Molecular genetic analysis of weak B blood group allele in Jinan population reveals distribution of ABw phenotype

The aim of this study was to investigate the distribution of the ABw phenotype of ABO blood group in the Jinan population. 31 856 samples were tested during the period 2018 to 2019. Thirty-nine samples with discrepant results, as identified by micro-column gel method, were further investigated by serological (tube technique) and molecular (fluorescence PCR, DNA sequencing) methods. Eight samples showed ABw phenotype, which accounted for 0.025% of the population tested. From the sequencing analysis, six samples (6/8) were typed as ABO*A1.02/ABO*BW.12 and two samples (2/8) as ABO*A1.02/ABO*BW.03. The study suggests that ABw12 account for 75% of ABw phenotype and indicate ABw12 is the main ABw phenotype in Jinan population.     

ABO-histo blood group incompatibility in hematopoietic stem cell and solid organ transplantation

The ABO gene is mainly composed of A, B, and O alleles. The most common O alleles share one nucleotide deletion of G at position 261 in the ABO gene. This report found a novel nonsense mutation in an ABO allele which led to group O in a Chinese individual. Forward and reverse typing tests were carried out first using the manual tube method. Weak expression of A or B antigens on red blood cells (RBCs) was confirmed by absorption and elution test. Exons 6 and 7 in the ABO gene were amplified and direct-sequenced. The haplotypes of the ABO gene were identified by clone-sequencing. Serologic results showed that the phenotype of proband was group O. Based on direct sequencing results, the proband was heterozygous for the ABO*A1.01 allele and ABO*O.01.01 allele, except for a heterozygous c.618C>G mutation. The clone sequencing demonstrated that a nonsense C>G mutation at position 618 was identified in exon 7 of the ABO*A1.01-like allele, which caused a p.Tyr206Ter exchange in the ABO glycosyltransferase. Thus, the novel ABO allele was classified as O allele. The study suggested that a novel nonsense mutation in the ABO gene was identified in a Chinese individual with group O, resulting in the truncated, 205-amino-acid ABO glycosyltransferase, which lost its transferase activity.     

GST, CYP and PON1 polymorphisms in farmers attributing ill health to organophosphate-containing sheep dip

Previously we reported that in sheep dippers exposed to organophosphates the frequency of paraoxonase (PON1) polymorphisms differed between those with or without self-reported ill health. We have now examined whether polymorphisms in other genes involved in xenobiotic metabolism alter disease risk in this population. There were elevated but non-significant risks associated with the CYP2D6 WT genotype (odds ratio (OR) 1.47, 95% CI 0.83-2.60), or a GSTP1*B or *C allele (OR 1.37, 95% CI 0.88-2.01) or being GSTM1*2/GSTT1*2 homozygous (OR 1.61, 95% CI 0.74-3.48). Similar results were generally obtained after the exclusion of subjects to obtain a more homogenous case-referent population: for double null GSTM1 and GSTT1 homozygotes the OR was 2.06 (95% CI 0.85-2.04). In those also likely to have been exposed to diazinon, risks associated with a GSTP1*B or *C allele (OR 1.82, 95% CI 0.92-3.63) or a GSTM1*2/GSTT1*2 homozygous (OR 2.60, 95% CI 0.72-10.42) were elevated but not to a significant extent. Risk associated with PON1 genotype and phenotype varied with CYP2D6 and GSTP1 genotype but not consistently with a priori hypotheses. Further work is necessary to delineate more clearly pathways of organophosphate activation and non-PON1 pathways of detoxification and to confirm whether CYP and GST polymorphisms alter disease risk in populations exposed to organophosphates.     

