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Tau is modified with O-GlcNAcylation extensively in human brain. The O-GlcNAcylation levels of tau are decreased in Alzheimer's disease (AD) brain. Sirtuin type 1 (SIRT1) is an enzyme that deacetylates proteins including transcriptional factors and associates with neurodegenerative diseases, such as AD. Aberrant SIRT1 expression levels in AD brain is in parallel with the accumulation of tau. cAMP response element binding protein (CREB), a cellular transcription factor, plays a critical role in learning and memory. In this present study, we found SIRT1 deacetylates CREB and inhibits phosphorylation of CREB at Ser133. The inactivated CREB suppresses OGT expression and therefore decreases the O-GlcNAcylation of tau and thus increases the phosphorylation of tau at specific sites. These findings suggest that SIRT1 may be a potential therapeutic target for treating tauopathies.

We describe a new species of cave-dwelling loach, Triplophysa wulongensis sp. nov., based on specimens collected in a subterranean pool in a cave in Wulong County, Chongqing, Southwest China. The pool is connected to the Wujiang River drainage. Triplophysa wulongensis differs from its congeners by the following combination of characters: eyes present, caudal fin with 18 branched rays; posterior chamber of the air bladder degenerate; stomach U-shaped; intestine without bends or loops immediately posterior to stomach; body smooth and scaleless, and lateral line complete. The mitochondrial cytochrome b sequence differs from those of other published sequences of species of Triplophysa by 14.9–24.9% in K2P distance. Phylogenetic analysis based on cytochrome b gene sequences recovered T. wulongensis as sister taxon to all other cave-dwelling species of Triplophysa .

Environmental DNA (eDNA) techniques refer to utilizing the organisms’ DNA extracted from environment samples to genetically identify target species without capturing actual organisms. eDNA metabarcoding via high‐throughput sequencing can simultaneously detect multiple fish species from a single water sample, which is a powerful tool for the qualitative detection and quantitative estimates of multiple fish species. However, sequence counts obtained from eDNA metabarcoding may be influenced by many factors, of which primer bias is one of the foremost causes of methodological error. The performance of 18 primer pairs for COI, cytb, 12S rRNA, and 16S rRNA mitochondrial genes, which are all frequently used in fish eDNA metabarcoding, were evaluated in the current study. The ribosomal gene markers performed better than the protein‐coding gene markers during in silico screening, resulting in higher taxonomic coverage and appropriate barcode lengths. Four primer pairs—AcMDB07, MiFish‐U, Ve16S1, and Ve16S3—designed for various regions of the 12S and 16S rRNA genes were screened for tank metabarcoding in a case study targeting six freshwater fish species. The four primer pairs were able to accurately detect all six species in different tanks, while only MiFish‐U, Ve16S1, and Ve16S3 revealed a significant positive relationship between species biomass and read count for the pooled tank data. The positive relationship could not be found in all species within the tanks. Additionally, primer efficiency differed depending on the species while primer preferential species varied in different fish assemblages. This case study supports the potential for eDNA metabarcoding to assess species diversity in natural ecosystems and provides an alternative strategy to evaluate the performance of candidate primers before application of eDNA metabarcoding in natural ecosystems., The maintenance of fish diversity is critical for aquatic ecosystem healthy, but in order to properly evaluate this, we must ensure that the tools used are properly evaluated and that we know how to identify problems or biases. As aquatic ecosystem management is a global issue, we feel that this research will have a broad audience in the world of freshwater and marine ecosystem research.

