Yi chuan xue bao = Acta genetica Sinica最新文献

Previous studies suggested that the catecholaminergic systems may be involved in the pathogenesis of attention-deficit hyperactivity disorder(ADHD). Since catechel-O-methyltransferase (COMT) is an enzyme involved in the degradation of catecholaminergic neurotransmitters of the dopaminergic and noradrenergic systems,it is possible that COMT may play a role in ADHD. To test this hypothesis, we used two family-based analyses,the transmission disequilibrium test (TDT) and the haplotype-based haplotype relative risk (HHRR), to examine the possible association between COMT gene and DSM-IV-diagnosed ADHD in a Chinese sample consisting of 79 ADHD probands and their parents. Both TDT (chi2 = 1.03, df=1, P > 0.05) and HHRR (chi2 = 1.08, df = 1, P > 0.05) analyses failed to detect preferential transmission of a COMT allele to the ADHD children. Our data suggested that there was no association between ADHD and the COMT gene in the Chinese population.

Site-directed mutagenesis was performed at the codon 15 of the MS2 bacteriophage coat protein gene,which had been cloned to the virus-like particles expression vector containing non-self RNA fragment. The produced expression vector,termed pARSC, was transformed to E. coli DH5alpha. The positive clones were selected and proliferated. The harvested cells were treated with sonication and the supernatant was then subjected to linear sucrose density gradients centrifugation (15% to 60%) at 32000 r/min for 4 h at 4 degrees C. The virus-like particles, VLP-Cy, were collected at 35% sucrose density. The particles were examined by transmission electron microscopy and the spherical viral particles of approximately 27 nm in diameter were found. The thiolated VLP-Cy was then chemically modified with fluorescein -5'-maleimide. The covalent fluorescent labeling was confirmed by absorption analysis, SDS-PAGE and MALDI-TOF mass spectroscopy. This is the first report of preparation of RNA-containing natural fluorescent nanoparticles. The study highlight the versatility of MS2 bacteriophage capsids as building blocks for functional nanomaterials construction for a variety of application purposes.

A mapping population of 81 F11 lines (Recombinant Inbred Lines, RILs), derived from a cross between a japonica variety Kinmaze and an indica variety DV85 by single-seed descent method, was used to detect quantitative trait loci (QTL) for traits associated with photosynthetic functions. Total leaf nitrogen content (TLN), chlorophyll a/b ratio (Chl. a:b) and chlorophyll content (Chl) were measured in leaves of rice (Oryza sativa L.) at the 7th day after heading. A total of six putative QTLs were detected with percentage of variance explained (PVE) ranging between 11.2% -29.6%, and LOD of QTLs 2.66-4.81. Of those putative QTLs, three for TLN were detected on chromosomes 1,2 and 11, with PVE of 17.3%, 15.3% and 13.7%, respectively;Two controlling Chl. a:b on chromosomes 3 and 4, PVE of 13.8% and 29.6%, one for Chl on chromosome 1, PVE of 11.2%. Four of those detected QTLs were newly reported in this study. Interestingly, the QTL controlling chlorophyll content,namely qCC-1 reported here,was detected in the region of the RFLP marker C122 on chromosome 1, where harbored NADH-glutamate synthase structure gene according to a previous study. Because the biosynthesis of chlorophyll begins with glutamate, qCC-1 would play a vital role in photosynthetic functions. Whereas,no QTL controlling chlorophyll content were detected at the 30th day after heading, suggesting that the effect of the QTL controlling chlorophyll content decreased during leaf senescence.

Three wheat spindle streak mosaic viruses (WSSMV) resistant cultivars ('Yining Xiaomai', 'Xu87-633', and 'Xifeng') and one susceptible cultivar ('Zhen9523') were used as parents of 3 crosses in this experiment. WSSMV resistance of the parents, F1, and F2 was evaluated under field condition. Based on the segregation ratios of resistant and susceptible plants in F, and F2 populations, it was deduced that the resistance to WSSMV was dominant and the inheritable factors controlling WSSMV resistance were encoded by the nuclear genome. WSSMV resistances in 'Yining Xiaomai' and 'Xifeng' were controlled by two pairs of alleles, which showed complementary effects. However the resistance in 'Xu-87633' was controlled by a single dominant gene. 266 pairs of SSR primers located on 21 wheat chromosomes were used for polymorphic analysis of the two resistant and the susceptible parents 'Yining Xiaomai' and 'Zhen9523', and 108 of them amplified polymorphic DNA products. By Bulk Segregant Analysis of resistant and susceptible pools, one pair of primer located on chromosome arm 2DS, Xgwm261, were found being linked to WSSMV resistance. The 224 F2 individuals were then amplified with marker Xgwm261. The statistic genetic distance between Xgwm261 and the resistance locus was calculated to be 22.9 cM using the software Mapmaker 3.0.

