共查询到19条相似文献,搜索用时 46 毫秒
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小球藻和莱茵衣藻原生质体的电转化研究 总被引:1,自引:0,他引:1
以小球藻及莱茵衣藻原生质体为受体细胞,利用电击法将质粒p CAMBIA1301转入小球藻和莱茵衣藻,摸索电击转化条件并进行分子检测。结果表明:两类藻都对潮霉素敏感,小球藻及莱茵衣藻分别在含25 mg/L和100 mg/L潮霉素的固体培养基上的生长被完全抑制;小球藻和莱茵衣藻原生质体电击转化的最佳电击场强分别为0.8 k V/cm和0.6 k V/cm,最佳脉冲时间均为10 ms;制备原生质体和通过2-脱氧-D-葡萄糖处理可明显提高转化效率;分子检测说明GUS报告基因成功转入两种藻并可稳定遗传。 相似文献
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微藻中脂质代谢产生的化合物,可用于生物燃料、营养品和生物药品的生产,因此具有重要的经济价值。脂质代谢贯穿微藻的全部生命过程,对微藻的生长发育和应对外界胁迫都具有重要意义。微藻与研究较清楚的真菌和陆地植物在脂质代谢过程方面具有相似性。当然,随着微藻脂质代谢相关功能基因逐渐被鉴定,人们发现微藻的脂质代谢也具有区别真菌和陆地植物的独特性,因此针对微藻脂质代谢过程的分析具有重要意义。莱茵衣藻是研究脂质代谢过程的模式生物,已经通过基因组、转录组、蛋白质组和代谢组等方法,对其质体、内质网和过氧化物酶体中进行的脂质合成和分解过程进行了研究。本文总结了近年来莱茵衣藻质体、内质网和过氧化物酶体中脂质代谢过程的研究成果,并进行综合阐述。 相似文献
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通过将莱菌衣藻回复合成叶绿素b能力的14种回复突变株和野生型杂交并对其后代进行四分子分析与随机分析,发现导致回复突变的抑制基因sub位于第一染色体,并根据其连锁程度的不同初步鉴定出5个同功能的非等位sub基因。杂交分析表明sub基因不 专一性,以及在促cbnⅠ基因重新获得合成叶绿素b的能力的过程中具有单一基因决定性状的特点,不同的sub基因具有其独立的表型效应。sub/Sub杂合二倍体的表型分析证 相似文献
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同步化培养后莱茵衣藻生物量和总RNA含量的变化 总被引:2,自引:0,他引:2
为了探索莱茵衣藻经光/暗同步化培养后的细胞生长和总RNA的变化规律。本研究检测了16h光/8h暗同步化培养后莱茵衣藻的生物量和总RNA含量的变化规律。结果,在同步化培养结束后的前28h,莱茵衣藻的生物量呈现有节律的阶梯增长;在同步化培养结束后的28~48h,这种阶梯式增长方式逐步消失。在同步化培养结束后的前24h,总RNA含量呈现有节律的峰-谷-峰变化;在同步化培养结束后的24~48h,这种变化幅度逐步减小,节律周期也逐步缩短。对比同步化培养后莱茵衣藻生物量和总RNA含量的变化可以得出,同步化培养后莱茵衣藻的同步化节律仍然可以维持一定时间;但随着连续光培养时间的延长,这种节律逐步消失,通过测定生物量和总RNA含量的变化可以跟踪同步化培养后莱茵衣藻的同步化变化。 相似文献
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Nikola Petkovic;Nick Colegrave; 《Journal of evolutionary biology》2024,36(12):1783-1795
The continued existence of sex, despite many the costs it entails, still lacks an adequate explanation, as previous studies demonstrated that the effects of sex are environment-dependent: sex enhances the rate of adaptation in changing environments, but the benefits level off in benign conditions. To the best of our knowledge, the potential impact of different patterns of environmental change on the magnitude of these benefits received less attention in theoretical studies. In this paper, we begin to explore this issue by examining the effect of the rate of environmental deterioration (negatively correlated with population survival rate), on the benefits of sex. To investigate the interplay of sex and the rate of environmental deterioration, we carried out a long-term selection experiment with a unicellular alga (Chlamydomonas reinhardtii), by manipulating mode of reproduction (asexual, facultative or obligate sexual) and the rate of environmental deterioration (an increase of salt concentration). We monitored both the population size and extinction dynamics. The results revealed that the relative advantage of sex increased at the intermediate rate and plateaued at the highest rate of environmental deterioration. Obligate sexual populations had the slowest extinction rate under the intermediate rate of environmental deterioration, while facultative sexuality was favoured under the high rate-treatment. To the best of our knowledge, our study is the first to demonstrate that the interplay of sex and the rate of environmental deterioration affects the probability of survival, which indicates that mode of reproduction may be an important determinant of survival of the anthropogenic-induced environmental change. 相似文献
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衣藻细胞玻璃化超低温保存技术的研究 总被引:4,自引:1,他引:4
本研究以衣藻为材料,探讨其玻璃化超低温保存的条件和方法,结果表明,衣藻经含0.25mol/L蔗糖溶液的TAP培养基预培养一天后,在玻璃化冷冻保护剂中脱水5分钟,直接投稿液氮,48小时后快速化冻,去保护剂并用含0.5mol/L蔗糖溶液的TAP培养基境培养一天,再转到ATP培养基暗培养一天,最后置光照条件下恢复培养,其存活率可达31.45%,恢复培养后衣藻细胞的生长规律与未冻存的衣藻相一致。 相似文献
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Kaoru Suzuki Satoru Shimizu Ella Czarina Magat Juan Takahiro Miyamoto Zhang Fang Md. Mominul Hoque Yoshiteru Sato Masaru Tsunoda Takeshi Sekiguchi Akio Taknaka Shi‐Yuan Yang 《Acta Crystallographica. Section F, Structural Biology Communications》2010,66(9):1082-1085
