Peroxiredoxin Ⅰ和Ⅱ在小鼠输卵管和子宫的分布与表达

目的:观察PeroxiredoxinⅠ和Ⅱ(PrxⅠ和Ⅱ)在小鼠输卵管和子宫的分布及其周期性变化。方法:免疫组织化学和蛋白免疫印迹技术。结果:在输卵管中,PrxⅠ和Ⅱ免疫阳性反应见于输卵管上皮;而子宫内,PrxⅠ免疫阳性反应分布于内膜上皮、腺体上皮和内膜基质,而PrxⅡ主要见于内膜基质。蛋白免疫印迹技术也显示这两型蛋白在输卵管和子宫均表达,动情期和动情间期这两型蛋白在输卵管和子宫中的表达水平无显著性差异。结论:提示PrxⅠ与Ⅱ在输卵管和子宫中表达稳定,可能为受精和早期胚胎发育提供抗氧化的良好微环境。

靶向PeroxiredoxinⅠ基因的shRNA真核表达载体的构建及生物学功能鉴定

目的构建针对PeroxiredoxinⅠ(PrxⅠ)基因的短发夹RNA(short hairpin RNA,shRNA)真核表达载体,观察下调PrxⅠ基因表达后对乳腺癌MCF-7细胞生物学功能的影响。方法构建针对PrxⅠ基因的shRNA真核表达载体,经酶切和测序鉴定正确后,转染入乳腺癌MCF-7细胞。流式细胞术检测细胞转染效率,RT-PCR及Western blot分别检测干扰前后PrxⅠmRNA和蛋白表达,MTT法及流式细胞术检测干扰前后乳腺癌MCF-7细胞体外的增殖情况及细胞周期和细胞凋亡。结果成功构建真核表达载体pGPU6-HK、pGPU6-Prx1、pGPU6-Prx2、pGPU6-Prx3、pGPU6-Prx4,并转染入乳腺癌MCF-7细胞中,转染率为80%左右,RT-PCR及Westernblot分析表明转染pGPU6-Prx1、pGPU6-Prx2、pGPU6-Prx3、pG-PU6-Prx4后的细胞EGFR mRNA和蛋白表达均不同程度地受抑,以pGPU6-Prx3为甚,其mRNA和蛋白表达抑制率分别为82.6%和80.5%。与未转染组和pGPU6-HK组相比,pGPU6-Prx3组的细胞生长明显延迟(P<0.05),细胞凋亡率显著增加,G1期细胞明显增多,而S期细胞减少(P<0.05)。结论靶向PrxⅠ基因的shRNA真核表达载体构建成功,能够特异性下调乳腺癌MCF-7细胞的PrxⅠ基因的表达,并明显抑制乳腺癌细胞增殖,促进细胞凋亡,调控细胞周期再分布。

沉默PeroxiredoxinⅠ基因对乳腺癌裸鼠移植瘤放射敏感性的影响

目的探讨PeroxiredoxinⅠ(PrxⅠ)沉默后对乳腺癌裸鼠移植瘤放射敏感性的影响及其作用机制。方法将稳定表达PrxⅠshRNA的pGPU6-PrxⅠ和阴性对照pGPU6-HK细胞接种于裸鼠皮下,建立乳腺癌裸鼠移植瘤模型。实验共分为4组:pGPU6-HK组、pGPU6-PrxⅠ组、pGPU6-HK+照射(ionizing radiation,IR)组、pGPU6-PrxⅠ+IR组。用6MVX线照射裸鼠瘤组织,测量肿瘤体积,称取肿瘤质量,计算抑瘤率;免疫组化检测肿瘤组织中PrxⅠ和Caspase3蛋白表达;电镜观察肿瘤细胞超微结构,Western blot测定肿瘤组织中γ-H2AX和Rad51蛋白表达。结果成功构建了裸鼠移植瘤模型,pGPU6-PrxⅠ+IR组裸鼠移植瘤生长肿瘤明显迟缓,体积较小,抑瘤率为79.76%,与pGPU6-PrxⅠ(34.92%)和pGPU6-HK+IR(56.94%)比较差异具有显著性(P<0.05);给予pGPU6-PrxⅠ及IR处理后,肿瘤细胞凋亡和坏死增多,PrxⅠ和Rad51蛋白表达减少,而Caspase3和γ-H2AX蛋白表达增加,以pGPU6-PrxⅠ+IR组更为显著,其Rad51蛋白下降了84.8%,γ-H2AX蛋白表达升高5.6倍(P<0.05)。结论沉默PrxⅠ表达可提高乳腺癌移植瘤的放射敏感性,其作用机制与DNA双链断裂增加、DNA损伤后修复能力降低有关。PrxⅠ可能是一个理想的乳腺癌放射增敏分子靶点。

