸激酶的结构域;第3类带信号肽且定位在细胞外,有GH19几丁质酶结构域,同时具有溶菌酶的活性;第4类仅有一个基因,是个无信号肽的跨膜蛋白,有GH18几丁质酶结构域,同时具有糖基水解酶的功能,除此之外还含有抗病蛋白中常见的PPR重复结构域。【结论】对柑橘几丁质酶家族进行分析,有助于了解几丁质酶抗病的分子机制,找出起主效抗病作用的几丁质酶基因,从而为提高柑橘的抗病育种提供帮助。 相似文献
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为研究家蚕核型多角体病毒(BmNPV)orf126基因(Bm126)在感染宿主中的作用机制,采用PCR方法从BmNPV陕西株中克隆了切除N端23个氨基酸(预测信号肽序列)的Bm126基因,并将其和谷胱甘肽巯基转移酶(GST)融合后在大肠杆菌中进行了表达。利用纯化的BM126重组蛋白与几丁质进行体外结合实验,Western blot分析没有检测到BM126重组蛋白与几丁质结合的复合物,推测原核表达的重组BM126融合蛋白在体外不能与几丁质结合。 相似文献
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家蚕GH18家族几丁质酶的系统进化和BmChi的时期表达分析 总被引：2，自引：0，他引：2
昆虫GH18家族几丁质酶主要参与昆虫蜕皮、细胞增殖和免疫等生理过程。为了系统开展家蚕GH18家族基因的研究,通过多物种几丁质酶的系统进化分析鉴定了8个家蚕GH18家族成员,并根据含有糖苷水解酶18(Glyco_18)催化结构域和几丁质结合结构域的不同将其分为6类,其中,各物种的CHT5具有典型几丁质酶结构。家蚕GH18家族成员中,BmChiR-1具有5个Glyco_18催化结构域和6个几丁质结合结构域,其它7个成员均只有1个Glyco_18催化结构域,BmCHT12还有1个ChitnaseA_N端结构域。8个家蚕GH18家族成员的基因分布在7条染色体上。通过半定量RT-PCR调查家蚕CHT5基因Bm-Chi在家蚕各发育时期的转录表达模式,该基因在蜕皮、化蛹、羽化等发育时期均有高水平表达,推测BmChi在蚕体旧表皮几丁质的降解过程中发挥重要作用。 相似文献
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几丁质是构成家蚕微孢子虫细胞壁的主要成分,广泛分布于原生生物、真菌、节肢动物和甲壳类生物之中,能够被几丁质酶(EC 3.2.1.14)水解。本文基于家蚕微孢子全基因组数据,采用生物信息学方法,鉴定获得家蚕微孢子虫几丁质酶基因,命名为Nb_chi。该基因有2个拷贝,其中一个Nb_chi_1长度为2 286bp,编码761aa,pI为6.35。含有一个信号肽以及一个Glyco_hydro_19结构域。另一个拷贝Nb_chi_2仅含552bp,183aa,仅含Glyco_hydro_19结构域部分,可能为一不完整的拷贝。系统进化分析显示,家蚕微孢子虫与其他种类的微孢子虫聚在同一个进化枝,均属几丁质酶第19族。本文为深入进行家蚕微孢子虫几丁质酶的功能研究奠定了基础。 相似文献
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几丁质酶基因在大肠杆菌中的表达及其酶对柱花草胶孢炭疽病原菌的？… 总被引：3，自引：0，他引：3
构建了几丁质酶基因植物表达载体,该基因大大肠杆菌中能表达３５ＫＤ的蛋白质。几丁质酶粗提高在体外对柱花草胶孢炭疽病原菌有极显著的抑菌效果。 相似文献
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为了研究家蝇几丁质结合蛋白(Md-CBPⅠ)在家蝇防御体系中的相关活性,采用PCR技术,对从鸡源沙门氏菌诱导家蝇幼虫构建的抑制性消减文库(SSH)中筛选到的家蝇幼虫几丁质结合蛋白Ⅰ基因(Musca domestica chitin binding proteinⅠ,Md-CBPⅠ)进行扩增,并成功构建了重组表达质粒p ET-32a-Md-CBPⅠ,于大肠杆菌BL21(DE3)中得以高效表达,纯化并获得了MdCBPⅠ融合蛋白。进一步对该蛋白的亲和活性进行了研究,发现Md-CBPⅠ融合蛋白对几丁质以及纤维素均有一定的结合作用,且其对几丁质的结合作用相对较好。试验为家蝇几丁质结合蛋白生物学活性和免疫学活性的研究奠定了基础。 相似文献
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利用低分子量的脱乙酰几丁质可取代聚-L-赖氨酸制作做囊,所得脱乙酰几丁质微囊与聚赖氨酸微囊相比有相似的优红蛋白通透性和较强的机械强度。脱乙酰几丁质微囊能包埋葡萄糖氧化酶而不使之逸出。脱乙酰几丁质的脱乙酰度、分子量、浓度和复膜时间及溶液的pH值对微囊的通透性有一定的影响,以分子量的影响最大。 相似文献
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Rosenbaum A Guard CL Njaa BL McDonagh PL Schultz CA Warnick LD White ME 《The Veterinary record》2005,157(21):652-655
Twenty-one rejected kidneys from 2426 slaughtered dairy cows (0.87 per cent) had gross signs of pyelonephritis that were confirmed by histopathology. In all the kidneys the findings were consistent with a chronic rather than an acute infection. One species of bacteria was cultured from 12 of the kidneys and two species of bacteria were cultured from six. The most commonly isolated bacteria were Escherichia coli, from eight kidneys, Arcanobacterium pyogenes, from seven kidneys and Corynebacterium renale, from five kidneys. The other bacteria cultured were Corynebacterium cystitidis, Corynebacterium species, Streptococcus species group G and Enterococcus faecalis. E. coli was cultured from all the kidneys from which two species were isolated; the accompanying bacteria were A. pyogenes in three kidneys, C. renale in two and C. cystitidis in one. No bacteria were cultured from two of the kidneys and no significant bacteria were cultured from another. The kidneys with pyelonephritis were slightly larger than a comparison group of 72 kidneys without nephritis. 相似文献
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Boqvist S Hansson I Nord Bjerselius U Hamilton C Wahlström H Noll B Tysen E Engvall A 《Acta veterinaria Scandinavica》2003,44(3-4):181-197
This paper presents Salmonella data from animals, feedstuffs and feed mills in Sweden between 1993 and 1997. During that period, 555 isolates were recorded from animals, representing 87 serotypes. Ofthose, 30 serotypes were found in animals in Sweden for the first time. The majority of all isolates from animals were S. Typhimurium (n = 91), followed by S. Dublin (n = 82). There were 115 isolates from cattle, 21 from broilers, 56 from layers and 18 from swine. The majority of these isolates were from outbreaks, although some were isolated at the surveillance at slaughterhouses. The number of isolates from the feed industry was similar to that of the previous 5-year period. Most of those findings were from dust and scrapings from feed mills, in accordance with the HACCP programme in the feed control programme. It can be concluded that the occurrence of Salmonella in animals and in the feed production in Sweden remained favourable during 1993-97. 相似文献