OBJECTIVE To investigate the effects of Shenqi Yangxin decoction (SQYXD) on heart function in a rat model of dilated cardiomyopathy (DCM) and its potential mechanisms. METHODS Sprague-Dawley rats were randomly divided into normal (10 rats) and DCM (150 rats) groups. DCM was induced by an intraperitoneal injection of adriamycin. Then, DCM baseline group was randomly selected sixteen DCM rats. The remaining DCM rats were randomly divided into DCM control, perindopril, metoprolol, and SQYXD groups. Cardiac function and histological analysis plus biochemical measurement of serum levels of brain natriuretic peptide (BNP), and inflammatory factors were measured. The mRNA and protein expression levels of high-mobility group box 1 (HMGB1), Toll-like receptor 4 (TLR-4), receptor for advanced glycation end products (RAGE), and nuclear factor-κB (NF-κB) were determined. Myocardial metabolism imaging was performed on the normal, SQYXD and DCM control groups to evaluate the effectiveness of treatments. RESULTS Rats in the DCM control group exhibited dilated left ventricular diameter, impaired cardiac function, disorganized sarcomere, impaired glucose metabolism, increased heart weight index, and increased levels of BNP, which were improved by treatment with SQYXD. In addition, hearts from rats in the DCM baseline group exhibited significantly higher levels of HMGB1, TLR-4, RAGE, NF-κB, tumor necrosis factor-α, interleukin-1, interleukin-6, interleukin-10, compared with the normal group. Interestingly, the mRNA level of HMGB1 in the DCM baseline group was positively correlated with that of TLR-4, RAGE, NF-κB, BNP, and LVEDD, but negatively correlated with LVEF. SQYXD inhibited the upregulation of HMGB1 expression and its downstream inflammatory factors. CONCLUSION Shenqi Yangxin decoction effectively reduced the dilated left ventricular diameter and improved heart function in dilated cardiomyopathy. The mechanisms underlying the action on DCM involve regulating the gene and protein expression of HMGB1 and its inflammatory signal pathways in the DCM rat model.

Environmental DNA (eDNA) techniques are gaining attention as cost-effective, non-invasive strategies for acquiring information on fish and other aquatic organisms from water samples. Currently, eDNA approaches are used to detect specific fish species and determine fish community diversity. Various protocols used with eDNA methods for aquatic organism detection have been reported in different eDNA studies, but there are no general recommendations for fish detection. Herein, we reviewed 168 papers to supplement and highlight the key criteria for each step of eDNA technology in fish detection and provide general suggestions for eliminating detection errors. Although there is no unified recommendation for the application of diverse eDNA in detecting fish species, in most cases, 1 or 2 L surface water collection and eDNA capture on 0.7-μm glass fiber filters followed by extraction with a DNeasy Blood and Tissue Kit or PowerWater DNA Isolation Kit are useful for obtaining high-quality eDNA. Subsequently, species-specific quantitative polymerase chain reaction (qPCR) assays based on mitochondrial cytochrome b gene markers or eDNA metabarcoding based on both 12S and 16S rRNA markers via high-throughput sequencing can effectively detect target DNA or estimate species richness. Furthermore, detection errors can be minimized by mitigating contamination, negative control, PCR replication, and using multiple genetic markers. Our aim is to provide a useful strategy for fish eDNA technology that can be applied by researchers, advisors, and managers. National Natural Science Foundation of China

Sialic acid, the major component of edible bird's nests, was evaluated for its hypotensive and antioxidant activities. In the mesenteric arteries with complete endothelium but not with stripped off endothelium, sialic acid exhibited a dose-dependent relaxant effect suggesting a strong antihypertensive effect. In addition, sialic acid exhibited free radical elimination ability with a stronger scavenging ability for hydroxide radicals compared to DPPH radicals. In conclusion, the results presented herein provide a basis for clinical investigations into application of sialic acid as functional food for management of hypertension.

