Yi chuan xue bao = Acta genetica Sinica最新文献

Peak bone mass (PBM) is a complex trait, determined by both genetic and environmental factors and also their interactions. Vitamin D receptor (VDR) estrogen receptor alpha (ERalpha), interleukin 6 (IL6), parathyroid hormone (PTH), collagen type I alpha 2 (COL1A2), bone Gla protein (BGP), alpha2-HS glycoprotein (AHSG) are among the important candidate genes of bone metabolism. The study aims to detect significant effect of potential inter-genic action underlying PBM in Chinese females. 361 unrelated healthy premenopausal Chinese females (aged 20 -44 years) with Han ethnicity were recruited from the Shanghai city in China. Bone mineral density (BMD) at the hip and the lumbar spine (L1-4) was measured using a Hologic QDR 2000 + dual-energy X-ray absorptiometry (DXA) scanner. Eight polymorphisms among the seven genes were genotyped, i. e. Apa I in VDR, Pvu II and Xba I in ERa (ERX and ERP, respectively), BsrB I in IL6, BstB I in PTH, Msp I in COL1A2, Hind III in BGP, and Sac I in AHSG, using PCR-RFLP (polymerase chain reaction-restriction fragment length polymorphism) methods. Two-way analysis of variance (ANOVA) showed significant effects of IL6 x ERP interaction on PBM at the total hip (P = 0.019), intertrochanter (P = 0.016), and femoral neck (P =0. 019). The BMD difference between GGPp carriers and GGpp subjects (at these two loci) amounted to 18.0%, 19.5%, and 14.8% at the hip,intertrochanter,and femoral neck,respectively. The potential interaction effect of AHSG x IL6 was observed on femoral neck PBM (P = 0.046). GGSS individuals (at these two loci) had, on average, 18.8% higher femoral neck BMD than those subjects with GGSs genotype. The population-level statistical analysis indicates that IL6 x ERP and AHSG x IL6 have significant inter-genic effect on the genetic determination of PBM in Chinese females.

FACE (free air carbon dioxide enrichment) technology may provide a means by which the environment around growing plants can be modified to realistically simulate the concentration of atmospheric CO2 in the future. The plant growth and its yield of plant species can be enhanced under FACE. Identification of genomic regions influencing the response of yield and its components to elevated CO2 will be useful for understanding the genetics of active response to changed CO2 environment and developing higher yield cultivars, which will be adapted to future enriched atmospheric CO2 environment. A mapping population of 65 indica (IR24) chromosome segment substitution lines (CSSLs) in japonica (Asominori) background and their parents were used to detect QTLs for yield and its components, e. g. number of fertile tillers per plant (FT), 1000-grain weight (TGW), number of grains per panicle (GP) and grain yield per plant (GY) under FACE (200 micromol CO2/mol above current levels) and current CO2 concentration (Ambient, about 370 micromol CO2/mol) in the field experiment. The results showed that, GY, GP and FT of two parents under FACE were significant greater than that under Ambient. The transgressive segregation of the four traits was observed in the CSSLs population under both FACE and Ambient. A total of 20 QTLs for the four traits were detected on chromosome 1, 2, 4, 6, 7, 9 and 12 with LOD (Log10-likelihood ratio) of QTLs ranging from 2.5 to 5.7. Three QTLs were detected under both FACE and Ambient. However,other QTLs were detected only under one level of CO2, which indicated that these loci were sensitive to CO2 concentration. Additionally, two QTLs qFT12 and qGP4 were found for the QTL x Environment (QE) interaction effects. It is suggested that there is a high possibility to improve the yield of rice under elevated CO2 through marker-assisted selection.