沉默PeroxiredoxinⅠ基因增强乳腺癌细胞放射敏感性及其作用机制的实验研究

目的采用RNA干扰技术沉默过氧化物酶Ⅰ(peroxiredoxinⅠ,PrxⅠ)基因,观察乳腺癌MCF-7细胞对X线敏感性变化,探讨其作用机制。方法将PrxⅠshRNA真核表达载体pGPU6-PrxⅠ和阴性对照质粒pGPU6-HK转染入乳腺癌MCF-7细胞中,经G418稳定筛选后RT-PCR和Western blot检测PrxⅠ表达变化。6 MV X线照射6 Gy后48 h,流式细胞术检测细胞的活性氧水平、细胞周期和细胞凋亡;MTT法测定细胞增殖能力;克隆形成实验观察克隆形成率,计算Do、N、Dq、SF2及放射增敏比(sensitive enhancement ratio,SER)等放射生物学参数,Western blot法检测Rad51及γ-H2AX蛋白变化。结果获得2个稳定转染细胞株:pGPU6-HK和pGPU6-PrxⅠ。RT-PCR和Western bolt检测显示pGPU6-PrxⅠ组中PrxⅠmRNA和蛋白表达均明显抑制。6 Gy的X线照射48 h后,pGPU6-PrxⅠ及联合照射(ionizing radiation,IR)组细胞中的活性氧水平、G1期细胞和细胞凋亡明显增加,而细胞增殖能力和S期细胞明显降低,Western blot分析表明Rad51蛋白表达降低,而γ-H2AX蛋白表达升高(P<0.05),以pGPU6-PrxⅠ+IR组变化最显著,其Rad51蛋白表达下降了79.3%,而γ-H2AX蛋白表达升高了3.7倍。pGPU6-PrxⅠ组细胞的Do、N、Dq和SF2值分别为1.354、3.106、1.547和0.504,均低于pG-PU6-HK组,SF2时的SER为1.353。结论下调PrxⅠ基因表达可提高乳腺癌MCF-7细胞的放射敏感性,其作用机制与细胞内活性氧清除能力减弱、DNA双链断裂增加及DNA损伤后修复能力降低有关。PrxⅠ可能是1个理想的肿瘤放射增敏分子靶点。

Phylogeny of Apaturinae Butterflies (Lepidoptera: Nymphalidae) Based on Mitochondrial Cytochrome OxidaseⅠ Gene

The phylogenetic relationships of genera in the subfamily Apaturinae were examined using mtDNA sequence data from 1,471 bp of cytochrome oxidase subunit Ⅰ （COI）. The mitochondrial COI gene from a total of 16 species in 11 genera were sequenced to obtain mtDNA data, along with those of 4 species obtained from GenBank, to construct the MP and the NJ trees using Athyma jina, Penthema adelma, Polyura nepenthes, and Charaxes bernardus as outgroups. The transitions at the third codon positions of the COI data set were found saturated, but they were retained for analysis, because they contain the majority of the phylogenetic information. The impacts of equal weight assumptions for all characters in the parsimonious analysis were assessed by potential alternations in clades in response to different transition/transversion weighting schemes. The results indicated four distinct major groups in Apaturinae. Moreover, several well supported and stable clades were found in the Apaturinae. The study also identified undetermined taxon groups whose positions were weakly supported and were subject to changes under different weighting schemes. Within the Apaturinae, the clustering results are approximately identical to the classical morphological classification. The mtDNA data suggest the genus Mimathyma as a monophyletic group. Lelecella limenitoides and Dilipa fenestra have close relationship with very strong support in all phylogenetic trees. It also supports the taxonomic revision of removing several species from Apatura to other genera, namely Mimathyma schrenckii, M. chevana, M. nycteis, Chitoria subcaerulea, C. fasciola, C. pallas, and Helcyra subalba.

