染色体缩合调控子2对食管癌小鼠细胞增殖的影响及其机制研究

目的探讨染色体缩合调控子2(RCC2)对食管癌小鼠细胞增殖的影响及其作用机制。方法提取食管癌小鼠食管组织及原代细胞,分组进行转染,采用CCK-8检测细胞增殖水平,RT-PCR和Western blotting检测RCC2、SOX2及增殖细胞核抗原(PCNA)、锌指蛋白(Snail)的表达,荧光素酶实验分析RCC2与SOX2的靶向关系。结果RCC2在食管癌组织中表达上调(P<0.05);过表达RCC2后食管癌小鼠细胞增殖水平升高,而抑制RCC2表达后细胞增殖水平降低(P<0.05);过表达RCC2后细胞中SOX2和SOX2靶基因PCNA、Snail相对表达量升高(P<0.05),而抑制RCC2表达后SOX2、PCNA、Snail相对表达量降低(P<0.05);荧光素酶实验结果显示RCC2与SOX2存在靶向调控关系。结论RCC2通过上调SOX2及其靶基因表达,提高食管癌小鼠细胞增殖能力,促进肿瘤细胞的发生、发展。

细胞分裂中非姐妹子染色体的组合行为解析

每对姐妹子染色体分离的同时,非姐妹子染色体会随机组合,如果姐妹子染色体的基因或标记有差异,就会出现非姐妹子染色体随机组合的复杂行为,子细胞获得的染色体或DNA将出现较复杂的差异。

宫颈癌组织长链非编码RNA XIST、小分子RNA miR-101-3p表达变化及其意义

目的观察宫颈癌组织长链非编码RNA(LncRNA)X染色体失活特异转录子(XIST)、小分子RNA miR-101-3p表达变化,并探讨其临床意义。方法选取91例宫颈癌患者的宫颈癌组织标本为观察组,癌旁正常组织(距离宫颈癌组织>5cm且经病例检查证实为正常组织)标本为对照组。采用实时荧光定量PCR法检测两组标本中的XIST、miR-101-3p表达,并分析其与宫颈癌临床病理参数的关系。结果观察组、对照组XIST表达量分别为8.97±3.56、7.01±3.82,miR-101-3p表达量分别为8.24±4.22、10.15±3.97。观察组XIST表达量高于对照组(P<0.05),miR-101-3p表达量低于对照组(P<0.05)。Pearson积矩相关分析结果显示宫颈癌组织miR-101-3p、XIST表达量呈负相关性(r=-0.716,P<0.05)。肿瘤最大径≥4 cm、FIGO分期Ⅲ+Ⅳ期、低分化、有淋巴结转移的宫颈癌组织中miR-101-3p表达量分别低于于肿瘤最大径<4 cm、FIGO分期Ⅰ+Ⅱ期、中高分化、无淋巴结转移的宫颈癌组织(P均<0.05),XIST表达量分别高于于肿瘤最大径<4 cm、FIGO分期Ⅰ+Ⅱ期、中高分化、无淋巴结转移宫颈癌组织(P均<0.05)。结论宫颈癌组织XIST表达升高、miR-101-3p表达降低。检测宫颈组织XIST、miR-101-3p有助于宫颈癌的病情判断。

美推出鉴别牲畜精子性别的激光系统

美国的农业专家研制成一种能够准确鉴别牲畜精子性别的激光系统。该系统根据X精子染色体中的脱氧核糖核酸比Y精子与卵子染色体更明亮,由电脑记录其荧光亮度,然后在电场作用下分离X精子与Y精子。若选用X精子与卵子受精则生母畜,选用Y精子与卵子受精则生公畜。

Isolation and Chromosomal Mapping of a Corn B Chromosome Specific RAPDs

B染色体存在于多种动植物中 ,具有很多独特的性状。B染色体与正常染色体在DNA组成方面十分相似 ,寻找B染色体特异序列一直是B染色体研究的难点和热点。通过对含有和不含有B染色体的两种玉米 (ZeamaysL .)基因组进行了RAPD分析 ,筛选到一个B染色体特异性分子标记B480。该标记与玉米的自主复制起始序列ARS1和ARS2同源 ,特别是该序列中的 2 5bp出现在多种模式生物基因组中。FISH的结果显示 。

