Iron deficiency on corn root mitochondrial adenosine triphosphatase activity

Abstract

Iron deficiency significantly reduced corn root mitochondrial ATPase (adenosine triphosphatase) activity. The root mitochondrial ATPase had two pH optima. In the presence of K and Mg ions, ferrous ion stimulated the ATPase activity especially when plants were Fe‐deficient.     

Peroxisome proliferator-activated receptor-γ coactivator 1 α (PGC-1 α) expression and the formation of slow-twitch muscle fibers in porcine and bovine skeletal muscles

The peroxisome proliferator‐activated receptor‐γ coactivator‐1 α (PGC‐1 α) induces mitochondria biogenesis in skeletal muscles. To determine the relationships between PGC‐1 α and the muscle fiber types, the expression levels of PGC‐1 α were analyzed in porcine and bovine skeletal muscles. As a first step, the nucleotide sequences of the porcine and bovine PGC‐1 α were determined. The porcine and bovine PGC‐1 α cDNA encoded 796 amino acid sequences and showed 95.1% identity between the two species. The expression levels of the PGC‐1 α mRNA were analyzed in the same 10 skeletal muscles from four pigs and three cattle. The contents of porcine and bovine PGC‐1 α were higher in the tongue, masseter and diaphragm, and lower in the Biceps femoris, semimembranosus, Longissimus thoracis and semitendinosus muscles. The contents of myosin heavy chain slow‐type protein (MyHC‐slow) were also determined in the same muscles by ELISA. The analysis of MyHC‐slow showed results similar to those for the PGC‐1 α contents in all of the muscles except for the tongue. The content of MyHC‐slow in the tongue was the lowest among the porcine muscles, and moderate among the bovine muscles. The results suggest that PGC‐1 α relates to the development of oxidative muscle fibers, but is not the principal factor in determining type I fiber content.     

Muscle atrophy induced in broiler chicks by parts of Senna occidentalis seeds

Senna occidentalis (formerly Cassia occidentalis) is a common contaminant of agricultural commodities. It is toxic to cattle and poultry, reportedly being responsible for skeletal myodegeneration in these animals. All parts of the plant present toxicity, but the seeds are the most toxic. The toxin(s) responsible for the myodegeneration have not been definitively identified, nor is it known which part of the seeds is most toxic. Intoxication by this plant leads to weight loss with considerable economic repercussions. The effects of the whole seed and of parts of S. occidentalis seeds (1% in commercial feed) were compared on the pectoralis major muscle of broiler chicks intoxicated from birth until 22 days of life. There were severe clinical signals and reduced body weight in birds that received the external tegment of the seed, whereas no adverse effects were observed in birds that received the whole seed or other parts of the seed. Histological and morphometric studies showed an intense muscle fibre atrophy (both type 1 and type 2 fibres were affected) in the group that received 1% external tegment. This study may be the first step to identifying the substance(s) involved in this pathological process.     

Following the dynamics of strobilurin resistance in Blumeria graminis f.sp. tritici using quantitative allele-specific real-time PCR measurements with the fluorescent dye SYBR Green I

Strobilurin-resistant isolates of Blumeria ( Erysiphe ) graminis f.sp. tritici , the cause of wheat powdery mildew, were more than 10-fold less sensitive to azoxystrobin than sensitive isolates. In all resistant isolates, a mutation resulting in the replacement of a glycine by an alanine residue at codon 143 (G143A) in the mitochondrial cytochrome b gene was found. Allele-specific primers were designed to detect this point mutation in infected wheat leaves. Using quantitative fluorescent allele-specific real-time polymerase chain reaction (PCR) measurements, strobilurin-resistant A143 alleles could be detected amongst strobilurin-sensitive G143 alleles at a frequency of at least 1 in 10 000, depending on the amount of target and nontarget DNA. Most isolates tested were dominant homoplasmic for either the A143 or G143 allele, although mixed populations of alleles could be detected in some isolates. In some of these isolates, strobilurin resistance was not always stable when they were maintained for many generations in the absence of selection. The allele-specific real-time PCR assay was also used to follow the dynamics of A143 alleles in field populations of B . graminis f.sp. tritici before and after application of fungicides. As expected, the A143 allele frequency only increased under selection pressure from a strobilurin fungicide. After three sprays of azoxystrobin, a pronounced selection for the strobilurin-resistant allele, with an increase in average frequency from 2·2 to 58%, was measured. The use of quantitative real-time PCR diagnostics for early detection of fungicide resistance genes at low frequency, coupled with risk evaluation, will be invaluable for further resistance risk assessment and validation of antiresistance strategies.     

