Morphological Studies on Four Brackish Water Ciliates of the Class Spirotrichea(Protista,Ciliophora)

We reinvestigate the morphology of two oligotrich and two hypotrich ciliates collected from the coasts of north and south China, viz., Parallelostrombidium obesum Liu et al., 2015, Spirostrombidium apourceolare Liu et al., 2013, Protogastrostyla pulchra(Pereyaslawzewa, 1886) Gong et al., 2007, and Uncinata bradburyae(Gong et al., 2001) Luo et al., 2015. All the populations match well with the original samples identified in previous studies. Supplemental taxonomic data were supplied for these four species of the new populations. The species Parallelostrombidium obesum is characterised by its dorsal-ventrally flattened body shape with anterior and posterior ends transversely truncating, as well as two thigmotactic membranelles and girdle kinety that spirals around the cell one and a half times. Spirostrombidium apourceolare is characterised by its elongate ellipsoidal and dorsal-ventrally flattened body shape, two thigmotactic membranelles, about 11-27 ovoid macronuclear nodules, and girdle kinety that spirals around the cell twice with two undulations. Protogastrostyla pulchra is characterised by its elongate body shape and unique, caudally located food vacuole. Based on the new populations, we described the smaller cortical granules, clustered around dorsal bristles for the first time. The new population of Uncinata bradburyae shares the diagnostic features with the type population, which include prominent beak-like projection in anterior region, the conspicuous gap of adoral zone, proximalmost adoral membranelles distinctly elongated, and infraciliature.     

钼兰比色法测定硅灰石含量

本文用0.35mol/1浓度的稀硫酸于沸水浴上提取试样中的蛙灰石矿物,是在稳定剂(乙醇)存在条件下,以钼兰比色法测定硅,并根据测得的硅量计算硅灰石的含量。本法使用双向差式分光光度技术,测定蛙灰石的准确度较高,标准偏差为0.22,变动系数为0.38%。     

Effects of drought and heat on the productivity and photosynthetic characteristics of alpine meadow plants on the Qinghai-Tibetan Plateau

Alpine meadow plants, adapted to humid and cold environments, are highly sensitive to environmental factors such as drought and heat. However, the physiological responses of individual alpine meadow species to drought and heat stress remain unclear. In this study, four representative species of typical functional groups in an alpine meadow of the Qinghai-Tibet Plateau were selected as experimental materials. Heat(H1, H2), drought(D1, D2), and combined stress(D1 H1, D2 H2) treatments were implemented to reveal the biomass and physiological characteristics' response to a constant drought and heat environment. Our results showed that the leaf water content(LWC) of Kobresia humilis and Poa annua increased significantly under heat stress and the compound stress(P0.05). The effect of a single factor on LWC was greater than that of multiple factors. The aboveground biomass(AGB) of Oxytropis ochrocephala and Saussurea pulchra decreased significantly under compound stress(P0.05). The response patterns of the net photosynthetic rate(Pn) and transpiration rate(Tr) of K. humilis and P. annua under various stress treatments were similar; as were those of O. ochrocephala and S. pulchra. The stomatal conductance(Gs) variation in K. humilis, P. annua, O. ochrocephala, and S. pulchra were the same under three kinds of stress treatments. The photosynthetic characteristics were more sensitive to the effects of composite than those of single factors. The drought × heat × species treatment had a significant influence on various indexes except on height(Ht) and the belowground biomass(BGB)(P0.01). Within a certain range, daytime temperature(DT) promoted the Ht and increased the LWC of the plants, while it inhibited their AGB and intercellular CO2 concentration(Ci). The Pn, Tr, and Gs were more sensitive to soil moisture than to DT. The results help improve understanding of the physiological response regularity of representative alpine meadow plant species to continuous drought and high temperature conditions at the species level, and provided experimental data and theoretical basis to identify the decisive factors of stress response.     

六带石斑鱼(Epinephelus sexfasciatus)的核型分析

以六带石斑鱼肾细胞为材料,采用 PHA 和秋水仙素进行分步活体注射,经低渗处理,空气干燥制片法制作染色体标本。对染色体初步的分析结果表明,六带石斑鱼体细胞染色体数目为2n=48。其中2条为亚中着丝点染色体,46条为端着丝点染色体(包括两条有明显的次缢痕的染色体),故总臂数 NF=50。     

棕点石斑鱼(♀)与蓝身大斑石斑鱼(♂)杂交子代核型分析

【目的】研究棕点石斑鱼(Epinephelus tukula,♀)与蓝身大斑石斑鱼(Epinephelus fuscoguttatus,♂)杂交F1代(下称"金虎斑")的染色体核型。【方法】采用头肾-PHA注射法制备金虎斑染色体,并分析其核型。【结果与结论】金虎斑二倍体染色体数为48,包括23对端部着丝粒染色体,1对亚中部着丝粒染色体,核型公式是2n=48=2sm+46t,染色体臂数(NF)为50。与其他石斑鱼核型相比,金虎斑染色体核型特点符合典型的高位类群鱼类核型特征;根据染色体臂数,金虎斑属于特化类群。     