Carbonic anhydrases (CAs) are ubiquitously distributed and are grouped into three structurally independent classes (αCA, βCA and γCA). Most αCA enzymes are monomeric, but αCA1 from Chlamydomonas reinhardtii is a dimer that is uniquely stabilized by disulfide bonds. In addition, during maturation an internal peptide of 35 residues is removed and three asparagine residues are glycosylated. In order to obtain insight into the effects of these structural features on CA function, wild‐type C. reinhardtiiαCA1 has been crystallized in space group P65, with unit‐cell parameters a = b = 134.3, c = 120.2 Å. The crystal diffracted to 1.88 Å resolution and a preliminary solution of its crystal structure has been obtained by the MAD method. 相似文献
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Kaoru Suzuki Shi‐Yuan Yang Satoru Shimizu Ella Czarina Morishita Jiandong Jiang Fang Zhang Md. Mominul Hoque Yoshiteru Sato Masaru Tsunoda Takeshi Sekiguchi Akio Takénaka 《Acta Crystallographica. Section D, Structural Biology》2011,67(10):894-901
Chlamydomonas reinhardtiiα‐type carbonic anhydrase (Cr‐αCA1) is a dimeric enzyme that catalyses the interconversion of carbon dioxide and carbonic acid. The precursor form of Cr‐αCA1 undergoes post‐translational cleavage and N‐glycosylation. Comparison of the genomic sequences of precursor Cr‐αCA1 and other αCAs shows that Cr‐αCA1 contains a different N‐terminal sequence and two insertion sequences. A 35‐residue peptide in one of the insertion sequences is deleted from the precursor during maturation. The crystal structure of the mature form of Cr‐αCA1 has been determined at 1.88 Å resolution. Each subunit is cleaved into the long and short peptides, but they are linked together by a disulfide bond. The two subunits are linked by a disulfide bond. N‐Glycosylations occur at three asparagine residues and the attached N‐glycans protrude into solvent regions. The subunits consist of a core β‐sheet structure composed of nine β‐strands. At the centre of the β‐sheet is the catalytic site, which contains a Zn atom bound to three histidine residues. The amino‐acid residues around the Zn atom are highly conserved in other monomeric and dimeric αCAs. The short peptide runs near the active site and forms a hydrogen bond to the zinc‐coordinated residue in the long chain, suggesting an important role for the short peptide in Cr‐αCA1 activity. 相似文献
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W J Rogers M Hodges P Decottignies J M Schmitter P Gadal J P Jacquot 《FEBS letters》1992,310(3):240-245
A cDNA clone coding for mature C. reinhardtii ferredoxin has been isolated from a cDNA library using PCR and two oligonucleotide primers based on the N- and C-termini of the protein's amino acid sequence. The nucleotidic sequence of the PCR fragment (299 bp) agreed well with the amino acid sequence since a single conservative substitution (Thr-7 to Ser) could be deduced. The PCR fragment was inserted into the expression vector pTrc 99A, using the incorporated NcoI and BamHI restriction sites and the construction used to transform E. coli (DH5 F′). After subsequent large scale expression and purification of the recombinant protein, biochemical and biophysical analysis have indicated that the product isolated from E. coli is homologous to native ferredoxin isolated from green algae. 相似文献
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Roberta J. Garcia Andrew S. Kane David Petullo Renate Reimschuessel 《Journal of phycology》2008,44(5):1282-1289
