Effects of glucagon on the redox states of cytochromes in mitochondria in situ in perfused rat liver

The effects of glucagon on the respiratory function of mitochondria in situ were investigated in isolated perfused rat liver. Glucagon at the concentrations higher than 20 pM and cyclic AMP (75 microM) stimulated hepatic respiration, and shifted the redox state of pyridine nucleotide (NADH/NAD) in mitochondria in situ to a more reduced state as judged by organ fluorometry and beta-hydroxybutyrate/acetoacetate ratio. The organ spectrophotometric study revealed that glucagon and cyclic AMP induced the reduction of redox states of cytochromes a(a3), b and c+c1. Atractyloside (4 micrograms/ml) abolished the effects of glucagon on these parameters and gluconeogenesis from lactate. These observations suggest that glucagon increases the availability of substrates for mitochondrial respiration, and this alteration in mitochondrial function is crucial in enhancing gluconeogenesis.     

虎嘉鱼保护生物学的研究V.生境特点及保护对策

本文报道了虎嘉鱼的生境特点及保护对策,主要是加强宣传教育,严禁滥捕,深入研究,开展人工养殖试验和建立自然保护区等措施,确保物种生存和繁衍。     

Estimating the inbreeding level and genetic relatedness in an isolated population of critically endangered Sichuan taimen (Hucho Bleekeri) using genome‐wide SNP markers

Sichuan taimen (Hucho bleekeri) is critically endangered fish listed in The Red List of Threatened Species compiled by the International Union for Conservation of Nature (IUCN). Specific locus amplified fragment sequencing (SLAF‐seq)‐based genotyping was performed for Sichuan taimen with 43 yearling individuals from three locations in Taibai River (a tributary of Yangtze River) that has been sequestered from its access to the ocean for more than 30 years since late 1980s. Applying the inbreeding level and genetic relatedness estimation using 15,396 genome‐wide SNP markers, we found that the inbreeding level of this whole isolated population was at a low level (2.6 × 10^?3 ± 0.079), and the means of coancestry coefficients within and between the three sampling locations were all very low (close to 0), too. Genomic differentiation was negatively correlated with the geographical distances between the sampling locations (p < .001), and the 43 individuals could be considered as genetically independent two groups. The low levels of genomic inbreeding and relatedness indicated a relatively large number of sexually mature individuals were involved in reproduction in Taibai River. This study suggested a genomic‐relatedness‐guided breeding and conservation strategy for wild fish species without pedigree information records.     

How soil granulometry,temperature, and water predict genetic differentiation in Namibian spiders (Ariadna: Segestriidae) and explain their behavior

The Namib Desert is a biodiversity hotspot for many invertebrates, including spiders. Tube‐dwelling spiders belonging to the Ariadna genus are widespread in gravel plains. These sit‐and‐wait predators share a particular behavior, as they spend their life in tunnels in the soil, surrounding the entrance of their burrow with stone rings. We investigated five spider populations taking into account environmental parameters, functional traits, and molecular data. We have chosen the temperature at the soil surface and at the bottom of the burrow, the air humidity, and the soil granulometry to define the environment. The chosen functional traits were the diameter and depth of the burrows, the ratio between weight and length, the thermal properties of their silks, and the number of ring elements. The molecular branch lengths and the evolutionary distance emerging from cytochrome oxidase I gene sequences summarized the molecular analysis. Our study highlights a strong coherence between the resulting evolutionary lineages and the respective geographical distribution. Multivariate analyses of both environmental and molecular data provide the same phylogenetic interpretation. Low intrapopulation sequence divergence and the high values between population sequence divergence (between 4.9% and 26.1%) might even suggest novel taxa which deserve further investigation. We conclude that both the Kimura distance and the branch lengths are strengthening the environmental clustering of these peculiar sites in Namibia.     

Isolation of microsatellite DNA and analysis on genetic diversity of endangered fish,Hucho taimen (Pallas)

Hucho taimen (Pallas) is an endangered species in China. To evaluate the species’ genetic diversity and population genetic structure, we isolated six polymorphic microsatellite markers from its genomic libraries by (ACA)₁₆ enriched, and characterized using 61 wild individuals. The number of alleles per locus ranged from two to seven, expected heterozygosity ranged from 0.3200 to 0.7410, polymorphism information content ranged from 0.3047 to 0.6896. These markers will be useful for the genetic variation assessment of taimen.     

铁皮石斛微卫星SSR设计与应用

通过Websat对来源于NCBI公共数据库的2 447条石斛属(Dendrobium)核苷酸序列进行简单重复序列SSR的搜索,剔除冗余序列后,找到124个SSR位点。利用primer3.0软件设计引物75对,并通过改良的方法提取铁皮石斛DNA作为模板,对铁皮石斛(Dendrobium officinaleKimuraetMigo)的SSR引物进行筛选,选出21对有较清晰且稳定的目标扩增产物的引物,对8个种源的铁皮石斛进行多态性分析和聚类分析,得到8个种源的铁皮石斛进行遗传多样性和亲缘关系。     

Can one learn history from the allelic spectrum?

It is well known that the neutral allelic frequency spectrum of a population is affected by the history of population size. A number of authors have used this fact to infer history given observed allele frequency data. We ask whether perfect information concerning the spectrum allows precise recovery of the history, and with an explicit example show that the answer is in the negative. This implies some limitations on how informative allelic spectra can be.     

Synthesis and evaluation of a [18F]formyl–Met–Leu–Phe derivative: A positron emission tomography imaging probe for bacterial infections

The tripeptide formyl–Met–Leu–Phe (fMLF) is a prototype of N-formylated chemotactic peptides for neutrophils owing to its ability to bind and activate the G protein-coupled formyl peptide receptor (FPR). Here, we developed an ¹⁸F-labeled fMLF derivative targeting FPR as a positron emission tomography (PET) imaging probe for bacterial infections. The study demonstrates that the fMLF derivative fMLFXYk(FB)k (X?=?Nle) has a high affinity for FPR (Ki?=?0.62?±?0.13?nM). The radiochemical yield and purity of [¹⁸F]fMLFXYk(FB)k were 16% and >96%, respectively. The in vivo biodistribution study showed that [¹⁸F]fMLFXYk(FB)k uptake was higher in the bacterial infected region than in the non-infected region. We observed considerably higher infection-to-muscle ratio of 4.6 at 60?min after [¹⁸F]fMLFXYk(FB)k injection. Furthermore, small-animal PET imaging studies suggested that [¹⁸F]fMLFXYk(FB)k uptake in the bacterial infected region was clearly visualized 60?min after injection.     

Threatened fishes of the world: <Emphasis Type="Italic">Hucho bleekeri</Emphasis> Kimura, 1934 (Salmonidae)

Conservation status, identification, distribution, habitat and ecology, reproduction, threats, conservation actions and recommendations of a critically endangered fish, Hucho bleekeri Kimura, which is endemic to China, was introduced.