SNP mapping of QTL affecting growth and fatness on chicken GGA1

An F2 chicken population was established from a crossbreeding between a Xinghua line and a White Recessive Rock line. A total of 502 F2 chickens in 17 full-sib families from six hatches was obtained, and phenotypic data of 488 individuals were available for analysis. A total of 46 SNP on GGA1 was initially selected based on the average physical distance using the dbSNP database of NCBI. After the polymorphism levels in all F0 individuals (26 individuals) and part of the F1 individuals (22 individuals) were verified, 30 informative SNP were potentially available to genotype all F2 individuals. The linkage map was constructed using Cri-Map. Interval mapping QTL analyses were carried out. QTL for body weight (BW) of 35 d and 42 d, 49 d and 70 d were identified on GGA1 at 351–353 cM and 360 cM, respectively. QTL for abdominal fat weight was on GGA1 at 205 cM, and for abdominal fat rate at 221 cM. Two novel QTL for fat thickness under skin and fat width were detected at 265 cM and 72 cM, respectively.     

Improving the prediction of RNA secondary structure by detecting and assessing conserved stems

The prediction of RNA secondary structure can be facilitated by incorporating with comparative analysis of homologous sequences. However, most of existing comparative methods are vulnerable to alignment errors and thus are of low accuracy in practical application. Here we improve the prediction of RNA secondary structure by detecting and assessing conserved stems shared by all sequences in the alignment. Our method can be summarized by: 1) we detect possible stems in single RNA sequence using the so-called position matrix with which some possibly paired positions can be uncovered; 2) we detect conserved stems across multiple RNA sequences by multiplying the position matrices; 3) we assess the conserved stems using the Signal-to-Noise; 4) we compute the optimized secondary structure by incorporating the so-called reliable conserved stems with predictions by RNAalifold program. We tested our method on data sets of RNA alignments with known secondary structures. The accuracy, measured as sensitivity and specificity, of our method is greater than predictions by RNAalifold.     

Gypsophin: a novel alpha-glucosidase inhibitory cyclic peptide from the roots of Gypsophila oldhamiana

An unusual new cyclic peptide with a pyrrolidine-2,5-dione unit, gypsophin (1), was isolated from Gypsophila oldhamiana. Its structure was elucidated by the spectroscopic evidences. The stereochemistry was determined by application of the Marfey's method and the single-crystal X-ray diffraction. Compound 1 exhibited inhibitory activity against alpha-glucosidase with IC50 of 305 microM.     

Diversity of tropical forest landscape types in Hainan Island, China

A novel landscape classification system was proposed in this study based on landscape ecological theory and the differentiation in climate, topography, soil, vegetation and land use mode. Five basic units (zone, tract, province, region and type) and two assistant units (sub and group) were used in this system. The tropical forest landscape in Hainan Island was regarded as a landscape province, belonging to global tropical forest landscape zone, Asiatic (oriental) tropical forest landscape tract and Chinese tropical forest landscape subtract. Based on the grade system of region, sub-region, type-group and type, this landscape province (Hainan Island) is divided into 6 landscape regions (east moist forest landscape, west semi-arid forest landscape, central-south mountainous forest landscape, tropical evergreen needle-leaved forest landscape, tropical bamboo landscape and tropical plantation landscape), 11 tropical forest landscape sub-regions represented by tropical lowland valley rain forest landscape, 26 tropical forest landscape-type groups represented by tropical lowland valley Dipterocarpaceae forest landscape, and 54 forest landscape types (FLT) represented by lowland valley Vatica mangachapoi forest. Generally, this classification system represents the landscape diversity of the tropical forest in Hainan Island. Further studies are needed to better understand the landscape diversity of Hainan Island.     

