Hexaploid H1 (ES) cells established from octaploid H1 cells are as DNA stable as pentaploid H1 cells

Hexaploid H1 (ES) cells (6H1 cells) were established from octaploid H1 cells (8H1 cells), as were pentaploid H1 cells (5H1 cells). 6H1 cells were compared with 5H1 cells. The number of chromosomes of 6H1 cells was 115, 20 more than the 95 of 5H1 cells. The durations of G(1), S, and G(2)/M phases of 6H1 cells were 3, 7, and 6 h, respectively, almost the same as those of 5H1 cells. The cell volume of 6H1 cells was equivalent that of 5H1 cells. The morphology of 6H1 cells was flattened circular cluster, different from the spherical cluster of 5H1 cells. 6H1 cells exhibited alkaline phosphatase activity as well as 5H1 cells. The DNA content of 6H1 cells was stable and maintained for 300 days of culturing, the same as that of 5H1 cells. The DNA stability of 6H1 cells was explained using a hypothesis concerning the DNA structure of polyploid cells because the asymmetric configuration of homologous chromosomes in 6H1 cells inhibited chromosome loss.     

Immunoglobulin (IgG) allotypes of the American mink with Aleutian disease

Mink Aleutian disease (AD) is characterized by intensive proliferation of B-lymphocytes and hypergammaglobulinemia. Populational distribution of five genetic immunoglobulin markers (light chain allotype L1 and C gamma-allotypes H2, H3, H6 and H8) in minks of different coat color (Sapphire, Standard and Topaz) was studied. The groups of infected minks differed significantly from healthy ones in the distribution of the H3 allotype: the frequencies of some phenotypes--H3, H6, H8 and L1, H3, H6, H8 (Sapphire, Standard). H2, H3, H6, H8 and L1, H2, H3, H6, H8 (Sapphire) were increased significantly. At the same time, the frequencies of H6, H8; L1, H6, H8 and H2, H6, H8; L1, H2, H6, H8 were decreased in the AD population. The preferential stimulation of proliferation of the H3 + B-lymphocyte clones is suggested.     

Fractionation of avian erythrocyte histones by hydrophobic interaction chromatography.

The interactions of H1 (H1A, H1B), H2A, H2B, H3, H4, and H5 with phenyl cross-linked agarose were studied. Procedures are described whereby all six histones can be bound, released, and fractionated by using appropriate salt concentrations or pH. The binding can be totally abolished by inclusion of hydrophobic disrupting agents. Control experiments with nonderivated cross-linked agarose ruled out a passive aggregation-disaggregation phenomenon governing the binding patterns. The absorption sequence based on the identification and quantitation of individual histones from either unfractionated (whole) histone or separate histone classes is as follows: H3 greater than or equal to H4 greater than H2B greater than or equal to H5 greater than or equal to H2A greater than H1A greater than or equal to H1B. The order differs only slightly from the reverse of the desorption sequence, H1B less than or equal to H1A less than or equal to H5 less than H2A less than or equal to H3. Preferential interaction of H2A-H2B, H3-H4, and H2A-H2B-H4 occur; these interactions can modify the original relative affinity of each individual component for the matrix. The variability in matrix affinity appears to involve simple stoichiometry of the histone components.     

DNA stable pentaploid H1 (ES) cells obtained from an octaploid cell induced from tetraploid cells polyploidized using demecolcine