Glucose-dependent insulinotropic polypeptide (GIP) receptor (GIPR) has been identified in multiple genome-wide association studies (GWAS) as a contributor to obesity, and GIPR knockout mice are protected against diet-induced obesity (DIO). On the basis of this genetic evidence, we developed anti-GIPR antagonistic antibodies as a potential therapeutic strategy for the treatment of obesity and observed that a mouse anti-murine GIPR antibody (muGIPR-Ab) protected against body weight gain, improved multiple metabolic parameters, and was associated with reduced food intake and resting respiratory exchange ratio (RER) in DIO mice. We replicated these results in obese nonhuman primates (NHPs) using an anti-human GIPR antibody (hGIPR-Ab) and found that weight loss was more pronounced than in mice. In addition, we observed enhanced weight loss in DIO mice and NHPs when anti-GIPR antibodies were codosed with glucagon-like peptide-1 receptor (GLP-1R) agonists. Mechanistic and crystallographic studies demonstrated that hGIPR-Ab displaced GIP and bound to GIPR using the same conserved hydrophobic residues as GIP. Further, using a conditional knockout mouse model, we excluded the role of GIPR in pancreatic β-cells in the regulation of body weight and response to GIPR antagonism. In conclusion, these data provide preclinical validation of a therapeutic approach to treat obesity with anti-GIPR antibodies.

The 10 microsatellite markers (XBM7, XBM11, XBM16, XBM19, XBM24, XBM31, XBM84, TGLA53, SRCRSP-10 and ILS005) were selected to investigate the genetic diversity of Tibetan goat of Plateau type (NM, n=108), and the other 5 goat populations, i.e., Tibetan goat of Valley type (TG, n=36), Baiyu black goat (BY, n=36), Jianchang black goat (JC, n=36), Meigu goat (MG, n=36) and Xinjiang goat (XJ, n=32) were served as control. The mean polymorphism information content, heterozygosity and effective allele number of these 6 populations were 0.660/0.777/4.476, 0.716/0.797/4.9416, 0.631/0.673/3.061, 0.649/0.680/3.125, 0.629/0.680/3.125 and 0.561/0.793/4.840 respectively. The allele frequencies of Tibetan goat of plateau type in 10 microsatellite loci were greatly different with other 5 goat populations. The 6 goat populations were grouped into three distinct clusters: the Tibetan goat cluster (NM goat and TG goat), Sichuan goat cluster (JC goat, MG goat and BY goat), and Xinjiang goat cluster (XJ goat). These 3 distinct clusters were finally clustered together. The genetic differences among populations were in accordance with their geographical and historical origins.

ObjectiveTo observe the effect of Liandouqingmai recipe (Chinese herbal medicine compound preparation) on the quality of life (QOL) and inflammatory reaction of patients with coronary heart disease (CHD).MethodsA total of 101 CHD patients were randomized into two groups: treatment group (n=45) receiving standard treatment for CHD plus Liandouqingmai recipe, and control group (n=56) receiving standard treatment only. The control group contained 16 normal healthy subjects. Changes in hs-C-reactive protein (CRP), peripheral blood leucocytes (PBL), and interleukin (IL)-6 and IL-10 levels were measured. The Seattle Angina Questionnaire (SAQ) was used to determine patient QOL before and after treatment for 2 weeks.ResultsBefore treatment, SAQ scores [physical limitation (PL), angina stability (AS), angina frequency (AF), treatment satisfaction (TS), and disease perception (DP)] were not statistically different between groups. After treatment, AS and DP levels of controls were significantly increased compared with the other groups, while PL, AS, AF, TS, and DP levels of the treatment group were significantly increased compared with controls. Treatment group SAQ scores (PL, AS, AF, TS, and DP) were significantly higher than for controls. CHD patient IL-6 and IL-10 levels were significantly higher than controls. Before treatment, mean levels of IL-6, hs-CRP and PBL of the two groups were not statistically different. After treatment, mean levels of IL-6, IL-10, hs-CRP and PBL of the two groups were significantly decreased compared with their before treatment values, and levels of IL-6, hs-CRP, and PBL of the treatment group were lower than controls. Although mean IL-10 levels of both groups decreased, there was no significant difference in between-group and in-group comparisons before and after treatment. Mean levels of IL-6 and IL-10 in the normal group were lower than in CHD patients. SAQ scores of QOL were negatively associated with the inflammatory index (IL-6/IL-10), and there was a significant negative association of IL-10 with AS (r= − 0.15, P

