钙调素一级结构保守性和变异性的数量分析──Ⅰ全序列主要免疫反应位点和靶酶结合位点保守性和变异性的数量分析

用计算机为工具对３２种生物钙调素（ＣａＭ）一级结构的保守性和变异性进行了数量分析,结果表明ＣａＭ分子高度保守,其保守性强于同类生物的细胞色素ｃ,脊椎动物ＣａＭ间的同源性在９８％以上,被子植物ＣａＭ间以及被子植物与脊椎动物ＣａＭ间的同源性高于８８％;脊椎动物与单细胞藻类ＣａＭ间的同源性也在８０％以上。对亲源关系较近的物种,它们的ＣａＭ主要免疫反应位点和靶酶结合位点间的同源性大于全序列间的同源性;对亲源关系较远的物种,它们的ＣａＭ主要免疫反应位点和靶酶结合位点间的差异大于它们全序列间的差异。     

钙调素一级结构保守性和变异性的数量分析Ⅱ钙结合区和疏水穴保守性和变异性的数量分析

用计算机为工具对３２种生物钙调素（ＣａＭ）的四个钙结合区和两个疏水穴一级结构的保守性和变异性进行了数量分析。结果表明第一、二钙结合区（Ｎ端）比第三、四钙结合区（Ｃ端）更保守;即大多数物种ＣａＭ的第一、二钙结合区的同源性大于它们全序列间的同源性。而第三、四钙结合区则因亲缘关系和高低等生物而异,情况较复杂。Ｎ端疏水穴比Ｃ端疏水火保守,前者的同源性高于它们全序列间的同源性;而后者亦因亲缘关系及高低等生物而异规律不明显。     

钙调素一级结构保守性和变异性的数量分析Ⅱ钙结合区和疏水穴保守性和变异性的数量分析

用计算机为工具对３２种生物钙调素（ＣａＭ）的四个钙结合区和两个疏水穴一级结构的保守性和变异性进行了数量分析。结果表明第一、二钙结合区（Ｎ端）比第三、四钙结合区（Ｃ端）更保守;即大多数物种ＣａＭ的第一、二钙结合区的同源性大于它们全序列间的同源性。而第三、四钙结合区则因亲缘关系和高低等生物而异,情况较复杂。Ｎ端疏水穴比Ｃ端疏水火保守,前者的同源性高于它们全序列间的同源性;而后者亦因亲缘关系及高低等生物而异规律不明显。     

猪獾和黄鼬mtDNA物理图谱及位点变异性初探

本实验用ＡｐａⅠ,ＢｇｌⅠ,ＢｇｌⅡ,ＣｌａⅠ,ＥｃｏＲⅠ,ＥｃｏＲⅤ,ＨｉｎｄⅢ,ＨｐｅⅠ,ＰｓｔⅠ,ＰｖｕⅠⅡ,ＳａｃⅠ,ＳａｌⅠ等１２种限制性内切酶分析猪獾和黄鼬的ｍｔＤＮＡ限制性片段,并用双酶解法构建限制性内切酶图谱。结合以往积累的资料,我们对哺乳动物ｍｔＤＮＡ限制性位点在远缘物种间的保守性和变异性进行了初步讨论。     

10个近交系小鼠的微卫星位点分析及其在遗传监测中应用的探讨（一）

选用不同染色体上的８个微卫星位点,应用ＰＣＲ技术对１０个品系的近交系小鼠进行遗传分析,研究结果表明：在无任何亲缘关系的近交系小鼠品系之间,该８个微卫星位点均具有不同的等位基因。含有不同等位基目的微卫星位点所占的百分比从ＭＳＭ／ＭＳ与Ｃ３Ｈ／ＨｅＪ的１００％到（ＣｘＳ）Ｆ与Ｃ５７ＢＬ／６Ｊ间的２５％,平均５６．７２％,在重组近交系间及重组近交系与亲本之间,此比率从（ＣｘＳ）Ｄ或（ＣｘＳ）Ｍ与ＢＡＬＢ／ＣＨｅＡ间的５０％到（ＣｘＳ）Ｄ或（ＣｘＳ）Ｍ与ＳＴＳ／Ａ,（ＣｘＳ）Ｄ与（ＣｘＳ）Ｍ间的２５％,此８个微卫星位点有可能做为在基因水平上进行近交系小鼠遗传监测的标记。     

