Yi chuan xue bao = Acta genetica Sinica最新文献

Human nuclear receptor hb1 f(nr5a2) was cloned and characterized as a novel member of the Ftz-F1 (nr5a) nuclear receptor subfamily,whose its biological function remained largely unidentified. The aim of this study was to establish transgenic mouse model that specifically expressed hB1F in the liver to faciliate the functional study of hB1F. hb1f cDNA was placed downstream of mouse albumin gene enhancer/promoter to construct a liver-specific hb1f expression vector. Transgene fragments were microinjected into fertilized eggs of mice. The manipulated embryos were transferred into the oviducts of pseudopregnant female mice. Four offspring were identified as carrying the transgenes by PCR,from which one was also verified by Southern blotting. RT-PCR and Western blotting results showed that the transgene was expressed in the liver of the transgenic mice. Transgenic founder mice were used to establish transgenic mouse lineages. The F1 mice were identified by PCR analysis. Genetic analysis of the transgenic mice demonstrated that the transgene had been integrated into the chromosome at a single site and could be stably transmitted.

Based on two major QTLs that control high fiber strength which originated from an elite fiber germ-plasm line 7235 (Gossypium hiusutum L.), the efficiency of molecular marker-assisted selection (MAS) was investigated using two populations from pedigree selection and modified backcrossing pyramiding developed for the breeding purpose. Simian 3 (SM3), a widely planted variety in the Yangtze River Valley, and 7235 were used as parents to develop the two populations. In the two major QTLs for fiber strength from 7235, QTLfs-1 could explain more than 30% of the phenotypic variation (PV) in the (7235 x TM-1) F2 population. QTLfs-2 was at first identified in another super quality fiber line HS427-10 from (HS427-10 x TM-1) F2 population with 12.5% of PV explanation,which was further also identified in 7235 line but was non-allelic with QTLfs-1. The result of molecular marker-assisted selection for fiber strength showed that the genetic effect of the QTLfs-1 was stable under different environmental conditions, and its molecular marker-assisted selection showed significant selective efficiency among breeding populations with different genetic backgrounds. QTLfs-2 also showed high selective efficiency in advanced generation populations though its effect was a little lower than the former. When QTLfs-1 was selected simultaneously with 2 molecular markers with known genetic distance, the selection efficiency for the fiber strength was greatly increased. The pyramiding for two QTLs that control high fiber strength by MAS greatly improved the selection efficiency for cotton fiber strength. This report provides a successful example of MAS pyramiding for QTL for favorable traits in breeding programs.

Genetic diversity and population genetic structure of Excoecaria agallocha, a typical mangrove associate species,were surveyed at divergent habitats (intertidal and inland). In general, intertidal populations had higher genetic diversity than inland populations. Genetic differentiation among intertidal populations (G(ST) = 0.191) were smaller than that among inland populations (G(ST) = 0.218), suggesting that gene flow via seed among intertidal populations were stronger. In an analysis of molecular variance (AMOVA), we found that 15.13% of the genetic variance could be explained by the differentiation between habitats, as compared to only 11.63% to geographical effects among five sits 181 -759 km distant from each other. This implies that markedly selection regimes result in habitat adaptation. Isolation-by-distance, Southwest Monsoon Current,China Coastal Current and genetic drift played important role in genetic differentiation of China population of Excoecaria agalocha.

This study determined a genetic basis for the phenomenon of significant asymmetric ratio of the two component nuclear types from dikaryons of Lentinula edodes via protoplast formation and regeneration by clarifying the influence of A or B mating-type factor on recovery of nuclear types from dikuaryons. The results revealed that B factor or some supposed genes linked to the B factor appeared to influence survival of dedikaryotized nuclei,whereas A factor had no apparent effect on this phenomenon. Specificity of B factor was shown to correlate with percentage survival of the component nuclear types recovered from both kinds of heterokaryons (A not equal to B not equal to and A = B not equal to). It can be put in an hierarchical order with respect to this function,the hierarchical order of these B factors was B1 > B3 > B4 > B2 between two tested strains.

Diacylgycerol Acyltransferase (DGAT) plays an important role in the formation of lipid in different tissues of biological body. DGAT catalyzes the final step in triacylglycerol (TAG) biosynthesis by converting diacylgycerol (DAG) and fatty acyl-coenzyme A (CoA) into triacylglycerol. This enzyme is coded by both DGAT1 and DGAT2. DGAT1 belongs to the gene family of cholesterol acyltransferase (ACAT). DGAT2 belongs to the gene family of monoacylgycerol acyltransferases (MGAT1). This paper reviewed the structure, location on chromosome and biological effect of DGAT-related genes. The relationship between polymorphism and performance of animal was also discussed.

