Genes, Mitochondrial

基因, 线粒体
  • 文章类型: Journal Article
    尽管基因组规模的数据生成对于系统发育变得越来越容易处理,公共存储库中有大量的单基因片段数据,这些数据仍在生成中。因此,与使用完整的有丝分裂基因组相比,我们研究了单个线粒体基因是否适合用于系统发育重建。对南部非洲矮人变色龙(Bradypodion)进行了几乎完整的分类单元采样,我们估计并比较了完整的有丝分裂基因组的系统发育和由单个线粒体基因和这些基因的各种组合产生的拓扑结构。我们的结果表明,由单基因(ND2,ND4,ND5,COI,和COIII)类似于完整的有丝分裂体,表明这些基因可能是产生线粒体系统发育的可靠标记,而不是产生完整的有丝分裂基因组。相比之下,通常用于爬行动物系统学的16S的短片段,产生了与完整的有丝分裂体非常不同的拓扑结构,其与ND2的串联削弱了ND2的分辨率。因此,我们建议在未来的系统发育工作中避免使用此16S片段。
    Although genome-scale data generation is becoming more tractable for phylogenetics, there are large quantities of single gene fragment data in public repositories and such data are still being generated. We therefore investigated whether single mitochondrial genes are suitable proxies for phylogenetic reconstruction as compared to the application of full mitogenomes. With near complete taxon sampling for the southern African dwarf chameleons (Bradypodion), we estimated and compared phylogenies for the complete mitogenome with topologies generated from individual mitochondrial genes and various combinations of these genes. Our results show that the topologies produced by single genes (ND2, ND4, ND5, COI, and COIII) were analogous to the complete mitogenome, suggesting that these genes may be reliable markers for generating mitochondrial phylogenies in lieu of generating entire mitogenomes. In contrast, the short fragment of 16S commonly used in herpetological systematics, produced a topology quite dissimilar to the complete mitogenome and its concatenation with ND2 weakened the resolution of ND2. We therefore recommend the avoidance of this 16S fragment in future phylogenetic work.
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  • 文章类型: Journal Article
    Smiliogastrinae因其高营养和观赏价值而闻名。在这项研究中,我们采用高通量测序技术获得了Dawkinsiafilamentosa和Pethianigrofasciata的完整线粒体基因组序列。这些物种的基因组成和排列顺序与典型脊椎动物相似,包含13个蛋白质编码基因,22个tRNA基因,2个rRNA基因,和1个非编码区。丝裂原和黑斑原的线粒体基因组测量为16,598和16,948bp,分别。丝状D.和黑质P.nigrofasciata均表现出对AT碱基的显着偏好和抗G偏见。值得注意的是,ND6基因的AT和GC偏斜值波动明显,这表明该基因的选择和突变压力可能与影响其他基因的压力不同。系统发育分析,基于23种鲤科鱼类的完整线粒体基因组,发现丝状D.与Dawkinsiadenisonii和Sahyadriachalakkudiensis的姐妹群体密切相关。同样,黑质链球菌与Pethiaticto和Pethiastoliczkana组成姐妹组。
    Smiliogastrinae are recognized for their high nutritional and ornamental value. In this study, we employed high-throughput sequencing technology to acquire the complete mitochondrial genome sequences of Dawkinsia filamentosa and Pethia nigrofasciata. The gene composition and arrangement order in these species were similar to those of typical vertebrates, comprising 13 protein-coding genes, 22 tRNA genes, 2 rRNA genes, and 1 non-coding region. The mitochondrial genomes of D. filamentosa and P. nigrofasciata measure 16,598 and 16,948 bp, respectively. Both D. filamentosa and P. nigrofasciata exhibit a significant preference for AT bases and an anti-G bias. Notably, the AT and GC skew values of the ND6 gene fluctuated markedly, suggesting that the selection and mutation pressures on this gene may differ from those affecting other genes. Phylogenetic analysis, based on the complete mitochondrial genomes of 23 Cyprinidae fishes, revealed that D. filamentosa is closely related to the sister group comprising Dawkinsia denisonii and Sahyadria chalakkudiensis. Similarly, P. nigrofasciata forms a sister group with Pethia ticto and Pethia stoliczkana.
