基于RNA-Seq技术筛选影响猪肌纤维性状的候选基因

旨在探究影响肌纤维性状的候选基因和信号通路。本研究以马身猪和大白猪为研究对象,采用HE染色法分析6月龄马身猪和大白猪背最长肌肌纤维直径和密度,利用RNA-Seq分析马身猪和大白猪背最长肌组织中基因表达情况,并对差异表达基因进行GO和KEGG富集分析,再通过qRT-PCR验证RNA-Seq结果的准确性。结果显示,马身猪背最长肌肌纤维直径极显著低于大白猪(P<0.01),而肌纤维密度极显著高于大白猪(P<0.01)。转录组测序结果显示,在6月龄马身猪和大白猪背最长肌中,差异倍数在2倍以上的基因共105个,其中,马身猪相对于大白猪上调的基因有55个,下调的基因有50个。GO富集分析表明,差异表达基因主要富集在与线粒体相关的细胞组分和骨骼肌分化有关的生物学过程中;KEGG分析结果显示,这些差异表达基因主要参与到与氧化磷酸化有关的信号途径。qRT-PCR和RNA-Seq对6个DEGs表达情况的检测结果表明它们的表达趋势相同,说明RNA-Seq结果准确可靠。结合差异基因表达丰度、GO和KEGG富集分析结果,本研究发现,MYL3、MYH3、MYH6基因通过影响肌纤维的组成而影响肌纤维特性,ND6基因通过参与线粒体氧化磷酸化过程影响肌纤维类型,MICU2基因通过维持线粒体Ca²⁺浓度的稳态影响细胞功能,编码转录因子的EGR1和FOS基因通过调节细胞增殖、分化和凋亡等过程影响肌肉生长发育。本研究初步揭示了造成马身猪和大白猪肌纤维性状差异的主要原因,为猪肉品质的改善提供了相应的理论依据。     

小鼠钼中毒的毒性试验

为了评价钼的生物毒性,用钼酸铵对小鼠进行中毒试验.通过腹腔注射剂量分为600、720、863、1 036、1 244 mg/kg的(NH4)6 Mo7O24·4H2O,48 h统计死亡率并计算LD50;32只小鼠分为4组,分别在饮水加入含0、80、100、120 mg/L的(NH4)6Mo7O24·4H2O,每隔3 d称重,7 d后进行血液学和病理学分析.结果腹腔注射的LD50为813.264 mg/kg±0.0426 mg/kg;饮水中毒试验5 d时各剂量组均表现严重中毒症状,中毒小鼠尸体消瘦,小肠壁出血并有红白相间花斑,肾脏体积肿大,肝脏肿大发生脂肪变性;血液稀薄,血细胞压积降低,红细胞数和血红蛋白量减少,精子畸形率显著增加.表明钼酸铵对小鼠属于中等毒性,可造成贫血、组织脏器病变及精子畸形等.     

The comparative pathogenicity of four serovars of Actinobacillus (Haemophilus) pleuropneumoniae

The pathogenicity of 2 isolates of each of serovars 7, 3, 1 and 2 of Actinobacillus pleuropneumoniae was tested by intranasal inoculation into 60, 6-week-old large white pigs. Four dose rates varying from 0.27 to 560 x 10(6) organisms per pig with 10-fold serial dilutions were used. Surviving pigs were necropsied 7 days after inoculation. The proportion of pigs dying and developing gross lesions following infection was significantly greater for pigs given serotype 1 than for each of the other 3 serotypes, which did not differ significantly from each other. Twelve of 16 pigs given either of the 2 isolates of serovar 1 died after acute illness and 1 of 44 pigs given either of the 2 isolates each of serovars 7, 3 and 2 died. Pigs given serovar 1 showed high temperatures, severe respiratory distress, frothy haemorrhagic nasal discharge and weight loss. Lung lesions were produced in all 16 pigs given serovar 1, in 7 of 14 pigs given serovar 7, 7 of 14 pigs receiving serovar 3 and in 5 of 16 pigs given serovar 2. The lethal infections were characterised by a severe acute fibrinohaemorrhagic necrotising pleuropneumonia, whereas non-lethal cases had lung lesions ranging from necrotising purulent pleuropneumonia to abscessation. Significant differences between isolates in proportions of tissues culture positive for A. pleuropneumoniae for serovars 7 and 2, but not for serovars 3 and 1 suggested that isolates may vary in virulence within serovars, but more detailed studies are needed to clarify this point.     

