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991.
Chang Liu Rebecca Reese Simon Vu Lionel Rougé Shannon D. Shields Satoko Kakiuchi-Kiyota Huifen Chen Kevin Johnson Yu Patrick Shi Tania Chernov-Rogan Demi Maria Zabala Greiner Pawan Bir Kohli David Hackos Bobby Brillantes Christine Tam Tianbo Li Jianyong Wang Brian Safina Jun Chen 《Neuron》2021,109(2):273-284.e4
992.
Kim YK Hong YJ Min MS Kim KS Kim YJ Voloshina I Myslenkov A Smith GJ Cuong ND Tho HH Han SH Yang DH Kim CB Lee H 《The Journal of heredity》2011,102(2):165-174
The Asiatic black bear is one of the most endangered mammals in South Korea owing to population declines resulting from human exploitation and habitat fragmentation. To restore the black bear population in South Korea, 27 bear cubs from North Korea and Russian Far East (Primorsky Krai) were imported and released into Jirisan National Park, a reservoir of the largest wild population in South Korea, in 2004. To monitor the success of this reintroduction, the genetic diversity and population structure of the reintroduced black bears were measured using both mitochondrial and nuclear DNA markers. Mitochondrial D-loop region DNA sequences (615 bp) of 43 Japanese black bears from previous study and 14 Southeast Asian black bears in this study were employed to obtain phylogenetic inference of the reintroduced black bears. The mitochondrial phylogeny indicated Asiatic black bear populations from Russian Far East and North Korea form a single evolutionary unit distinct from populations from Japan and Southeast Asia. Mean expected heterozygosity (H(E)) across 16 microsatellite loci was 0.648 for Russian and 0.676 for North Korean populations. There was a moderate but significant level of microsatellite differentiation (F(ST) = 0.063) between black bears from the 2 source areas. In addition, genetic evidences revealed that 2 populations are represented as diverging groups, with lingering genetic admixture among individuals of 2 source populations. Relatedness analysis based on genetic markers indicated several discrepancies with the pedigree records. Implication of the phylogenetic and genetic evidences on long-term management of Asiatic black bears in South Korea is discussed. 相似文献
993.
We completed a biophysical characterization of the c-MYC proto-oncogene P1 promoter quadruplex and its interaction with a cationic porphyrin, 5,10,15,20-tetra(N-methyl-4-pyridyl)porphyrin (TMPyP4), using differential scanning calorimetry, isothermal titration calorimetry, and circular dichroism spectroscopy. We examined three different 24-mer oligonucleotides, including the wild-type (WT) sequence found in the c-MYC P1 promoter and two mutant G→T sequences that are known to fold into single 1:2:1 and 1:6:1 loop isomer quadruplexes. Biophysical experiments were performed on all three oligonucleotide sequences at two different ionic strengths (30 mM [K+] and 130 mM [K+]). Differential scanning calorimetry experiments demonstrated that the WT quadruplex consists of a mixture of at least two different folded conformers at both ionic strengths, whereas both mutant sequences exhibit a single two-state melting transition at both ionic strengths. Isothermal titration calorimetry experiments demonstrated that both mutant sequences bind 4 mols of TMPyP4 to 1 mol of DNA, in similarity to the WT sequence. The circular dichroism spectroscopy signatures for all three oligonucleotides at both ionic strengths are consistent with an intramolecular parallel stranded G-quadruplex structure, and no change in quadruplex structure is observed upon addition of saturating amounts of TMPyP4 (i.e., 4:1 TMPyP4/DNA). 相似文献
994.