RTN4-C gene is a member of RTNs. To investigate its expression in human hepatocellular carcinoma tissues and study its function on SMMC7721 cells, RT-PCR was conducted to detect its expressions in human hepatocellular carcinoma tissues. RTN4-C-pcDNA3. 1 plasmid was reconstructed and stably transfected into SMMC7721 cells by Lipofect AMINE. Growth curve of SMMC7721 measured by MTT and apoptosis indentified with acridine orange staining were examined to demonstrate the effect of RTN4-C on SMMC7721. Immunocytochemical analysis for mutant p53, c-Fos, Hsp70 proteins were conducted. The results showed that the transfected SMMC7721 cells grew more slowly than control and the average inhibition rate at the 1st, 2nd and 3rd day were 33.8% +/- 0.026, 56.2% +/- 0. 094, 34.8% +/- 0.077 respectively. In transfected SMMC7721 cell line, the apoptosis was strengthened,mutant p53 protein tranferred from nucleus to cytoplasm and c-Fos, Hsp70 proteins were decreased. Our data indicated RTN4-C gene was expressed differently in hepatocellular carcinoma and its paracancerous tissues. By tranferring mutant p53 protein from nucleus to cytoplasm and decreasing c-Fos, Hsp70 protein expression, RTN4-C inhibited SMMC7721 cells growth and promoted its apoptosis.

Simple sequence repeats (SSRs) and amplified fragment length polymorphisms (AFLPs) have become the most important markers for molecular mapping. Primarily based on restriction fragment length polymorphism (RFLP) markers, extensive linkage maps of maize had been developed. To construct a near-saturated genetic linkage map, an expanded maize genetic linkage map was constructed using a population of 234 F2 individuals derived from a cross of X178 and B73 base on an essential SSR framework map of maize. The level of polymorphisms and genetic properties of SSR and AFLP markers were characterized. A total of 249 markers consisting of 130 SSRs and 119 AFLPs have been landed on 10 chromosomes of maize. The 249-locus map spanned 1 659.3 centi-morgans (cM) and had a mean density of 6.66 cM. This mapping population and related information should connect further research involving analysis of quantitative trait loci, comparative genomics, and heterosis. Moreover, in many studies, AFLPs were analyzed on the basis of the presence or absence of a band on the electrophoresis gels. A new method based on double polymorphic bands of co-dominant scoring of AFLPs was explored according to the similarity of loci amplified from AFLP enzyme combination.

Endothelial cells participate in angiogenesis, vascular homeostasis, thrombosis, inflammation and vascular wall remodeling. To study the function of genes in endothelial cells using Cre-loxP system, we generated Tie2-Cre transgenic mice, in which expression of Cre recombinase is driven by Tie2 promoter. Total six founder mice carrying the Tie2-Cre transgene were identified by genomic PCR and Southern blot. The integration efficiency is 11%. In order to test the excision activity and tissue distribution of the Cre recombinase, the Tie2-Cre transgenic line was crossed with the mouse strain carrying the Smad4 conditional alleles (Smad4(Co/Co)) or the reporter line ROSA26. PCR of multiple tissue DNA from Tie2-Cre; Smad4(Co/+) mice revealed the Cre activity in all tissues containing endothelial cells. We detected pan-endothelial expression of the Cre transgene in Tie2-Cre; ROSA26 double transgenic embryos by lacZ staining. Therefore, this mouse line may serve as a valuable tool for endothelial cell lineage analyses and conditional gene ablation in endothelial cells.

Transient expression system was used to analyze the functions of three resistance- related genes: TaTBL, TaPK1 and TaTST. Target genes were constructed into plant expression vectors and transformed into leaf epidermal cells of a powdery mildew-susceptible wheat variety by gene gun. GUS gene was co-transformed with target gene to mark the transformed cells. After transformation, leaf surface was inoculated with powdery mildew conidiospores. Forty eight hours after inoculation, penetration of the fungus and formation of haustoria in transformed cells were observed to evaluate the effects of the target gene's products on the invasion of powdery mildew. The results implied that all these three genes, when transiently expressed in leaf epidermal cells of susceptible wheat variety, could partly inhibit the penetration of conidiospores and formation of haustoria, and to some extent increase the resistance of cells to powdery mildew.