Studies on Ultra-dry Storage and Genetic Stability of Vegetable Seeds

[Objective] To study the long-term ultra-dry storage method and genetic stability of vegetable seeds.[Method] Seeds of Lycopersicum esculentum,Raphanus satuvus and Apium graveolen.were chosen as material.The changes of seed vigor,viability and genetic stability after ultra-storage were discussed by studying the seed potentiality,shoot length,germination percentage and the chromosome aberration rate of root tip cells.[Results] Maintaining the low moisture content,different vegetable species had different storage effects of the long-term storage seeds under normal temperature.The Lycopersicum esculentum and Raphanus satuvus seeds were more suitable to ultra-dry storage at normal temperature,and could keep good genetic stability,while the seeds of Apium graveolen had bad performance.[Conclusion] This study established the foundation of studying ultra-dry storage of vegetable seeds.

Development and Utilization of 1S^1 Chromosomearm-specific Molecular Markers of Aegilops longissima

Introducing the 1S^1 chromosome of Aegilops longissima into wheat genome can significantly improve wheat grain quality and contents of iron and zinc. Therefore, the development of molecular markers specific to 1S^1 chromosome of A. longissima is of important significance for breeding high-quality wheat with high contents of iron and zinc in grains. In this study, nine molecular markers specific to 1S^1 chromosome of A. longissima were developed, including two 1S^1S specific markers,six 1S^1L specific markers and one 1S^1 specific marker which was located on both short and long arms. The practicability of these molecular markers were verified using hybrid population as materials. The results showed that hybrid population could be effectively screened and identified, which indicated that the developed 1S^1 chromosome-specific molecular markers could be used for screening and identification of hybrid population and could be used in marker-assisted breeding of high-quality wheat with high contents of Fe and Zn in grains.

Screening of the Metastasis-Associated Genes by Gene Chip in High Metastatic Human Ovarian Cancer Cell Lines

Affymetrix U133A oligonucleotide microarrays were used to study the differences of gene expressions between high （H） metastatic ovarian cancer cell line, HO-8910PM, and normal ovarian tissues （C）. Bioinformatics was used to identify their chromosomal localizations. A total of 1,237 genes were found to have a difference in expression levels more than eight times. Among them 597 were upregulated [Signal Log Ratio （SLR） ≥3], and 640 genes were downregulated （SLR≤-3）. Except one gene, whose location was unknown, all these genes were randomly distributed on all the chromosomes. However, chromosome 1 contained the most differentially expressed genes （115 genes, 9.3%）, followed by chromosome 2 （94 genes, 7.6%）, chromosome 12 （88 genes, 7.1%）, chromosome 11 （76 genes, 6.1%）, chromosomes X （71 genes, 5.7%）, and chromosomes l7 （69 genes, 5.6%）. These genes were localized on short-arm of chromosome （q）, which had 805 （65.1%） genes, and the short arms of No.13, 14, 15, 21, and 22 chromosomes were the only parts of the chromosomes where the differentially expressed genes were localized. Functional classification showed that most of the genes （306 genes, 24.7%） belonged to the enzymes and their regulator groups. The subsequent group was the nucleic acid binding genes （144 genes, 11.6%）. The rest of the top two groups were signal transduction genes （137 genes, 11.1%） and proteins binding genes （116 genes, 9.4%）. These comprised 56.8% of all the differentially expressed genes. There were also 207 genes whose functions were unknown （16.7 %）. Therefore it was concluded that differentially expressed genes in high metastatic ovarian cancer cell were supposed to be randomly distributed across the genome, but the majority were found on chromosomes 1, 2, 12, 11, 17, and X. Abnormality in four groups of genes, including in enzyme and its regulator, nucleic acid binding, signal transduction and protein binding associated genes, might play important roles in ovarian cancer metastasis. Those genes need to be further studied.