Piyush Behari Lal Barbara L. Schneider Khoan Vu Larry Reitzer 《Molecular microbiology》2014,94(4):843-856
Aminotransferases can be redundant or promiscuous, but the extent and significance of these properties is not known in any organism, even in Escherichia coli. To determine the extent of redundancy, it was first necessary to identify the redundant aminotransferases in arginine and lysine synthesis, and then complement all aminotransferase‐deficient mutants with genes for all aminotransferases. The enzymes with N‐acetylornithine aminotransferase (ACOAT) activity in arginine synthesis were ArgD, AstC, GabT and PuuE; the major anaerobic ACOAT was ArgD. The major enzymes with N‐succinyl‐l ,l ‐diaminopimelate aminotransferase (SDAP‐AT) activity in lysine synthesis were ArgD, AstC, and SerC. Seven other aminotransferases, when overproduced, complemented the defect in a triple mutant. Lysine availability did not regulate synthesis of the major SDAP‐ATs. Complementation analysis of mutants lacking aminotransferases showed that the SDAP‐ATs and alanine aminotransferases were exceptionally redundant, and it is proposed that this redundancy may ensure peptidoglycan synthesis. An overview of all aminotransferase reactions indicates that redundancy and broad specificity are common properties of aminotransferases. 相似文献
995.
Quang Minh Dinh Jian G. Qin Sabine Dittmann Dinh Dac Tran 《Ichthyological Research》2014,61(4):332-340
Some fish species living in mudflats construct burrows for dwelling and hiding. The goby Parapocryptes serperaster is a burrowing fish in mudflats of many estuaries in South East Asia. This study was carried out in the Mekong Delta, Vietnam, to examine burrow morphology and usage by this species. Morphology of the burrows constructed by P. serperaster was investigated by resin castings in situ to obtain the physical structure and configuration of each burrow. Fish from the burrows were caught and measured before burrow casts were made. Fish burrows comprised several openings, a few branching tunnels and multi-bulbous chambers. The surface openings were circular, and the shapes of branching tunnels were nearly round. The burrows had interconnected tunnels and various short cul-de-sac side branches. The burrow structure differed between fish sizes, but burrow dimensions were positively correlated with fish size, indicating that larger fish can make larger and more sophisticated burrow. The burrow structure and dimensions were not different between the dry and wet seasons. Laboratory observations showed that P. serperaster used body movements to dig burrows in the sediment. Burrows could provide a low-tide retreat and protection from predators, but were not used for spawning and feeding for this goby species. This study indicates that the burrowing activity of gobies is an important adaptation for living in shallow and muddy habitats. 相似文献
996.
Fish monogeneans are lethal parasites in aquaculture. We provide the first experimental evidence that a notorious fish monogenean, Neobenedenia sp., can produce viable eggs in isolation for three consecutive generations. We infected individual, isolated, farmed barramundi, Lates calcarifer (Bloch) with a single oncomiracidium (larva) of the hermaphroditic monogenean Neobenedenia sp. Isolated parasites reached sexual maturity at day 10 post-hatch (24°C, 35‰) and laid ∼3,300 embryonated eggs over 17 days. Egg production rapidly increased following sexually maturity on day 10 (58±15 eggs) and peaked on day 15 (496±68 eggs) before gradually decreasing. Neobenedenia sp. exhibited egg laying and egg hatching rhythms. Parasites laid eggs continuously, but egg production increased in periods of darkness (64.3%), while the majority of oncomiracidia (81%) emerged from eggs in the first three hours of light. Eggs laid by isolated ‘parent’ parasites hatched and individual emerging oncomiracidia were used to infect more individual, isolated fish, with three consecutive, isolated, parasite generations (F1, F2 and F3) raised in the laboratory. Infection success and egg hatching success did not differ between generations. Our data show that one parasite, in the absence of a mate, presents a severe threat to captive fish populations. 相似文献
997.