泰国虎纹蛙与中国虎纹蛙早期胚胎发育比较研究

比较了泰国虎纹蛙与中国虎纹蛙在控温条件下的胚胎发育过程。结果表明:两亚种蛙在右鳃封闭期与鳃盖完成期之间有明显的"角质颌出现"的特征,因而在传统分期的基础上增加了一个"角质颌出现期",从而将两者自受精卵开始到鳃盖完成期为止划分为26个时期;两亚种蛙大部分发育时期外形特征基本相同,但八细胞期细胞的排列方式,两亚种蛙神经褶期的神经沟形状、纤毛出现期的神经褶棱高度等均不同;泰国虎纹蛙的发育速度较快,自受精卵期到鳃盖完成期共耗时70.4h,中国虎纹蛙在相同的条件下则需92.5h,但在四细胞期、八细胞期、神经管期和尾芽期,泰国虎纹蛙的发育速度却较中国虎纹蛙慢。     

黑斑蛙(Rana nigromaculata)早期发育过程中乳酸脱氢酶同工酶

用垂直平板聚丙烯酸胺凝胶电泳技术对黑斑蛙早期胚胎发育过程中乳酸脱氢酶（LDH）同工酶进行研究。结果表明,黑斑蛙胚胎各个不同发育时期LDH同工酶谱有很大差异：LDH1在整个胚胎发育过程中均处于活化状态,LDH2、LDH4在原肠中期开始出现,LDH3在尾芽期开始出现。从尾芽期到尾血循环期只出现LDH－1、－2、－3和-4四条酶带,但不同时期各种同工酶的表达活性不同。     

洛氏鱥染色体核型分析

以洛氏鱥(Phoxinus lagowskii)肾组织为材料,采用腹腔注射植物血球凝集素(PHA)、秋水仙素和空气干燥法制备染色体标本,进行染色体组型分析。结果表明:洛氏鱥染色体为50条,核型公式为2n=50=24m+14sm+12t,臂数NF=88,未发现异型染色体、随体染色体和次缢痕。     

哲罗鱼(Hucho taimen)染色体组型与DNA含量分析

采用体内注射PHA和秋水仙素、肾细胞短期培养、常规空气干燥法制备哲罗鱼(Hucho taimen)的染色体。对其肾细胞染色体数目统计分析表明,哲罗鱼染色体组有84条染色体,核型公式为2n=18m+16sm+34st+16t,其染色体总臂数(NF)为118。采用流式细胞分析仪测定哲罗鱼的DNA含量,与鸡血细胞标准对照的比值为2.23±0.17,以鸡红细胞DNA含量2.30pg·N~(-1)计,则哲罗鱼的体细胞DNA含量为5.12pg·N~(-1)。哲罗鱼染色体数目和DNA含量体现为四倍体特征。     

黑斑蛙（Rana nigromaculata）早期发育过程中乳酸脱氢酶同工酶

用垂直平板聚丙烯酰胺凝胶电泳技术对黑斑蛙早期胚胎发育过程中乳酸脱氢酶（ＬＤＨ）同工酶进行研究,结果表明,墨斑蛙胚胎各个不同发育时期ＬＤＨ同工酶谱有很大差异;ＬＤＨ１在整个胚胎发育过程中均处于活化状态,ＬＤＨ２、ＬＤＨ４在原肠中期开始ＬＤＨ３在尾芽期开始出现,从尾芽期到尾血循环期只出现ＬＤＨ－１、－２、－３和－４四条酶带,但不同时期各种同工酶的表达活性不同。     

斑带石斑鱼与黑边石斑鱼核型的研究

以斑带石斑鱼与黑边石斑鱼为材料，胸腔注射秋水仙碱溶液，取全肾经空气干燥制片法制片。姬姆萨染色和银染，分析核型及Ａｇ－ＮＯＲ带，结果表明斑带石斑鱼的核型为２ｎ＝４８、４８ｔ、ＮＦ＝４８。黑边石斑鱼的核型为２ｎ＝４８、４８ｔ、ＮＦ＝４８。在最小一对端部着丝粒染色体上均具有明显的次缢痕。银染结果显示该次缢痕部位即为核仁组织者区域。     

斜带石斑鱼与赤点石斑鱼的核型研究

采用PHA体内注射肾细胞直接制片法研究斜带石斑鱼和赤点石斑鱼的核型。结果表明 ,斜带石斑鱼的核型为 2n =4 8,2sm +46t ,NF =5 0 ;赤点石斑鱼的核型为 2n =4 8,5st+43t ,NF =4 8。两种鱼的 2n数相同 ,它们的核型特点符合典型的高位类群鱼类核型特征。     

