泰山赤鳞鱼同工酶的研究

采用琼脂糖凝胶电泳或聚丙烯酰胺垂直板凝胶电泳（ＰＡＧＥ）技术研究了泰山赤鳞鱼早期发育阶段（受精后０—１２０ｈ）及成体眼、脑、心、肾、肝、肌６种组织中的ＬＤＨ同工酶分化表达谱式。结果表明：（１）赤鳞鱼在胚胎发育过程中Ｌｄｈ－Ａ基因和－Ｂ基因同时表达,形成５种不同形式的四聚体（Ｂ４、ＡＢ３、Ａ２Ｂ２、Ａ３Ｂ、Ａ４）。与大多数硬骨鱼相比,赤鳞鱼ＬＤＨ同工酶具有独特的早期个体发育谱式：在整个胚胎发育时期,Ａ亚基与Ｂ亚基的活性几乎相等。（２）赤鳞鱼的ＬＤＨ同工酶谱具有明显的组织特异性。Ｌｄｈ－Ｃ基因仅在肝脏组织表达,以向阴极迁移的分子形式（ＬＤＨ－Ｃ４）特异地表达。     

泰山郝鳞鱼同工酶的研究

采用琼脂糖凝胶电泳或聚丙酰胺垂直板凝胶电泳（ＰＡＧＥ）技术研究了泰赤鳞鱼早期发育阶段（受精后０－１２０ｈ）及成体眼、脑、心、肾、肝、肌６种组织中的ＬＤＨ同工酶分化表达谱式。结果表明：（１）赤鳞鱼在胚胎发育过程中Ｌｄｈ－Ａ基因和－Ｂ基因同时表达,形成５种不同形式的四聚体（Ｂ４、ＡＢ３、Ｂ３Ｂ、Ａ４）。与大多数硬骨鱼相比,赤鳞鱼ＬＤＨ同工酶具有独特的早期个体发育谱式：在整个胚胎发育时期,Ａ亚基与Ｂ亚基     

两种泥鳅RAPD标记遗传稳定性分析

用从20个随机引物中筛选出的7个引物对泥鳅（Misgurnus anguillicaudatus）和大鳞副泥鳅（Paramisgurnus dabryanus）及其自交与杂交子代进行了RAPD遗传稳定性分析。结果表明,RAPD谱带主要呈孟德尔式遗传,该类带纹明亮稳定,在泥鳅子代中占99．11％;在大鳞副泥鳅子代中占100％;在杂交子代中占99．36％。也存在非孟德尔式遗传谱带,该类带纹较暗、稳定性差,在泥鳅子代中为0．89％;在杂交子代中为0．64％;在大鳞副泥鳅中未见此类带纹。实验结果说明RAPD谱带具有很高的遗传稳定性。     

白鲢个体发育过程中同工酶基因的表达与调控研究

采用淀粉或聚丙烯酰胺凝胶电泳及特异性组织化学染色技术研究了白链早期发育过程中（从未受精卵到卵黄吸尽期）及成体不同组织（脑、眼、心、肌、肾、肝）中六种同工酶系统（ＬＤＨ,ＭＤＨ,ＩＤＨ,ＡＤＨ,ＳＤＨ,ＥＳＴ）的分化表达谱式,白链各同工酶基因的表达具有明显的组织特异性早期发育过程中,ＡＤＨ和ＳＤＨ基因均无活性,其它四种同工酶则具有不同的个体发育谱式。值得一提的是,由取自同一地区的两对白链的受精卵的形     

暗纹东方同工酶生化表现型的研究

利用聚丙烯酚胺凝胶垂直平板电泳方法,对暗纹东方的心、肝、肾,肌、性腺５种不同组织的７种同工酶（ＥＳＴ、ＬＤＨ、ＰＯＤ、ＭＤＨ、ＳＯＤ、ＳＤＨ、α－ＡＭＹ）进行了研究,讨论了各同工酶的基因表达谱式,观察到ＥＳＴ同工酶存在着多态现象;ＬＤＨ同工酶有二个基因位点,但只表现３条带,Ａ与Ｂ亚基的结合受阻;ＭＤＨ同工酶存在性别差异,说明决定ＭＤＨ同工酶表达的因素在不同性别中存在差异;ＳＯＤ同工酶有３个基因位点。各同工酶酶谱稳定,有组织特异性,倡ＥＳＴ、ＭＤＨ、ＳＯＤ、ＰＯＤ同工酶在各组织器官中又表现出较大的一致性,有利于物种的鉴定。α－ＡＭＹ与ＳＤＨ只在个别组织中有活性,可能与特定组织与器官的形态发生与机能分化有关。     