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  • 文章类型: Journal Article
    背景:在媒介蚊子中PCR检测人类血餐中DNA所需的时间可能会有所不同,根据使用的分子标记,基于扩增子的大小和拷贝数。对自然界中蚊子种群的采血行为的详细了解是评估其媒介能力和评估个别脊椎动物作为媒介传播疾病的潜在宿主的作用的重要组成部分。
    方法:进行了实验室实验,以比较PCR检测来自个体血液喂养的按蚊的人血餐中DNA的时间过程,使用具有不同特征的基因座,包括两个线粒体DNA(mtDNA)基因,血餐后不同时间点的cytB(228bp)和16S核糖体RNA(rRNA)(157bp)和核Alu重复元件(226bp)。
    结果:在采血后84-120小时内可检测到人类DNA,取决于基因座的长度和拷贝数。我们的结果表明,16SrRNA和Alu-repeat标记可以在血餐后5天内从人类DNA中成功回收。16SrDNA和Alu重复序列基因座的下降速率明显(P=0.008)比cytB基因座慢。扩增子的中位检测周期(T50)为Alu重复序列的117、113和86.4小时,16SrDNA和cytB,分别,表明扩增子大小/拷贝数和消化时间之间的反线性关系。
    结论:这项比较研究表明,Alu-repeat基因座是鉴定雌性蚊子血餐中人类DNA时程的最有效标记。它也是确定嗜血指数(AI)或人类血液指数(HBI)的有前途的工具,即人类血粉的比例,这通常被报道为不同蚊子媒介的食人症的相对衡量标准,因此衡量了在野外收集的蚊子的媒介能力。
    BACKGROUND: The time required for PCR detection of DNA in human blood meals in vector mosquitoes may vary, depending on the molecular markers used, based on the size and copy number of the amplicons. Detailed knowledge of the blood-feeding behavior of mosquito populations in nature is an essential component for evaluating their vectorial capacity and for assessing the roles of individual vertebrates as potential hosts involved in the transmission of vector-borne diseases.
    METHODS: Laboratory experiments were conducted to compare the time course of PCR detection of DNA in human blood meals from individual blood-fed Anopheles stephensi mosquitoes, using loci with different characteristics, including two mitochondrial DNA (mtDNA) genes, cytB (228 bp) and 16S ribosomal RNA (rRNA) (157 bp) and nuclear Alu-repeat elements (226 bp) at different time points after the blood meal.
    RESULTS: Human DNA was detectable up to 84-120 h post-blood-feeding, depending on the length and copy number of the loci. Our results suggest that 16S rRNA and Alu-repeat markers can be successfully recovered from human DNA up to 5 days post-blood-meal. The 16S rDNA and Alu-repeat loci have a significantly (P = 0.008) slower decline rate than the cytB locus. Median detection periods (T50) for the amplicons were 117, 113 and 86.4 h for Alu-repeat, 16S rDNA and cytB, respectively, suggesting an inverse linear relationship between amplicon size/copy number and digestion time.
    CONCLUSIONS: This comparative study shows that the Alu-repeat locus is the most efficient marker for time-course identification of human DNA from blood meals in female mosquitoes. It is also a promising tool for determining the anthropophilic index (AI) or human blood index (HBI), i.e. the proportion of blood meals from humans, which is often reported as a relative measure of anthropophagy of different mosquito vectors, and hence a measure of the vector competence of mosquito species collected in the field.
