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101.
Sathiyamoorthy Meiyalaghan Philippa J Barrell Jeanne ME Jacobs Anthony J Conner 《BMC biotechnology》2011,11(1):1-10
Background
Tools for authenticating cell lines are critical for quality control in cell-based biological experiments. Currently there are methods to authenticate human cell lines using short tandem repeat (STR) markers based on the technology and procedures successfully used in the forensic community for human identification, but there are no STR based methods for authenticating nonhuman cell lines to date. There is significant homology between the human and vervet monkey genome and we utilized these similarities to design the first multiplex assay based on human STR markers for vervet cell line identification.Results
The following STR markers were incorporated into the vervet multiplex PCR assay: D17S1304, D5S1467, D19S245, D1S518, D8S1106, D4S2408, D6S1017, and DYS389. The eight markers were successful in uniquely identifying sixty-two vervet monkey DNA samples and confirmed that Vero76 cells and COS-7 cells were derived from Vero and CV-1 cells, respectively. The multiplex assay shows specificity for vervet DNA within the determined allele range for vervet monkeys; however, the primers will also amplify human DNA for each marker resulting in amplicons outside the vervet allele range in several of the loci. The STR markers showed genetic stability in over sixty-nine passages of Vero cells, suggesting low mutation rates in the targeted STR sequences in the Vero cell line.Conclusions
A functional vervet multiplex assay consisting of eight human STR markers with heterozygosity values ranging from 0.53-0.79 was successful in uniquely identifying sixty-two vervet monkey samples. The probability of a random match using these eight markers between any two vervet samples is approximately 1 in 1.9 million. While authenticating a vervet cell line, the multiplex assay may also be a useful indicator for human cell line contamination since the assay is based on human STR markers. 相似文献102.
以金属框架结构材料MOF-199为载体对漆酶进行固定化,并对固定化酶的性质进行初步研究。首先,以3-氨基丙基三乙氧基硅烷对载体MOF-199进行表面氨基化修饰,再用戊二醛对载体进行活化,最后对漆酶进行固定化。固定化条件优化结果表明:在漆酶质量浓度0.3 g/L,戊二醛用量1%(体积分数),pH 4.8下固定7 h,制得固定化酶活性最高。对固定化酶的研究发现:最适反应温度为40℃,最适pH为5.2,在连续操作7次后,固定化酶的活力仍能保持在51%。固定化漆酶热稳定性,pH耐受性,贮存稳定性均明显高于游离漆酶。 相似文献
103.
104.
Allosathes anitae n. sp. Casanueva & González-Acu?a (Astigmata: Crypturoptidae), collected on the Chilean tinamou Nothoprocta perdicaria (Tinamiformes: Tinamidae) from different localities of the ?uble Province, Chile, is described. Comments on its affinities and differences with Allosathes anepiandrius Gaud, Atyeo & Berla are also included. 相似文献
105.
JÉRÔME ATEUDJIEU JOHN WILLIAMS MARIE HIRTLE CÉDRIC BAUME JOYCE IKINGURA ALASSANE NIARÉ DOMINIQUE SPRUMONT 《Developing world bioethics》2010,10(2):88-98
Background: As actors with the key responsibility for the protection of human research participants, Research Ethics Committees (RECs) need to be competent and well‐resourced in order to fulfil their roles. Despite recent programs designed to strengthen RECs in Africa, much more needs to be accomplished before these committees can function optimally. Objective: To assess training needs for biomedical research ethics evaluation among targeted countries. Methods: Members of RECs operating in three targeted African countries were surveyed between August and November 2007. Before implementing the survey, ethical approvals were obtained from RECs in Switzerland, Cameroon, Mali and Tanzania. Data were collected using a semi‐structured questionnaire in English and in French. Results: A total of 74 respondents participated in the study. The participation rate was 68%. Seventy one percent of respondents reported having received some training in research ethics evaluation. This training was given by national institutions (31%) and international institutions (69%). Researchers and REC members were ranked as the top target audiences to be trained. Of 32 topics, the top five training priorities were: basic ethical principles, coverage of applicable laws and regulations, how to conduct ethics review, evaluating informed consent processes and the role of the REC. Conclusion: Although the majority of REC members in the targeted African countries had received training in ethics, they expressed a need for additional training. The results of this survey have been used to design a training program in research ethics evaluation that meets this need. 相似文献
106.