新疆呼图壁种牛场地区优势植物K,Na,Ca,Mg,S的含量特征和数量分析

新疆呼图壁种子牛场地区草地２５种植物中的Ｋ,Ｎａ,Ｃａ,Ｍｇ,Ｓ在含量水平上Ｎａ＞Ｓ＞Ｋ＞Ｍｇ＞Ｃａ。不同植物种类Ｎａ,Ｓ含量差异较大,如盐节木,囊果碱蓬等Ｎａ,Ｓ含量分别达１０００００ｐｐｍ和３００００ｐｐｍ以上,而芦苇,獐茅草Ｎａ,Ｓ含量分虽在３００００ｐｐｍ和４０００ｐｐｍ以下;种间变异系数Ｎａ,Ｓ分别为９５．１０％,６３．１６％,Ｋ含量变异系数较小,为３４．４２％。同一种植物在不同地点Ｎａ     

小鼠中血清因子结合位点位置分布及保守性的生物信息学分析

目的：血清反应因子在与心血管相关的疾病基因调控方面的作用越来越重要。血清反应因子识别的结合位点CArG元件因其重要的基因调控作用近年来随之备受关。本研究目的是揭示血清因子结合位点的位置分布与功能的关系及CArG元件内部各个住点的保守性。方法：本研究应用生物信息学方法结合遗传学方法对小鼠中CArG元件的位置分布、位点替换率及G0分类进行深入研究。结果：结果表明,71％的功能CArG元件分布在转录起始位点上游,且距离转录起始位点越近,CArG元件的数量越多。保守性分析发掘出元件内部的替换冷点、热点及替换规律。GO分类结果显示,CArG依赖性基因多为信号转导和细胞骨架蛋白。结论：上述研究结果将为准确预测候选CArG元件提供重要理论基础,同时也将为更为深入阐述SRF的调控模式奠定基础。     

植物microRNA的保守性及其分布的分析

MicroRNA(miRNA)是真核生物中具有重要调控作用的小分子非编码RNA。本文对miRNA官网miRBase数据库Release 22.1中隶属于植物界的绿藻门、苔藓植物门、蕨类植物门、裸子植物门、被子植物门共计82个物种的miRNA进行了统计分析。miRBase共收录植物miRNA 前体8 615个,成熟miRNA 10 414条,隶属于2 892个miRNA家族。绿藻门miRNA与其他4个门miRNA无同源性;对其他4个门植物miRNA的保守性进行研究,发现存在于2个植物门的miRNA家族有26个,属于中度保守miRNA家族;14个miRNA家族存在于3个及3个以上植物门中,属于高度保守miRNA家族,其中7个miRNA家族系苔藓、蕨类、裸子和被子植物共有,是植物中最保守的miRNA。分析表明,超过30个miRNA家族的植物有35种。进一步对40个中度或者高度保守miRNA在35种植物中的分布进行研究,发现miRNA家族及其成员在物种间的分布存在较大的差异。这些分布上的差异一方面反映不同植物中miRNA的研究深度不同,另一方面也反映出miRNA在植物进化过程中的适应性调整。研究不同植物中miRNA家族的分布,可在miRNA水平为植物早期进化同源性的研究提供分子依据。     

植物microRNA的保守性及其分布的分析

MicroRNA(miRNA)是真核生物中具有重要调控作用的小分子非编码RNA。本文对miRNA官网miRBase数据库Release 22.1中隶属于植物界的绿藻门、苔藓植物门、蕨类植物门、裸子植物门、被子植物门共计82个物种的miRNA进行了统计分析。miRBase共收录植物miRNA 前体8 615个,成熟miRNA 10 414条,隶属于2 892个miRNA家族。绿藻门miRNA与其他4个门miRNA无同源性;对其他4个门植物miRNA的保守性进行研究,发现存在于2个植物门的miRNA家族有26个,属于中度保守miRNA家族;14个miRNA家族存在于3个及3个以上植物门中,属于高度保守miRNA家族,其中7个miRNA家族系苔藓、蕨类、裸子和被子植物共有,是植物中最保守的miRNA。分析表明,超过30个miRNA家族的植物有35种。进一步对40个中度或者高度保守miRNA在35种植物中的分布进行研究,发现miRNA家族及其成员在物种间的分布存在较大的差异。这些分布上的差异一方面反映不同植物中miRNA的研究深度不同,另一方面也反映出miRNA在植物进化过程中的适应性调整。研究不同植物中miRNA家族的分布,可在miRNA水平为植物早期进化同源性的研究提供分子依据。     

豚鼠小肠EC细胞的免疫细胞化学和银染法的比较研究

本实验利用同一切片标本,在光镜水平上,对豚鼠小肠ＥＣ细胞进行了免疫细胞化学和不同银染法的比较研究。实验结果显示,全部Ｍａｓｓｏｎ－Ｆｏｎｔａｎａ亲银染色阳性细胞均呈ＰＡＰ染色阳性;另一方面,小部分（１５％）Ｇｒｉｍｅｌｉｕｓ嗜银染色阳性细胞却表现为亲银染色和ＰＡＰ染色双阴性。以上结果表明,在显示ＥＣ细胞上,亲银染色具有很高的特异性,因此仍不失为一种经济和实用的方法;嗜银染色显示ＥＣ细胞,尽管其敏感性稍高于亲银染色法,但不具有免疫细胞化学与亲银染色技术那样明显的特异性。     

