基于COI序列的DNA条形码在中国沿海缀锦蛤亚科贝类中的应用分析

该研究探讨了将COI序列应用于中国沿海缀锦蛤亚科贝类物种鉴定的可行性,获得了该亚科5属11种贝类51个个体的43个单倍型序列.碱幕替换饱和性分析表明,颠换未出现饱和现象,而转换在序列分化达到10%至15%时即到达饱和.单倍犁Hap33可能是由杂交引起的,排除此瞥倍型,种内个体间遗传距离在0%到2.02%之间,平均为0.46%,属内不同种个体间遗传距离在17.21%～32.24%之间,平均为24.96%,存在条形码问隙:11种缀锦蛤哑科贝类在邻接树和贝叶斯树上都独立的单系群.该研究表明,基于COI的DNA条形码技术能够将研究所涉及的约98%的缀锦蛤亚科贝类鉴定剑种的水平,因此,利用DNA条形码技术可以对缀锦蛤亚科贝类进行有效地分类鉴定.     

Toll-like receptor 9 agonists up-regulates the expression of cyclooxygenase-2 via activation of NF-κB in prostate cancer cells

CpG-oligonucleotides (CpG-ODNs), mimicking bacterial DNA, have recently been shown to stimulate prostate cancer invasion in vitro via Toll-like receptor 9 (TLR9). Since cyclooxygenase 2 (COX-2), frequently overexpressed in multiple tumor types including prostate cancer, is a causal factor for tumor development, invasion and metastasis, an interesting question is raised whether TLR9 regulates COX-2 expression in prostate cancer cells. To address this question, herein we examined COX-2 expression in PC-3 cells stimulated with different doses and time courses of CpG-ODNs. The regulatory role of NF-κB in TLR9-mediated COX-2 expression was also investigated. CpG-ODN was found to up-regulate the expression of COX-2 in PC-3 cells in a dose- and time-dependent manner, but have little impact on COX-1 expression. Moreover, CpG-ODN also promoted nuclear translocation and activation of NF-κB, which appeared to be required for COX-2 induction by CpG-ODN. Overall, TLR9 up-regulates COX-2 expression in prostate cancer cells, at least partially through the activation of NF-κB, which may be implicated in tumor invasion and metastasis.     

Low penetrance of Leber's hereditary optic neuropathy in ten Han Chinese families carrying the ND6 T11484C mutation

Background

Leber’s hereditary optic neuropathy (LHON) is a maternally inherited disorder. The purpose of this investigation is to understand the role of mitochondrial haplotypes in the development of LHON associated with ND6 T14484C mutation in Chinese families.

Methods

One hundred fourteen subjects from ten Han Chinese families with LHON were studied by the clinical and genetic evaluation as well as molecular and biochemical analyses of mitochondrial DNA (mtDNA).

Results

Clinical evaluation revealed that ten families exhibited extremely low penetrance of visual impairment, with an average of 10%. In particular, ten (8 males/2 females) of 114 matrilineal relatives in these families exhibited the variable severity and age-at-onset in visual dysfunction. The average age-of-onset of vision loss was 19 years old. Molecular analysis of mitochondrial DNA (mtDNA) identified the homoplasmic T14484C mutation and distinct sets of variants, belonging to the Asian haplogroups B5b, D4, D4g1b, G3a2, R11, R11a and Z3, respectively. However, there was the absence of secondary LHON-associated mtDNA mutations in these ten Chinese families.

Conclusion

The low penetrance of vision loss in these Chinese pedigrees strongly indicated that the T14484C mutation was itself insufficient to produce a clinical phenotype. The absence of secondary LHON mtDNA mutations suggests that these mtDNA haplogroup-specific variants may not play an important role in the phenotypic expression of the T14484C mutation in those Chinese families with low penentrace of vision loss. However, nuclear modifier genes and environmental factors appear to be modifier factors for the phenotypic manifestation of the T14484C mutation in these Chinese families.     

Assessment of the genetic diversity among Glyptosternum maculatum, an endemic fish of Yarlung Zangbo River, Tibet, China using SSR markers

The genetic diversity of Glyptosternum maculatum populations from Nyang River, Lhasa River, and Shetongmon Reach of Yarlung Zangbo River was assessed using six microsatellite markers. Overall, the genetic diversity across the three populations was low. The Shetongmon population exhibited the highest level of genetic diversity in terms of number of alleles and effective alleles, heterozygosity, and polymorphic information content value, followed by the Nyang population and Lhasa population. The analysis of molecular variance demonstrated that almost the variation (86.64%) occurred within populations. The differentiation among populations was not significant, and population structure was weak. These results revealed that three natural populations of G. maculatum are not genetically differentiated and the large disparity of living altitude did not caused genetic differentiation between different populations. Our observations will help identify the genetic relationship among populations to understand the genetic diversity of G. maculatum.     

