口蹄疫流行病学及感染机制的研究进展

口蹄疫(Foot-and-mouth disease FMD)是由口蹄疫病毒(Foot-and-mouth disease virus FMDV)引起偶蹄动物的一种急性、热性、高度接触性传染病。FMDV有多种血清型及其亚型,目前主要引起动物致病的就有7种,即A、O、C、SATⅠ、SATⅡ、SATⅢ和亚洲Ⅰ型(AsiaⅠ型)。病毒通常在细胞受体的参与下才入侵宿主细胞,进行扩增生命循环,感染宿主细胞,使得该病得以广泛流行。但由于口蹄疫病毒的高度变异性和适应性而在流行中出现新的特点,以及被发现的病毒在动物体内和细胞中长期存在而引发FMDV的持续感染等问题,使得本病不能有效被控制而在许多国家和地区重新暴发和流行。为此本文将口蹄疫病原学、流行病学、病毒细胞受体及其病毒在体内持续感染形成的原因方面进行的论述,为口蹄疫病毒感染机制的研究提供了科学的依据。     

控制原蚕♀♂性别比例对制种量及卵质的影响

采用人工控制♀性别比例的方法,对家蚕限性斑纹品种原蚕进行了不同性别比例下的制种量研究.结果表明,提高原蚕中的♀蚕比例,可以大幅度提高斤茧制种量.当♀、比例为2.2∶1时,与常规比例1∶1相比,斤茧制种量提高37%以上,蛾不存在交配问题,而且对后代卵质的影响差异不显著.但随着二交雄蛾的增加,不产卵♀蛾的比例也会增加,与增加的产卵量相比,其负效应可以忽略不计.同时,提出了生产中通过饲养限性斑纹品种871及陕蚕三号795×122、适当增加限性品种收蚁量、淘汰部分白蚕()的人工调控原蚕♀、性别的方法及操作注意事项.     

The inheritance of two novel subgynoecious genes in cucumber (Cucumis sativus L.)

Cucumber (Cucumis sativus L.), which is a vegetable crop, has served as the model system for sex expression in flowering plants, and the inheritance of sex expression in cucumber is well documented. However, the genetics of subgynoecism expression in cucumber had rarely been described. In this study, we investigated the inheritance of subgynoecious traits in cucumber plants with the inbred cucumber lines of subgynoecious (C. sativus L. var sativus cv 97-17 and S-2-98) as the materials. Genetic analysis had showed the two subgynoecious inbred lines were controlled by one pair of recessive gene and one pair of incompletely dominant gene, which were designated presently as mod-F2 and Mod-F1, respectively. Furthermore, the mod-F2 and Mod-F1 loci, which enhance the intensity of femaleness, also inherited independently with F and M genes.     

Agricultural practices alter sex ratios in a reptile with environmental sex determination

Anthropogenic changes to the environment have the opportunity to impact natural systems, particularly in organisms that exhibit phenotypic plasticity. Species with environmental sex determination (ESD) are uniquely susceptible to changes in the stimuli that affect sexual development, potentially leading to maladaptive sex ratios. We studied the factors affecting sex determination and sex ratios in the common snapping turtle, Chelydra serpentina, in an area heavily impacted by agricultural practices. We investigated the effects of soybean, corn, and sunflower planting on incubation temperatures, sex ratios, and depredation in naturally laid nests. We also identified and analyzed a novel mitochondrial microsatellite in order to examine the presence of natal homing and determine the likelihood that nest sites impacted by agricultural practices could be transmitted across generations. Females frequently chose to nest in agricultural fields over sand prairie sites, and offspring sex ratios and depredation rates were significantly influenced by crop planting. Despite detecting considerable genetic variation in our population, we found no relationship between relatedness and nesting location, suggesting that females are not transmitting nesting sites across generations. Our results suggest that agricultural practices can directly impact populations of animals with ESD, and will need to be considered in management decisions.     

成年大鼠睾丸去精索上神经对睾丸功能及肾上腺素能受体表达的影响

试验旨在研究精索上神经（superior spermatic nerve,SSN）对睾丸功能的影响,25只成年Wistar大鼠随机分为2组,试验组左右睾丸切除精索上神经,手术30 d后两组大鼠同时处死取样分析。结果显示,睾丸去精索上神经不影响睾丸指数的大小但使附睾尾精子数极显著降低（P＜0.01）,平均日增重显著增加（P＜0.05）。增殖细胞核抗原（PCNA）免疫组织化学染色结果显示,睾丸去精索上神经不影响曲细精管精原细胞和初级精母细胞的增殖,但影响曲细精管的形态和生殖细胞的规则排列。RT-PCR结果显示,睾丸去精索上神经明显上调β1AR mRNA的表达,下调β2AR mRNA的表达;另外切除精索上神经不影响睾丸3β-羟胆固醇脱氢酶（3β-HSD）mRNA表达,但显著抑制类固醇快速调节蛋白（StAR）、胆固醇侧链裂解酶（P450scc）mRNA表达（P＜0.05）。结果表明,支配睾丸的精索上神经通过调节肾上腺素能受体β1AR和β2AR的表达及StAR和P450scc影响睾丸睾酮的合成和精子的发生。     