人源抗PeroxiredoxinⅠ肺腺癌噬菌体抗体的制备及鉴定

目的构建人源噬菌体抗体库,从中筛选出抗PeroxiredoxinⅠ(PrxⅠ)肺腺癌人源单链抗体。方法提取肺癌患者癌旁淋巴结组织,通过RT-PCR扩增出重链可变区基因(VH)和轻链可变区基因(VL),再经剪切-重叠-延伸PCR(SOE-PCR)将VH和VL连接得到单链抗体(ScFv);将双酶切后的ScFv基因片段克隆入噬菌体表达载体pCANTAB5E,得到初级噬菌体抗体库。PCR检测TG1中ScFv基因插入率;1%琼脂糖凝胶电泳鉴定SfiI和NotI双酶切质粒的结果;以肺腺癌细胞株D549及在肺癌中高表达的抗氧化蛋白PrxI为靶抗原对抗体库进行筛选富集。将阳性克隆用IPTG诱导表达。用SDS-PAGE及Westernblotting鉴定该抗体;用ELISA法、免疫细胞化学法鉴定该抗体与人肺腺癌细胞的结合特异性。结果成功构建噬菌体单链抗体库。ScFv基因插入率为77%,双酶切鉴定检测到目的条带。在亲和筛选过程中,肺癌单链抗体得到富集,收获率逐轮提高,第6轮为第1轮的180倍。随机选取10个克隆,通过ELISA法检测到其中6个与A549细胞呈阳性反应,阳性率为60%。SDS-PAGE及Westernblotting证实抗体得到可溶表达。ELISA及免疫细胞化学检测表明抗体能相对特异地与肺腺癌细胞结合。结论成功构建肺腺癌人源噬菌体抗体库,并从中筛选得到能相对特异地与高表达PrxI的肺腺癌细胞D549结合的单链抗体。

采用RNAi技术抑制PeroxiredoxinⅠ的表达

Peroxiredoxin Ⅰ(PrxⅠ) is involved in many important cellular progresses such as cell proliferation and differentiation. To further elucidate its roles in ionizing radiation, eukaryotic expression vector containing siRNA targeting mRNA of peroxiredoxin 1 gene was constructed and transected into NIH3T3 cell line following sequencing.Western blot analysis showed that this siRNA significantly inhibited PrxⅠ expression by 65% at protein level; cell proliferation experiment demonstrated that the double proliferation time of NIH 3T3PrxⅠ cells was postponed for 1.8 hours as compared with control group. MTT results showed that 12 and 48 hours after irradiation the survival rate of NIH 3T3PrxⅠ was dramatically decreased when comparing with sham-irradiated group.These results suggested that peroxiredoxin 1 has radiation-cytoprotection role.