中华大蟾蜍人工诱发冬眠后组织内LDH同工酶的变化

非冬眠中华大蟾蜍７种组织中分离出３－５种具不同活力的ＬＤＨ轴工酶谱带,Ｌｄｈ－Ａ,Ｌｄｈ－Ｂ基因的表达有一定的组织特异性,其酶谱特征可分为心肌型和骨骼肌型两种类型。经４±１℃低温条件诱眠６周后,脾脏,肺,肝脏和脂肪中的ＬＤＨ同工酶谱带减少,但从Ｌｄｈ－Ａ,Ｌｄｈ－Ｂ两个基因表达能力看,其各组织内表达活性（Ａ：Ｂ规律性）没有产生明显变化。     

两种泥鳅中PdSox8和PdSox9的RFLP分析

以α-32P-dCTP标记的大鳞副泥鳅的PdSox8和PdSox9基因片段为探针,研究了二者在泥鳅和大鳞副泥鳅中的限制性片段长度多态性。结果表明两种探针在6尾大鳞副泥鳅（3♀3 ♂）和6尾泥鳅（3♀3 ♂）的经EcoRI和HindIII完全酶切的基因组DNA中检测到了较丰富的阳性杂交带,并讨论了其产生的可能原因。未发现性特异杂交带。 Abstract：With the α-32 P-dCTP-labeled PdSox8 and PdSox9 fragments of Paramisgurnus dabryanus as probes, the Restricted Fragment Length Polymorphism(RFLP) were analyzed in two species of loaches P. dabryanus and Misgurnus anguillicaudatus. The results showed that the plentiful positive bands were observed in the genomic DNA of 6 individuals(3♀3♂) of P. dabryanus and 6 individuals(3♀3♂) M.anguillicaudatus, which were digested thoroughly by EcoRI and HindIII. The possible reasons were discussed. No sex-specific band was observed.     

大鳞副泥鳅、泥鳅和北方泥鳅肉质比较分析

文章采用组织切片、生化组分分析以及实时荧光定量PCR等方法, 研究了大鳞副泥鳅(Paramisgurnus dabryanus)、泥鳅(Misgurnus anguillicaudatus)和北方泥鳅(Misgurnus bipartitus)肉质差异。结果显示: 大鳞副泥鳅、泥鳅和北方泥鳅的肌纤维横截面积分别为 (3589.17±2326.01)、(2809.7±1818.69) 和(2511.93±1949.03) μm2。粗蛋白和粗脂肪含量均是大鳞副泥鳅最高[分别为(17.07±0.31)%和(2.57±0.38)%], 依次为泥鳅[分别为(14.57±0.59)%和(1.37±0.12)%]和北方泥鳅[分别为(12.33±0.15%和0.57±0.06%]。必需氨基酸指数(EAAI)依次为泥鳅(74.38)、大鳞副泥鳅(65.11)和北方泥鳅(60.14); 呈味氨基酸含量依次为泥鳅(32.60±1.64)%、大鳞副泥鳅(27.75±2.13)%和北方泥鳅(24.86±1.00)%; 除亚油酸以外的总多不饱和脂肪酸含量依次为北方泥鳅(24.43±0.26)%、泥鳅(24.18±1.99)%和大鳞副泥鳅(7.86±0.24)%。大鳞副泥鳅的肌肉生长相关基因myod的表达量高, myog和mrf4的表达量低; 泥鳅和北方泥鳅的myog和mrf4的表达量高, myod的表达量低。elovl5等8个脂肪代谢相关基因的表达特征: 大鳞副泥鳅整体表达水平最高, 北方泥鳅次之, 泥鳅最低。结果表明, 大鳞副泥鳅肉质油润, 但是质地相对粗糙; 泥鳅营养价值高且鲜味程度高; 北方泥鳅肉质细嫩, 但是氨基酸营养价值不高, 鲜味程度较差。三种鳅的上述肉质差异可能与肌肉生长和脂肪代谢活动不同有关。     

PCR扩增泥鳅和大鳞副泥鳅SRY盒基因

以特异扩增人ＳＲＹ基因保守区的一对引物,研究了泥鳅和大鳞副泥鳅基因组中ＳＲＹ盒基因的扩增。结果表明,该引物可以在泥鳅中扩增出四条带,其长度分别为２００,５５０、９４０和１０００ｂｐ。在大鳞副泥鳞中扩增出三条带,大小为２００,５５０和９００ｂｐ。经Ｓｏｕｔｈｅｒｎ杂交显示出二者的阳性带为２００和５５０ｂｐ。阳性带在雌雄个体间和两个物种间无差异。     