一种准确简便的东方白鹤性别分子鉴定方法

东方白鹤为国家Ⅰ级重点保护动物，在自然条件下繁殖率很低，进行迁地保护及再引入措施对遗传多样性保护具有举足轻重的作用，成功地进行性别鉴定是其笼养人工繁殖的前提。本研究对4只东方白鹤，运用CHD基因的一对引物2550F／27181K进行了准确简便的性别鉴定，并对其序列结合其他5种远缘鸟类相应序列进行分析，证实了此种方法的科学性和可信度，分析了性别鉴定机理。这种安全、方便、准确的性别分子鉴定方法将有助于东方白鹤迁地保护及再引入措施的实施。通过分析可以看出，此种方法未来存在着广阔的应用前景。     

REGIONAL BINDING INDEX OF THE RADIOLABELED SELECTIVE 5-HT2A ANTAGONIST 123I-5-I-R91150 IN THE NORMAL CANINE BRAIN IMAGED WITH SINGLE PHOTON EMISSION COMPUTED TOMOGRAPHY

The pattern of the specific 5-HT2A (5-hydroxytryptamine 2A receptor) antagonist 123I-5-I-R91150 was measured in 10 healthy dogs without neurologic and behavior abnormalities. Eight cortical regions (left and right fronto-, temporo-, parieto-, and occipitocortical area), one global subcortical region (including the thalamic system) were compared with a reference region lacking receptors; that is, the cerebellum. The 123I labeled radioligand was injected intravenously 100-200 minutes before acquisition. Both transmission and emission data were obtained with a triple head gamma camera equipped with high-resolution fanbeam collimators. The emission data were corrected for scatter and attenuation. To delineate different cerebral regions more accurately, the regions of interest (ROI) defined in a former study on brain perfusion measured with 99mTc-ethyl cysteinate dimer (ECD) in the same dogs were used. The co-registration of the 99mTc-ECD and the 123I-5-I-R91150, obtained from each dog, was realized with the help of corresponding transmission maps. By normalizing each regional cerebral activity to the activity observed in the cerebellum, the regional radioactivity (binding index) could be relatively quantified. Highest brain uptake was noted in the frontocortical brain areas (right: 1.85, left: 1.89), followed by the temporocortical region (right: 1.58, left: 1.56). Least uptake was noted in the more caudal and middle brain regions [occipito- (right: 1.46, left: 1.41), parietocortical (right: 1.30, left: 1.26), and striatal region (1.19)]. No gender nor age influence was noted in this series. The 123I labeled serotonin-2A receptor ligand seems to have similar cortical binding in the normal canine brain, as shown in humans and other animal species. A frontocortical to occipitocortical (rostrocaudal) binding index gradient was identified within the dog, which has not been seen in imaging studies from humans and other animal species. The significance of these results will need further investigation. This normative data can be used to compare regional brain uptake of the 123I-radioligand to dogs with behavioral disorders related to the serotonergic system, in future studies.     

性诱剂与树枝把对棉铃虫的诱蛾效果分析

通过对3、4代棉铃虫在棉田的落卵量、幼虫量、为害量动态及效益分析，表明了利用性诱剂诱娥具有效果好、探作简便、省工、节本和能反映田间蛾卵量消长等特点。因而认为性诱剂可以替代树枝把诱蛾在棉花生产上推广应用。     

荆豆凝集素-1受体在犬子宫内的分布与激素调节

采用组织化学方法对荆豆凝集素-1(ulex europaeus agglutinin-1,UEA-1)受体在发情周期和早期妊娠犬子宫内的分布以及激素调节进行了研究。结果显示,UEA-1受体主要存在于犬子宫内膜腔上皮和腺上皮,其表达量随妊娠阶段的不同而发生动态性变化。UEA-1受体在休情期犬子宫内未见表达,而在发情期犬子宫内膜腔上皮和腺上皮内的表达量很高。在早期妊娠犬子宫内,在妊娠第6天和12天犬子宫内的表达量较低,此后其表达量逐渐增加,在妊娠第17天时,UEA-1受体在子宫内膜腔上皮和腺上皮内的表达量达到峰值,此后其表达量又逐渐下降,在妊娠第23天时未见表达。注射雌激素可明显促进卵巢切除后犬子宫内膜UEA-1受体的表达。结果表明,犬子宫内UEA-1受体的分布与胚胎着床前胚胎与子宫内膜之间的黏附和植入有关,UEA-1受体在犬子宫内的表达受母体分泌的激素所调控。     

Comparison of steroid receptor expression in normal, dysplastic, and neoplastic canine and feline mammary tissues

Steroid receptor expression was assessed by immunohistochemistry in neoplastic, hyperplastic/dysplastic, and normal mammary tissue samples removed from 68 queens and 47 bitches, using monoclonal antibodies against human oestrogen-alpha (ER) and progesterone receptors (PR). Mammary lesions were classified according to World Health Organization (WHO) criteria, and all animals with invasive carcinomas were clinically followed for 2 years. Stromal and/or lymphatic invasion and histological grading were also recorded. In both species, ER expression was significantly higher in healthy tissues, hyperplastic/dysplastic lesions, and benign tumours than in carcinomas. The loss of ER expression was more marked in feline than in canine carcinomas. In queens, PR expression increased in dysplastic lesions and "in situ" carcinomas and decreased in invasive carcinomas, even if parts of these tumours were still PR-positive. In bitches no significant variation in PR expression was observed between normal tissue, dysplasias, and benign neoplasms, but was significantly lower in carcinomas. In both species ER and PR expression in invasive carcinomas did not correlate either with histological parameters or overall survival time. This study demonstrates several differences in steroid hormone dependency between the two species. The percentage of PR-positive feline carcinomas suggests a possible role of progesterone in promoting early tumour cell growth in queens. The low percentage of ER-positive invasive carcinomas further demonstrated the aggressive phenotype and behaviour of feline mammary tumours.