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Isolation of viruses from outbreaks of suspected tenosynovitis (viral arthritis) in chickens 总被引：1，自引：1，他引：0
Specimens from the legs of chickens from 84 outbreaks of suspected tenosynovitis were examined for the presence of viruses by culture in chick embryo lung or liver cell monolayers. All samples were from broilers or broiler breeders, ranging in age from dead-in-shell embryos to 36 weeks old. Twenty-five outbreaks (29.8 per cent) yielded viruses of which 12 were reoviruses alone, 12 adenoviruses alone, and one, a mixture of both types of virus. Rupture of the gastrocnemius tendon was seen in 12 outbreaks and viruses were isolated from six of these: three were reoviruses and three were adenoviruses. Approximately half the affected flocks from which specimens were received were in the six to 14 week age range. With one exception, all the reovirus isolations were made from chickens of 11 weeks or under, while adenovirus isolations showed more scatter with regard to age. 相似文献
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M L Thonney T C Perry G Armbruster D H Beermann D G Fox 《Journal of animal science》1991,69(12):4866-4870
Boneless rib eye steaks from 32 Holstein and 32 Simmental x Angus steers were evaluated by 55 supermarket meat managers. Within breed, steers were divided into light or heavy initial weights. Within initial weight groups, steers were either implanted with Revalor or not implanted. Steers were slaughtered commercially when they reached a small degree of marbling, and rib eye steaks were cut from the carcass and stored at -20 degrees C until the day before evaluation. After thawing overnight in a 0 to 4 degrees C cooler, uncooked steaks were randomly assigned to positions on paper plates. Each of the 55 evaluators was then told to record whether each steak was from a Holstein or a traditional beef breed. The percentage identified correctly was 50.9 +/- .96, which was not different from being random. Steaks were later assigned to blocks of eight treatments and cooked to an internal temperature of 68 degrees C before six or seven participants evaluated steaks from each block. Sensory attributes were acceptable for all steaks. Steaks from Holstein steers generally were superior to those from Simmental x Angus steers. Steaks from steers with heavy initial weights generally were superior to steaks from steers with light initial weights. Steaks from steers implanted with Revalor were slightly less acceptable than steaks from unimplanted steers for several sensory attributes, but the difference in overall acceptability was minor and nonsignificant. All the differences were small, and may have limited commercial relevance.(ABSTRACT TRUNCATED AT 250 WORDS) 相似文献
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Serological examination of 177 strains of haemolytic Escherichia coil from pigs from 95 piggeries showed that 50 isolates from 28 piggeries were agglutinated by serums prepared against 0141:K85ab, 45 from 20 piggeries by 0141:K85ac, 32 isolates from 19 piggeries by 08 and four isolates from two piggeries by 0139:K82. Forty-six strains from 26 piggeries were unclassified. Ninety strains were isolated from intestine and/or mesenteric lymph nodes and 87 from other organs. Of the 95 outbreaks associated with haemolytic E. coli, 41 were diagnosed as oedema disease, 40 as coli-enteritis and the remainder were miscellaneous conditions. The clinical and pathological features of outbreaks associated with colibacillosis and septicaemic salmonellosis were compared and discussed. 相似文献
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Angles of inclination were calculated from ventrodorsal (VD) and caudocranial horizontal beam (CaCrHB) radiographs of 17 anesthetized dogs, and from radiographs of left femurs of the same dogs positioned 0 degree, 10 degrees, 15 degrees, and 20 degrees from the cassette in the sagittal plane. Angles of inclination also were measured directly from radiographs of the bones rotated to correct for anteversion. Calculated angles of inclination from the bones at 10 degrees, 15 degrees, and 20 degrees from the cassette were significantly different from the 0 degree values obtained by calculation and direct measurement. Inclination angles from live dogs were consistently larger than those from 0 degree bones. Differences between angles of inclination calculated from VD and CaCrHB radiographs of live dogs were not significant. 相似文献