绿豆5个产量相关性状的QTL分析

利用绿豆(Vigna radiata)品种苏绿16-10和潍绿11杂交构建的F2和F3群体发掘调控绿豆产量相关性状的遗传位点。同时对绿豆产量相关性状进行表型鉴定和相关性分析,并利用构建的遗传连锁图谱进行QTL定位。结果表明,单株产量与单株荚数、单荚粒数、百粒重和分枝数均呈正相关。单株产量与单株荚数的相关性最高,这2个性状在F2和F3群体中的相关系数分别为0.950和0.914。在F2群体中,共检测到8个与产量性状相关的QTL位点,其中与单株荚数、单荚粒数和单株产量相关的QTL位点各1个,分别解释11.09%(qNPP3)、17.93%(qNSP3)和14.18%(qYP3)的表型变异;2个与分枝数相关的QTL位点qBMS3和qBMS11,分别解释18.51%和7.06%的表型变异;3个与百粒重相关的QTL位点qHSW3、qHSW7和qHSW10,分别解释5.33%、46.07%和4.24%的表型变异。在F3群体中,qNSP3和qHSW7再次被检测到,表明这2个QTLs有较好的遗传稳定性。同时,开发了1个与百粒重主效QTLqHSW7紧密连锁的InDel标记R7-13.4,并利用自然群体对...     

Benzo(a)pyrene diolepoxide adducts to albumin in workers exposed to polycyclic aromatic hydrocarbons: association with specific CYP1A1, GSTM1, GSTP1 and EHPX genotypes

We investigated whether the presence of (+)-anti-benzo(a)pyrene diolepoxide adducts to serum albumin (BPDE-SA) among workers exposed to benzo(a)pyrene (BaP) and unexposed reference controls was influenced by genetic polymorphisms of cytochrome P4501A1 (CYP1A1), microsomal epoxide hydrolase (EHPX), glutathione S-transferases M1 (GSTM1) and P1 (GSTP1), all involved in BaP metabolism. Exposed workers had significantly higher levels of adducts (0.124 ± 0.02 fmol BPTmg^-1 SA, mean ± SE) and a higher proportion of detectable adducts (40.3%) than controls (0.051 ± 0.01 fmol BPT mg^-1 SA; 16.1%) (p = 0:014 and p = 0:012). Smoking increased adduct levels only in occupationally exposed workers with the GSTM1 deletion (GSTM1 null) (p = 0:034).

Smokers from the exposed group had higher adduct levels when they were CYP1A1 *1/*1 wild-type rather than heterozygous and homozygous for the variant alleles (CYP1A1 *1/*2 plus *2/*2) (p = 0:01). The dependence of BPDE-SA adduct levels and frequency on the CYP1A1 *1/*1 genotype was most pronounced in GSTM1-deficient smokers. Exposed workers with GSTM1 null/GSTP1 variant alleles had fewer detectable adducts than those with the GSTM1 null/GSTP1*A wild-type allele, supporting for the first time the recent in vitro finding that GSTP1 variants may be more effective in the detoxification of BPDE than the wild-type allele. Logistic regression analysis indicated that occupational exposure, wild-type CYP1A1*1/*1 allele and the combination of GSTM1 null genotype+EHPX genotypes associated with predicted low enzyme activity were significant predictors of BPDE-SA adducts. Though our findings should be viewed with caution because of the relatively limited size of the population analysed, the interaction between these polymorphic enzymes and BPDE-SA adducts seems to be specific for high exposure and might have an impact on the quantitative risk estimates for exposure to polycyclic aromatic hydrocarbons.     

Study of molecular mechanism and antigen expression of CisAB01 blood group

The paper aims to analyze a rare blood sample in Ganzhou City Hospital with CisAB subtype and explore a feasible pattern for blood typing of rare blood type patients, so as to ensure clinical transfusion safety. The routine serological methods were used for ABO forward and reverse blood typing and the fluorescence real-time PCR technique was used for sample genotyping. A human ABO blood group 6-7 exon sequencing kit was used for sequence analysis. The nucleic acid sequence of the sample was compared with reference sequences. The forward typing results demonstrated that the sample was ABw, RhD positive. The sample exhibited 4+ agglutination with anti-H and anti-AB antibodies. Reverse typing by microcolumn gel method showed an AB result, but the serum sample demonstrated weak agglutination with B cell under room temperature, 4 °C and 37 °C in saline when tested with tube method respectively. The serological results matched with the A₂B₃ serotype. The fluorescent real-time PCR genotyping results displayed A/O01. The sequence analysis demonstrated deletion of guanine in 261-position 467C>T (heterozygote) and 803G>T (heterozygote) mutation respectively. The mutation caused the A glycosyltransferase peptide chain to change from proline to leucine (P156L) at 156 and from glutamate to alanine (G268A) at 268. The result demonstrated that the sample's genotype was CisAB01/O01. The mutation of glycosyltransferase coding gene leads to an abnormal serological reaction pattern. Only by combining the results of genetic analysis can we get the true sample blood type and better ensure the safety of clinical blood transfusion.     