Wang, Y., Fang, H., Cao, Y., Liu, L. and Jiang, M. 2010. Jintang black goat (Capra hircas) hnRNP K: molecular cloning, sequence analysis and expression detection. J. Appl. Anim. Res., 38: 159–164. The cDNA encoding hnRNP K gene in Jintang Black goat was cloned by RT-PCR method. The entire cDNA sequence (1641 bp) contains a 1326 bp open reading frame and encodes 441 amino acids (48.709 kDa). Subsequent amino acid sequence analysis indicated that it showed a high level of sequence identity to Oryctolagus cuniculus (96.6%), Rattus norvegicus (94.5%), Bos taurus (99.7%), Homo sapiens (96.5%), Mus musculul (95.1%). Conserved domain and functional site analysis results showed that it has 3 KH domains, 3 RGG boxes, 1KNS signal, 1 acetylation site, was almost the same structure as hnRNP K proteins from other species. On the contrary, there is deletion mutation between 293 and 294, which amino acids sequence was “PGRGGRGGSRARNLPLPPPPP” in others species. Only 2 RGG-boxes (arginine-glycine- glycine boxes) ...

Background The dysfunction of baroreflex plays an important role in the pathogenesis of essential hypertension. Recent studies suggest that approximately 40% of the variation in baroreflex sensitivity (BRS) may be accounted for by genetic factors. However, only a few such genetic polymorphisms have been explicitly identified. Methods A total of 182 normotensive young men were included in the study. They were tested for the occurrence of genotypes involving nine polymorphisms in six genes that have a role in the regulation of the cardiovascular system. BRS was calculated from the spontaneous fluctuation of systolic blood pressure (SBP) and heart interval, using a sequence method. Results BRS was negatively correlated with body mass index (BMI), SBP, and family history of hypertension. Univariate analysis revealed that BRS is significantly associated with three of the polymorphisms studied. At the polymorphism T-786C in the endothelial nitric oxide (NO) synthase (eNOS) gene, the subjects with TT genotype had lower BRS than subjects carrying either the TC or the CC genotype. At the polymorphism of C-344T in the aldosterone synthase gene (CYP11B2), subjects with the TT genotype had higher BRS as compared to those with CC. At the polymorphism of T-58C in the bradykinin B2 receptor (B2R) gene, subjects with CC genotype had lower BRS as compared to subjects with TT. A multivariable linear regression analysis indicated that 16% of the BRS variation could be explained by these three polymorphisms. Conclusions Baroreflex function plays an important role in regulating blood pressure, both in the short term and in the long term. Three polymorphisms that are associated with the variation in BRS were identified in the eNOS, CYP11B2, and B2R genes, respectively; overall, they accounted for 16% of the BRS variation.

Hypertrophic scars (HSc) have an excess of microvessels, most of which are partially or totally occluded. The mechanisms underlying microvessel endothelial cell accumulation and microvessel occlusion are poorly understood. In this study, we observed the microvessels with H&E staining and electron microscopy, and detected the cytokine expression with immunochemistry. In addition, we isolated fibroblasts and endothelial cells from both human HSc tissue and normal skin and studied their cytokine expression. Furthermore, we assayed the endothelial cell proliferation when co-cultured with normal endothelial cells and blocked with anti-VEGF and anti-bFGF neutralizing. The results revealed that more endothelial cells in HSc microvessels and the cells were swollen. The cultured HSc fibroblasts secreted significantly more while HSc endothelial cells secreted significantly less cytokines, and the same trend was found with cytokines and collagen mRNAs, which was also confirmed by immunochemistry finding. In addition, endothelial cells proliferated faster when co-cultured with HSc fibroblasts, and reduced by anti-VEGF and anti-bFGF neutralizing. This is the first report regarding the function of endothelial cells in hypertrophic scars. The hyperactivity in cytokine secretion and collagen production is largely responsible for over-proliferation and functional regression of endothelial cells, and the malfunctioning of both cell types contributes to microvessel occlusion.