Paramecium calmodulin mutants defective in ion channel regulation can bind calcium and undergo calcium-induced conformational switching

Calmodulin (CaM) is an essential eukaryotic protein that binds calcium ions cooperatively at four EF-hand binding sites to regulate signal transduction pathways. Interactions between the apo domains of vertebrate CaM reduce the calcium affinities of sites I and II below their intrinsic values, allowing sequential opening of the two hydrophobic clefts in CaM. Viable domain-specific mutants of Parameciumcalmodulin (PCaM) differentially affect ion channels and provide a unique opportunity to dissect the roles of the two highly homologous half-molecule domains. Calcium binding induced an increase in the level of ordered secondary structure and a decrease in Stokes radius in these mutants; such changes were identical in direction to those of wild type CaM, but the magnitude depended on the mutation. Calcium titrations monitored by changes in the intrinsic fluorescence of Y138 in site IV showed that the affinities of sites III and IV of wild type PCaM were (i) higher than those of the same sites in rat CaM, (ii) equivalent to those of the same sites in PCaM mutants altered between sites I and II, and (iii) higher than those of PCaM mutants modified in sites III and IV. Thus, calcium saturation drove all mutants to undergo conformational switching in the same direction but not to the same extent as wild type PCaM. The disruption of the allosteric mechanism that is manifest as faulty channel regulation may be explained by altered properties of switching among the 14 possible partially saturated species of PCaM rather than by an inability to adopt two end-state conformations or target interactions similar to those of the wild type protein.     

1H, 15N and 13C resonance assignments of yeast Saccharomyces cerevisiae calmodulin in the Ca2+-free state

Calmodulin (CaM) is a small Ca²⁺-binding protein, which has been found in all of eucaryotic cells examined. CaMs isolated from various species have highly conserved amino acid sequence (more than 90% identical), and show the same biological functions. CaM isolated from the baker's yeast (Saccharomyces cerevisiae) (yCaM), however, shares only 60% identity in the amino acid sequence with CaM from vertebrate, and shows quite distinct conformational and biochemical properties compared with those of CaM from other species. The conformational details of yCaM, however, have not been revealed yet. We achieved the chemical shift assignments of yCaM (146 amino acids) in the apo-state using uniformly ¹⁵N- and ¹³C-labeled protein. Consequently, the resonances of 95% atoms in the backbone amides were successfully assigned.     

Biomass changes and bentho-pelagic transfers throughout the Benthic Boundary Layer in the English Channel

One hundred and eight suprabenthic hauls were taken from sixsites in the English Channel with a modified Macer-GIROQ sledgethat permitted the sampling of three kinds of organisms in thebenthic boundary layer: mesozooplankton, macrozooplankton andsuprabenthos. A complete annual cycle was sampled in the Bayof Saint-Brieuc but only spring and autumn samplings were takenfrom the other sites. Meso- and macrozooplankton biomasses wereusually higher at every site during the daytime than at night;in contrast, suprabenthic biomasses were lower during the daythan at night. However, at site 5, on pebble substrates, everyfaunistic group showed a higher biomass during the day thanat night, while at site 2 the opposite occurred. Meso- and macrozooplanktonbiomasses were at their maximum during spring whereas the highestbiomass of suprabenthos was observed from summer to autumn.Daytime exchanges were by mesozooplanktonic organisms and night-timeexchanges were by suprabenthic species, especially amphipods,mysids and large decapods. Daily transfers showed the same patternfor every faunistic group, and transfers were higher in autumnthan in spring, except at site 1 where it was similar duringboth seasons. Three groups of sites were identified from theirannual transfers: sites 1 and 3, on the Brittany coasts, withlowest annual transfers; site 2, offshorePlymouth, with thehighest transfer, and the three eastern sites (4, 5 and 6) showingsimilar annual transfers. The rate between macrobenthic productionand annual transfers was high at coarse sand and pebble siteswhere the benthic macrofauna was endobenthic and sessile, suggestinga concentration of carbon in the bottom. On the other hand,this rate was low on medium sand substrates where the benthicmacrofauna was vagile, suggesting that carbon remained concentratedin the benthic boundary layer where exchanges were most importantby the migration of both pelagic and benthic organisms in thiscompartment.     

