孵育温度对虾蟹幼体质量影响的初步研究

研究了亲体催产、幼体孵化和幼体培养温度对斑节对虾和中华绒螯蟹胚胎及早期幼体生长发育的影响．在实验温度（中华绒螯蟹,17～21℃;斑节对虾,26～30℃）范围内,胚胎及幼体的生长发育随温度升高而加快,但幼体的大小和蜕皮变态存活率随温度升高而降低．虾蟹幼体孵育的温度效应决定于亲体催产温度及升温方式、幼体孵化温度和培养温度．着重探讨了孵育温度等环境条件对幼体质量的影响,并提出从虾蟹胚胎和幼体发育期间能量代谢和物质代谢等途径开展进一步研究．     

对虾幼体的藻类饵料

浮游藻类植物含有丰富的蛋白质、脂肪和糖类,还含有氨基酸、维生素、微量金属元素等营养成分,能为对虾幼体从蚤状期到糠虾期的生长发育提供较全面的营养保障。从本世纪三十年代开始,人们在从事对虾人工产卵孵化育苗的试验工作中,遭受无数次的挫折与失败,大凡成功的例子,无不重视饵料的选择。经验告诉我们,藻类饵料是对虾幼体生长发育必不可少的。到七十年代,人们普遍采纳以藻类植物喂养对虾幼体这一生产模式,使对虾人工育苗成活率大幅度提高,从而推动了对虾养殖业的发展。目前,有几十种海洋浮游藻类被人们分离提纯,进行保种培养…     

镉对黑斑蛙蝌蚪生长发育的影响

两栖动物幼体的生长发育过程对环境变化和化学污染物都很敏感,为研究镉对两栖动物幼体生长发育的影响,将37—38期黑王证蛙（Rana．nigromaculata）蝌蚪暴露于含不同浓度镉的水中饲养,直至完全变态,观察幼体生长发育过程,记录蝌蚪完全变态所需时间,平均体重和平均长度增长率的测定。结果表明,随着Cd^2＋浓度的升高,蝌蚪的啤均体重和平均长度的增长率降低,完全变态所需时间增长。说明Cd^2＋污染可抑制黑斑蛙蝌蚪的生长发育,延缓变态。     

温度对海洋底栖端足类日本大螯蜚（Grandidierella japonica）存活, …

日本大螯蜚（Ｇｒａｎｄｉｄｉｅｒｅｌｌａｊａｐｏｎｉｃａ）生长发育的适温范围为２０～２６℃,不同发育期耐受温度范围不同,刚孵化幼体温度下限为１１℃,上限３２℃,以后随着幼体发育,其对低温的适应力逐渐增强,雄性个体对极限温度的忍耐力低于雌性,耐受温度范围内,幼体的生长发育随温度的提高而加快,研究结果表明,日本大螯蜚实验室培养温度宜选择在２０～２６℃,用其进行的沉积物急性和慢性毒性生物检验的实验温度均     

生态育苗池中的桡足类与河蟹苗产量的关系

探讨了辽宁盘锦辽河三角洲地区中华绒螯蟹(Eriocheir sinensis)生态育苗池中出现的近亲真宽水蚤(Eurytemor affinis)和细巧华哲水蚤(Sinocalanus tenellus)与中华绒螯蟹幼体的关系.结果表明：近亲真宽水蚤和细巧华哲水蚤都严重地影响Ⅰ期中华绒螯蟹溞状幼体的成活率,其密度越大,Ⅰ期溞状幼体的成活率就越低(P＜0.01); Ⅲ期中华绒螯蟹溞状幼体可捕食桡足类无节幼体,且捕食量随着无节幼体密度增加而变大(P＜0.01);Ⅴ期中华绒螯蟹溞状幼体和大眼幼体容易捕食到近亲真宽水蚤而很难捕食到细巧华哲水蚤;蟹苗池中大眼幼体的产量与育苗初期池塘中桡足类的数量呈负相关关系,且不同桡足类密度下大眼幼体收获量差异极显著(P＜0.01).提出了控制和利用蟹苗池中桡足类的措施.     