Previous studies have shown that in Saccharomyces cerevisiae the mitochondrial and cytoplasmic forms of alanyl-tRNA synthetase are encoded by a single nuclear gene, ALA1, through alternative use of in-frame successive ACG triplets and a downstream AUG triplet. Here we show that despite the obvious participation of the non-AUG-initiated leader peptide in mitochondrial localization, the leader peptide per se cannot target a cytoplasmic passenger protein into mitochondria under normal conditions. Functional mapping further shows that an efficient targeting signal is composed of the leader peptide and an 18-residue sequence downstream of Met1. Consistent to this observation, overexpression of the cytoplasmic form enables it to overcome the compartmental barrier and function in the mitochondria as well, but deletion of as few as eight amino acid residues from its amino-terminus eliminates such a potential. Thus, the sequence upstream of the first in-frame AUG initiator not only carries an unusual initiation site, but also contributes to a novel pattern of protein expression and localization.

Although initiation of translation at non-AUG codons occurs occasionally in prokaryotes and higher eukaryotes, it has not been reported in yeast until very recently. Evidence presented here shows that redundant ACG codons are recognized as alternative translation start sites for ALA1, the only gene in Saccharomyces cerevisiae coding for alanyl-tRNA synthetase. ALA1 is shown to be a bifunctional gene that provides both cytoplasmic and mitochondrial activities. Unlike most bifunctional genes that contain alternative in-frame AUG initiators, there is only one AUG codon, designated AUG1, close to the 5'-end of the ALA1 open reading frame. Transcriptional mapping identified three overlapping transcripts, with 5'-ends at positions 54, 105, and 117 nucleotides upstream of AUG1, respectively. Site-specific mutagenesis demonstrated that the cytoplasmic and mitochondrial functions of ALA1 are provided by two protein isoforms with distinct amino termini; that is, a short cytoplasmic form initiated at AUG1 and a longer mitochondrial isoform initiated at two upstream in-frame ACG codons, i.e. ACG(-25) and ACG(-24). These two ACG codons function redundantly in initiation of translation. Either codon can function in the absence of the other. The short transcript appears to serve as the template for the cytoplasmic form, whereas the longer transcripts are likely to code for both isoforms via alternative initiation. Because yeast ribosomes in general cannot efficiently recognize a non-AUG initiator, this unique feature of redundancy of non-AUG initiators in a single mRNA may in itself represent a novel paradigm for translation initiation from poor initiators.

Objective: To compare the therapeutic effects of Astragaloside and Perindopril on myocardial sarco/endoplasmic reticulum Ca2+ -ATPase (SERCA) activity and the SERCA type 2 mRNA level in Coxsack-ievirus B3 (CVB3)-infected cardiomyocytes.Methods: Cultured cardiomyocytes of rats were divided into normal, model, Astragaloside and Perindopril groups. The model, Astragaloside and Perindopril groups were infected with CVB3. Meanwhile, the Astragaloside and the Perindopril groups were treated with Astragaloside (10 μg/ml) and Perindopril (1.3 μg/ml) respectively. Cytopathic effect (CPE), cardiac troponin I (cTnI), the SERCA activity and mRNA level of the SERCA type 2 were observed after 96 hours.Results: The CPE and cTnI of model group were significantly higher than those of normal, Astragaloside and Perindopril groups (P 0.05).Conclusion: Astragaloside and Perindopril were able to reverse the down-regulations of cardiac SERCA activity and mRNA expression caused by virus infection to alleviate the cardiomyocyte injury.

