Biology and life history of Dabry's sturgeon, Acipenser dabryanus, in the Yangtze River

Dabry's sturgeon, Acipenser dabryanus, is a relatively small (130 cm, 16 kg) and now rare sturgeon restricted to the Yangtze River Basin. It behaves as a resident freshwater fish, does not undertake long distance migrations (except for spawning), and lives in a variety of habitats. It historically spawned in the upper Yangtze River, but the spawning sites are unknown. Acipenser dabryanus reaches maturity earlier than do other Chinese sturgeons, which gives the species aquaculture potential, and artificial spawning has been carried out. However, the native population in the Yangtze has sharply declined in the last two decades due to overfishing, pollution and habitat alteration and destruction, especially since the construction of the Gezhouba Dam, which was built in 1981 across the Yangtze River at Yichang, Hubei Province. Since 1981, Dabry's sturgeon rarely occurs below the Gezhouba Dam because downstream movements are blocked. Clearly, conservation of Dabry's sturgeon must be emphasized. Conservation methods may include protecting habitats, controlling capture and stock replenishment.     

Structure of YciA from Haemophilus influenzae (HI0827), a hexameric broad specificity acyl-coenzyme A thioesterase

The crystal structure of HI0827 from Haemophilus influenzae Rd KW20, initially annotated "hypothetical protein" in sequence databases, exhibits an acyl-coenzyme A (acyl-CoA) thioesterase "hot dog" fold with a trimer of dimers oligomeric association, a novel assembly for this enzyme family. In studies described in the preceding paper [Zhuang, Z., Song, F., Zhao, H., Li, L., Cao, J., Eisenstein, E., Herzberg, O., and Dunaway-Mariano, D. (2008) Biochemistry 47, 2789-2796], HI0827 is shown to be an acyl-CoA thioesterase that acts on a wide range of acyl-CoA compounds. Two substrate binding sites are located across the dimer interface. The binding sites are occupied by two CoA molecules, one with full occupancy and the second only partially occupied. The CoA molecules, acquired from HI0827-expressing Escherichia coli cells, remained tightly bound to the enzyme through the protein purification steps. The difference in CoA occupancies indicates a different substrate affinity for each of the binding sites, which in turn implies that the enzyme might be subject to allosteric regulation. Mutagenesis studies have shown that the replacement of the putative catalytic carboxylate Asp44 with an alanine residue abolishes activity. The impact of this mutation is seen in the crystal structure of D44A HI0827. Whereas the overall fold and assembly of the mutant protein are the same as those of the wild-type enzyme, the CoA ligands are absent. The dimer interface is perturbed, and the channel that accommodates the thioester acyl chain is more open and wider than that observed in the wild-type enzyme. A model of intact substrate bound to wild-type HI0827 provides a structural rationale for the broad substrate range.     

Molecular Characterization of High Plant Species Using PCR with Primers Designed from Consensus Branch Point Signal Sequences

A novel method is introduced for producing molecular markers in plants using single 15- to 18-mer PCR primers designed from the short conserved consensus branch point signal sequences and standard agarose gel electrophoresis. This method was tested on cultivated peanut and verified to give good fingerprinting results in other plant species (mango, banana, and longan). These single primers, designed from relatively conserved branch point signal sequences within gene introns, should be universal across other plant species. The method is rapid, simple, and efficient, and it requires no sequence information of the plant genome of interest. It could be used in conjunction with, or as a substitute for, conventional RAPD or ISSR techniques for applications including genetic diversity analysis, phylogenetic tree construction, and quantitative trait locus mapping. This technique provides a new way to develop molecular markers for assessing genetic diversity of germplasm in diverse species based on conserved branch point signal sequences.     

Ursolic acid benzaldehyde chalcone,leads to inhibition of cell proliferation and arrests cycle in G1/G0 phase in colon cancer

The present study investigates the effect of matrine on colon cancer cell viability and apoptosis and tumor growth in mice xenograft model. The results from MTT assay revealed a concentration and time dependent reduction in viability of HCT8 and HT29 colon cancer cells by matrine. The viability of HCT8 and HT29 cells was reduced to 24.67 and 29.32% on treatment with 4 µM/ml concentration of matrine after 48 h (P < 0.05). The results from flow cytometry revealed increase in population of HCT8 and HT29 cells to 77.6 ± 0.3 and 54.0 ± 5.4%, respectively compared to 1.4 ± 0.3 and 2.4 ± 0.7% in control on exposure to 1 µM/ml concentration of matrine. Histone H2AX phosphorylation and expression of Myt1, cyclin A2, cyclin B1 and p53 were increased in HCT8 and HT29 cells on treatment with matrine for 48 h. Matrine treatment also increased the phosphorylation of cdc2 significantly compared to control cells at 48 h (P < 0.05). Results from Annexin-V/FITC-staining showed increase in proportion of apoptotic cells in HCT8 and HT29 cells 67.52 and 68.56 on treatment with 1 µM/ml of matrine. Matrine treatment caused a marked reduction in the growth of HCT8 cell xenograft after 21 days. Thus matrine inhibits cell viability, induces apoptosis and inhibits tumor growth in colon cancer.     