肥胖孕妇肠道菌群与子代肥胖的相关性

妊娠期肥胖发生率在世界范围内呈上升趋势,成为影响人类健康的公共卫生问题。肥胖母亲肠道菌群失调导致婴儿早期定植菌群异常,而婴儿早期菌群定植情况与其日后生长发育密切相关,容易导致成年后出现肥胖、胰岛素抵抗、代谢综合征等疾病。因此针对肥胖孕妇肠道菌群分析,以及婴儿肠道菌群及生长发育的分析,对于孕妇孕期管理、健康宣教提高国民整体身体素质具有重要意义。     

布氏田鼠体温调节能力的胎后发育

为探讨布氏田鼠幼体体温调节能力的发育特点,我们对其胎后发育过程中代谢产热和体温的变化进行了观察。测定记录了1—40日龄的布氏田鼠幼体在巢中的体温,在23℃和30℃条件下的静止代谢率,以及在23℃和30℃时暴露1．52h后体温的变化,计算了幼体的总热传导率和恒温指数,并测定了聚群对幼体代谢产热的影响。布氏田鼠是典型的晚成型发育类型,幼体出生时身体裸露,体温调节能力很差。17日龄前,幼体在23℃冷暴露1．5—2h不能维持恒定的体温,9—17日龄幼体的恒温能力发育迅速,1713龄后幼体在23℃时开始表现出有效的恒温能力。幼体发育过程中逐渐升高的恒温指数和逐渐下降的总热传导率,也反映了幼体不断增强的恒温能力。虽然幼体在发育早期恒温能力差,表现出变温性的特点,但代谢率的测定表明,即使刚出生的幼体也具有受到冷刺激而增加产热的反应。聚群实验结果表明,幼体的聚群行为在降低代谢率、节约能量方面有明显的作用。巢中幼体体温的测定表明,1—40日龄幼体体温逐渐升高的趋势明显,且始终保持在33℃以上。这些结果说明,布氏田鼠的幼体在生长发育过程中,主要靠细致的母体关怀、聚群行为、巢的保温作用以及自身较弱的产热能力来使体温维持在较高的水平,从而不会因体温过低而使幼体的生长速度降低[动物学报51（5）：780—789,2005]。     

晚成性哺乳动物体温调节能力的胎后发育

按照体温调节能力的发育情况,哺乳动物的生长发育可分为早成性、晚成性和未成熟性3类。本文主要综述了晚成性哺乳动物体温调节能力的发育特点。这类动物的幼体出生时一般身体裸露,热传导率较高,产热能力较差,不能进行有效的体温调节。当环境温度低于热中性区时,单独的个体不能维持较高的恒定体温。但晚成性幼体也具有一定的体温调节能力,当受低温刺激时,即使新生幼体也会具有增加代谢率的反应;同时结合亲体关怀和幼体之间的聚群效应以及巢的保温作用等方式,仍能使其体温维持在一个较高的水平。晚成性幼体生理性产热的不足,也可看作是一种有利的特点,这样可以减少能量在体温调节方面的消耗,从而增加用于生长发育的能量。文章最后对可能的发展方向进行了展望。     

温度对海洋底栖端足类日本大螯蜚(Grandi-dierella japonica)存活、生长和发育的影响

日本大螯蜚（ Ｇｒａｎｄｉｄｉｅｒｅｌｌａ ｊａｐ ｏｎｉｃａ）生长发育的适温范围为 ２０～２６℃。不同发育期耐受温度范围不同,刚孵化幼体温度下限为１１℃,上限为３２℃,以后随着幼体发育,其对低温的适应力逐渐增强。雄性个体对极限温度的忍耐力低于雌性。在耐受温度范围内,幼体的生长发育随着温度的提高而加快。研究结果表明,日本大螯蜚实验室培养温度宜选择在２０～２６℃,用其进行的沉积物急性和慢性毒性生物检验的实验温度均宜选择在 ２０℃。     

香蕉组培苗生产中污染苗的利用研究

本文对香蕉组培污染苗的利用进行试验研究。结果表明,用高锰酸钾、络氨铜溶液浸泡污染苗根部,然后进行沙床假植,能显著提高污染苗成活率,促进污染苗生长发育。     

Entwicklungsgeschichte und Ultrastruktur von Pollenkitt und Exine bei nahe verwandten entomophilen und anemophilen Angiospermensippen derAlismataceae,Liliaceae, Juncaceae,Cyperaceae, Poaceae undAraceae