教师教学质量评估研究

本着以人为本、求真务实的理念,根据教育评价理论,运用数理统计原理,采用高阶综合评价方法对评估原则、体系建构、评估指标等进行分析研究,建构教师教学质量评估模型。     

Stocking rate effects on the worm burdens of Angora goats and Merino sheep

Worm egg counts of yearling Angora or Merino wethers grazing in mixed flocks at either 4/ha or 8/ha were observed over a 5 month period. Based on faecal egg counts infection levels in the sheep increased for the first 3 months and then decreased as the animals developed resistance. Egg counts in the goats did not decrease during the experiment. Post mortem worm counts indicated that there was a significant host species--stocking rate interaction on worm burdens of Haemonchus contortus adults and Ostertagia circumcincta adults and larvae. Goats had more H. contortus and O. circumcincta adults than sheep at the 8/ha stocking rate. At 4/ha goats had fewer O. circumcincta fourth stage larvae than sheep. There was no stocking rate effect on the numbers of Trichostrongylus axei or T. colubriformis. Sheep had more T. axei and fewer T. colubriformis than goats.     

Settling of insecticide from dip wash mixed with dam water and zinc sulphate and used to control sheep lice (Bovicola ovis)

SUMMARY Insecticidal dipping fluid emulsions, mixed in vitro in dam water containing suspended clay particles and 1% w/v zinc sulphate, were analysed to determine rates of settling of diazinon, cyhalothrin and cypermethrin. Fifteen minutes after mixing, the concentration of the insecticides 5 cm below the surface had declined by 72.5%, 72.8% and 89.4%, respectively. On remixing, the concentration of insecticide in suspension was close to or greater than the initial concentration. In 2 trials, lice were eradicated from sheep showered with dip wash mixed in cloudy dam water to which 1% w/v of zinc sulphate was added. In 12 flock treatments in which 1000 to 2000 sheep were dipped with added zinc sulphate, the concentration of insecticide remained above the minimum lethal for susceptible strains of lice. However, lice were still present 6 months later in 8 of these flocks. When zinc sulphate is added to dip wash, agitation is needed to maintain the insecticide in suspension.     

Why implantation of bio‐loggers may improve our understanding of how animals cope within their natural environment

Bio‐loggers are miniaturized autonomous devices that record quantitative data on the state of free‐ranging animals (e.g. behavior, position and physiology) and their natural environment. This is especially relevant for species where direct visual observation is difficult or impossible. Today, ongoing technical development allows the monitoring of numerous parameters in an increasing range of species over extended periods. However, the external attachment of devices might affect various aspects of animal performance (energetics, thermoregulation, foraging as well as social and reproductive behavior), which ultimately affect fitness. External attachment might also increase entanglement risk and the conspicuousness of animals, leaving them more vulnerable to predation. By contrast, implantation of devices can mitigate many of these undesirable effects and might be preferable, especially for long‐term studies, provided that the many challenges associated with surgical procedures can be mastered. Implantation may then allow us to gather data that would be impossible to obtain otherwise and thereby may provide new and ecologically relevant insights into the life of wild animals. Here, we: (i) discuss the pros and cons of attachment methods; (ii) highlight recent field studies that used implanted bio‐loggers to address eco‐physiological questions in a wide range of species; and (iii) discuss logger implantation in light of ethical considerations.     

广灵驴成纤维细胞系的建立及其相关生物学特性研究

试验旨在建立广灵驴成纤维细胞库,以期在细胞水平上对广灵驴进行保护。本研究以1月龄广灵驴耳缘皮肤组织为试验材料,采用组织块贴壁法进行成纤维细胞培养,建立了广灵驴耳缘皮肤组织成纤维细胞系,并对其相关生物学特性进行了鉴定。结果发现,试验所建立的广灵驴成纤维细胞系大多数细胞呈长梭形,部分细胞呈三角状或星型。在培养过程中,广灵驴原代成纤维细胞在贴壁4 d时开始有细胞从组织边缘游离出来,贴壁14 d后,细胞汇合率达到80%,可以进行第一次传代培养;细胞生长态势良好,生长曲线呈典型的S型曲线;细胞冻存复苏后活率有所下降,但生长状态良好。细胞分裂中期染色体数2n=62,说明成功建立了广灵驴成纤维细胞系。通过本方法建立的广灵驴成纤维细胞系为后续广灵驴的相关研究奠定了基础。     

杂交稻新组合“Ⅱ优明62”选育及其产量构成因素分析

介绍了高产、优质、抗病晚稻新组合Ⅱ优明62的选育过程、主要特征特性,并对其产量构成因素进行相关、通径分析。