Overexpression of glutathione S-transferase gene increases salt tolerance of arabidopsis

The Suaeda salsa glutathione S-transferase gene (GST) was introduced into arabidopsis under the control of the cauliflower mosaic virus 35S promoter. Transformants were selected for their ability to grow on medium containing kanamycin. Southern and northern blot analyses confirmed that GST was transferred into the arabidopsis genome, and the GST and GPX activities in transgenic plants (GT) were much higher than in wild-type plants (WT). There were no obvious morphological or developmental differences between transgenic and wild-type plants. One transgenic homozygous line (GT_6–8) and WT plants were evaluated for salt tolerance and gene expression. Seed germination and seedling salt tolerance were improved after overexpression of GST in arabidopsis; the photosynthesis rate and the fresh weight of the GT_6–8 line were distinctly higher than those of WT plants after NaCl treatment. Glutathione content increased substantially in salt-stressed arabidopsis plants of both genotypes, and the glutathione pool in GT_6–8 plants was more oxidized than in WT plants under both control and stressful conditions. The MDA content, an indicator of lipid peroxidation, increased in WT plants but was not affected distinctly in GT_6–8 seedlings after NaCl treatment. Results from different tests indicated that the expression of the GST gene promoted a higher level of salt tolerance in vivo in transgenic arabidopsis plants.     

Phylogeny of the paleotropical fern genus Lepisorus (Polypodiaceae,Polypodiopsida) inferred from four chloroplast DNA regions

Phylogenetic relationships within the paleotropical genus Lepisorus (Polypodiaceae) were investigated using plastid DNA sequences from four regions: rbcL, rps4 and rps4-trnS IGS, trnL intron plus trnL-F IGS, rbcL-atpB IGS. Over 4000 nucleotides were sequenced for 77 specimens belonging to 54 species. Each cpDNA region was analyzed separately and combined into a single dataset. All phylogenetic analyses, maximum parsimony, maximum likelihood and Bayesian Inference of phylogeny, revealed the paraphyly of Lepisorus with the monotypic Drymotaenium miyoshianum and of the paleotropical genus Belvisia nested within the Lepisorus clade. Nine well-supported major clades were found. The phylogenetic results provided new evidence for the sectional classification of Lepisorus. The evolution of three morphological characters, clathrateness of rhizome scales, margin of rhizome scales and defoliated leaves, and the evolution of the karyotype, were reconstructed to identify lineage specific phenotypic character states or combination of characters. Unique character combinations, rather than synapomorphies, were found to be of systematic value in sectional delimitation. The variation of chromosome numbers is largely due to a single aneuploidy event instead of a stepwise reduction during the evolutionary history of this genus.     

Compatibility of neural stem cells with functionalized self-assembling peptide scaffold <Emphasis Type="Italic">in vitro</Emphasis>

In this study, we evaluated the behavior of neural stem cells (NSCs) using a new peptide hydrogel scaffold named IKVAVmx, which was made by mixing self-assembling peptide RADA16 and designer peptide RADA16-IKVAV solutions. NSCs derived from rat cerebral cortex were culture-expanded in neuorobasal medium and seeded on the RADA16 and IKVAVmx hydrogels. Cells could penetrate the hydrogels and form a 3D cellular network. Compared to pure RADA16 scaffold, we found that IKVAVmx scaffold significantly promoted cell proliferation and stimulated cell migration into the 3D scaffold. Moreover, Immunocytochemistry and Western blot analysis indicated that the differentiation ratio of neurons from NSCs in IKVAVmx scaffold was higher than that in pure RADA16 scaffold. These results suggested that this new hydrogel scaffold provided an ideal substrate for NSCs 3D culture and suggested its further application for neural tissue engineering.     

Functional analysis of the inhibitor of apoptosis genes in <Emphasis Type="Italic">Antheraea pernyi</Emphasis> nucleopolyhedrovirus

The inhibitor of apoptosis proteins (IAP) plays an important role in cell apoptosis. We cloned two novel IAP family members, Ap-iap1 and Ap-iap2, from Antheraea pernyi nucleopolyhedrovirus (ApNPV) genome. Ap-IAP1 contains two baculoviral IAP repeat (BIR) domains followed by a RING domain, but Ap-IAP2 has only one BIR domain and RING. The result of transient expression in Spodoptera frugiperda (Sf21) showed that Ap-iap1 blocked cell apoptosis induced by actinomycin D treatment and also rescued the p35 deficient Autographa californica nucleopolyhedrovirus (AcNPV) to replicate in Sf9 cells, while Ap-iap2 does not have this function. Several Ap-IAP1 truncations were constructed to test the activity of BIRs or RING motif to inhibit cell apoptosis. The results indicated that BIRs or RING of Ap-IAP1 had equally function to inhibit cell apoptosis. Therefore deletion of above both of the above domains could not block apoptosis induced by actinomycin D or rescue the replication of AcMNPVΔp35. We also screened two phage-display peptides that might interact with Ap-IAP1.