The genomes of bacteriophages T4 and RB69 are phylogenetically related but diverge in nucleotide sequence at many loci and are incompatible with each other in vivo. We describe here the biological implications of divergence in a genomic segment that encodes four essential DNA replication proteins: gp45 (sliding clamp), gp44/62 complex (clamp loader), and gp46 (a recombination protein). We have cloned, sequenced, and expressed several overlapping segments of the RB69 gene 46-45.2- ( rpbA ) -45-44-62 cluster and compared its features to those of the homologous gene cluster from T4. The deduced primary structures of all four RB69 replication proteins and gp45.2 from this cluster are very similar (80 to 95% similarity) to those of their respective T4 homologs. In contrast, the rpbA region (which encodes a nonessential protein in T4) is highly diverged (∼49% similarity) between the two phage genomes and does not encode protein in RB69. Expression studies and patterns of high divergence of intercistronic nucleotide sequences of this cluster suggest that T4 and RB69 evolved similar transcriptional and translational control strategies for the cistrons contained therein, but with different specificities. In plasmid-phage complementation assays, we show that posttranslationally, RB69 and T4 homologs of gp45 and the gp44/62 complex can be effectively exchanged between the two phage replicase assemblies; however, we also show results which suggest that mixed clamp loader complexes consisting of T4 gp62 and RB69 gp44 subunits are not active for phage DNA replication. Thus, specificity of the gp44-gp62 interaction in the clamp loader marks a point of departure between the T4 and RB69 replication systems.

To clarify the effects of an antithyroid drug on the kinetics of thyroglobulin synthesis, secretion, and reabsorption in the thyroid follicles, propylthiouracil (PTU) was administered to rats and the thyroid glands were examined by a refined post-embedding immunogold technique during and after withdrawal of PTU. Seven-wk-old male Wistar rats were administered with S mg of PTU/d through a gastric tube, and sacrificed at 1 and 2 wk of administration and at 1, 2, and 3 d, and 1, 2, 3, and 4 wk, after discontinuation. The administration of PTU caused a remarkable dilatation of the rER and Golgi apparatus, but these areas gradually recovered after withdrawal of PTU. During the experiment, no significant change in the density of thyroglobulin (Tg) was observed except for a transient increase immediately after withdrawal of PTU. The expression of Tg on subapical vesicles (SV) and follicular colloid took a relatively parallel course; increasing during administration of PTU and decreasing with a transient peak immediately after treatment was discontinued. In contrast to the remarkable changes in the morphology of compartments involved in Tg synthesis, the development of colloid droplets and formation of secondary lysosomes were suppressed during and after discontinuing administration of PTU. However, the basic pattern of the gradient of Tg density among the cellular compartments was essentially retained in the experimental group. Thus the present immunoelectron-microscopic study provided evidence that administration of PTU stimulates the synthesis and secretion of Tg in the follicular epithelium in vivo, and, also, suppresses reabsorption and degradation of Tg. Further, it was speculated that the density gradient of Tg among the compartments involved in Tg synthesis, secretion and storage is regulated by an unknown constitutive mechanism and not by the thyroid-stimulating hormone (TSH)-TSH receptor-mediated system.

We describe the use of a phylogenetic approach to analyze the modular organization of the single-chained (898 amino acids) and multifunctional DNA polymerase of phage T4. We have identified, cloned in expression vectors, and sequenced the DNA polymerase gene (gene 43) of phage RB69, a distant relative of T4. The deduced primary structure of the RB69 protein (RB69 gp43) differs from that of T4 gp43 in discrete clusters of short sequence that are interspersed with clusters of high similarity between the two proteins. Despite these differences, the two enzymes can substitute for each other in phage DNA replication, although T4 gp43 does exhibit preference to its own genome. A 55-amino acid internal gp43 segment of high sequence divergence between T4 and RB69 could be replaced in RB69 gp43 with the corresponding segment from T4 without loss of replication function. The reciprocal chimera and a deletion mutant of the T4 gp43 segment were both inactive for replication and specifically inhibitory (“dominant lethal”) to the T4 wild-type allele. The results show that phylogenetic markers can be used to construct chimeric and truncated forms of gp43 that, although inactive for replication, can still exhibit biological specificity.