Oxytetracycline (OTC) is an important antimicrobial used in aquaculture. However, residues of OTC have been isolated from nontarget aquatic organisms, sediments, and water located near aquaculture facilities. Identifying OTC in plant material is particularly difficult due to interference from pigments and polyphenol substances but is important especially for algae since they are a primary food source for fish in early life stages. In this study, we describe the effect of OTC (0.1, 1, 10, 25, 50, 100 μg · mL?1) on cell growth, and the localization of OTC (0, 1, 25, 100 μg · mL?1) in vacuoles of Chlamydomonas reinhardtii P. A. Dang. (wildtype, ATCC 18798). We also present a method for semiquantifying OTC in living cells using fluorescent microscopy and Adobe Photoshop. We exposed algal cells to OTC and sampled after 2 or 7 d exposure. On day 7, OTC significantly inhibited algal growth at 1, 10, 25, 50, and 100 μg · mL?1. When viewed with fluorescent microscopy, cells exposed to the 25 and 100 μg · mL?1 contained yellow fluorescent areas, ≤1 μm in diameter that were easily discernable against the red fluorescence of the intracellular chl. The fluorescent areas corresponded to small spherical vacuoles (i.e., polyphosphate bodies that contain calcium and magnesium complexed with polyphosphate) seen in the cells by LM. Since OTC has a high affinity for divalent cations, we suggest that OTC is localized in these vacuoles. 相似文献
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综述了利用衣藻生产氢气作为再生能源的研究进展。分别介绍了衣藻产氢的代谢机理、培养条件、衣藻氢化酶的特性以及利用分子生物学手段、生物信息学手段和生物工程技术提高衣藻生物制氢效率的方法,包括氢化酶的氧耐受性的改造、外源氢化酶基因的表达、影响衣藻产氢的关键基因的筛选、利用缺硫培养基和固定化培养方法提高氢气产量等。最后,还对利用衣藻生物制氢的可行性和经济性进行了分析,对其发展方向提出自己的看法。 相似文献
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Insertional mutagenesis to isolate acetate-requiring mutants in Chlamydomonas reinhardtii 总被引:1,自引:0,他引:1
Abstract An arg 7 mutant of the green alga Chlamydomonas reinhardtii was transformed with pARG7.8, a plasmid bearing the wild-type ARG 7 gene. Out of 4100 arg+ transformants selected on an arginine-free medium supplemented with acetate, nine failed to grow on acetate-free medium (ac− mutants). The results of the genetic and molecular analysis of several ac− mutants are in agreement with the hypothesis that they originated from insertion of the incoming plasmid into the nuclear genome. These mutants should constitute valuable tools for isolating the corresponding wild-type genes after plasmid rescue into Escherichia coli . 相似文献
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Charles Packianathan Jitesh K. Pillai Ahmed Riaz Palani Kandavelu Banumathi Sankaran Barry P. Rosen 《Acta Crystallographica. Section F, Structural Biology Communications》2014,70(10):1385-1388
Arsenic is one the most toxic environmental substances. Arsenic is ubiquitous in water, soil and food, and ranks first on the Environmental Protection Agency's Superfund Priority List of Hazardous Substances. Arsenic(III) S‐adenosylmethionine methyltransferases (AS3MT in animals and ArsM in microbes) are key enzymes of arsenic biotransformation, catalyzing the methylation of inorganic arsenite to give methyl, dimethyl and trimethyl products. Arsenic methyltransferases are found in members of every kingdom from bacteria to humans (EC 2.1.1.137). In the human liver, hAS3MT converts inorganic arsenic into more toxic and carcinogenic forms. CrArsM, an ortholog of hAS3MT from the eukaryotic green alga Chlamydomonas reinhardtii, was purified by chemically synthesizing the gene and expressing it in Escherichia coli. Synthetic purified CrArsM was crystallized in an unliganded form. Crystals were obtained by the hanging‐drop vapor‐diffusion method. The crystals belonged to space group R3:H, with unit‐cell parameters a = b = 157.8, c = 95.4 Å, γ = 120° and two molecules in the asymmetric unit. Complete data sets were collected and processed to a resolution of 2.40 Å. 相似文献