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  • 文章类型: Journal Article
    Bilateria的线粒体基因组在蛋白质编码方面相对保守,rRNA和tRNA基因补体,但是这些基因的顺序可以从非常保守到非常可变,这取决于分类单元。Annelida的所谓保守基因顺序已用于支持Annelida中某些分类单元的放置。最近,作者对Annelid基因顺序的保守性表示怀疑。各种因素可能会影响基因顺序变异性,包括,其中,增加替代率,碱基组成差异,非编码区的结构,寄生,生活在极端的栖息地,短生成时间和生物矿化。然而,这些分析都没有系统地进行,也不是基于完善的参考树。一些只关注其中几个因素,通常在没有严格测试或相关分析的情况下对生物因素进行临时探索。在这里,我们研究了环形动物基因顺序的变异性和进化,以及潜在影响其进化的因素,采用全面系统的方法。分析基于170个基因组,包括33个以前没有代表的物种。我们的分析包括706种不同的分子性质,20个生活史和生态特征,以及对应于有关环节树的最新改进的参考树。结果表明,有和没有tRNA的基因顺序通常是保守的。然而,个体分类群表现出更高的变异性。所有分析的生活史和生态特征都不能解释线粒体基因序列中观察到的变异性。相比之下,替代率和碱基组成的最佳预测因素的组合和相互作用解释了多达30%的观察到的变异性。因此,对线粒体基因组不同分子特性的相关分析显示,不同分子因素之间存在复杂的直接和间接相关网络。因此,基因顺序进化似乎是由分子进化方面驱动的,而不是由生活史或生态学驱动的。另一方面,基因顺序的变异性无法预测分类单元是否难以使用序列数据进行分子系统发育重建。我们还讨论了环状线粒体基因组的分子特性,考虑了基因进化的规范观点,以及为什么规范观点不总是适合观察到的模式而不进行一些调整的潜在原因。
    The mitochondrial genomes of Bilateria are relatively conserved in their protein-coding, rRNA, and tRNA gene complement, but the order of these genes can range from very conserved to very variable depending on the taxon. The supposedly conserved gene order of Annelida has been used to support the placement of some taxa within Annelida. Recently, authors have cast doubts on the conserved nature of the annelid gene order. Various factors may influence gene order variability including, among others, increased substitution rates, base composition differences, structure of noncoding regions, parasitism, living in extreme habitats, short generation times, and biomineralization. However, these analyses were neither done systematically nor based on well-established reference trees. Several focused on only a few of these factors and biological factors were usually explored ad-hoc without rigorous testing or correlation analyses. Herein, we investigated the variability and evolution of the annelid gene order and the factors that potentially influenced its evolution, using a comprehensive and systematic approach. The analyses were based on 170 genomes, including 33 previously unrepresented species. Our analyses included 706 different molecular properties, 20 life-history and ecological traits, and a reference tree corresponding to recent improvements concerning the annelid tree. The results showed that the gene order with and without tRNAs is generally conserved. However, individual taxa exhibit higher degrees of variability. None of the analyzed life-history and ecological traits explained the observed variability across mitochondrial gene orders. In contrast, the combination and interaction of the best-predicting factors for substitution rate and base composition explained up to 30% of the observed variability. Accordingly, correlation analyses of different molecular properties of the mitochondrial genomes showed an intricate network of direct and indirect correlations between the different molecular factors. Hence, gene order evolution seems to be driven by molecular evolutionary aspects rather than by life history or ecology. On the other hand, variability of the gene order does not predict if a taxon is difficult to place in molecular phylogenetic reconstructions using sequence data or not. We also discuss the molecular properties of annelid mitochondrial genomes considering canonical views on gene evolution and potential reasons why the canonical views do not always fit to the observed patterns without making some adjustments. [Annelida; compositional biases; ecology; gene order; life history; macroevolution; mitochondrial genomes; substitution rates.].