紫茉莉开花过程中花色和花色素的变化规律

紫茉莉是我国广泛分布的庭院花卉之一,具有丰富的花色。但不同花色紫茉莉在开花过程中的花色变化规律及其呈色机制还不清楚。以紫红色、黄色和白色紫茉莉为研究对象,分别通过色差仪测定法和紫外-可见分光光度法测定了不同开花时期不同花色紫茉莉花色表型及各类色素含量,探讨了其花色和色素变化规律,揭示其呈色机制。结果表明,从花蕾期到盛开期,紫红色紫茉莉花冠由淡绿色转变为紫红色,明度L^*值和色相b^*值减小,而色相a^*值、色度C^*值和色度角h值增大,叶绿素含量逐渐下降,类胡萝卜素、花色素苷和总黄酮含量逐渐升高;黄色紫茉莉花冠由淡绿色转变为黄色,盛开期具有最高的色度C^*值、色相a^*值和b^*值,整个开花过程具有较稳定的叶绿素和总黄酮含量,同时具有较高的类胡萝卜素含量;白色紫茉莉花冠由淡绿色转变为白色,过渡期具有最高的明度L^*值、色度C^*值、色相a^*值和b^*值,整个开花过程花色素苷和总黄酮含量较低,但随着开花进程逐渐升高,而类胡萝卜素含量稳定,过渡期总叶绿素含量显著低于其他2个时期。可见,不同花色紫茉莉开花过程中花色变化规律存在差异,而其差异性与其相应的色素成分变化密切相关。     

Ideal phenotypes and mismatching haplotypes – errors of mtDNA treeing in ants (Hymenoptera: Formicidae) detected by standardized morphometry

A total of 401 nest samples of Formica lugubris Zetterstedt, F. pratensis Retzius, F. aquilonia Yarrow, F. rufa Linnaeus, and F. polyctena Förster, covering the entire Palaearctic range of these species and including 2100 individual workers, was phenotypically investigated by a system of standardized morphometry, pairwise removal of allometric variance, and canonical discriminant functions. A mitochondrial DNA fragment including the cytochrome b gene was sequenced in 148 samples from basically the same range. In the more difficult F. pratensis vs. F. lugubris case, the phenotypic system correctly determined 99.6% of all nest samples, and 95.1% with p<0.05. In all other pairwise species discriminations any nest sample was correctly determined with p<0.01, and three samples with hybrids F. rufa×lugubris were identified. At four localities in the Pyrenees and the Urals, 9 samples with F. pratensis phenotypes (7 of them ideal) but F. lugubris mtDNA haplotypes could be identified, resulting in 14.5% of phenotype/haplotype mismatches. A local dominance of this mismatch combination was observed at one Pyrenean and one Ural locality. There was no indication of an F. pratensis haplotype associated with an F. lugubris phenotype. One ideal F. polyctena phenotype was associated with an F. aquilonia haplotype in a sample from the Urals, and one ideal F. aquilonia phenotype was combined with an F. lugubris haplotype in a sample from central Siberia, resulting in overall phenotype/haplotype mismatch frequencies of 12.5% and 11.1%, respectively. We conclude that all these samples cannot represent actual F₁ hybrids but are the result of hybridizations in the past followed by unidirectional purging of the nuclear genome. Whether this process of purging worked very fast or over longer periods of population history, and whether or not it was complete or incomplete, cannot be assessed from the available information. These facts of hybridizing in two thirds of the W Palaearctic wood ant species, of extreme regional hybrid frequencies (up to 26%), of unidirectional purging of nDNA associated with mismatching mtDNA haplotypes, and of occasional achievement of local dominance of these mismatch combinations, may serve as urgent warning not to perform isolated mtDNA phylogenetic studies without a geographically and locally wide sampling basis and without control by nDNA information or reliable phenotypic determination. The latter two systems definitely have superior significance when conflicts with mtDNA indications arise.     