海南岛热带森林景观类型多样性

依据景观生态学原理,按地貌、气候、土壤、植被和土地利用方式的分异,以带、域、省、区、类型为5个基本单位及亚、组等为辅助单位,组建海南岛热带森林景观类型分类体系。把海南岛热带森林景观作为省级单位,它隶属于全球热带林景观带、亚洲（东方）热带林景观域、中国热带林景观亚域,其下划分为东部潮湿森林景观、西部半干旱森林景观、中南部山地森林景观、热带常绿针叶林景观、热带竹林景观和热带人工林景观6个森林景观区;以热带低地沟谷热带雨林为代表的11个森林景观亚区;以热带低地沟谷龙脑香森林景观为代表的26个森林景观类型组;以热带低地沟谷青皮林为代表的54个森林景观类型。海南岛热带森林景观类型分类体系较全面地表达了海南岛热带森林景观类型多样性。     

花脸香蘑菌丝体氨基酸分析

以花脸香蘑菌丝体为实验材料,用美国戴安AAA型氨基酸分析仪测定了18种氨基酸的组成及含量,得出花脸香蘑菌丝体18种氨基酸质量分数为259.7 g.kg-1干样,其中100 g干样中谷氨酸2.84 g,天冬氨酸2.56 g,亮氨酸2.24 g,赖氨酸1.79 g,苯丙氨酸1.76 g,蛋氨酸0.47 g,人体必需氨基酸质量分数为133.7 g.kg-1干样,占所测氨基酸的51.49%,因此花脸香蘑菌丝体具有很高的营养价值。     

Purification and characterisation of a calcium-independent lectin (PjLec) from the haemolymph of the shrimp Penaeus japonicus

A natural lectin (nominated PjLec) was isolated from haemolymph of the shrimp Penaeus japonicus by affinity chromatography with fetuin-Sepharose. The result of SDS-PAGE showed that the purified PjLec protein consisted of 37kDa subunits. The native PjLec behaved as a 452kDa protein in gel filtration chromatography. Those data suggest that PjLec is composed of 12 subunits of similar molecular weight. PjLec has a broad spectrum of bacterial-agglutination activities against both Gram-positive and Gram-negative bacteria, including two Vibrio species and two other strains pathogenic for shrimp. In addition, PjLec could agglutinate all the vertebrate erythrocytes tested, and the haemagglutination was calcium-independent. The haemagglutination of PjLec was inhibited by ManNAc, Neu5A and lipopolysaccharide. Bovine submaxillary mucin, which contains mainly Neu5A, was the most potent inhibitor of PjLec (MIC of 0.0006mgml(-1)). The haemagglutination activity of PjLec was stable between pH 6 and pH 8, and was temperature-dependent. Our results suggested that PjLec may be an important humoral defence factor against bacterial infection in P. japonicus.     

Purification and characterisation of a natural lectin from the serum of the shrimp Litopenaeus vannamei

A natural lectin from the serum of the shrimp Litopenaeus vannamei was purified to homogeneity by a single-step affinity chromatography using fetuin-coupled agarose. The purified serum lectin (named LVL) showed a strong affinity for human A/B/O erythrocytes (RBC), mouse RBC, chicken RBC and its haemagglutinating (HA) activity was specifically dependent on Ca2+ and reversibly sensitive to EDTA. LVL inactive form had a molecular mass estimate of 172 kDa and was composed of two non-identical subunits (32 and 38 kDa) cross-linked by interchain disulphide bonds. Significant LVL activity was observed between pH 7 and 11. In HA-inhibition assays performed with several carbohydrates and glycoproteins, LVL showed a distinct and unique specificity for GalNAc/GluNAc/NeuAc which had an acetyl group, while glycoproteins fetuin and bovine submaxillary mucin (BSM) had sialic acid. Moreover, this agglutinin appeared to recognise the terminal N- and O-acetyl groups in the oligosaccharide chain of glycoconjugates. The HA activity of L. vannamei lectin was also susceptible to inhibition by lipopolysaccharides from diverse Gram-negative bacteria, which might indicate a significant in vivo role of this humoral agglutinin in the host immune response against bacterial infections.