内毒素诱导山羊肝线粒体膜流动性的变化及654—2效应

用１,６－二苯基－１,３,５－己三烯（１,－６－ｄｉｐｈｅｎｙｌ－１,３,５－ｈｅｘａｔｒｉｅｎｅ,ＤＰＨ,Ｓｉｇｍａ Ｃｈｅｍｉｃａｌ Ｃｏ。）分子荧光振技术研究了内毒素（ＥＴ）诱导的山羊肝线粒体膜（ＭｉＭ）损伤过程中膜脂的流动性,膜脂区微粘度及脂双层分子排列有序性系数的变化及６５４－２的影响。     

StudiesontheUltrastructureofFlightMuscleinAdultDendrolimustabulaeformi

本研究利用透射电子显微镜对油松毛虫成虫飞翔肌超显微结构进行了观察．结果表明，油松毛虫成虫具有善于飞翔的超显微结构；初羽化时，肌纤维中的肌节及线粒体发育已基本成熟；但肌纤维中的横管系统则是随着蛾龄的增加而明显变化，可以肯定成虫的飞翔能力与肌纤维的横管系统密切相关；从飞翔肌的基本结构来看，羽化后１～３日龄为油松毛虫成虫的最适飞翔阶段，这与室内成虫吊飞模拟实验相一致；同日龄吊飞与未吊飞的成虫，其飞翔肌结构基本一致，所以油松毛虫成虫飞翔与否对其飞翔肌的发育无明显影响．     

Mitochondrial Proteomic Analysis of Cytoplasmic Male Sterility Line and Its Maintainer in Wheat （Triticum aestivum L.）

To investigate the CMS mechanism of wheat on proteomic level and find the crucial proteins which related to fertility,mitochondria was isolated from young spike of wheat by differential centrifugation and Percoll density-gradient methods.Determined by marker enzyme assays and chlorophyll content,the mainly contaminants in the spike mitochondrial fraction were caused by peroxisomes,plastids and chloroplasts after the first discontinuous Percoll density gradient centrifugation.In order to improve the purity of spike mitochondria,a second 28% Percoll self-forming density gradient centrifugation was further carried out,the result showed that the contaminants were decreased to negligible amount,meanwhile the integrity of mitochondria （88%） was improved to 90%.The spike mitochondria proteins extracted from uninucleate stage of （S）-1376A and （A）-1376B were separated by two-dimensional electrophoresis （2-DE）,and the silver stained gels were analyzed by PDQuest 2-DE software,about 326 protein spots could be visualized on the 2-DE maps,and also revealed a similar pattern between the male sterile line and its maintainer line,except 11 spots were differentially expressed.A total of five differentially expressed proteins were analyzed by matrix-assisted laser desorption ionization time of flight mass spectrometry （MALDI-TOF-MS）,three of them were identified as manganese superoxide dismutase and T5E216 following NCBInr database by the Mascot software.These results may contribute to further understanding of the mechanisms of CMS in wheat.     

基于线粒体COI和ND1基因分析 三尾凤蝶遗传多样性

以云南和四川分布的3个种群(云南丽江种群、云南东川种群、四川种群)共36头三尾凤蝶为研究对象,选取线粒体COI和ND1基因作为分子标记,对三尾凤蝶的遗传多样性进行了研究.结果表明,PCR扩增测得COI和ND1基因联合序列长度为1913 bp,A+T含量为74.3%,表现出明显的A/T碱基偏向性;共检测到4个变异位点,定义了5个单倍型,其中,Ha1出现的频率较高,为共享单倍型.核苷酸和单倍型多样性指数分别为0.0002和0.2180;遗传分化系数(Gst)、固定系数(Fst)、基因流(Nm)和遗传距离分别为0.05998、0.05995、3.92000和0.分析显示,三尾凤蝶遗传多样性低,各地理种群基因交流频繁,没有形成明显分化.     

绵羊8—16细胞胚胎的超微结构

利用透射电镜技术研究了绵羊８－１６细胞胚胎的超微结构，并与２细胞胚胎作了比较．结果表明，８－１６细胞胚胎卵裂球间以间隙连接联系，胞质主要成分是一种带有界膜的囊泡，线粒体丰富，以带帽线粒体为主，也有少量横嵴线粒体，１６细胞胚胎中，后者的比例高于８细胞胚胎．与２细胞胚胎相比，８─１６细胞胚胎的高尔基体发达．但滑面内质网数量减少、８细胞胚胎卵裂球具有数个致密的球形或环形核仁前体，１６细胞胚胎的核仁中出现次级小泡腔，标志着ｒＲＮＡ开始合成．     

茭白线粒体蛋白双向电泳体系建立

[目的]建立适合于茭白线粒体蛋白质组分析的双向电泳技术体系,为进一步开展茭白线粒体差异蛋白质组学研究提供参考.[方法]以茭白为试验材料,比较不同线粒体提取纯化方法、IPG胶条pH范围及蛋白上样量等条件对双向电泳图谱的影响.[结果]差速离心(3000~14000×g)联合Percoll不连续密度梯度离心(20%∶24%∶40%=2∶4∶2)对茭白线粒体的提取纯化效果优于仅采用差速离心.采用改良酚抽法提取茭白线粒体蛋白,17 cm、pH 3~10的IPG胶条,1.0 mg上样量,12% SDS-PAGE进行双向电泳,0.12%考马斯亮蓝G-250胶体考染法染色,茭白线粒体蛋白主要分布在pH 4~8范围内,pH 3~4和pH 8~10范围内蛋白点较少;进一步选用pH 4~7和pH 5~8的IPG胶条对茭白线粒体蛋白进行双向电泳,分离效果均明显提高,且pH 4~7范围内IPG胶条的双向电泳图谱清晰,蛋白点分辨率较高.分别采用0.8、1.0和1.2 mg 3个不同的上样量进行双向电泳,结果表明上样量为1.0 mg时,电泳图谱质量最好.[结论]通过差速离心联合Percoll不连续密度梯度离心提取纯化茭白线粒体,并控制好双向电泳体系的pH范围、上样量等因素,可获得蛋白质点清晰、分辨率高、重复性好的双向电泳图谱.