Development and Clinical Application of a Single-tube Nested PCR Method to Amplify the DNA Polymerase Ⅰ Gene of Treponema Pallidum

Objective: To develop a sensitive, specific and simple method for detection of extremely low numbers of T. pallidum in clinical specimens, as a significant addition to the serologic tests for syphilis diagnosis. Methods: Double-tube nested PCR(DN-PCR) and single-tube nested PCR(SN-PCR) assays were performed to amplify specific fragments of the DNA poly-merase I gene(polA) of T. pallidum. Sensitivity and specificity of the two PCR assays were tested. Eighty-six whole blood specimens from persons with suspected syphilis were detected by the two nested PCR methods. The TPPA test was used as a comparison for detecting syphilis in sera from corresponding patients. Results: Only specific amplicons could be obtained during amplification of the T. pallidum polA gene and the detection limit was approximately 1 organism when analyzed on gel by the two PCR methods. Of 86 clinical specimens, 62 were positive by TPPA. Of these, 54 and 51 were positive by the DN-PCR and SN-PCR, respectively, which does not represent a statistically significant difference between the two PCR tests. Of 24 TPPA-negative specimens, 5 were positive by both DN-PCR assay and SN-PCR assay. Conclusion: The SN- polA PCR method is extremely sensitive, specific and easy to perform for detecting low numbers of T. pallidum in clinical blood specimens as a complementary to serology for syphilis diagnosis.

腺病毒介导的RNAi技术抑制Peroxiredoxin Ⅰ的表达

目的:为深入研究PeroxiredoxinⅠ(Prx-Ⅰ)基因与肿瘤细胞放射敏感性的关系,构建基于腺病毒的抑制Prx-Ⅰ基因表达的RNAi载体。方法:从质粒载体pAVU6-Prx切下包含U6启动子在内的表达盒,连接到腺病毒穿梭载体pAdTrack,然后在大肠杆菌中重组为完整腺病毒DNA,并将其转染293包装细胞制备腺病毒颗粒,再利用腺病毒感染目的肿瘤细胞,干扰其Prx-I基因的表达。结果:成功地将U6表达盒连接到穿梭载体,获得重组的腺病毒DNA,并制备出高滴度病毒。将病毒感染肿瘤细胞SW480以后可以明显抑制Prx-Ⅰ基因的表达,并使细胞受辐射后的细胞凋亡比例增大。结论:基于腺病毒的RNAi干扰是有效的,这为进一步在体内探讨肿瘤放疗增敏机制奠定了基础。

抗PeroxiredoxinⅠ肺腺癌噬菌体抗体的筛选及其在荷瘤裸鼠体内的分布

目的:通过对已构建的肺腺癌相关人源单链抗体库进行筛选,得到抗过氧化物酶PeroxiredoxinⅠ(PrxⅠ)肺腺癌单链抗体,评价抗体在动物模型体内分布及靶向显像作用。方法:PCR法检测大肠杆菌TG1中单链抗体single-chain variable fragment(scFv)基因插入率;凝胶电泳鉴定SfiⅠ和NotⅠ双酶切质粒结果;以肺腺癌细胞株A549和在肺癌中高表达的抗氧化蛋白PrxⅠ为靶抗原,对抗体库进行富集筛选。阳性克隆用IPTG诱导表达并检测。放射性核素131I标记纯化抗体,进行荷瘤裸鼠体内分布及SPECT放射免疫显像研究。结果:scFv基因插入率为77%(23/30),双酶切鉴定证实目的条带。通过亲和筛选,肺腺癌单链抗体得到富集,收获率逐轮提高,第6轮是第1轮的180倍。选取10个克隆经ELISA法检测,其中6个克隆与A549细胞呈阳性反应,阳性率60%(6/10)。SDS-PAGE及ELISA检测证实得到人源抗PrxⅠ肺腺癌单链抗体。竞争ELISA显示抗体能有效结合A549细胞。核素标记抗体的放射化学纯度为(95.6±3.7)%,比活度为(2.8±0.2)TBq·g-1。体内分布研究显示抗体与肺腺癌组织有效结合。尾静脉注射48h后,瘤/血和瘤/肌肉放射性比值均达最大值,分别为(4.06±0.13)和(5.17±0.97)%ID·g-1。SPECT示抗体与肿瘤有效结合。抗体注射后48h的T/NT值(3.73±0.20)明显高于12h(1.26±0.15)、24h(2.18±0.16)和72h(2.85±0.18)(均P<0.01)。结论:利用肺腺癌细胞A549和PrxⅠ为靶抗原,从噬菌体抗体库中筛选获得具有较高特异性的抗PrxⅠ肺腺癌单链抗体。在体内抗体能与肺腺癌组织特异性结合。