Does temperature preference relate to the anaerobic capacity of Atlantic cod (Gadus morhua L.) with different haemoglobin phenotype?

The effect of Hb-I* phenotype on white muscle lactate dehydrogenease (LDH, E. C. 1.1.1.27) activity and buffering capacity was studied in Atlantic cod (Gadus morhua), acclimated and measured at temperatures near their behavioral temperature preference. It was hypothesized that these conditions would optimize biochemical processes but no difference was found in LDH activity between the Hb-I* phenotype after 56 d of acclimation to 6 and 14°C. However, LDH activity was both mass- and temperature-dependent; mean activity was 162.2±5.0 and 275.9±6.4 IU g^-1 wet mass (mean±SEM) at 6 and 14°C respectively and larger fish had the highest rate of enzyme activity. White muscle buffer capacity was unaffected by Hb-I* phenotype but higher in cod held at 14°C.     

Chiral phase analysis of warfarin enantiomers in patient plasma in relation to CYP2C9 genotype

A direct chiral-phase high-performance liquid chromatographic method for measuring the ratio of S-warfarin/R-warfarin in patient plasma is described. Plasma samples are first extracted using solid-phase C₁₈ extraction columns, and the concentrated extracts analyzed using an (R,R) Whelk-O 1 column with a mobile phase of 0.5% glacial acetic acid in acetonitrile. The resulting chromatography provides baseline resolution of the warfarin enantiomers and internal standard (racemic ethylwarfarin), and is free from interference from other plasma components. Calibration curves were linear (mean r² of 0.999 for both enantiomers) over the concentration range 0.25–1.5 μg/ml. The intra-day and inter-day coefficients of variation for analysis of plasma spiked with 0.33 μg/ml S-warfarin and 0.67 μg/ml R-warfarin (S/R=0.5:1) was less than 7% for each enantiomer, with an accuracy of more than 93%. Plasma extracts from thirty-one patients homozygous for wild-type CYP2C9*1 provided an S/R ratio of 0.51±0.15. Two warfarin patients homozygous for the mutant CYP2C9*2 and CYP2C9*3 alleles exhibited elevated S/R ratios relative to the mean for individuals homozygous for the wild-type CYP2C9*1 allele. This method is suitable for population studies aimed at establishing the effect of polymorphic expression of CYP2C9 alleles on S-warfarin elimination in humans.     

灵芝液态深层发酵产物中10种不饱和脂肪酸类化合物的鉴定

通过规模化液态深层发酵获得灵芝发酵产物,采用多种硅胶色谱柱层析及重结晶的方式,从中分离得到10个化合物.通过核磁、质谱等波谱分析,鉴定出这些化合物均属于含羟基或酮基的不饱和脂肪酸类化合物,分别为(9S,10R,11E,13R)-9,10,13-trihydroxyoctadec-11-enoic acid(1)和(9S...     

3株多环芳烃高效降解菌株的分离鉴定及降解特性

筛选分离降解多环芳烃(PAHs)的优势菌种对开展多环芳烃污染生态系统修复具有重要的现实意义。本研究以焦化厂周围受多环芳烃污染的土壤为菌源,经过富集培养驯化和平板分离,获得11株能降解多环芳烃的菌株。通过形态观察、生理生化特征及16S rRNA序列比对对菌株进行鉴定,筛选出3株PAHs高效降解菌,分别命名为DJ-3、DJ-8、DJ-10。经16S rRNA序列分析鉴定,DJ-3为假单胞菌属、DJ-8为克雷伯氏菌属、DJ-10为芽孢杆菌属。对菌株降解能力的研究表明,3株菌(DJ-3、DJ-8、DJ-10)培养7 d后对混合多环芳烃中菲(200 mg·L^-1)、芘(200 mg·L^-1)和萘(160 mg·L^-1)的降解率分别为48.9%～65.9%、38.9%～43.1%和57.6%～64.9%。3株菌对多环芳烃混合样品(1200 mg·L^-1)的降解率分别为49.1%、44.5%、53.9%,远高于其他8株筛选菌,为PAHs高效降解菌株。3种菌株两两之间和三者组合均无拮抗关系。研究结果将为构建高效的多环芳烃降解菌群、提高多环芳烃原位污染土壤的生物修复效果奠定基础。     