The Self-incompatibility (S) Locus of Antirrhinum Resides in a Pericentromeric Region

The self-incompatibility ( S) loci from the Solanaceae, Rosaceae and Scrophulariaceae encode a class of ribonucleases, known as S RNases, which have been shown to control the pistil expression of self-incompatible reaction. In the former two families, the S loci have been shown to be located near centromere. However, the chromosomal location of the S locus in Antirrhinum, a species of the Scrophulariaceae, is not known. To determine its chromosomal location and genomic organization, an S-2 RNase gene and its corresponding 63 kb BAC clone were separately used for fluorescence in situ hybridization (FISH) of mitotic metaphase chromosomes of a self-incompatible Antirrhinum line Of S2S5. The results showed that the S-2 RNase detected a doublet signal near the centromere of the smallest chromosome (2n = 16). Two separate doublet signals of the tested BAC sequence were shown on both sides of the centromeres of all eight pairs of the chromosomes, suggesting that the Antirrhinum S locus is located in a pericentromeric region. Furthermore, a retrotransposon, named RIS1 (retrotransposon in the S locus), which has not been identified yet in. Antirrhinum, was found next to S-2 RNase. Taken together, the centromeric location of the S locus from the three S-RNase-based self-incompatible families provides a further support on a common origin of their evolution as well as suppressed recombination.

Genome Analysis in Wheat Breeding for Disease Resistance

A brief review on the development of wheat germplasm with introduced powdery mildew and scab resistance from Haynaldia villosa Sch. and Leymus racemosus Lam., Roegneria ciliaris (Trin.) Nevski as well as R. kamoji C. Koch respectively was made. In the course of germplasm development, genome analysis by means of chromosome banding, genomic in situ hybridization (GISH) or fluorescence in situ hybridization (FISH), molecular markers, particularly restriction fragment length polymorphism (RFLP) coupled with aneuploid analysis was employed for the purpose of improving breeding efficiency. Potential use of such germplasm in wheat breeding practice, basic studies and some related problems were also discussed.

性别的奥秘

人类有史以来就在苦苦探寻性别的奥秘,今天,随着显微镜的诞生,性别的奥秘也终于被扯下了神秘的面纱。

雌激素通过调控RCC2参与乳腺癌细胞凋亡

目的探索雌激素刺激乳腺癌病变过程中染色体缩合调控子2(RCC2)的作用及机制。方法收集乳腺标本,用蛋白免疫印迹法检测RCC2蛋白表达水平;分别用雌激素(雌二醇)、RCC2小干扰RNA(siRNA),雌激素联合RCC2 siRNA处理MCF-7细胞,检测细胞增殖与凋亡。结果与乳腺纤维瘤组织相比,RCC2在雌激素受体阳性(ER+)乳腺癌组织中的表达水平升高(P=0.001),在ER-乳腺癌组织中无升高(P=0.404)。抑制RCC2后ER+乳腺癌细胞系MCF-7增殖无变化(F_(处理)=0.003,P=0.957),但凋亡比例比Allstars siRNA组高(t=2.679,P=0.037);雌二醇处理MCF-7后增殖能力增强(F=110.323,P<0.001),细胞凋亡比例减弱(t=5.881,P=0.004);雌二醇与RCC2siRNA的交互效应在MCF-7细胞增殖方面无统计学意义(F=0.281,P=0.604),在细胞凋亡方面有统计学意义(F=18.897,P=0.002)。结论雌激素可能通过调控RCC2来抑制细胞凋亡,从而促进ER+乳腺癌癌变进程。

Phase Separation and Microstructure of Mixed Surfactants Solution Containing Cationic Geminis and Traditional Anionic Surfactant

The properties of aqueous two-phase system (ATPS) of mixed solution containing gemini cationic surfactant trimethylene-1,3-bis(dodecyldimethyl ammonium) bromide (12-3-12, 2Br-) and traditional anionic surfactant sodium dodecyl sulfate (SDS) with or without added salt have been studied. An ATPS is formed in a narrow region of the ternary phase diagram different from that of traditional aqueous cationic-anionic surfactant systems. In ATPS region, the lowest total concentration of surfactants varies with the mixing ratio of geminis to SDS. Photographs obtained from freeze-etching, negative-staining and transmission electron microscopy show that the microstructures of two phases are different from each other. Micelles and vesicles can coexist in a single phase. The addition of salts can change the phase diagram of ATPS. Furthermore, the added salts promote the aggregation of rod-like micelles to form coarse network structure that increase the viscosity of solutions. The negative ions of the added salts are the determining factor.