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Barutzki D De Nicola A Zeziola M Reule M 《Berliner und Münchener tier?rztliche Wochenschrift》2006,119(7-8):342-347
To determine the prevalence of Anaplasma phagocytophilum in dogs in Germany serum samples from 1124 dogs that were under suspicion of having anaplasmosis were examined. The samples were tested by an indirect immunofluorescence test (OFT) for antibodies to A. phagocytophilum. The geographical origin of positive cases were analysed with an geographic information system. Antibodies to A. phagocytophilum were found in 563 (50.1%) of the tested dogs. 166 dogs came from Saarland, 161 from North Rhine-Westphalia, 134 from Baden-Wuerttemberg, 33 from Bavaria, 22 from Rhineland-Palatinate, 11 from Hamburg, 10 from Brandenburg, 9 from Lower Saxony, 8 from Hesse and Berlin respectively and 1 from Schleswig-Holstein. Clinical signs and laboratory findings of 26 seropositive dogs were analysed. Those dogs showed a low haematocrit, thrombocytopenia and leucocytoses as well as higher values for alkaline phosphatase, ALAT und bilirubin. The clinical signs were lameness in 13 dogs, lethargy in 5, and uveitis in 3 dogs. Rhinitis and lymphadenopathy was found in 2 dogs and retinal detachment with blindness in 1 dog. 相似文献
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A total of 192 isolates of Clostridium perfringens were isolated from 99 broiler chickens and 93 capercaillies (Tetrao urogallus). Fifty of the isolates from broilers and 44 of the isolates from capercaillies were from birds with necrotizing enteritis, and the remainder were from birds without this disease. The isolates were tested for the production of three major toxins (alpha, beta, and epsilon) and four minor toxins (theta, gelatinase, mu, and nu). All isolates were found to be C. perfringens type A. Alpha toxin was produced in significantly larger amounts by isolates from birds with necrotizing enteritis than by isolates from birds without the disease, regardless of bird species. Isolates from broilers produced significantly more alpha toxin than did isolates from capercaillies. 相似文献
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Samples from blowhole and pharynx of 1 dolphin ill with a respiratory tract infection and 31 healthy dolphins at 2 oceanariums were examined by bacteriologic cultural technique. During the same period, nasal and volar forearm skin samples were collected from 32 healthy personnel and from a furuncle on the forearm of 1 attendant. Coagulase-positive staphylococci were isolated from 8 dolphins (including the ill dolphin) and from 14 persons. Antibiotic sensitivity patterns (8 drugs were tested) differed markedly for the staphylococcal isolates recovered from dolphins, as compared with those from persons. Staphylocci from the dolphins were totally or partially sensitive to every antibiotic, whereas almost all of the isolates from persons were resistant to penicillin and ampicillin, as well as to certain other antibiotics. Staphylococcus bacteriophage typing revealed that only 1 isolate from a dolphin could be typed (type D11). Six of the isolates from persons were typable, but no isolate was sensitive to only type D11. It was concluded that, although Staphylococcus aureus could be isolated commonly from captive dolphins, there was no evidence of cross infection between the dolphins and the oceanarium personnel. 相似文献
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Vaginal swab specimens were obtained from 41 prepuberal and 81 postpuberal bitches. Uterine swab specimens were obtained from 22 bitches at ovariohysterectomy and from 4 bitches during cesarean section. The specimens were cultured for aerobic bacteria. Most bitches harbored some type of bacteria in the vagina, but coagulase-positive staphylococci were isolated more frequently from prepuberal bitches than from postpuberal bitches. Postpuberal bitches were placed in various groups, based on the stage of the estrous cycle at the time specimens were obtained. Differences in bacterial types isolated from the postpuberal groups were not statistically significant. Uterine culture results suggested that bitches do not normally harbor aerobic bacteria in the uterus. 相似文献