细胞外信号调节激酶1/2通路在Peroxiredoxin-1抑制转化生长因子-β_1诱导的Ⅰ、Ⅲ型胶原蛋白表达中的作用

目的探讨细胞外信号调节激酶1/2(ERK1/2)在转化生长因子-β1(TGF-β1)诱导的肺成纤维细胞合成Ⅰ、Ⅲ型胶原蛋白中的作用,及新型过氧化物酶Peroxiredoxin-1(Prx-1)对该作用的影响。方法体外培养肺成纤维细胞随机分为4组:对照组(0.4%血清)、TGF-β1组(5μg/L)、阴性转染组(TGF-β1+阴性对照si RNA)和Prx-1 si RNA转染组(TGF-β1+Prx-1 si RNA)。采用脂质体转染法转染si RNA,实时定量逆转录-聚合酶链反应(RT-PCR)检测转染后Prx-1 m RNA表达;Western blot检测Ⅰ和Ⅲ型胶原蛋白、ERK1/2及Prx-1表达;2,7-二氯荧光素二乙酸(DCFH-DA)检测活性氧(ROS)水平。结果 Prx-1 si RNA转染肺成纤维细胞后,Prx-1 m RNA表达明显降低,最大抑制率为92%。与对照组比较,TGF-β1组的Ⅰ和Ⅲ型胶原蛋白、ROS、磷酸化ERK1/2(p-ERK1/2)及Prx-1蛋白的表达水平均明显提高。与TGF-β1组比较,阴性转染组中的上述观察指标无明显变化,但Prx-1转染组的Ⅰ和Ⅲ型胶原蛋白、ROS、p-ERK1/2水平进一步提高,而Prx-1蛋白的表达被抑制。结论 TGF-β1能够诱导肺成纤维细胞生成ROS,并促进ERK1/2通路的激活,导致Ⅰ、Ⅲ型胶原蛋白合成增加,而Prx-1 si RNA可通过提高ROS水平进一步促进TGF-β1该作用。

Analysis of Rb gene Xba Ⅰ polymorphism in Shaanxi aged atherosclerosis population

Objective:To investigate variable number tandem repeat (VNTR) polymorphism of the 17th intron of Rb gene in Shaanxi aged population and the relationship between the polymorphism of Rb gene and atherosclerosis(AS) genetic suscepti- bility. Methods: VNTR polymorphism of the 17th intron of Rb gene were examined in 100 Shaanxi aged AS patients and 100 Shaanxi aged control individuals by PCR-Rb-Xba Ⅰ-RFLP. Results::Two alleles were found both in AS group and control group, which were separately 945 bp(S1) and 630bp + 315bp(S2). S1S2 genotype was the most frequent one in the two populations. Significant difference in allele frequency was not found between AS group and control group, and allele frequency was no significant difference between Chinese and Caucasian. Conclusion: Xba Ⅰ enzyme site of Rb gene could have been certainly stable in AS population, and it was inferred that the polymorphism locus was not liable to cause mutation, which might not implicated in the formation of AS.

The gene diagnosis and mutation survey of autosomal dominant polycystic kidney disease Ⅰ

Objective: To explore gene diagnosis of autosomal dominant polycystic kidney disease (ADPKD Ⅰ ),and to look for the typical mutation in order to improve the gene diagnosis. Metbods: southern blot and PCR wasused to observe the mutation condition of 3' end single copy region of ADPKD Ⅰ gene ; Amplifying and analyzingthe microsatellite SM7 by PCR. Results: ①After the probe AH4 was hybridized with 16 patients' genomic DNAby Southern blot, the common 15 kb fragments were found in every one; ②For 27 patients, 5. 72 kb genomicDNA, which is between the probe AH4 and JH14, was amplified by PCR, and no 5. 5 kb genomic DNA deletionwas found in this region; SM7 was amplified in lO9 health persons, its PIC was 0.76, and was closely linked towith ADPKD Ⅰ gene in three patient families. Conclusion: In Han nation, ①No large genomic DNA segmentdeletion could be found frequently in ADPKD Ⅰ gene 3' end single copy region; ②The PIC of SM7 is high, it canbe used to make rapid gene diagnosis in about 70% ~80% ADPKD Ⅰ families.

