Relationship between seasonal cold acclimatization and mtDNA haplogroup in Japanese

Background

The purpose of this study was to elucidate the interaction between mtDNA haplogroup and seasonal variation that contributes to cold adaptation.

Methods

There were 15 subjects (seven haplotype D subjects and eight haplotype non-D subjects). In summer and winter, the subjects were placed in an environment where the ambient temperature dropped from 27 °C to 10 °C in 30 minutes. After that, they were exposed to cold for 60 minutes.

Results

In summer, the decrease in rectal temperature and increase in oxygen consumption was smaller and cold tolerance was higher in the haplotype non-D group than in the haplotype D group. In winter, no significant differences were seen in rectal temperature or oxygen consumption, but the respiratory exchange ratio decreased in the haplotype D group.

Conclusions

The results of the present study suggest that haplogroup D subjects are a group that changes energy metabolism more, and there appears to be a relationship between differences in cold adaptability and mtDNA polymorphism within the population. Moreover, group differences in cold adaptability seen in summer may decrease in winter due to supplementation by seasonal cold acclimatization.     

青海高原两种沙蜥mtDNA的渐渗杂交

青海沙蜥和贵德沙蜥在共和沙珠玉地区重叠分布,形态和遗传显著不同。线粒体基因序列分析说明在重叠区两种蜥蜴mtDNA基因相互渗透。重叠区19个青海沙蜥个体中有1个具有贵德沙蜥线粒体基因型,但形态与青海沙蜥相似。6个贵德沙蜥个体中有1个具有青海沙蜥线粒体基因型,形态与贵德沙蜥相似。两种沙蜥在该地区的基因流动可能发生在共和古湖的退缩消失后次级相遇形成的。分子钟推测杂交发生的时间大约在19至16万年前,与古湖的消失时间(15万年前)相符。     

Phylogeographic congruence between mtDNA and rDNA ITS markers in brown trout

Variation in the internal transcribed spacer (ITS) of rDNA was examined throughout the range of the brown trout (Salmo trutta) to analyze the usefulness of this molecular marker for phylogeographic analysis. The results were compared with those previously obtained with mtDNA, a region exhaustively analyzed along the brown trout distribution. ITS2 was essentially conserved at all populations sampled, no informative characters being detected across the main lineages described in this species. Conversely, ITS1 showed a greater homogenization than other genetic markers at a microgeographic scale, with variation partitioning into several major phylogenetic groups. Phylogeographic patterns were partially congruent between both ITS1 and mtDNA. The main discrepancies were the detection of intra-individual variation and putative recombinant ITS1 sequences in hybridization areas between genetically different, yet historically overlapping, assemblages. Also, the existence of an ancient ITS1 sequence in the Mediterranean-southeastern area (rMEDA), not revealed by mtDNA analysis, was evidenced after rDNA ITS1 analysis.     

Allozyme and mtDNA divergence between Atlantic salmon populations in North Wales

Allozyme variation differentiates between Atlantic salmon Salmo salar populations in North Wales to a greater extent than mtDNA diversity.     

小麦杂种世代生育期与产量的遗传关系

用二个杂交组合的F2-F4代材料, 研究了小麦生育期性状的遗传变异以及与产量的关系。各生育期的变异如下:开花-成熟期>拔节-抽穗期>播种-拔节期>抽穗-开花期。各生育期性状在杂种早期世代(F2、F3)具较高遗传力。单株产量与开花-成熟期正相关,与拔节-开花期负相关,与全生育期相关不显著。对开花-成熟期正向选择,拔节-开花期负向选择,产量可获较大遗传改进。     

Evidence for mtDNA admixture between the Finns and the Saami

OBJECTIVES: The Finns, and to a more extreme extent the Saami, are genetic outliers in Europe. Despite the close geographical contact between these populations, no major contribution of Saami mtDNA haplotypes to the Finnish population has been detected. METHODS: To examine the extent of maternal gene flow from the Saami into Finnish populations, we determined the mtDNA variation in 403 persons living in four provinces in central and northern Finland. For all of these samples, we assessed the frequencies of mtDNA haplogroups and examined sequence variation in the hypervariable segment I (HVS-I). The resulting data were compared with published information for Saami populations. RESULTS: The frequencies of the mtDNA haplogroups differed between the populations of the four provinces, suggesting a distinction between northern and central Finland. Analysis of molecular variance suggested that the Saami deviated less from the population of northern Finland than from that of central Finland. Five HVS-I haplotypes, including that harboring the Saami motif and the Asian-specific haplogroup Z, were shared between the Finns and the Saami and allowed comparisons between the populations. Their frequency was highest in the Saami and decreased towards central Finland. CONCLUSIONS: The high frequency of certain mtDNA haplotypes considered to be Saami specific in the Finnish population suggests a genetic admixture, which appears to be more pronounced in northern Finland. Furthermore, the presence of haplogroup Z in the Finns and the Saami indicates that traces of Asian mtDNA genotypes have survived in the contemporary populations.     