Using partial genomic fosmid libraries for sequencing complete organellar genomes

Organellar genome sequences provide numerous phylogenetic markers and yield insight into organellar function and molecular evolution. These genomes are much smaller in size than their nuclear counterparts; thus, their complete sequencing is much less expensive than total nuclear genome sequencing, making broader phylogenetic sampling feasible. However; for some organisms, it is challenging to isolate plastid DNA for sequencing using standard methods. To overcome these difficulties, we constructed partial genomic libraries from total DNA preparations of two heterotrophic and two autotrophic angiosperm species using fosmid vectors. We then used macroarray screening to isolate clones containing large fragments of plastid DNA. A minimum tiling path of clones comprising the entire genome sequence of each plastid was selected, and these clones were shotgun-sequenced and assembled into complete genomes. Although this method worked well for both heterotrophic and autotrophic plants, nuclear genome size had a dramatic effect on the proportion of screened clones containing plastid DNA and, consequently, the overall number of clones that must be screened to ensure full plastid genome coverage. This technique makes it possible to determine complete plastid genome sequences for organisms that defy other available organellar genome sequencing methods, especially those for which limited amounts of tissue are available.     

Arthropods in biodiversity hotspots: the case of the Phytoseiidae (Acari: Mesostigmata)

The biodiversity hotspot concept was defined by Myers in 1988 to determine priority areas for conservation. They have high endemism levels and have lost more than 70% of their original vegetated area. To date, there is little information on arthropod diversity in these zones. This work focuses on the biodiversity of the Phytoseiidae (Acari), one of the best known among the order Mesostigmata, in these threatened areas. These mites are usually predators and they are worldwide spread. Geographic distribution of phytoseiids in 27 biodiversity hostspots was assessed from data of the last world catalogue published in 2004. One thousand two hundred and thirty species are reported from at least one hotspot (62% of the total species number) and 604 species (30% of the total species number) are endemic to the 27 hotspots considered. The number of reports/publication in hotspot areas (2.6) is higher than in non-hotspot zones (1.5). Hotspots areas could be thus considered as a great reservoir of the Phytoseiidae diversity, just as they are for vertebrates and plants. Correlations between plant, vertebrate, mite diversity and endemism, as well as congruence rates between endemism levels of these three organisms suggest that the biodiversity patterns of plants and vertebrates mirror well those of the Phytoseiidae (both for endemicity and species richness). More intense conservation efforts in biodiversity hotspots would thus be assumed to affect plant and vertebrate biodiversity, as already known, but also arthropod biodiversity, as it was assumed. These results further support thus the importance of these zones in biodiversity conservation, even for organisms like mites, very small and poorly studied in this regards. More data on arthropods are, however, required to confirm these preliminary observations.     

Mouse pathogenicity studies of Nocardia asteroides complex species and clinical correlation with human isolates

Abstract Nocardia asteroides complex organisms derived from human specimens between 1979 and 1992 were identified on the species level. Of 117 N. asteroides complex organisms, 34 (29%) were N. farcinica , 28 (24%) were N. nova , and 55 (47%) were N. asteroides sensu stricto . An analysis of the specimen sites from which the organisms were derived showed that isolates derived from blood, brain, or bone marrow were more likely to be N. farcinica than the other two species. A study of the virulence of ten strains of each species was undertaken, using a mouse model with intravenous inoculation. The 50% lethal doses (LD₅₀) for N. farcinica were significantly lower than those of the other two species. LD₅₀ values for N. nova and N. asteroides were not significantly different. The above data confirming the greater virulence of N. farcinica support the identification of species within the N. asteroides complex.     

The Phylogenetic Association Between Salt Tolerance and Heavy Metal Hyperaccumulation in Angiosperms

Salt tolerance and heavy metal hyperaccumulation are two rare plant abilities that are heavily studied for their potential to contribute to agricultural sustainability and phytoremediation in response to anthropogenic environmental change. Several observations suggest that it is worth investigating the link between the abilities to tolerate high levels of soil salinity or accumulate more of a particular heavy metal from the soil than most plants. Firstly, several angiosperm families are known to contain both salt tolerant plants (halophytes) and heavy metal hyperaccumulators. Secondly, some halophytes can also accumulate heavy metals. Thirdly, although salinity tolerance and heavy metal hyperaccumulation typically require many physiological or anatomical changes, both have apparently evolved many times in angiosperms and among closely related species. We test for a significant relationship between halophytes and hyperaccumulators in angiosperms using taxonomic and phylogenetic analyses. We test whether there are more angiosperm families with both halophytes and hyperaccumulators than expected by chance, and whether there are more species identified as both halophyte and hyperaccumulator than if the abilities were unconnected. We also test whether halophytes and hyperaccumulators are phylogenetically clustered among species in seven angiosperm families. We find a significant association between halophytes and hyperaccumulators among angiosperm families and that there are significantly more species identified as both halophytes and hyperaccumulators than expected. Halophytes and hyperaccumulators each show low phylogenetic clustering, suggesting these abilities can vary among closely related species. In Asteraceae, Amaranthaceae, Fabaceae, and Poaceae, halophytes and hyperaccumulators are more closely related than if the two traits evolved independently.