黄鳝性逆转过程中同工酶的分析研究 Ⅰ．雌雄个体不同组织的同工酶分析

作者采用三种垂直板聚丙烯酰胺凝胶电泳对雌雄黄鳝６种组织的乳酸脱氢酶（ＬＤＨ）、酯酶（ＥＳＴ）进行了研究。结果表明ＬＤＨ同工酶谱为细带型,可分为３区８条带,其迁移率为Ａ＞Ｂ＞Ｃ,其中Ｃ＿４仅出现在心、脑和肌肉中。ＬＤＨ在肝中表达甚微。ＥＳＴ同工酶显示３区７条带。黄鳝的同工酶有明显的组织特异性,在两性中的表达也存在一定的差异,这种差异ＥＳＴ比ＬＤＨ明显;肝、肾和性腺比其它组织较明显。这两种同工酶在雌性中的表达均比在雄性中强。以上反映了差别的基因活性。本文还讨论了黄鳝同工酶的遗传基础,亚基的组成以及ＬＤＨ迁移率和黄鳝演化地位的关系。     

不同亚细胞定位的alpha-突触核蛋白对SK-N-SH细胞的毒性影响

在帕金森病中,alpha-突触核蛋白(α-synuclein)累积与聚集所产生的细胞毒性是发病的重要原因。本文目的是探求不同亚细胞定位的α-突触核蛋白对于细胞的毒性影响。分别在α-突触核蛋白前插入核输出序列(nuclear export sequence,NES)或核定位序列(nuclear localization sequence,NLS),使其特定地表达在细胞质或细胞核中。构建成功的质粒分别在神经母细胞瘤SK-N-SH细胞中表达,通过免疫荧光与Western印迹法检测蛋白质的表达情况。结果显示,NES-α-synuclein特异性地在细胞质中表达,NLS-α-synuclein特异性地在细胞核中表达。乳酸脱氢酶法检测结果表明,相较于WT-α-synuclein组,NES-α-synuclein组的乳酸脱氢酶的释放量减少26. 54%,NLS-α-synuclein组的乳酸脱氢酶释放量增加12. 85%。CCK8法检测细胞活性结果表明,相较于WT-α-synuclein组,NES-α-synuclein组的细胞活力提高35. 51%,NLS-α-synuclein组的细胞活力减少7. 93%。上述结果提示,胞质内表达α-synuclein对于细胞的毒性更小,而细胞核内表达的α-synuclein对细胞有更强的毒性作用。这些发现为研究帕金森病的分子机制提供了新的研究思路。     

Streptococcus uberis: an Approach to its Classification

Thirty-one strains of streptococci, selected because they were considered to be or were similar to Streptococcus uberis , were examined by physiological tests and for properties of their lactate dehydrogenases (LDHs) and deoxyribonucleic acid (DNA). Twenty-nine of the 31 strains fell into two main genotypes as judged by DNA/DNA hybridization. One genotype (Group I) included the type strain of Strep. uberis and most other strains in this group were physiologically similar to it and had the same percent guanine + cytosine (%GC) in their DNA. The other genotype (Group II) contained strains which were more variable physiologically and had DNA of a lower % GC than the type strain. The European strains examined contained two distinct LDH types, one being associated with the Group I and the other with Group II strains. Three American strains examined however had LDH's which were unlike those of the European strains.     

PLOIDAL CHANGES IN CLONAL CULTURES OF SPIROGYRA COMMUNIS AND IMPLICATIONS FOR SPECIES DEFINITION

A clonal culture of Spirogyra filaments of initially uniform width produced filaments of three additional significantly different widths. Group I filaments of the original clone were 30.9 ± 0.7 μm wide (mean ± SD, N = 50). Group I filaments produced Group II filaments (22.0 ± 1.1 μm) through vegetative growth and sexual reproduction. Zygospores from homothallic Group I filaments produced germlings representative of Groups I and II; zygospores from homothallic Group II filaments produced germlings representative of Group II only. Germlings of Groups III (27.7 ± 1.0 μm) and IV (44.9 ± 0.8 μm) were produced in the cross of I × II. Viable zygospores from homothallic Group III filaments were obtained. Cells of Group IV filaments were initially binucleate and did not conjugate. Of the six intergroup crosses possible, four resulted in conjugation-tube formation only; two crosses yielded zygospores (I × II and III × IV). Germlings from the successful cross of Groups III and IV produced filaments of all four groups. Chromosome counts were: Group I (24), Group II (12), Group III (18), and Group IV (24, one nucleus). Relative nuclear fluorescence values of mithramycin-stained DNA were (mean ± SD, N ≥ 30): Group I (11.1 ± 1.4), Group II (5.7 ± 0.7), Group III (8.8 ± 1.3), and Group IV (10.0 ± 0.9, one nucleus). Cytologically, Group II appears to be a diploid (2x), Group I a tetraploid (4x), and Group III a triploid (3x). Systematically, Groups I, II, and III key out to Spirogyra singularis, S. communis, and S. fragilis, respectively, using Transeau's mongraph of the family Zygnemataceae. These species are interpreted to represent a species complex of S. communis (whose name has priority) with the ancestral haploid (x = 6) missing.     