Phylogeography of two European newt species--discordance between mtDNA and morphology

The newts Triturus vulgaris and Triturus montandoni are sister species that exhibit contrasting levels of intraspecific morphological variation. Triturus vulgaris has a broad Eurasiatic distribution encompassing both formerly glaciated and unglaciated areas and shows substantial morphological differentiation in the southern part of its range, while T. montandoni, confined to the Carpathians, is morphologically uniform. We analysed sequence variation of two mtDNA fragments of the total length of c. 1850 bp in 285 individuals of both species collected from 103 localities. Phylogenetic analysis of 200 unique haplotypes defined 12 major clades, their age estimated at c. 4.5-1.0 million years (Myr). Most of the older clades were found in the southern part of the range, and also in central Europe, mainly in Romania. The distribution of mtDNA clades points to the existence of several glacial refugia, located in the Caucasus region, Anatolia, the Balkan Peninsula, Italy, and more to the north in central Europe. The concordance between mtDNA based phylogeny and the distribution of T. vulgaris subspecies was weak. Triturus montandoni haplotypes did not form a monophyletic group. Instead they were found in six clades, in five of them mixed with T. vulgaris haplotypes, most likely as a result of past or ongoing hybridization and multiple introgression of mtDNA from T. vulgaris to T. montandoni. Patterns of sequence variation within clades suggested long-term demographic stability in the southern groups, moderate and relatively old demographic growth in the populations inhabiting central Europe, and high growth in some of the groups that colonized northern parts of Europe after the last glacial maximum.     

2种珍稀裂腹鱼类线粒体DNA部分序列片段的比较分析

对扁吻鱼(Aspiorhynchus laticeps)及塔里木裂腹鱼(Schizothorax biddulphi)线粒体CO I(624 bp)、Cyt b(712 bp)和D-loop(457 bp)基因片段进行了PCR扩增和序列测定.通过分析比较发现,3个片段A+T含量与其他鱼类相比均较高,G含量偏低这一现象在...     

Generations of interdisciplinarity in bioinformatics

Bioinformatics, a specialism propelled into relevance by the Human Genome Project and the subsequent -omic turn in the life science, is an interdisciplinary field of research. Qualitative work on the disciplinary identities of bioinformaticians has revealed the tensions involved in work in this “borderland.” As part of our ongoing work on the emergence of bioinformatics, between 2010 and 2011, we conducted a survey of United Kingdom-based academic bioinformaticians. Building on insights drawn from our fieldwork over the past decade, we present results from this survey relevant to a discussion of disciplinary generation and stabilization. Not only is there evidence of an attitudinal divide between the different disciplinary cultures that make up bioinformatics, but there are distinctions between the forerunners, founders and the followers; as inter/disciplines mature, they face challenges that are both inter-disciplinary and inter-generational in nature.     

Phylogenetic analysis between domestic and wild duck species in Korea using mtDNA d-loop sequences

Recently, the consumption of duck meat has increased; therefore, we need to reveal the origin and gene flow of domestic ducks in Korea. In order to discriminate between duck species, d-loop variations in mitochondrial DNA (mtDNA) have been investigated. In this study, 45 individuals from seven species of wild and domestic ducks in Korea were considered for the d-loop region sequences. With the participation of all the sequences, a phylogenetic neighbor-joining tree was constructed to differentiate between the wild and domestic duck species. In consideration of these sequences, a total 66 haplotypes were obtained (indel included) with an average haplotype of 76.9 %, and a haplotype and nucleotide diversity of 0.91 and 0.01, respectively. Also, an estimation of the sequence divergence within and between species was measured in 0.045 and 0.013–0.095, respectively. Meanwhile, the lowest distances of 0.024, 0.013 and 0.018 were observed in three species, including the Mallard, Spot-billed and domestic duck, respectively, which have relatively close genetic relationships. All haplotypes were used for the median-joining network analysis to differentiate all duck species, while three duck species were closely related. Moreover, 26 indel polymorphisms were identified which could be used for the discrimination among the duck species. Based on our results, duck species were effectively discriminated in a d-loop region, which could then be used for an appropriate genetic conservation program for the wild duck and domestic duck breeds in Korea.     

籼粳稻杂交后代花时性状的QTL分析

研究典型籼稻品种‘七山占’和典型粳稻品种‘秋光’杂交衍生的重组自交系群体及其双亲的花时性状,并用该群体的分子连锁图谱进行QTL分析,共检测到6个与水稻花时性状相关的QTL,包括1个始花时QTL、3个盛花时QTL和2个终花时QTL,分别位于第1、2、7、8、10和12染色体,单个QTL的贡献率在7.08%～26.95%之间。有4个增效等位基因来源于粳型亲本‘秋光’,2个来源于籼型亲本‘七山占’。     

Intimate Relationship between mtDNA, Plasmids, and the Fusion of Mitochondria

Physarum polycephalum. The conformation of Physarum mtDNA is currently thought to be circular. The inheritance of its mtDNA depends on the multiallelic mating type loci, matA. In a cross with ordinary matA combinations, the strain that has the higher matA status transmits its mtDNA to the progeny (uniparental inheritance). The mF plasmid promotes the fusion of mitochondria in the zygote and during sporulation. When it exists in a strain with a lower status matA, the mF plasmid overcomes the force of uniparental inheritance and is preferentially transmitted to the progeny via mitochondrial fusion. Moreover, the conformation of mtDNA is changed from circular to linear by recombination with the mF plasmid. Since biparental inheritance usually occurs in a cross involving a combination of matA1 and matA15, two types of inheritance of Physarum mtDNA exist. Considering the existence of the mF plasmid, there are four patterns of cytoplasmic inheritance in P. polycephalum: 1) uniparental inheritance of mtDNA, 2) uniparental inheritance of mtDNA and preferential transmission of the mF plasmid, 3) biparental inheritance of mtDNA, and 4) biparental inheritance of mtDNA and the mF plasmid. This article describes the events involved in each pattern. Finally, we discuss a hypothetical mechanism for mitochondrial fusion. The essential protein may be the ORF640 protein encoded in the mF plasmid. Received 8 March 2000/ Accepted in revised form 23 March 2000