Some closely related members of the monocotyledonous familiesAlismataceae, Liliaceae, Juncaceae, Cyperaceae, Poaceae andAraceae with variable modes of pollination (insect- and wind-pollination) were studied in relation to the ultrastructure of pollenkitt and exine (amount, consistency and distribution of pollenkitt on the surface of pollen grains). The character syndromes of pollen cementing in entomophilous, anemophilous and intermediate (ambophilous or amphiphilous) monocotyledons are the same in principal as in dicotyledons. Comparing present with former results one can summarize: 1) The pollenkitt is always produced in the same manner by the anther tapetum in all angiosperm sub-classes. 2) The variable stickiness of entomophilous and anemophilous pollen always depends on the particular distribution and consistency of the pollenkitt, but not its amount on the pollen surface. 3) The mostly dry and powdery pollen of anemophilous plants always contains a variable amount of inactive pollenkitt in its exine cavities. 4) A step-by step change of the pollen cementing syndrome can be observed from entomophily towards anemophily. 5) From the omnipresence of pollenkitt in all wind-pollinated angiosperms studied one can conclude that the ancestors of anemophilous angiosperms probably have been zoophilous (i.e. entomophilous) throughout.

     

Identification and Characterization of the First Equine Parainfluenza Virus 5

正Dear Editor,Parainfluenza virus 5 (PIV5), known as canine parainfluenza virus in the veterinary field, is a negative-sense,nonsegmented, single-stranded RNA virus belonging to the Paramyxoviridae family (Chen 2018). The virus was first reported in primary monkey kidney cells in 1954 (Hsiung1972), then it has been frequently discovered in various     

Pathogenic Characterization and Full Length Genome Sequence of a Reassortant Infectious Bursal Disease Virus Newly Isolated in Pakistan

<正>Dear Editor,Infectious bursal disease (IBD) is one of the most important diseases of the poultry. The IBD virus (IBDV), a nonenveloped virus belonging to the Birnaviridae family with a genome consisting of two segments of double-stranded RNA (segments A and B), targets B lymphocytes of bursa of Fabricious leading to immunosuppression. In Pakistan,poultry farming is the second biggest industry and IBD is the second biggest disease threating the poultry sector.However, there is limited genome information of IBDV     

Mink Circovirus Can Infect Minks,Foxes and Raccoon Dogs

正Dear Editor,Mink circovirus (MiCV), which is clustered in the genus Circovirus of the family Circoviridae, was first described in minks from farms in Dalian, China in 2013 (Lian et al.2014). The complete single-stranded circular genome of the virus is 1,753 nucleotides long and contains two major open reading frames (ORFs), designated ORF1 (Rep gene)and ORF2 (Cap gene)(Lian et al. 2014; Ge et al. 2018).Sequence analysis has shown that MiCV is most closely     

CypA Regulates AIP4-Mediated M1 Ubiquitination of Influenza A Virus

Cyclophilin A (CypA) is a peptidyl-prolyl cis/trans isomerase that interacts with the matrix protein (M1) of influenza A virus (IAV) and restricts virus replication by regulating the ubiquitin–proteasome-mediated degradation of M1. However,the mechanism by which CypA regulates M1 ubiquitination remains unknown. In this study, we reported that E3 ubiquitin ligase AIP4 promoted K48-linked ubiquitination of M1 at K102 and K104, and accelerated ubiquitin–proteasome-mediated degradation of M1. The recombinant IAV with mutant M1 (K102 R/K104 R) could not be rescued, suggesting that the ubiquitination of M1 at K102/K104 was essential for IAV replication. Furthermore, CypA inhibited AIP4-mediated M1 ubiquitination by impairing the interaction between AIP4 and M1. More importantly, both the mutations of M1 (K102 R/K104 R) and CypA inhibited the nuclear export of M1, indicating that CypA regulates the cellular localization of M1 via inhibition of AIP4-mediated M1 ubiquitination at K102 and K104, which results in the reduced replication of IAV.Collectively, our findings reveal a novel ubiquitination-based mechanism by which CypA regulates the replication of IAV.