Anke Vermehren-Schmaedick Wesley Krueger Thomas Jacob Damien Ramunno-Johnson Agnieszka Balkowiec Keith A. Lidke Tania Q. Vu 《PloS one》2014,9(4)
Accumulating evidence underscores the importance of ligand-receptor dynamics in shaping cellular signaling. In the nervous system, growth factor-activated Trk receptor trafficking serves to convey biochemical signaling that underlies fundamental neural functions. Focus has been placed on axonal trafficking but little is known about growth factor-activated Trk dynamics in the neuronal soma, particularly at the molecular scale, due in large part to technical hurdles in observing individual growth factor-Trk complexes for long periods of time inside live cells. Quantum dots (QDs) are intensely fluorescent nanoparticles that have been used to study the dynamics of ligand-receptor complexes at the plasma membrane but the value of QDs for investigating ligand-receptor intracellular dynamics has not been well exploited. The current study establishes that QD conjugated brain-derived neurotrophic factor (QD-BDNF) binds to TrkB receptors with high specificity, activates TrkB downstream signaling, and allows single QD tracking capability for long recording durations deep within the soma of live neurons. QD-BDNF complexes undergo internalization, recycling, and intracellular trafficking in the neuronal soma. These trafficking events exhibit little time-synchrony and diverse heterogeneity in underlying dynamics that include phases of sustained rapid motor transport without pause as well as immobility of surprisingly long-lasting duration (several minutes). Moreover, the trajectories formed by dynamic individual BDNF complexes show no apparent end destination; BDNF complexes can be found meandering over long distances of several microns throughout the expanse of the neuronal soma in a circuitous fashion. The complex, heterogeneous nature of neuronal soma trafficking dynamics contrasts the reported linear nature of axonal transport data and calls for models that surpass our generally limited notions of nuclear-directed transport in the soma. QD-ligand probes are poised to provide understanding of how the molecular mechanisms underlying intracellular ligand-receptor trafficking shape cell signaling under conditions of both healthy and dysfunctional neurological disease models. 相似文献
998.
999.
Gregory J. Fox Dinh Ngoc Sy Nguyen Viet Nhung Bing Yu Magda K. Ellis Nguyen Van Hung Nguyen Kim Cuong Luu Thi Lien Guy B. Marks Bernadette M. Saunders Warwick J. Britton 《PloS one》2014,9(7)
Background
Tuberculosis (TB) is an infectious disease that remains a major cause of morbidity and mortality worldwide, yet the reasons why only 10% of people infected with Mycobacterium tuberculosis go on to develop clinical disease are poorly understood. Genetically determined variation in the host immune response is one factor influencing the response to M. tuberculosis. SP110 is an interferon-responsive nuclear body protein with critical roles in cell cycling, apoptosis and immunity to infection. However association studies of the gene with clinical TB in different populations have produced conflicting results.Methods
To examine the importance of the SP110 gene in immunity to TB in the Vietnamese we conducted a case-control genetic association study of 24 SP110 variants, in 663 patients with microbiologically proven TB and 566 unaffected control subjects from three tertiary hospitals in northern Vietnam.Results
Five SNPs within SP110 were associated with all forms of TB, including four SNPs at the C terminus (rs10208770, rs10498244, rs16826860, rs11678451) under a dominant model and one SNP under a recessive model, rs7601176. Two of these SNPs were associated with pulmonary TB (rs10208770 and rs16826860) and one with extra-pulmonary TB (rs10498244).Conclusion
SP110 variants were associated with increased susceptibility to both pulmonary and extra-pulmonary TB in the Vietnamese. Genetic variants in SP110 may influence macrophage signaling responses and apoptosis during M. tuberculosis infection, however further research is required to establish the mechanism by which SP110 influences immunity to tuberculosis infection. 相似文献1000.
Le Van Tan Le Hong Thai Nguyen Hoan Phu Ho Dang Trung Nghia Ly Van Chuong Dinh Xuan Sinh Nguyen Duy Phong Nguyen Thi Hoang Mai Dinh Nguyen Huy Man Vo Minh Hien Nguyen Thanh Vinh Jeremy Day Nguyen Van Vinh Chau Tran Tinh Hien Jeremy Farrar Menno D. de Jong Guy Thwaites H. Rogier van Doorn Tran Thi Hong Chau 《PLoS neglected tropical diseases》2014,8(8)