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  • 文章类型: Journal Article
    本文是第6次对中国拟南芥进行研究,并报道了云南省的一个新物种,中国,viz.A.(翼展)maguanensissp。11月。(中文名称:)。同时,确定并注释了新物种的完整线粒体基因组。15,962bp环状基因组由13个蛋白质编码组成,22转移RNA,2核糖体RNA基因,和富含A+T的区域。它具有典型的无脊椎动物线粒体基因排列。所有蛋白质编码基因(PCGs)均由典型的ATN密码子起始。核苷酸组成明显偏向AT。所有转移RNA(tRNA)基因都具有典型的三叶草叶结构,除了trnS1,其中缺乏二氢尿苷(DHU)臂的碱基对。总的来说,预测了rrnL的六个结构域和49个螺旋,并预测了rrnS的三个结构域和27个螺旋。
    This paper is sixth study the Chinese Anabropsinae and reports one new species from Yunnan Province, China, viz. A. (Pteranabropsis) maguanensis sp. nov. (Chinese name: ). Meanwhile, the complete mitochondrical genome of the new species was determined and annotated. The 15, 962 bp circle genome consisted of 13 protein-coding, 22 transfer RNA, 2 ribosomal RNA genes, and an A+T-rich region. It has the typical invertebrate mitochondrial gene arrangement. All protein-coding genes (PCGs) were initiated by typical ATN codon. The nucleotide compositions were significant bias towards AT. All transfer RNA (tRNA) genes had a typical clover-leaf structure, except trnS1 in which the base pairs of the dihydrouridine (DHU) arm was lacking. Overall, six domains and 49 helices were predicted for rrnL, and three structural domains and 27 helices were predicted for rrnS.
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  • 文章类型: Journal Article
    Two new species of the weevil genus Rhamphus from Italy are herein described: R. bavierai n. sp. (Sicily) and R. hampsicora n. sp. (Sardinia). Both are morphologically and from a molecular perspective close to R. oxyacanthae (Marsham, 1802) and R. monzinii Pesarini Diotti, 2012. Aside from a diagnostic description and a synoptic key, distribution data and notes on the host plants of the four species are reported. Whereas R. monzinii can be distinguished by several morphological characters, the other three species are morphologically very similar to each other and separable only by the combination of a few subtle characters. On the contrary, a preliminary molecular study revealed substantial divergences of mtCOI from 6.2 to 14.9% between the species, confirming the importance of an integrative taxonomy.
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  • 文章类型: Journal Article
    Poaching of South Asian river dolphins is considered one of the main reasons for the rapid decline of their natural populations. To curb the escalated rate of poaching, high numbers of oil and meat seizures are recovered with subsequent convictions by the law enforcement agencies. In this connection, we report a case where suspected animal oil was confiscated by the forest official of West Bengal. We extracted DNA and successfully amplified partial fragments of Cytb and 16S rRNA mitochondrial genes. The generated sequences identified that the seized oil belonged to the Ganges river dolphin (Platanista gangetica) which is protected as Schedule I under the Wildlife (Protection) Act, 1972 of India and listed as \"Endangered\" under IUCN and APPENDIX I in CITES. In routine case work analysis, oil samples are not preferred for forensic DNA investigation due to low DNA yield and presence of inhibitors or contaminants leading to high failure rate. However, the present study generates hope for identifying species from seized animal oil and supports law enforcement in successful prosecution of the case.
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  • 文章类型: Journal Article
    Pareiorhaphis hystrix is a widely distributed species, occurring in the upper and middle Uruguay River and in the Taquari River basin, Patos Lagoon system, southern Brazil. Morphological variation has been detected throughout the distribution of P. hystrix, and this work seeks to test the conspecific nature of populations in several occurrence areas. Specimens from six areas in the Uruguay River basin and three in the Taquari River basin were compared. Variance analysis (ANOVA) was performed for the meristic data, and Principal Component Analysis (PCA) and Linear Discriminant Analysis (LDA) were conducted for morphometric data. Molecular analyses used coI, cytb, 12S and 16S mitochondrial genes, examining nucleotide diversity, haplotype diversity, genetic distance, and delimitation of possible multiple species through the Generalized Mixed Yule Coalescent (GMYC) method. Phylogenetic relationships of studied populations were also investigated through Bayesian inference. While PCA indicated a tendency of overlap between areas, ANOVA and LDA detected a subtle differentiation between populations from the two hydrographic basins. Yet, both latter analyses recovered the population from Pelotas River, a tributary to Uruguay River, as more similar to populations from Taquari River, which is congruent to morphological observations of anterior abdominal plates. The molecular data indicated a nucleotide diversity lower than the haplotypic diversity, suggestive of recent expansion. The concatenated haplotype network points to slight differentiation between areas, with each locality presenting unique and non-shared haplotypes, although with few mutational steps in general. The species delimitation by coalescence analysis suggested the presence of a variable number of OTUs depending on the inclusion or exclusion of an outgroup. In general, the morphological data suggest a subtle variation by river basin, while the genetic data indicates a weak population structuration by hydrographic areas, especially the Chapecó and Passo Fundo rivers. However, there is still not enough differentiation between the specimens to suggest multiple species. The iterative analyses indicate that Pareiorhaphis hystrix is composed of a single, although variable, species.