楸树不同单株花性状变异分析

楸树是我国中部地区重要的珍贵阔叶用材和著名的园林观赏树种,已有2 600多年的栽培历史。研究其花性状多样性与变异性旨在揭示花表型性状在楸树种内存在的巨大变异,为新花色育种和优良观花新品种的选育及新品种的鉴定和保护提供理论依据。以1985~1990年收集的优良单株和杂种F1共27株为材料,测定了花性状中的2个质量性状和7个数量性状,并采用方差分析、聚类分析等方法进行统计分析。①27株的开花物候期差异可达5 d,花大小、花序长短和单株花量均有较大差异,并且由于叶柄长度和花枝长度的差异导致不同单株表现出显花和隐花特征。②楸树为二强雄蕊,分为雄性可育和败育,调查的27株中有12株为雄性可育,且花粉量差异较大。③花冠檐部5裂,上唇3瓣,下唇2瓣,上唇瓣长度大于下唇瓣。27株的花枝长度、花序长度、单花枝花数、花上唇瓣长度、花下唇瓣长度和花冠直径均存在极显著差异,单株间的变幅分别为10.7~16.4 cm、5.6~9.6cm、2~13朵、3.8~5.2 cm、3.0~4.3 cm、3.9~5.4 cm,表型变异系数分别为12.8%、12.5%、36.7%、7.5%、9.1%和9.2%。④16株间花色L^*值(亮度值)、a^*值(红绿值)、b^*值(黄蓝值)、C^*值(彩度)和h值(色相)均存在极显著差异,a^*值、b^*值以及彩度C^*值的表型变异系数分别为35.1%、52.5%和29.8%;以L^*、a^*和b^*值度量花色,通过聚类分析将16株聚为3类,红色系、粉红色系和白色系。楸树27株的花枝长度、花序长度、花大小差异极显著,16株的花色也具有明显的差别,依据L^*、a^*和b^*值进行聚类分析,当欧氏距离为15时可将16株聚为3类:红色系、粉红色系和白色系。     

BW1023U90: A new GRP receptor antagonist for small-cell lung cancer cells

Gastrin-releasing peptide (GRP) receptor antagonists were synthesized and their ability to interact with small-cell lung cancer (SCLC) cells determined. [¹²⁵I]BW1023U90, bound with high affinity (K_d = 2 nM) to a single class of sites (Bmax = 55 fmol/mg protein) using SCLC cell line NCI-H345. [¹²⁵I]BW1023U90 binding was time dependent and reversible even at 37°C as the ligand was minimally internalized. Specific [¹²⁵I]BW1023U90 binding was inhibited with high affinity by GRP as well as bombesin (BB) but not neuromedin B (NMB). BW1023U90 inhibited the ability of BB to elevate cytosolic Ca²⁺ and increase the growth of SCLC cells. A BW1023U90 analogue, BW2258U89 (10 μg/day, SC) slowed SCLC xenograft formation in nude mice and [¹²⁵I]BW1023U90 localized to SCLC tumors 1 h after injection into nude mice. BW2258U89 (4% by weight) was placed in microspheres and slowly released over a 3-week period in nude mice bearing SCLC xenografts. The microspheres containing BW2258U89 strongly inhibited SCLC growth in vivo. A radioimmunoassay was developed for the GRP receptor antagonists and the rabbit antiserum cross-reacted totally with BW2258U89 or BW1023U90. BW2258U89 immunoreactivity (5 nM) was detected in the plasma of nude mice containing the microspheres after 1 week. These data suggest that GRP receptor antagonists bind to receptors on SCLC tumors.     