Molecular cytogenetic of the Amoy croaker,A rgyrosomus amoyensis(Teleostei,Sciaenidae)

The family Sciaenidae is remarkable for its species richness and economic importance. However, the cytogenetic data available in this fish group are still limited, especially those obtained using fl uorescence in situ hybridization(FISH). In the present study, the chromosome characteristics of a sciaenid species, Argyrosomus amoyensis, were examined with several cytogenetic methods, including dual-FISH with 18 S and 5 S rDNA probes, and a self-genomic in situ hybridization procedure(Self-GISH). The karyotype of A. amoyensis comprised 2 n=48 acrocentric chromosomes. A single pair of nucleolar organizer regions(NORs) was located at the proximal position of chromosome 1, which was positive for silver nitrate impregnation(AgNO_3) staining and denaturation-propidium iodide(DPI) staining but negative for Giemsa staining and 4',6-diamidino-2-phenylindole(DAPI) staining, and was confi rmed by FISH with 18 S rDNA probes. The 5 S rDNA sites were located at the centromeric region of chromosome 3. Telomeric FISH signals were detected at all chromosome ends with dif ferent intensities, but internal telomeric sequences(ITSs) were not found. Self-GISH resulted in strong signals distributed at the centromeric regions of all chromosomes. C-banding revealed not only centromeric heterochromatin, but also heterochromatin that located on NORs, in interstitial and distal telomeric regions of specifi c chromosomes. These results suggest that the karyotype of Amoy croaker was relatively conserved and primitive. By comparison with the reported cytogenetic data of other sciaenids, it can be deduced that although the karyotypic macrostructure and chromosomal localization of 18 S rDNA are conserved, the distribution of 5 S rDNA varies dynamically among sciaenid species. Thus, the 5 S rDNA sites may have different evolutionary dynamics in relation to other chromosomal regions, and have the potential to be ef fective cytotaxonomic markers in Sciaenidae.     

花染色体组型分析及细胞核DNA含量的测定

采用PHA、秋水仙碱腹腔或背部肌肉注射,活体培养法,取花肾细胞制成悬浮液,用空气干燥法制片。经Giemsa染色,镜检细胞分裂相,统计结果为2n=50,核型公式为:2n=20m+12sm+10st+8t,NF=82。同时,取花肌肉和肝脏为材料,以鸡血细胞为DNA标准(2.30pg/2c),使用EPICS-XL型流式细胞仪测定了花细胞DNA含量,分别为2.219±0.055pg/2c和2.214±0.083pg/2c。     

Cytogenetic mechanism for the aneuploidy and mosaicism found in tetraploid Pacific oyster Crassostrea gigas (Thunberg)

Chromosome constitution was investigated in adult tetraploid Pacific oyster produced by blocking the first polar body of triploid eggs which were fertilized with haploid sperms. A high incidence of aneuploid and heteroploid mosaics were found among the offspring. Of 20 individuals identified, only 9 (45%) were eutetraploid which contained 40 chromosomes; 2 (10%) were aneuploid (hypotetraploid), which contained 39 and 38 chromosomes, respectively; and 9 (45%) were heteroploid mosaics. One mosaic was consisted of cells containing 40 and 39 chromosomes, respectiovely (1:1 in cell number), while the other 8 were consisted of cells containing chromosomes varying between tetraploid and triploid. It was also interesting to note that 3 mosaics even contained some diploid cells with 20 chromosomes. A certain number of cells of 2 tetraploids and 8 mosaics spread with 32–37 well-scattered and some clumped chromosomes at metaphase. The percentage of aneuploid cells with chromosomes varying between triploid and tetraploid correlated significantly with that of heteroploid mosaics cells with clumping chromosomes (P<0.05). Our findings suggested that reversion existed in both tetraploid and triploid oyster and chromosome clumping may underline the chromosome elimination in tetraploid oyster. It seems that the reversing cells, at least some of them, continuously eliminate their chromosomes until the most stable diploid state is established.     

近江牡蛎的染色体组型

以近江牡蛎的担轮幼虫为材料,采用秋水仙素——低渗处理——空气干燥制片法制作染色体标本,对其核型进行分析,结果表明,近江牡蛎体细胞染色体数目2n=20,NF=40,核型公式为20m。     

管角螺、细角螺的核型研究

以管角螺、细角螺鳃组织为材料,经过秋水仙素处理,空气干燥法制片,Giemsa染色,观察分析获得染色体核型。结果表明,管角螺核型公式为2n=60=44m+10sm+6t,染色体总臂数NF=114。细角螺核型公式为2n=42m+10sm+2st+6t,总臂数NF=112。两种螺的全套染色体中未发现次缢痕、随体,也无性染色体。