Thirty-two burned or plastic surgery patients were grafted with allogeneic cultured epidermis on autograft donor sites. Two techniques, the indirect enzyme conjugated Staphylococcus Protein A assay with monoclonal antibodies against A or B blood group antigens and the polymerase chain reaction to detect a Y chromosome-specific DNA sequence, were employed to identify the presence of cultured epidermal allograft based on different ABO blood grouping or sex between donor and recipient. The methods have the advantage of high sensitivity and specificity in identifying the existence of allogeneic skin cells in grafts. The results indicated that the survival time of cultured epidermal allograft was prolonged up to 35 days. In addition, the intact coverage on some grafting sites may be composed of both host and donor origin cells, after about 3 weeks postgrafting.

It was previously shown that ALA1, the only alanyl-tRNA synthetase gene in Saccharomyces cerevisiae, codes for two functionally exclusive protein isoforms through alternative initiation at two consecutive ACG codons and an in-frame downstream AUG. We reported here the cloning and characterization of a homologous gene from Candida albicans. Functional assays show that this gene can substitute for both the cytoplasmic and mitochondrial functions of ALA1 in S. cerevisiae and codes for two distinct protein isoforms through alternative initiation from two in-frame AUG triplets 8-codons apart. Unexpectedly, although the short form acts exclusively in cytoplasm, the longer form provides function in both compartments. Similar observations are made in fractionation assays. Thus, the alanyl-tRNA synthetase gene of C. albicans has evolved an unusual pattern of translation initiation and protein partitioning and codes for protein isoforms that can aminoacylate isoaccepting tRNAs from a different species and from across cellular compartments.

Total DNA preparations from 74 antibiotic-producing type strains and 102 natural Streptomyces isolates were examined by dot blots for homology to 6 antibiotic production and resistance genes. Pattern diversity of hybridizations decreased as stringency increased from 65% to 85%. There were 146 unique profiles at 65% stringency with 13 repeated patterns, whilst there were only 14 unique and 11 repeated profiles at 85% stringency. Most of the strains which hybridized at 85% reacted with one or two probes although a few strains showed multiple homologies. This data was used to cluster strains and the groups defined were examined for phenotypic antibiotic resistance. Producers of certain classes of antibiotics clustered to specific groups and some gene homologies were more common amongst strains which produced similar antibiotics.

Metapolypodium Ching, a monotypic genus endemic to Asia mainland (SW China and its neighboring regions), is still in dispute as to its systematic position. In this paper, the phylogenetic relationships of this genus was examined based on the chloroplast DNA sequences of rbcL gene and rps4-trnS region. The rbcL genes and rps4-trnS region of M. manmeiense (Christ) Ching and its closely related species were sequenced. The combined relative sequences downloaded from the GenBank, consisting of three data sets―rbcL genes, rps4-trnS region including rps4 and rps4-trnS intergenetic spacer, and the combined matrix―were used to assess relationships among them with the neighbor-joining (NJ), maximum-parsimony (MP) and Bayesian inference (BI) analyses. The phylogenetic trees based on individual sequence data and the combined data are topologically similar and reveal that M. manmeiense forms a clade with the members of Polypodiodes and Polypodiastrum, which is not related to any member of Polypodium. The trees also strongly support the close relationship between M. manmeiense and Polypodiodes microrhizoma (C. B. Clarke ex Baker) Ching. We should agree with Ching's opinion, recognizing Polypodium L. emend. Ching, Metapolypodium Ching, Polypodiodes Ching, Polypodiastrum Ching and Schellolepis J. Sm. as independent taxa according to the results of the present study. It is reasonable to transfer