RFLP mapping of QTLs for yield and related characters in rice (Oryza sativa L.)

Quantitative triat loci (QTLs) for yield and related traits in rice were mapped based on RFLP maps from two indica/indica F₂ populations, Tesanai 2/CB and Waiyin 2/CB. In Tesanai 2/CB, 14 intervals carrying QTLs for eight traits were detected, including 3 for grain weight per plant (GWT), 2 for number of panicles per plant (NP), 2 for number of grains per panicle (NG), 1 for total number of spikelets per panicle (TNS), 1 for spikelet fertility (SF), 3 for 1000-grain weight (TGWT), 1 for spikelet density (SD), and 1 for number of first branches per main panicle. The 3 QTLs for GWT were located on chromosomes 1, 2, and 4, with 1 in each chromosome. The additive effect of the single locus ranged from 2.0 g to 9.1 g. A major gene (np4) for NP was detected on chromosome 4 within the interval of RG143–RG214, about 4cM for RG143, and this locus explained 26.1% of the observed phenotypic variance for NP. The paternal allele of this locus was responsible for reduced panicles per plant (3 panicles per plant). In another population, Waiyin 2/CB, 12 intervals containing QTLs for six of the above-mentioned traits were detected, including 3 for GWT, 2 for each of NP, TNS, TGWT and SD, 1 for SF. Three QTLs for GWT were located on chromosome 1, 4, and 5, respectively. The additive effect of the single locus for GWT ranged from 6.7 g to 8.8 g, while the dominance effect was 1.7–11.5 g. QTL mapping in two populations with a common male parent is compared and discussed.     

Solution blowing of submicron-scale cellulose fibers

Solution blowing is an innovative process for spinning micro-/nano-fibers from polymer solutions using high-velocity gas flow as fiber forming driving force. Submicron-scale cellulose fibers were successfully solution blown by two improvement measures. First, cellulose solution was directly blown to fibers of 260-1900nm in diameter by raising the air temperature along the spinning line which was proved to accelerate the evaporation of solvent and fiber forming. Second, coaxial solution blowing technique was established with cellulose solution and polyethylene oxide (PEO) solution used as core and shell liquids, respectively. The core-shell structures of the fibers were examined by SEM and TEM. Cellulose fibers with diameter between 160nm and 960nm were further obtained after removing PEO shell. X-ray diffraction studies showed that the two kinds of submicron-scale cellulose fibers are mostly amorphous.     

Otolith shape lends support to the sensory drive hypothesis in rockfishes

The sensory drive hypothesis proposes that environmental factors affect both signalling dynamics and the evolution of signals and receivers. Sound detection and equilibrium in marine fishes are senses dependent on the sagittae otoliths, whose morphological variability appears intrinsically linked to the environment. The aim of this study was to understand if and which environmental factors could be conditioning the evolution of this sensory structure, therefore lending support to the sensory drive hypothesis. Thus, we analysed the otolith shape of 42 rockfish species (Sebastes spp.) to test the potential associations with the phylogeny, biological (age), ecological (feeding habit and depth distribution) and biogeographical factors. The results showed strong differences in the otolith shapes of some species, noticeably influenced by ecological and biogeographical factors. Moreover, otolith shape was clearly conditioned by phylogeny, but with a strong environmental effect, cautioning about the use of this structure for the systematics of rockfishes or other marine fishes. However, our most relevant finding is that the data supported the sensory drive hypothesis as a force promoting the radiation of the genus Sebastes. This hypothesis holds that adaptive divergence in communication has significant influence relative to other life history traits. It has already been established in Sebastes for visual characters and organs; our results showed that it applies to otolith transformations as well (despite the clear influence of feeding and depth), expanding the scope of the hypothesis to other sensory structures.     

Effect of lignocellulosic inhibitory compounds on growth and ethanol fermentation of newly-isolated thermotolerant Issatchenkia orientalis

A newly isolated thermotolerant ethanologenic yeast strain, Issatchenkia orientalis IPE 100, was able to produce ethanol with a theoretical yield of 85% per g of glucose at 42 °C. Ethanol production was inhibited by furfural, hydroxymethylfurfural and vanillin concentrations above 5.56 g L⁻¹, 7.81 g L⁻¹, and 3.17 g L⁻¹, respectively, but the strain was able to produce ethanol from enzymatically hydrolyzed steam-exploded cornstalk with 93.8% of theoretical yield and 0.91 g L⁻¹ h⁻¹ of productivity at 42 °C. Therefore, I. orientalis IPE 100 is a potential candidate for commercial lignocelluloses-to-ethanol production.