不同栖息环境的两种啮齿动物Vkorc1基因多态性

维生素K环氧化物还原酶复合物亚基1基因(Vkorc1)的变异与啮齿动物对抗凝血灭鼠剂的抗药性密切相关。为掌握Vkorc1基因变异在野栖类和家栖类啮齿动物中的流行情况,从山西省13个县(市、区)的农田和14个县(市、区)的养殖场采样,检测长尾仓鼠(Cricetulus longicaudatus)和黄胸鼠(Rattus tanezumi) Vkorc1基因编码区的变异位点及携带不同变异位点的个体的分布情况。结果显示,长尾仓鼠在13个采样地均有捕获,整体占野栖类啮齿动物的23.29%;黄胸鼠分布于8个采样地,整体占家栖类啮齿动物的68.63%。在长尾仓鼠样本(n=105)中检测到6个沉默突变位点和5个错义突变位点,其中,沉默突变C438T (His146His)的变异率最高,为67.62%;共有17只长尾仓鼠样本存在错义突变位点。黄胸鼠样本(n=70)中存在6个沉默突变位点和1个错义突变位点,其中,最常见的沉默突变位点A321C (Ile107Ile)和T411C (Thr137Thr)的变异率均达到18.57%;8只黄胸鼠样本存在与其抗药性相关的A416G (Tyr139Cys)错义突变...     

Effects of metabolic genotypes on intermediary biomarkers in subjects exposed to PAHS: results from the EXPAH study

Data from the EXPAH project on PAH exposure and intermediary biomarkers were analyzed with respect to individual genotypes at seven metabolic gene loci. The GSTM1 null allele was associated with significantly higher levels of two biomarkers, malondialdehyde-2′-deoxyguanosine and benzo[a]pyrene DNA adducts in the total population from three Central and Eastern European countries. The CYP1B1 Leu/Val variant demonstrated effects on both markers of oxidative DNA damage in opposite directions, producing a higher level of M₁dG with a trend from wild type (Leu/Leu) to heterozygotes to homozygous (Val/Val) variants, whereas the effects of these variants were reversed for 8-oxodG. Cluster Analysis was used to group composite genotypes in order to determine if combined genotypes of multiple loci could explain some of the variation seen with the biomarkers, expressed per unit of exposure, referred to as a sensitivity index. This analysis revealed two closely related genotypes each involving four of the loci (GSTM1*0/*0, CYP1A1*1*1, CYP1B1*1/*2, GSTP1*1/*1 and GSTT1*0/*0, CYP1A1*1*1, CYP1B1*1/*2, GSTP1*1/*1.) that conferred significant resistance to the DNA damaging effects of benzo[a]pyrene, measured as the level of a benzo[a]pyrene-like adduct per unit of benzo[a]pyrene exposed.     

The use of an improved transposon mutagenesis system for DNA sequencing leads to the characterization of a new insertion sequence of Streptomyces lividans 66

A DNA sequencing strategy was developed based on the tetracycline resistance transposon Tn1721. A universal M13 primer binding site (UP) for DNA sequencing and restriction sites for mapping were inserted near one end of Tn1721 and the new derivative, Tn5491, introduced onto a conjugative F' plasmid. The target sequence is inserted between two inverted resolution sites (res) of Tn1721 present on the high-copy plasmid pJOE2114. Due to the inviability of long palindromic sequences in Escherichia coli insertions between the inversely orientated res sites of pJOE2114 are positively selected. Transposition of Tn5491 into the target sequence is selected by cointegrate formation of Tn5491 during transposition, mating and transfer of the nonconjugative sequencing vector. After cointegrate resolution, the additional res sites in the vector result in a second site-specific recombination removing most of the transposon (except of 136 bp) and part of the target sequence. The reduced plasmid sizes and the use of the universal primer improved the quality of the sequencing results obtained on an automated fluorescent sequencer. A 3.35-kb EcoRI fragment from the 30-kb terminal inverted repeats (TIR) of the Streptomyces lividans chromosome was sequenced by this method. A 1304-bp sequence was found on this fragment with the features of insertion elements. The element called IS1372 had 27-bp IR and two potential open reading frames. The predicted gene products had similar sizes and high similarity to gene products encoded by insertion sequences of the IS3 family. Furthermore, a potential signal stimulating ribosomal shifts and typical for members of the IS3 family was identified. Five to seven copies of IS1372 were found in different strains of S. lividans but none in other Streptomyces species tested     

Video enhanced imaging of the fluorescent Na+ probe SBFI indicates that colonic crypts absorb fluid by generating a hypertonic interstitial fluid

