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Lu‐Xian Liu Pan Deng Meng‐Zhen Chen Li‐Min Yu Joongku Lee Wei‐Mei Jiang Cheng‐Xin Fu Fu‐De Shang Pan Li 《植物分类学报:英文版》2023,61(1):99-114
Oresitrophe and Mukdenia (Saxifragaceae) are epilithic sister genera used in traditional Chinese medicine. The taxonomy of Mukdenia, especially of M. acanthifolia, has been controversial. To address this, we produced plastid and mitochondrial data using genome skimming for Mukdenia acanthifolia and Mukdenia rossii, including three individuals of each species. We assembled complete plastomes, mitochondrial CDS and nuclear ribosomal ETS/ITS sequences using these data. Comparative analysis shows that the plastomes of Mukdenia and Oresitrophe are relatively conservative in terms of genome size, structure, gene content, RNA editing sites and codon usage. Five plastid regions that represent hotspots of change (trnH-psbA, psbC-trnS, trnM-atpE, petA-psbJ and ccsA-ndhD) are identified within Mukdenia, and six regions (trnH-psbA, petN-psbM, trnM-atpE, rps16-trnQ, ycf1 and ndhF) contain a higher number of species-specific parsimony-informative sites that may serve as potential DNA barcodes for species identification. To infer phylogenetic relationships between Mukdenia and Oresitrophe, we combined our data with published data based on three different datasets. The monophyly of each species (Oresitrophe rupifraga, M. acanthifolia and M. rossii) and the inferred topology ((M. rossii, M. acanthifolia), O. rupifraga) are well supported in trees reconstructed using the complete plastome sequences, but M. acanthifolia and M. rossii did not form a separate clade in the trees based on ETS + ITS data, while the mitochondrial CDS trees are not well-resolved. We found low recovery of genes in the Angiosperms353 target enrichment panel from our unenriched genome skimming data. Hybridization or incomplete lineage sorting may be the cause of discordance between trees reconstructed from organellar and nuclear data. Considering its morphological distinctiveness and our molecular phylogenetic results, we strongly recommend that M. acanthifolia be treated as a distinct species. 相似文献
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A suitable method for extraction of floridoside phosphate synthase (FPS, UDP-galactose: sn-3-glycerol phosphate: 1→2′α-D-galactosyl transferase)from Porphyra perforata J. Ag. was developed. Two assay methods for enzyme activity were utilized, one measuring the amount of floridoside formed by using gas-liquid chromatography, the other measuring the sn-3-glycerol phosphate-dependent formation of UDP; both assays gave similar results. FPS is a soluble protein, and FPS activity in the extract as determined by the amount of product formed in vitro compared well with the in vivo rate of floridoside synthesis (4–7 μMmol product formed·h?1·g?1 fresh wt). The rate of product formation in vitro was linear up to 45 min and proportional to protein concentration in the assay mixture. The temperature optimum was 30–35° C. FPS was active over a range of pH values from 7.0–8.5. It was stable in concentrated solutions in the presence of 0.3 M ammonium sulfate, but activity was lost in diluted solution (protein concentration below 0.2 mg·mL?1) or below 0.2 M ion strength. The data suggest that FPS may be an oligomeric protein which occurs free in the cytoplasm or loosely bound to a membrane. It may also be a regulatory protein controlling the overall rate of synthesis of floridoside in vivo. 相似文献
96.
利用改进的kar交配法,将一个含有340kb人基因组DNA的YAC片段的供体酵母菌株YAC23与受体菌株YLB504进行交配,以选择平板对所形成的候选YAC导入菌进行筛选。经PCR分析,候选YAC导入菌在404bp处有一个扩增带,即具有受体菌株的交配型(MAT α)。进一步用脉冲电泳进行核型鉴定,证实YACs己成功地进入受体,实现了YACs从一个宿主到另一个宿主之间的转移。 相似文献
97.
FNR-DNA interactions at natural and semi-synthetic promoters 总被引:8,自引:1,他引:7
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p21是近年来发现的一类调控细胞增殖的小分子,是依赖周期素的CDK抑制因子.这些蛋白因子可结合cyclin-CDK并抑制其激酶活性从而调节细胞周期p15、p16、p27均属该类分子,他们在G1期限制点及G1/S检查点调控中发挥作用.进一步的研究表明,p21为p53调控,在p53介导的DNA损伤诱发的细胞周期阻断中发挥作用p21在老化细胞中高表达、细胞分化的同时表达,表明其在细胞增殖、分化及老化中发挥调节作用. 相似文献
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异色瓢虫若虫对麦三叉蚜的捕食作用 总被引:5,自引:4,他引:1
研究表明,异色瓢虫高龄若虫捕食麦二叉蚜的功能反应为HollingⅡ型反应,喜好捕食低龄若蚜;在40℃下捕食率最低,10℃次之,25℃最高.在10~25℃内捕食率y与温度x的关系为y=28.1303+2.6665x,在25~40℃内为y=199.9275-3.642x;在种内干扰条件下,其捕食作用率E与开敌密度P的关系为E=0.6897P-0.7930,搜索常数Q为0.6897,干扰系数m为0.7930;其分摊竞争强度I与异色瓢虫密度P的关系为I=0.0400+1.0383logP. 相似文献
100.
Clark E. Hartsock III Jeffrey K. Lewis Ian Leslie Joseph A. Pope Jr. Larry B. Tsai Raj Sachdev Shi-Yuan Meng 《Biotechnology letters》1995,17(10):1025-1030
Summary A synthetic lactose-inducible promoter was chosen to study host cell responses to the over-expression of heterologous genes. Fermentations were conducted to compare the effect of induction strategies on the synthesis of -galactosidase versus the production of recombinant protein. The levels of lactose, IPTG and glucose during induction were manipulated to adjust the utilization of lactose as the inducer and/or the carbon source. In addition, the involvement of the gal operon in lactose metabolism was also explored in order to optimize lactose transport and utilization during induction. 相似文献