Identification of anrF gene, a homology of admM of andrimid biosynthetic gene cluster related to the antagonistic activity of Enterobacter cloacae B8

AIM： To identify the gene （s） related to the antagonistic activity of Enterobacter cloacae B8 and to elucidate its antagonistic mechanism. METHODS： Transposon-mediated mutagenesis and tagging method and cassette PCR-based chromosomal walking method were adopted to isolate the mutant strain （s） of B8 that lost the antagonistic activity and to clone DNA fragments around Tn5 insertion site. Sequence compiling and open reading frame （ORF） finding were done with DNAStar program and homologous sequence and conserved domain searches were performed with BlastN or BlastP programs at www.ncbi.nlm.nih.gov. To verify the gene involved in the antagonistic activity, complementation of a full-length clone of the anrFgene to the mutant B8F strain was used. RESULTS： A 3 321 bp contig around the Tn5 insertion site was obtained and an ORF of 2 634 bp in length designated as anrFgene encoding for a 877 aa polyketide synthase-like protein was identified. It had a homology of 83% at the nucleotide level and 79% ID/87% SIM at the protein level, to the admM gene of Pantoea agglomerans andrimid biosynthetic gene cluster （AY192157）. The Tn5 was inserted at 2 420 bp of the gene corresponding to the COG3319 （the thioesterase domain of type I polyketide synthase） coding region on BSF. The antagonistic activity against Xanthomonas oryzae pv. oryzae was resumed with complementation of the full-length anrFgene to the mutant B8F. CONCLUSION： The anrFgene obtained is related to the antagonistic activity of BS, and the antagonistic substances produced by B8 are andrimid and/or its analogs.

Streptozotocin-induced expression of Ngn3 and Pax4 in neonatal rat pancreatic α-cells

AIM： To investigate the mechanism behind β-cell regeneration in neonatal rat pancreas treated with strep- tozotocin （STZ）. METHODS： Neonatal Sprague Dawley rats were intra- peritoneally injected with 70 mg/kg STZ. Body weight, pancreas weight and blood glucose were recorded every two days after the treatment. To identify the expression and location of transcription factors in the rat pancreas, double immunofluorescent staining was performed using antibodies to specific cell markers and transcription factors. RESULTS： Expression of Neurogenin 3 （Ngn3）, a marker for endocrine precursor cells, was observed by immunofluorescence in a few β-cells and many a-cells. The expression reached a peak 12 d after treatment. Pax4, a transcription factor that lies downstream of Ngn3 and plays an important role in β-cell differentiation, was also expressed in the α-cells of STZ-treated rats. We did not observe significant changes in Nkx6.1, which is essential for β-cell maturation in the treated rats. CONCLUSION： α-cells dedifferentiated into endocrine precursor cells and acquired the ability to dedifferentiate in the neonatal rat pancreas after STZ treatment.

Evaluation of malignancy using Ki-67,p53,EGFR and COX-2 expressions in gastrointestinal stromal tumors