Isolation and Expression of Two Distinct Sox8 Genes in Mudloach (Misgurnus anguillicaudatus)

To investigate the function and evolutionary origin of the SOXE subgroup, we amplified the genomic DNA of Misgurnus anguillicaudatus using a pair of degenerate primers. Using RACE, we obtained two versions of Sox8 (MaSox8a and MaSox8b) from M. anguillicaudatus. The overall sequence identity of the deduced amino acids from the two genes was 54.38%, with only one amino acid change in the high-mobility group domain. Southern blotting and evidence from the phylogenetic tree provided further proof for the existence of two Sox8 genes at the genomic level. This is the first evidence of two distinct Sox8 genes in Cypriniformes. Semi-quantitative and real-time quantitative PCR assays showed the expression trend of the genes was opposite in early embryonic development, and both were expressed ubiquitously in several adult tissues. The similar expression patterns indicated that MaSox8a and MaSox8b have possible overlapping functions.     

All three chaperonin genes in the archaeon Haloferax volcanii are individually dispensable

The Hsp60 or chaperonin class of molecular chaperones is divided into two phylogenetic groups: group I, found in bacteria, mitochondria and chloroplasts, and group II, found in eukaryotic cytosol and archaea. Group I chaperonins are generally essential in bacteria, although when multiple copies are found one or more of these are dispensable. Eukaryotes contain eight genes for group II chaperonins, all of which are essential, and it has been shown that these proteins assemble into double-ring complexes with eightfold symmetry where all proteins occupy specific positions in the ring. In archaea, there are one, two or three genes for the group II chaperonins, but whether they are essential for growth is unknown. Here we describe a detailed genetic, structural and biochemical analysis of these proteins in the halophilic archaeon, Haloferax volcanii. This organism contains three genes for group II chaperonins, and we show that all are individually dispensable but at least one must be present for growth. Two of the three possible double mutants can be constructed, but only one of the three genes is capable of fully complementing the stress-dependent phenotypes that these double mutants show. The chaperonin complexes are made up of hetero-oligomers with eightfold symmetry, and the properties of the different combinations of subunits derived from the mutants are distinct. We conclude that, although they are more homologous to eukaryotic than prokaryotic chaperonins, archaeal chaperonins have some redundancy of function.     

Localization of somatostatin mRNAs in the brain and pancreas of rainbow trout (Oncorhynchus mykiss)

Rainbow trout possess three distinct mRNAs, each encoding a separate precursor: PPSS I, which contains a 14-amino acid sequence at its C-terminus (somatostatin-14) that is highly conserved among vertebrates, as well as two others, PPSS II' and PPSS II", both containing [Tyr(7), Gly(10)]-somatostatin-14 at their C-terminus. In this study, we used RNA template-specific PCR and in situ hybridization to determine the distribution and cellular localization of PPSS mRNAs in the brain and Brockmann body of rainbow trout. PPSS I, PPSS II' and PPSS II" were expressed in the Brockmann body and pituitary; the expression of PPSS mRNAs in the brain was region specific. PPSS I mRNA was expressed in the Brockmann body predominantly by cells other than those that expressed PPSS IIs; however, there were several instances where PPSS I and PPSS IIs were co-expressed within the same cell. Of the PPSS II-expressing cells, many were observed to express both PPSS II' and PPSS II" mRNA; however, some cells expressed only PPSS II' mRNA, while other cells expressed only PPSS II" mRNA. In the brain, PPSS I mRNA was expressed in the optic tectum (OT) and in many hypothalamic nuclei, including the nucleus rotundus (NR), nucleus anterioris hypothalami (NAH), nucleus anterior tuberis (NAT), nucleus lateral tuberis (NLT), as well as in the pituitary (adenohypophysis). PPSS II" mRNA was present in the same regions as PPSS I mRNA; however, PPSS II' mRNA was present primarily in OT, NAT, NLT and adenohypohysis. These results indicate that PPSS mRNAs are expressed differently by different cells, suggesting that cell-specific mechanisms are involved with the control of PPSS expression and that particular biological responses may be associated with a specific SS isoform.