Disseminated superficial actinic porokeratosis (DSAP) is an uncommon autosomal dominant chronic keratinization disorder,characterized by multiple superficial keratotic lesions surrounded by a slightly raised keratotic border. In previous studies,the disease gene was mapped to 12q23. 2-24.1 (DSAP1), and 15q25. 1-26.1 (DSAP2). In this study,genome-wide scan was performed in two unrelated six-generation DSAP pedigrees to localize and identify the candidate gene(s) of disease. Linkage analysis showed that the cumulative maximum two-point lod score of 8.28 was obtained with the marker D12S84 at a recombination fraction theta of 0.00. Haplotype analysis defined an 8.0 cM critical region for DSAP gene(s) between markers D12S330 and D12S354 on 12q24. 1-q24. 2, which partially overlapped with the region identified for DSAP1. DNA sequencing of the coding exons of six candidate genes (CRY1, PWP1, ASCL4, PRDM4, KIAA0789 and CMKLR1) on the basis of their location in the critical overlap interval, failed to detect any mutation in DSAP patients. Thus, it is likely that these genes are not involved in DSAP.

Beta-actin is a member of the actin family of genes,which play important roles in maintaining cytoskeletal structure, cell motility, cell division, intracellular movements and contractile processes. We report here the identification of a beta-actin cDNA of the rice field eel,a teleost fish with a characteristic of natural sex reversal. The cDNA sequence of this gene was 1860 bp in length,encoding a 375 amino acid protein. Amino acid identities of the beta-actin between the rice field eel and other vertebrates including human, chicken, and other fishes, were more than 98%. RT-PCR showed expression of the rice field eel beta-actin in testis, ovotestis, ovary, heart, liver, spleen and brain,suggesting a ubiquitous expression pattern. Phylogenetic tree including all beta-actin cds of teleost fishes was constructed,which suggested consistently that teleost beta-actin can be classified into four types,but no fish has been found contains all the four types of beta-actin gene in its genome. The results that suggest lineage-specific beta-actin loss might happen in the radical evolution of teleost fishes.

The H9020-17-5,a common wheat-Psathyrostachys huashanica Keng translocation line, possesses excellent resistance to wheat stripe rust. Genetic analysis of F2 and BC1 populations derived from H9020-17-5 x Mingxian169 indicated that resistance to stripe rust in H9020-17-5 was a dominant character controlling by single gene originated from Ps. huashanica. This resistance gene originated from Ps. huashanica was first reported in the present study and named as YrHua. In order to map the resistance gene YrHua, AFLP approach was employed to analyze the 119 individuals of H9020-17-5 x Mingxian169 F2 population which were inoculated by stripe rust isolate CY30. As a result,two markers, PM14(301) and PM42(249) were found to be linked to the resistance gene YrHua,and the genetic distances between the markers and target gene were 5.4 cM and 2.7 cM, respectively. For the convenience of marker-assisted selection in wheat breeding, one of the two AFLP markers was converted to PCR marker using a pair of special primers based on the DNA sequence of PM14 (301) and the polymorphism of restriction site. Our research results provided a useful tool for marker-assisted selection and laid a foundation of fine mapping and map based cloning of YrHua gene.

An extensive association analysis of PON gene cluster (PONs) with coronary heart disease (CHD) was performed in Chinese Han population. Eleven polymorphisms of PON1, PON2 and PON3 gene were investigated for association with CHD in 474 male patients and 475 controls. Univariate analyses showed the cases had significantly higher frequencies of PON1 192Q allele, 160R allele, -162A allele and PON2 311C allele than were seen in the controls. Logistic regression analyses revealed only the PON1 R160G and -162G/A polymorphisms remained significantly associated with CHD (P = 0.0054 and P = 0.0002). Haplotype analyses for various polymorphism combinations further confirmed the results of individual polymorphism analyses. Only the frequencies of haplotypes containing -162A allele were significantly higher,whereas only the frequencies of haplotypes containing 160G allele significantly lower in cases than those in controls in various polymorphism combinations. This extensive association study has identified the PON1 -162G/A and R160G polymorphisms to be independently associated with CHD in Chinese Han population,and warrants further study to elucidate the biological mechanism.

Two F2 populations with different kinds of spike derived from maize male sterility materials RP(3)195 (A) x S37 (inbred line) ,which had been sib-bred for many generations,were used for sterility analysis and gene location. There were 138 and 247 plants in the two F2 populations respectively. Among the 326 pairs of microsatellite primers selected,56 were found polymorphic. Linkage analysis of F2 populations with the 56 pairs of primers showed that microsatellite markers bnlg197 and umc1012 were linked with the male sterility gene. The genetic distance between marker bnlgl97 and the male sterility gene in the two different F2 populations were 7 cM and 14.5 cM respectively. The genetic distance between marker umc1012 and the male sterility gene in the 138 plants was 28.5 cM. Thus the male sterility gene was located on chromosome 3L.

Abstract: Snake venom contains a number of small proteins,enzymes and other components,which displays a broad spectrum of biological activities. With the ability of specifically binding on acetylcholine acceptor, alpha-bungarotoxins are not only useful molecular probes in investigating the mechanism of neural signal transmission, but also potential pharmic preparations for neural disease treatment. In current research,cDNAs of Bungarus multicinutus venom gland were synthesized using SMART cDNA amplification kit and then, alpha-bungarotoxin genes were cloned and sequenced. Total of 20 clones were sequenced representing 14 isotoxin mRNAs of alpha-bungarotoxins. Among those clones, a novel isotoxin gene was subcloned into two expression plasmids, alpha-BgTX/pQE30a and alpha-BgTX/pGEX-4T-1, and transformed into E. coli. After inducing with IPTG, fused protein of GST-alpha-BgTX was successfully expressed at level of 30% gross proteins of bacteria. More than 25% of fused protein was in the soluble fraction and the rest in inclusion body.