We report a rare ‘hypomorphic’ C4 allotype detected during routine screening in controls for the Rogers:1 epitope. C4B^*15 was distinguished by having only faint staining when using polyclonal anti-C4 antibody on agarose inimunoelectrophoresis (e.g. hypomorphic), having relatively weak hemolytic activity but being strongly reactive with monoclonal antibody to Rodgers 1. TaqI restriction fragment length polymorphism (RFLP) demonstrated that C4B^* 15 segregated with 7 kb and 5.4 kb C4 gene fragments and with the haplotype HLA-A2,C-, B50,BW6,DR7,DQ2,DR52,S07C2(1,15). The 5.4-kb fragment was more intense than the 7.0-kb fragment, suggesting duplication of the 5.4-kb fragment. This hypomorphic C4 allotype (genotype FREQUENCY = 0.0088) has diminished expression of C4 epitopes commonly recognized by polyclonal anti-C4 and may be missed by standard phenotyping methods.     

不同氧浓度下C2C12细胞的Nrf2抗氧化系统对H2O2刺激的反应*

目的:探讨不同氧浓度下小鼠骨骼肌卫星细胞系(C2C12细胞)对H₂O₂刺激反应的变化及其机制。方法:小鼠骨骼肌卫星细胞系(C2C12细胞),经培养复苏后,将细胞分为7组,每组设8个复孔,各组分别加入浓度为0.1 mmol/L、0.25 mmol/L、0.5 mmol/L、0.75 mmol/L、1 mmol/L、2 mmol/L的H₂O₂,分别作用1 h、2 h后测细胞活力,选择细胞H₂O₂刺激的最佳作用时间和浓度;C2C12细胞分为不同氧浓度组:21% O₂、12% O₂、8% O₂、5% O₂每组设8个复孔,12 h后,H₂O₂作用1 h,收集细胞;检测细胞Nrf2蛋白荧光和蛋白表达量,测定Nrf2和抗氧化酶SOD1、SOD2、CAT、NQO-1、HO-1、GPX-1 的mRNA表达量及细胞ROS水平。结果:选择H₂O₂作用时间相对较短的1 h和浓度0.5 mmol/L作为本实验的H₂O₂刺激条件。与21%O₂组相比,12%O₂组细胞Nrf2蛋白荧光增强,Nrf2 的mRNA和蛋白表达以及抗氧化酶SOD1、SOD2、CAT、NQO-1、HO-1、GPX-1的 mRNA表达均显著增加(P＜0.05或P＜0.01),细胞 ROS水平明显降低(P＜0.01);8%O₂组仅GPX-1 mRNA显著增加(P＜0.05),其他指标变化不大;5%O₂组细胞 Nrf2 mRNA和蛋白表达以及抗氧化酶SOD1、SOD2、NQO-1、GPX-1的 mRNA表达均明显降低(P＜0.05或P＜0.01),细胞 ROS水平则明显升高(P＜0.01)。结论:不同氧浓度下C2C12细胞中Nrf2介导的抗氧化系统对H₂O₂刺激反应不同,12 h的12% O₂浓度可促进C2C12细胞Nrf2的抗氧化作用,而5% O₂浓度的严重低氧则作用相反。     

水稻抽穗期QTL定位及候选基因分析

水稻(Oryza sativa)抽穗期是决定产量和品质的重要性状,在育种、制种及引种驯化过程中发挥重要作用。将热研2号(O. sativa subsp. japonica cv.‘Nekken2’)和华占(O. sativa subsp. indica cv.‘HZ’)杂交获得F₁代,经连续多代自交得到120个重组自交系(RILs)群体。在常规水肥管理条件下,对120个RILs株系的抽穗时间进行统计分析。利用已构建好的高密度遗传图谱,对水稻抽穗期相关性状进行QTL定位分析,结果共检测到11个QTLs,分别位于第1、3、4、5、6、8和12号染色体上,其中1个LOD值高达5.75。通过分析QTLs区间内的候选基因,筛选出可能影响两亲本抽穗期的相关基因,并利用实时定量PCR进行基因表达量分析,发现LOC＿Os03g03070、LOC＿Os03g50310、LOC＿Os03g55389、LOC＿Os04g55510、LOC＿Os08g07740和LOC＿Os08g01670共6个基因在双亲间的表达量差异显著,其中LOC＿Os03g50310在Nekken2中的表达量比H...