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  • 文章类型: Journal Article
    Maternal mitochondrial inheritance is a fundamental paradigm within reproductive biology, yet the molecular mechanisms which underlie this process remain poorly understood. The ubiquitin proteasome system (UPS) and branches of the autophagic pathway have been implicated in taking part in the active degradation of sperm mitochondria post-fertilization. Despite this knowledge, there remains much unknown about this process, including the cofactors and substrates involved, as well as the implications of what occurs when these systems of degradation fail. Mitochondrial inheritance research has utilized a variety of animal models. However, one model that is of particular importance, especially when attempting to link mitochondrial inheritance research to humans, is the domestic pig. Pigs offer relatively easy collection of gametes which are similar to those of humans. Furthermore, pigs are physiologically and anatomically more similar to humans than the majority of other model systems available. Porcine in vitro fertilization (IVF), intracytoplasmic sperm injection (ICSI), and novel cell-free systems are research tools which can be exploited to provide greater insight into the processes behind sperm mitochondrial degradation. In the future studies of mitochondrial inheritance, pigs will likely play a crucial role as an animal model system.
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  • 文章类型: Journal Article
    硬蜱广泛分布在温带地区,在宿主协会中表现出强烈的差异,是多种医学上重要的人畜共患病的潜在载体,比如莱姆病。为了解决某些物种或属之间的进化关系尚未解决的问题,我们为9种不同的Ixodes物种产生了新的RNA-Seq数据集。我们将这些新数据与从公共数据库获得的18个数据集相结合,对于Ixodes和非Ixodes硬蜱物种,使用软蜱作为外群。我们组装了转录组(总共27个物种),预测编码序列并鉴定单拷贝直向同源物(SCO)。使用最大似然和贝叶斯框架,我们重建了核基因组的硬蜱系统发育。我们还使用已发表的基因组序列和来自新转录组的线粒体序列获得了基于线粒体DNA的系统发育。我们的结果证实了先前的研究,表明Ixodes属是单系的,并阐明了Ixodes亚属之间的关系。这项工作为研究壁虱的进化史提供了一个基线:我们确实发现了Prostriata的线粒体序列取代的意外加速,以及两种动物的核和线粒体基因,这与基因组结构的模式和生命周期的变化有关,分别。
    Hard ticks are widely distributed across temperate regions, show strong variation in host associations, and are potential vectors of a diversity of medically important zoonoses, such as Lyme disease. To address unresolved issues with respect to the evolutionary relationships among certain species or genera, we produced novel RNA-Seq data sets for nine different Ixodes species. We combined this new data with 18 data sets obtained from public databases, both for Ixodes and non-Ixodes hard tick species, using soft ticks as an outgroup. We assembled transcriptomes (for 27 species in total), predicted coding sequences and identified single copy orthologues (SCO). Using Maximum-likelihood and Bayesian frameworks, we reconstructed a hard tick phylogeny for the nuclear genome. We also obtained a mitochondrial DNA-based phylogeny using published genome sequences and mitochondrial sequences derived from the new transcriptomes. Our results confirm previous studies showing that the Ixodes genus is monophyletic and clarify the relationships among Ixodes sub-genera. This work provides a baseline for studying the evolutionary history of ticks: we indeed found an unexpected acceleration of substitutions for mitochondrial sequences of Prostriata, and for nuclear and mitochondrial genes of two species of Rhipicephalus, which we relate with patterns of genome architecture and changes of life-cycle, respectively.
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