Validation of the periodicity of growth zone formation in the otoliths of four fish species from the Upper Zambezi ecoregion,southern Africa

In the Upper Zambezi and Okavango ecoregions, Brycinus lateralis, Hepsetus cuvieri, Schilbe intermedius and Serranochromis macrocephalus are important in subsistence fisheries, while S. intermedius and S. macrocephalus are often caught in commercial catches. Despite their importance, there is little information on their age and growth and age validation. Growth zone deposition rate in otoliths of B. lateralis, H. cuvieri, S. intermedius and S. macrocephalus was validated as annual using edge analysis in this study. Annual deposition of growth zones was corroborated by a fluorochrome marking experiment. Both methods demonstrated that one growth zone was deposited annually. Edge analysis demonstrated that the highest proportion of opaque zones was detected between August and December, most likely as a result of slow growth during lower temperature water during the preceding winter. With growth zone deposition validated as annual, future research should focus on determining the growth, maturity and mortality rates of these species, parameters which are important for their management.     

对猪腰荐尾部背侧区肌肉的解剖观察

猪的荐骨棘突很不发达,两侧的腰荐尾部背侧区的肌肉有如下特点:臀中肌、腰后多裂肌和荐尾背内侧肌的后端肌腹都与对侧同肌紧密为邻;腰多裂肌的后部肌腹发达,命名为腰后多裂肌;荐尾副背外侧肌是猪特有的肌肉,在解剖文献中没有任何记载,故而命此名称,呈窄长条状小肌,位于荐尾背外侧肌的外侧.     

两种炮制方法对附子品质的影响

探讨了两种不同的炮制方法对附子品质的影响.采用高压蒸煮法和微波加热法处理附片,测定炮制前后总生物碱、乌头碱、水浸出物和醇浸出物含量的变化.结果表明,附子经过高压蒸煮和微波炮制后,总生物碱、乌头碱含量大幅下降,水浸出物含量升高,醇浸出物含量变化较小.这两种炮制方法对附子品质有较大的影响.     

基于环介导等温扩增技术检测雪松疫霉根腐病菌

雪松疫霉根腐病菌(Phytophthora lateralis Tucker et Milbrath)是一种重要的毁灭性植物病原菌,也是我国进境植物检疫性有害生物。目前,我国未有该病害发生的报道,为了防止P.lateralis的传入和扩散,需对其进行快速、准确的检测。本文利用环介导等温扩增技术(loop-mediated isothermal amplification,LAMP),以Ypt1基因为靶标序列,设计LAMP特异性引物,建立LAMP反应体系,并对灵敏度和特异性进行检测。结果表明:整个检测过程仅需80 min,即可通过肉眼观察直接判定检测结果。在特异性检测中,P.lateralis菌株都能观察到天蓝色的阳性反应,而其他疫霉菌和真菌供试菌株均呈阴性反应。在灵敏度检测中,最低检测限为100 pg/μL。该方法的建立为P.lateralis的检疫鉴定及其所致病害的快速诊断提供了新技术。     

HPLC-MS测定江油附子中三种生物碱的含量

建立了附子中乌头碱、新乌头碱、次乌头碱的高效液相色谱-质谱联用检测方法,并用该方法测定不同秸杆覆盖处理的附于中3种生物碱成分.以PolarisC18-A(50 mm×2.0 mm,5.0 μm)为色谱柱;甲醇和水(体积比为80∶20)为流动相,流速为0.2 mL/min,检测波长为240 nm,柱温为30℃.结果表明,乌头碱、新乌头碱、次乌头碱分别在0.70～35.00 ng(r=0.999 6)、0.50～25.00 ng (r=0.999 6)、1.06～53.00 ng (r=0.9980)范围内线性良好;平均回收率分别为100.7％、99.2％和98.9％.该方法结果准确可靠,是一种快速灵敏、专属性强的分析方法.     

雏鸡投射向外侧膝状体腹侧核的视顶盖细胞形态研究

鸟类的一些视觉信息经由视顶盖Ⅰ层细胞（Ⅰ细胞）传递到外侧膝状体腹侧核（nucleus geniculatus lateralis ventralis,GLv）,用于色觉、瞳孔反射和视觉运动.使用羰花青荧光染料DiI逆向神经标记技术研究了这些投射向GLv核的视顶盖Ⅰ细胞的形态特征.根据标记细胞的胞体和树突野大小及树突分枝特点,雏鸡投射到GLv核的视顶盖Ⅰ细胞可分为“矛状树突Ⅰ细胞”和“叉状树突Ⅰ细胞”,前者具有小型纺锤状的细胞体和垂直伸延的1支尖端树突,后者具有较大三角形或多角形的细胞体和多支上行性树突.多数标记树突的末端部水平分布于视顶盖F层,和终止于此层的视神经终末部的形态相一致.     

Tetraploid induction by meiosis inhibition in the dwarf surfclam Mulinia lateralis (Say 1822): effects of cytochalasin B duration

Different durations of a cytochalasin B (CB) treatment were tested for tetraploid induction by meiosis inhibition in the dwarf surfclam Mulinia lateralis Say. Cytochalasin B, 0.67 mg L^?1, was applied to newly fertilized eggs at 8–10‐min post fertilization and removed when in the untreated eggs: (1) Polar body 1 (PB1) was released in 90% of the eggs and polar body 2 (PB2) began to form (T1); (2) Polar body 2 was released in about 25–30% of the eggs (T2); (3) Polar body 2 was released in about 70–75% of the eggs (T3); or (4) eggs began to enter mitosis I or the polar lobe began to form (T4). Three replicates were produced using different sets of parents. The ploidy of resultant larvae and juveniles was determined by flow cytometry. Blocking PB1 alone in T1 groups produced mostly tetraploids, and longer CB treatments in T2 and T3 resulted in increasing numbers of pentaploids. In T4 groups where both PB1 and PB2 were inhibited, larvae were predominantly pentaploids. Pentaploid larvae were arrested at the trochophore stage. The majority of tetraploid larvae died as trochophores, although a small fraction reached D‐stage. Among 478 juvenile clams sampled from a T1 group, three (0.6%) were confirmed as tetraploids. This study shows that tetraploid embryos can be produced at high efficiencies (40–90%) by blocking meiosis I. Tetraploids produced by meiosis inhibition in normal eggs are viable in M. lateralis, but their survival beyond metamorphosis is extremely low.     

雪松根部腐烂病传入我国的风险分析

按照国际植物保护公约中有害生物风险分析的原则,对雪松根部腐烂病进行了全面的风险分析。结果表明,雪松根部腐烂病传入我国的风险极大,应加强检疫,严防传入国内。     

羊侧脑室注射方法研究

本研究优选出羊侧脑室注射进针点。用１２号针头分别由侧脑室注射进针点６ｍｍ半径范围内的不同部位进针。结果表明，在侧脑室进针点６ｍｍ半径范围内刺入不易伤及血管脑组织，注射羊不出现临床反应。否则反应剧烈而造成死亡