A rapeseed population consisted of 282 doubled haploid (DH) lines derived from a cross between a European vality "Sallux" and a Chinese inbred line "Gaoyou" was planted in 4 locations, 2 in Xi'an and Hangzhou, China, and 2 in Goettingen, Germany. Field experiments were carried out to obtain agronomically phenotypic data from above four environments. A linkage map including 125 SSR-markers was constructed and QTL analyses was performed using mixed model approach to detect QTLs showing additive (a), epistasis (aa) as well as their interactions with environments (QE) for three important agronomic traits: plant height, flowering time and maturity. The results demonstrated that each trait was controlled by several QTLs with additive effect and a number of QTLs with epistatic and QE interaction effects. Plant height was controlled by many QTLs (12 loci with a or combined ae, 5 loci with ae). Additive effects were predominant,totally explained 75% of the phenotypic variation and often combined with digenic epistasis. Of 12 main QTLs, 9 showed Gaoyou alleles decreasing plant height. Most of QTLs with QE effects showed ecologically favourable alleles in diverse regions. Five of 7 ae loci showed Gaoyou alleles in Hangzhou and all the ae loci but one had Sollux alleles in two locations of Germany increasing plant height. The digenic epistatic main effect accounted for one third of total additive main effects. In this study,we discovered 7 and 8 loci having significant additive main effects upon flowering time and maturity, respectively. Of them, early flowering and maturity alleles were respectively 6 and 5 derived from Chinese parent Gaoyou. All these QTLs together accounted for around 60% of the phenotypic variation for each trait. Significant ae interactions were detected for flowering time and maturity and parental alleles showed almost evenly dispersal at all environments. Three of 8 main QTLs for maturity were located at similar or identical positions as QTLs for flowering time, which confirmed the close correlation between these two traits. Two QTLs for plant height on linkage groups N14-1 and 19 were located at similar positions as QTL for flowering time and as already known QTLs for oil content. Selection for reduced plant height and early flowering might reduce oil content. Digenic epistatic QTLs both for flowering time and maturity were detected but much less important than QTLs with additive effects.

Arachidonic acid is an essential fatty acid in human nutrition and a biogenetic precursor of the biologically active prostaglandins and leukotrienes. delta5 desaturase is a key enzyme in the biosynthetic pathway of arachidonic acid, which catalyze the delta5 dehydrogenation of di-homo-gamma-linolenic acid to form arachidonic acid. Complete cDNA encoding putative delta5 fatty acyl desaturase was isolated from Mortierella alpina M6 via RT-PCR. The full length cDNA consisted of 1366 nucleotides encoding 446 amino acids. The deduced protein had conserved domains of known delta5 fatty acyl desaturases including a cytochrome b5 domain in the N terminal and 3 conserved histidine box. To elucidate the function of the protein, the cDNA was subcloned into the expression vector pPIC9K. The resultant recombinant plasmid pPIC9K-D5 was transformed to Pichia pastoris GS115 by electroporation. Transformants containing multi-copy delta5 desaturase gene were screened by Geneticin resistance. The transformants were induced to express the inserted gene with methanol when di-homo-gamma-linolenic acid was provided as an exogenous substrate. Analysis of the recombinant yeast lipids by gas chromatograph showed that a novel peak corresponding to the standard of arachidonic acid was detected. The novel peak was further characterized by GC-MS and identified as arachidonic acid. The results showed that the gene isolated from fungi Mortierella alpina M6 was a delta5 desaturase gene.

The protein truncation test was established for analyzing mutations in the adenomatous polyposis coli (APC) gene which plays an important role in familial adenomatous polyposis (FAP). The sites of APC mutations and the clinic features of FAP patients were examined to find the relationship between them. Genomic DNA, which was extracted from peripheral blood lymphocytes of 22 FAP patients and the normal colon tissues of 43 sporadic colorectal cancers, were examined for mutations in exon15 of the APC gene by using PCR-TNT T7 Quick Coupled Tanscription/Translation System. The subsequent sequencing was used to confirm the mutation sites. Germline mutations were found in 5 of 22 FAP patients. All of the five mutations showed base pair deletions and led to produce truncated protein. No truncating germline mutation was found in normal tissues of 43 sporadic colorectal cancers. The protein truncation test is a sensitive and accurate technique to detect truncated mutations especially in the large exons of APC gene. It can be used as an routine method for assisting the early diagnosis of the FAP patients.

SSR analysis was performed using a wheat near-isogenic line (NIL) Taichuang29 * 6/ Lovrin13, which carried the resistance gene Yr9 against wheat stripe rust and its recurrent parent Taichung29 as materials. After screening with 32 SSR primers on 1B chromosome, reproducible polymorphic DNA fragment amplified by Xgwm582 was identified. Genetic linkage was tested in 177 segregating F2 plants. The results indicated that microsatellite marker Xgwm582 was linked with gene Yr9 resistant to wheat stripe rust. A genetic distance of 3. 7 cM was calculated.