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31.
Galium procurrens is described as a new diploid relic species from Montenegro/N. Albania and SW. Bulgaria. It is related to the tetraploidG. laevigatum and other diploid and polyploid taxa of theG. sylvaticum-group inhabiting European deciduous forests. 相似文献
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An Yan Jie Xiong Jiadong Zhu Xiangyu Li Shuting Xu Xiaoyu Feng Xin Ke Zhenyi Wang Yang Chen Hong-Wei Wang Michael Q Zhang Kehkooi Kee 《Nucleic acids research》2022,50(19):11255
Understanding the molecular and cellular mechanisms of human primordial germ cells (hPGCs) is essential in studying infertility and germ cell tumorigenesis. Many RNA-binding proteins (RBPs) and non-coding RNAs are specifically expressed and functional during hPGC developments. However, the roles and regulatory mechanisms of these RBPs and non-coding RNAs, such as microRNAs (miRNAs), in hPGCs remain elusive. In this study, we reported a new regulatory function of DAZL, a germ cell-specific RBP, in miRNA biogenesis and cell proliferation. First, DAZL co-localized with miRNA let-7a in human PGCs and up-regulated the levels of >100 mature miRNAs, including eight out of nine let-7 family, miR21, miR22, miR125, miR10 and miR199. Purified DAZL directly bound to the loops of precursor miRNAs with sequence specificity of GUU. The binding of DAZL to the precursor miRNA increased the maturation of miRNA by enhancing the cleavage activity of DICER. Furthermore, cell proliferation assay and cell cycle analysis confirmed that DAZL inhibited the proliferation of in vitro PGCs by promoting the maturation of these miRNAs. Evidently, the mature miRNAs up-regulated by DAZL silenced cell proliferation regulators including TRIM71. Moreover, DAZL inhibited germline tumor cell proliferation and teratoma formation. These results demonstrate that DAZL regulates hPGC proliferation by enhancing miRNA processing. 相似文献
34.
Haengdueng Jeong Youn Woo Lee In Ho Park Hyuna Noh Sung-Hee Kim Jiseon Kim Donghun Jeon Hui Jeong Jang Jooyeon Oh Dain On Chanyang Uhm Kyungrae Cho Heeju Oh Suhyeon Yoon Jung Seon Seo Jeong Jin Kim Sang-Hyuk Seok Yu Jin Lee Seung-Min Hong Se-Hee An Seo Yeon Kim Young Been Kim Ji-Yeon Hwang Hyo-Jung Lee Hong Bin Kim Dae Gwin Jeong Daesub Song Manki Song Man-Seong Park Kang-Seuk Choi Jun Won Park Jun-Young Seo Jun-Won Yun Jeon-Soo Shin Ho-Young Lee Ki Taek Nam Je Kyung Seong 《Disease models & mechanisms》2022,15(11)
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共表达口蹄疫病毒衣壳前体蛋白P1-2A基因和蛋白酶3C基因牛肾细胞株的筛选及稳定性 总被引:2,自引:0,他引:2
[目的]筛选稳定表达口蹄疫病毒衣壳蛋白的牛肾细胞(Madin-Darby bovinekidney,MDBK)株.[方法]采用聚合酶链式反应(Polymerase chain reaction,PCR)方法从重组质粒pMD-P1-2A和pMD-3C中分别扩增口蹄疫病毒衣壳前体蛋白P1-2A基因和蛋白酶3C基因,将两基因依次插入逆转录病毒载体pBABE-puro.重组逆转录病毒载体pBABE-puro/P1-2A-3C和pVSV-G质粒载体用脂质体介导共转染GP2-293包装细胞.产生的重组逆转录病毒感染MDBK细胞后使用嘌呤霉素筛选抗性细胞.利用克隆环套取法得到单克隆细胞.经间接免疫荧光和酶联免疫吸附测定(Enzyme-linkedimmunosorbent assay,ELISA)方法检测MDBK细胞中衣壳蛋白的表达,并在电镜下观察口蹄疫病毒空衣壳.[结果]成功筛选到稳定表达口蹄疫病毒衣壳蛋白的MDBK细胞株,衣壳前体蛋白P1-2A在蛋白酶3C裂解作用下正确组装成空衣壳.[结论]该研究为口蹄疫亚单位疫苗的研制提供了实验材料. 相似文献
36.