AIM:To investigate the role of expressions of Ki-67, p53,epidermal growth factor receptor(EGFR)and cyclooxygenase-2(COX-2)in gastrointestinal stromal tumor(GIST)grading and prognosis. METHODS:Tumor tissue was collected retrospectively from 96 patients with GIST.Antibodies against Ki-67, p53,EGFR and COX-2 were used for immunohistochemical staining.Tumor grading was designated according to a consensus system and the staining was quantified in 3 categories for each antibody in the statistical analysis. RESULTS:The Ki-67 expression in GISTs was significantly associated with the size of the tumors,mitotic rate and the risk of malignancy(x2=15.51,P=0.02; x2=22.27,P<0.001;x2=20.05;P<0.001).The p53 expression was also significantly correlated with mitotic rate and the risk of malignancy(x2=9.92,P= 0.04;x2=9.97;P=0.04).Over-expression of Ki-67 was strongly correlated with poor survival(x2=10.44, P=0.006),but no correlation was found between the expression of p53,EGFR or COX-2 and survival. Multivariate analysis further demonstrated that Ki-67 expression(relative risk=15.78,95%CI:4.25-59.37) could be used as an independent prognostic value for GIST patients.Adjuvant imatinib therapy could improve clinical outcomes in the patients with high risk and intermediate risk of recurrence after complete tumor resections(median survival time:52 mo vs 37 mo, x2=7.618,P=0.006). CONCLUSION:Our results indicated that the expression of Ki-67 could be used as an independent prognostic factor for GIST patients.

The Application of X-STR： Two Case Reports

The usefulness of the X-chromosomal STRs （short tandem repeats） for forensic purposes seems to be restricted, but may be valuable in some paternity cases. Due to the particular mode of inheritance, X-chromosomal X-STR has the advantage in female traces identification against male contamination and in complex kinship cases, such as deficiency cases （mother-son or father-daughter）, grandparent-grandchild comparisons, half-sisters testing, etc. In this study, 4 blood samples from two paternity cases without father were examined with TYPER19 Amplification kit first, from the result, it is hard to judge the relationship between the mother-sons, then TYPERX19 kit was conducted to obtain the full profiles of the two pairs of the mother-son, from the genetypes of the samples, it can be inferred that neither of the two pairs of mother-son were in line with the kinship, which provides important evidence for the two paternity cases. All together, the X-chromosome marks included in the TYPERX19 kit can offer the possibility to solve complex kinship cases where autosomal STR markers cannot provide the information needed.

Characterization of a novel rat cholangiocarcinoma cell culture model-CGCCA

AIM： TO characterize a culture model of rat CCA cells, which were derived from a transplantable TTA-induced CCA and designated as Chang Gung CCA （CGCCA）. METHODS： The CGCCA cells were cultured at in vitro passage 12 times on a culture dish in DMEM medium. To measure the doubling time, 103 cells were plated in a 96-well plate containing the growth medium. The cells were harvested 4 to 10 d after seeding, and a standard MTT assay was used to measure the growth. The phenotype of CACCA cell and xenograft was determined by immunohistochemical study. We also determine the chromosomal alterations of CGCCA, G-banding and spectral karyotyping studies were performed. The CGCCA cell line was transplanted into the nude mice for examining its tumorigenicity. 2-Deoxy-2-（18F）fluoro-D- glucose （FDG） autoradiography was also performed to evaluate the FDG uptake of the tumor xenograft. RESULTS： The doubling time for the CGCCA cell line was 32 h. After transplantation into nude mice, FDG autoradiography showed that the tumors formed at the cell transplantation site had a latency period of 4-6 wk with high FDG uptake excluding necrosis tissue. Moreover, immunohistochemical staining revealed prominent cytoplasmic expression of c-erb-B2, CK19, c-Met, COX-n, EGFR, MUC4, and a negative expression of K-ras. All data confirmed the phenotypic features of the CGCCA cell line coincide with the xenograft mice tumors, indicating cells containing the tumorigenicity of CCA originated from CCA. In addition, karyotypic band- ing analysis showed that the diploid （2n） cell status combines with ring and giant rod marker chromosomes in these clones; either both types simultaneously appeared or only one type of marker chromosome in a pair appeared in a cell. The major materials contained in the marker chromosome were primarily identified from chromosome 4. CONCLUSION： The current CGCCA cell line may be used as a non-K-ras effect CCA model and to obtain information and reveal novel pathways for CCA. Further applications regarding tumor markers or therapeutic targeting of CCA should be addressed accordingly.