Establishment of a Real-time Fluorescent Quantitative RTPCR Method for Detecting NP Gene of Class Ⅰ Newcastle Disease Virus(NDV)

Newcastle disease( ND) is one of the most serious infectious diseases that infect the poultry industry.There is only one serotype of Newcastle disease virus( NDV),but NDVs can be divided into two distinct classes( class Ⅰ,and class Ⅱ) according to their genetic relationship.To develop a method for rapid quantitative detection of class Ⅰ NDV,a pair of primers and a TaqM an probe were designed and synthesized according to the conservative sequence of NP gene of class Ⅰ NDV.The positive recombinant plasmid harboring NP gene of JS-18-05 isolate was used as a positive template to establish the standard curve.A real-time fluorescent quantitative RT-PCR method was established for rapid detection of class Ⅰ NDV with strong specificity,high sensitivity and good repeatability.The established method exhibited a good linear relationship within the concentration of 102 to 108 copies of NDV,by which 1 μl of 10 copy of NDV nucleic acid could be detected in the initial template.Compared with conventional virus isolation methods,the established method had similar sensitivity and led to the same results in detecting33 class Ⅰ,class Ⅱ NDV isolates.The study provided the basis for rapid quantitative detection of class Ⅰ NDVs and further clarification of their pathogenicity and pathogenic mechanism in poultry.

Inhibition of α_1(Ⅰ) collagen gene in vitro transcription by antisense oligodeoxynucleotides

Objective and Methods: Excessive accumulation of collagen typeⅠ and type Ⅲ causes the formation of keloids and hypertrophic scars. To understand the mechanism by which antisense oligodeoxynucleotide (Oligo) acts on in vitro transcrption α1 (I) collagen gene, isotopes (α-32pGTP) was incorporated into 2 SP6 in vitro transcription systems. Results and Conclu- sion: Oligo 2 (at the transcription start region) could effectively inhibit in vitro transcription of pGEM3-Col13 and the control (random oligodeoxynucleotides) showed no inhibition. However, oligo 1 (at the transcription start region) obviously inhibited the in vitro transcription of pGEM3-Col14, while Oligo 2, which targeted at the down stream region (about 200 bp) of the promoter showed no significant inhibition effect.

Characterization and Expression Analysis of Peroxiredoxin Genes in NNK-induced V79 Cells

4-（Methylnitrosamino）-1-（3-pyridyl）-1-butanone （NNK） is a potent and prevalent nitrosamine procarcinogen found in cigarette smoke. The aim of this work is to study alterations in peroxiredoxin （Prx） expression induced by NNK during carcinogenesis. Characterization of Prx genes from hamster was performed using bioinformatics.

南疆部分地区绵羊捻转血矛线虫苯并咪唑抗性相关分子Ⅰ型β-微管蛋白基因的多态性分析

为了解南疆地区绵羊捻转血矛线虫对苯并咪唑类药物的抗性相关分子β-微管蛋白基因的多态性,本研究对克州及喀什的183条捻转血矛线虫成虫进行ITS-2基因特异性PCR鉴定后,对抗药相关的Ⅰ型β-微管蛋白基因进行了扩增和测序,并对该抗药基因的单核苷酸多态性(SNP)167、198和200位点进行了分析。结果:在2个地区种群中,198位点及200位点均发生不同程度突变,且以198位点突变为主,暂未在167位点发生突变;两地共发现了5种基因型,其中198位点纯合敏感型及200位点纯合抗药型(喀什12条占12.37%,克州2条占2.33%),198位点纯合抗药型及200位点纯合敏感型(喀什23条占23.71%,克州7条占8.14%)两地均存在,提示这2个种群都存在抗药性。本研究首次报道了南疆部分地区捻转血矛线虫种群Ⅰ型β-微管蛋白基因存在苯并咪唑类药物抗药性突变,为新疆地区捻转血矛线虫病的有效防控及抗药性研究提供理论依据。