塔里木河下游河水漫溢后胡杨幼苗分布格局初探 总被引:1,自引:0,他引:1
采用最近邻体法,将Clark-Evans指数作为度量胡杨幼苗分布格局的指标,并用标准正态分布检验实际CE指数值偏离1的显著性,分析塔里木河下游河水漫溢后胡杨幼苗的分布格局。结果表明:(1)在3m×3m的样方尺度上,河水漫溢后0~1年和1~2年的胡杨幼苗呈聚集分布,漫溢后2~3年的胡杨幼苗呈均匀分布,漫溢后4~5年和5~7年的胡杨幼苗呈随机分布。(2)在3m×3m的样方尺度上,随着胡杨幼苗年龄的增长,胡杨幼苗的空间分布格局由聚集分布转变为均匀分布,最终呈现为随机分布的格局。(3)在2m×2m至10m×10m的样方尺度上,漫溢后5~7年的胡杨幼苗空间分布格局均表现为随机分布。(4)标准正态分布检验结果显示,各个尺度上胡杨幼苗的CE值与理论值1之间的偏离均不显著,说明随着尺度的增大,胡杨幼苗的空间分布格局并没有发生显著变化,始终呈现出随机分布的格局。 相似文献
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一株广谱中和抗原性出血热病毒株的发现 总被引:5,自引:0,他引:5
一株分离自杭州市褐家鼠的出血热病毒Gou_3株的免疫血清对10株I型病毒的中和滴度除二株为160外均为320,而对4株Ⅱ型病毒的滴度为320—640,说明Gou_3株免疫血清对两型毒株中和效价大多数无差异或只差2倍,是一株中和抗原广谱的毒株。用I型和Ⅱ型毒株免疫血清对Gou_3株进行型别检定结果表明Gou_3株是Ⅱ型病毒。 相似文献
39.
Cloning and expression of thermophilic catechol 1,2-dioxygenase gene (catA) from Streptomyces setonii 总被引:2,自引:0,他引:2
Streptomyces setonii (ATCC 39116) degrades various single aromatic compounds such as phenol or benzoate via an ortho-cleavage pathway using catechol 1,2-dioxygenase (C12O). A PCR using degenerate primers based on the conserved regions of known C12O-encoding genes amplified a 0.45-kbp DNA fragment from S. setonii total DNA. A Southern hybridization analysis and size-selected DNA library screening using the 0.45-kbp PCR product as a probe led to the isolation of a 6.4-kbp S. setonii DNA fragment, from which the C12O-encoding genetic locus was found to be located within a 1.4-kbp DNA fragment. A complete nucleotide sequencing analysis of the 1.4-kbp DNA fragment revealed a 0.84-kbp open reading frame, which showed a strong overall amino acid similarity to the known high-G+C Gram-positive (but significantly less to the Gram-negative) bacterial mesophilic C12Os. The heterologous expression of the cloned 1.4-kbp DNA fragment in Escherichia coli demonstrated that this C12O possessed a thermophilic activity within a broad temperature range (up to 65 degrees C) and showed a higher activity against 3-methylcatechol than catechol or 4-methylcatechol, but no activity against protocatechuate. 相似文献
40.
Here we describe a robust method, termed QuikChange shuffling, for efficient site-directed mutagenesis and random recombination of homologous genes. The homologous genes are fragmented, and the random fragments are reassembled in a self-priming polymerase reaction to obtain chimeric genes. The product is then mixed with linearized vector and two pairs of complementary mutagenic primers, followed by assembly of the chimeric genes and linearized vector through QuikChange-like amplification to introduce recombinant plasmids with a site-directed mutation. The method, which can yield 100% chimeric genes after library construction, is more convenient and efficient than current DNA shuffling methods. 相似文献