To determine the origin and gene diversity of the Chinese and Mongolian domestic sheep, a partial fragment of mitochondrial DNA D-loop was sequenced for total number of 314 individuals from nine Chinese sheep populations and 11 Mongolian sheep populations. The results show no difference in nucleotide composition between Chinese and Mongolian sheep mtDNA D-loop sequences. However, more variables were identified in Mongolian sheep (26.85% of the sites) than that in Chinese sheep (24.22%). In China, mtDNA haplotype diversity was the highest in Qinghai Tibetan sheep, followed then by Gansu Tibetan sheep, Gansu Alpine Merino, Qinghai Merino, Gannan Tibetan sheep, Small-tailed Han sheep, Tan sheep, Hu sheep and Minxian Black Fur sheep. In Mongolian sheep, mtDNA haplotype diversity was the highest in Bayad and Baidrag populations and the lowest in the Gobi-Altai population. In general, Mongolian sheep have a richer genetic diversity than the Chinese ones with larger number of haplotypes (86.06% (142/165) versus 78.83% (108/137)), higher haplotype diversity (Hd; 0.976 versus 0.936), higher nucleotide diversity (Pi (pi); 0. 036 versus 0.034) and higher average number of nucleotide differences (k; 23.50 versus 22.48). Phylogenetic analysis of the 217 haplotypes identified in both Mongolian and Chinese sheep supported the same origin of their domestication with three distinct maternal lineages defined as major haplotypes A, B and C, of which haplotype A are the commonest in all Chinese sheep populations and in the majority of Mongolian sheep populations (9/11) with an average frequency of 58.73%, followed by haplotype B present in eight of Chinese population and in all Mongolian sheep populations with an average frequency of 24.68%, and haplotype C present in eight Chinese and in 10 Mongolian sheep populations with an average frequency of 16.59%. Further network analysis of the phylogenetic relationship of the 87 haplotypes identified from 91 sequences retrieved from GenBank together with the 217 haplotypes detected in this study reveals clearly four distinct lineages with the European mouflon (O. musimon) mixed into one of the lineages (haplotype B). There is no evidence of contribution of Argali sheep (O. ammon), O. vignei bochariensis and/or O. ammon nigrimontana to the maternal origin of both Mongolian and Chinese domestic sheep.

Transgenic plant is an attractive bioreactor to produce recombinant protein, such as safe and economic vaccine. In present study, a plant expression binary vector pUNDV, containing the 1.7 kb fusion protein gene of Newcastle Disease Virus (NDV F) under the control of maize ubiquitin (Ubi) promoter and nos terminator was constructed, in which, the Hygromycin phosphotransferase (HPT) gene was used as the selectable marker. The expression cassette was introduced into a japonica rice variety by Agrobacterium-mediated transformation, and 6 independent transgenic rice lines were regenerated and verified by hygromycin resistance selection. The integration of target gene in transgenic plants was confirmed by PCR analysis. The results from ELISA and Western blot analyses revealed that NDV F could be expressed in the leaf of several transgenic plants. The total salt soluble proteins were extracted from leaf of transgenic plant F5, which contained the highest expressing level of NDV F protein, and used in immunization of BALB/c mice. The specific antibodies could be elicited in mice immunized with NDV F protein expressed in transgenic rice.

Plant-pathogen interaction is the more important phytopathological subjects. Landmark progress in the past 10 years have resulted in the identification of functional R genes from the host and Avr genes from the pathogen,additionally interaction between their encoded productions. This paper reviewed the two models of R-Avr interaction, namely "receptor-ligand model" and "guard model", and discussed how to utilize the R gene during crop breeding and commercial production.

The technique of promoter trapping was developed to investigate its viability in cotton ( Gossypium hirsutum L.) functional genomics. 141 independent transformants of cotton were generated via Agrobacterium tumefaciens mediated transformation, of which 97% showed positive by PCR detection. The reporter, GUS gene, was expressed to different extent in different organs, with a frequency of 48% in roots, 9.2% in vascular bundles of stem, 5.2% in leaves, and 51% in flowers. Meanwhile, we discovered that there existed great differences in expression patterns among different transgenic lines. Their GUS expression patterns were organ- or tissue-specific or ubiquitous in all of the plants. The promoter trapping system developed here was characterized as an effective method for creating mutants with diverse reporter gene expression patterns, which laid a solid foundation for further research of functional genomics in cotton.

Nuclear DNA of eukaryotic organism attaches to the proteinaceous nuclear matrices via specific matrix attachment regions (MARs). In order to investigate the interactions between chromosomal DNA and nuclear matrices,we isolated the MARs from unicellular alga Dunaliella salina. As the first step,a random MAR library was set up and then the binding affinity of the selected clones to nuclear matrices was tested in this study. Three DNA fragments were found to bind specifically to the nuclear matrices in vitro,of which two were strong binders and all contained known consensus motifs and a hairpin loop structure of MAR.