The Genetic Structure and Diversity of Repomucenus curvicornis Inhabiting Liaoning Coast Based on Mitochondrial COⅠ Gene and Control Region

[Object] This study was conducted to explore the genetic diversity and structure of the wild Repomucenus curvicornis inhabiting Liaoning Coast, China. [Method] The mitochondrial COⅠ gene and control region（CR） were PCR amplified from the wild R. curvicornis populations from the Liaodong Bay（n=22） and the northern Yellow Sea（n=18）, sequenced and analyzed for genetic diversity. [Result] The contents of A, T, C and G of 624 bp COⅠ gene were 24.09%, 31.04%, 25.28%, and 19.59%, and those of 460 bp CR fragment were 32.96%, 32.80%, 14.86% and 19.38%, respectively. The total number of variable sites, average number of nucleotide differences（ k）, haplotype diversity（H） and nucleotide diversity（π） based on COⅠ gene were 38, 4.67,（0.96±0.02） and（0.007 5±0.004 2）, and those based on CR fragment were 26, 3.35,（0.97 ±0.02） and（0.007 3±0.004 3）, respectively. Based on mitochondrial COⅠ gene and CR, the genetic diversity of Liaodong Bay population was lower than that of the northern Yellow Sea population. The AMOVA analysis based on CR fragments revealed almost significant genetic divergence between the Liaodong Bay and the northern Yellow Sea populations, while there was no significant genetic divergence based on COⅠ gene. The results showed that CR and COⅠ gene are effective molecular markers for detecting the genetic diversity of R. curvicornis population, while CR is more reliable than COⅠ gene in detecting the genetic structure. [Conclusion] CR is an appropriate marker for genetic analysis of marine fish population.

The Truncated Gene cfaD′ Positively Regulates CFA/Ⅰ Expression of Enterotoxigenic Escherichia coli

The gene cluster cfaABCED’ of enterotoxigenic Escherichia coli, encoding the fimbriae which is called colonization factor antigen located on a plasmid. It is positively regulated by cfaR, a member of the AraC family, and the cfaD’ gene region, which is located downstream of cfaE and is homologous to cfaR, had been described as a truncated cryptic gene. In the present study we observed that the CFA/ fimbriae subunit, cfaB, was expressed in lower amount by the cfaABCED’ clone pNTP513 in host E. coli HB101. The expression of CFA/ diminished by deletion of cfaD’ gene region from pNTP513, and was restored by acquisition of cfaD’ in trans. Furthermore, CFA/ expression by cfaD’ deletion mutant, the cfaABCE clone, was remarkably increased by the presence of cfaD’ in trans in a topoisomerase A deficient strain of E. coli DM800. These data suggest that cfaD’ region is a functional region of gene, that regulates the CFA/ expression with cfaR by unknown mechanism.

小鼠peroxiredoxin基因家族的生物信息学分析

目的 分析小鼠peroxiredoxin基因家族的基因组结构和进化。方法 利用已经公布的小鼠基因组数据库,采用BLAST程序检索该基因家族各成员的编码基因和假基因,并利用ClusterW软件进行序列联配,绘制其分子进化树。结果 分析表明该家族半数成员具有多个假基因序列,为返转座类型假基因。这些假基因的形成时间有先后,所具有返转座假基因的典型结构也各不相同。分析该家族的进化表明PrxⅠ Ⅳ有共同的祖先,归为一个亚类,而PrxⅤ和Ⅵ与前者的相似性较差,归为另一个亚类。结论 该家族每个成员长期进化所形成的多样性提示其功能具有独特性。