GUILLAUME EVANNO†‡ EMMANUEL CASTELLA§ CÉLINE ANTOINE§ GABRIELLE PAILLAT§ JÉRÔME GOUDET 《Molecular ecology》2009,18(6):1137-1144
We examined the spatial and temporal variation of species diversity and genetic diversity in a metacommunity comprising 16 species of freshwater gastropods. We monitored species abundance at five localities of the Ain river floodplain in southeastern France, over a period of four years. Using 190 AFLP loci, we monitored the genetic diversity of Radix balthica , one of the most abundant gastropod species of the metacommunity, twice during that period. An exceptionally intense drought occurred during the last two years and differentially affected the study sites. This allowed us to test the effect of natural disturbances on changes in both genetic and species diversity. Overall, local (alpha) diversity declined as reflected by lower values of gene diversity H S and evenness. In parallel, the among-sites (beta) diversity increased at both the genetic ( F ST ) and species ( F STC ) levels. These results suggest that disturbances can lead to similar changes in genetic and community structure through the combined effects of selective and neutral processes. 相似文献
107.
Boris Musset Susan ME Smith Sindhu Rajan Vladimir V Cherny Deri Morgan Thomas E DeCoursey 《Channels (Austin, Tex.)》2010,4(4):260-265
The voltage-gated proton channel exists as a dimer, although each protomer has a separate conduction pathway, and when forced to exist as a monomer, most major functions are retained. However, the proton channel protomers appear to interact during gating. Proton channel dimerization is thought to result mainly from coiled-coil interaction of the intracellular C-termini. Several types of evidence are discussed that suggest that the dimer conformation may not be static, but is dynamic and can sample different orientations. Zn2+ appears to link the protomers in an orientation from which the channel(s) cannot open. A tandem WT-WT dimer exhibits signs of cooperative gating, indicating that despite the abnormal linkage, the correct orientation for opening can occur. We propose that C-terminal interaction functions mainly to tether the protomers together. Comparison of the properties of monomeric and dimeric proton channels speaks against the hypothesis that enhanced gating reflects monomer-dimer interconversion.Key words: voltage-gated proton channels, voltage gating, voltage-sensing domains, phagocytes, coiled-coil, oligomerization, proton currents, pH, dimerization, C-terminus 相似文献
108.
本文对移植的5-HT神经元从蛛网膜下腔跨软脊膜迁移进入脊髓作了初步研究。将含有5-HT细胞的胚胎中缝核组织小块或神经细胞悬浮液作为移植物,以5-HT免疫组织化学方法跟踪移植细胞,结果如下:(1)在低胸水平横切脊髓,10d后,横断脊髓内的5-HT纤维消失。(2)横切脊髓(方法同上)后,立即将中缝核组织小块移植在胸腰段脊髓的蛛网膜下腔,一月后.在横断脊髓内出现5-HT阳性神经元和纤维。5-HT纤维能在灰白质内延伸。(3)脊髓横断后,若以中缝核的细胞悬浮液代替组织小块,作上述移植,则在移植区附近的灰质内出现大量的5-HT阳性神经元。这些神经元在灰质内的分布范围与神经细胞悬浮液在蛛网膜下腔的移植范围相一致。迁入神经元能在灰质内重新形成5-HT阳性纤维网。(4)经上述移植后,灰质内出现的5-HT阳性纤维随远离细胞体而变得稀疏。白质内的5-HT阳性纤维远比灰质内稀少。本实验结果表明:移植在脊髓蛛网膜下腔的脑干5-HT细胞能跨软脊膜迁移进入脊髓。 相似文献
109.
110.
Molecular phylogenetic evidence that the phylum Haplosporidia has an alveolate ancestry 总被引:1,自引:0,他引:1
The phylogenetic position of the phylum Haplosporidia among other protists
was investigated with the complete 16S-like rRNA gene sequences from two
species in the phylum: Haplosporidium nelsoni, a parasite of oysters, and
Minchinia teredinis, a parasite of shipworms. Because the lack of obvious
morphological homologies with other protists hampered decisions regarding
taxonomic composition for sequence alignment and phylogenetic analysis, the
complete sequences for these two haplosporidians were directed as search
queries to the blast/ncbi.nlm.nih.gov electronic mail server. The results
of this heuristic similarity search provided a basis for constructing a
preliminary higher-taxonomic-level analysis comparing the haplosporidians
with species from the slime molds, fungi, algae, amoebae, ciliates,
dinoflagellates, and apicomplexans. Maximum parsimony yielded equivocal
results, whereas transversionally weighted parsimony suggested an affinity
with the alveolates (i.e., the ciliates, dinoflagellates, and
apicomplexans). Multiple alignment of the two haplosporidian sequences
against 17 taxa in a secondary analysis focusing on the alveolates and
subsequent parsimony analysis placed the phylum Haplosporidia as a
monophyletic group within the Alveolata and as a taxon of equal rank with
the other three alveolate phyla. The precise placement within the Alveolata
was sensitive to weighting.
相似文献