Pentaploid H1 (ES) cells (5H1 cells) were accidentally obtained through one‐cell cloning of octaploid H1 (ES) cells (8H1 cells) that were established from tetraploid H1 (ES) cells (4H1 cells) polyploidized using demecolcine. The number of chromosomes of 5H1 cells was 100, unlike the 40 of diploid H1 (ES) cells (2H1 cells), 80 of 4H1, and 160 of 8H1 cells. The durations of G₁, S, and G₂/M phases of 5H1 cells were 3, 7, and 6 h, respectively, almost the same as those of 2H1, 4H1, and 8H1 cells. The cell volume of 5H1 cells was half of that of 8H1 cells, suggesting that 5H1 cells were created through abnormal cell divisions of 8H1 cells. The morphology of growing 5H1 cells was a spherical cluster similar to that of 2H1 cells and differing from the flagstone‐like shape of 4H1 and 8H1 cells. Pentaploid solid tumors were formed from 5H1 cells after interperitoneal injection into the mouse abdomen, and they contained endodermal, mesodermal, and ectodermal cells as well as undifferentiated cells, suggesting both that the DNA content of 5H1 cells was retained during tumor formation and that the 5H1 cells were pluripotent. The DNA content of 5H1 cells was stable in long‐term culturing as 2H1 cells, meaning that 5H1 and 2H1 cells shared similarities in DNA structure. The excellent stability of the DNA content of 5H1 cells was explained using a hypothesis for the DNA structure of polyploid cells because the pairing of homologous chromosomes in 5H1 cells is spatially forbidden. J. Cell. Physiol. 223: 369–375, 2010. © 2010 Wiley‐Liss, Inc.     

Numerical Cytotaxonomic Studies of Hemerocallis (Liliaceae) from China

Comparative studies of karyotypes in Hemerocallis from China have been carried out using numerical techniques. Taxa studied are as follows: Hemerocallis citrina, H. dumortieri , H. esculenta , H. forrestii , di- and triploid H. fulva , H. lilioasphodelus , H. middendorffii, H. minor, H. multiflora and H. plicata. The results show that variation in speciation has taken place at chromosomal level, and that karyotype variations have largely paralleled the morphological ones. Taxonomic proposals are given to treat H. citrina and H. minor as subspecies of H. lilioasphodelus, and H. esculenta as a variety of H. dumortieri. The results are not in favour of considering H. middendorffii as a variety ofH. dumortieri, and H. multiflora closely related to H. plicata.     

The histones of Caenorhabditis elegans: no evidence of stage-specific isoforms. An overview

The nematode Caenorhabditis elegans expresses one species of H2A and one species of H4 molecules, at least two species of H1 (H1.1, H1.2), two species of H2B (H2B.1, H2B.2) and 2-4 species of H3 (H3.1 and H3.3 and an unassigned Ile/Leu microheterogeneity in H3). The study of their primary structures has been completed now and all of them, with the exception of the Ile/Leu microheterogeneity in H3, have been assigned to protein spots on two-dimensional gels. One spot, previously designated H3.2, probably represents C-terminally cleaved H3.1. The relative abundance of the isohistones was essentially the same when derived from either eggs, gravid adults or postreproductive, senescent worms. The degree of post-translational modification, however, particularly acetylation of H2A, H2B and H3 histone species, was reduced at old age.     

长叶车前花叶病毒上海分离株单克隆抗体的制备及其免疫学特性 Ⅲ 病毒抗原决定簇的单克隆抗体识别

前文分别报道了长叶车前花叶病毒上海分离侏(RMVsh)单克隆抗体的制备及根据它们在不同免疫反应中的特性,将它们分为两组,分别识别性质不同的抗原决定簇。本文采用修改的Friguet方法测定了各组内各单克隆抗体之间的增值反应(Additivity Reaction)特性,并分析了它们识别抗原决定簇的特性。村料与方法一、病毒及单克隆抗体长叶车前花叶病毒上海分离株及其单克隆抗体1H2、7H1、10H1、11H2、12H3、17H6、29H1来源、制备和特性见前文报道。二、抗原饱和曲线的测定抗原饱和曲线测定采用间接ELISA办法,抗原浓度为2μg/ml。     

Sequence, organization and expression of the core histone genes of Aspergillus nidulans

Summary The core histone gene family ofAspergillus nidulans was characterized. The H2A, H2B and H3 genes are unique in theA. nidulans genome. In contrast there are two H4 genes, H4.1 and H4.2. As previously reported for the H2A gene (May and Morris 1987) introns also interrupt the other core histone genes. The H2B gene, like the H2A gene, is interrupted by three introns, the H3 and H4.1 gene are each interrupted by two introns and the H4.2 gene contains one intron. The position of the single intron in H4.2 is the same as that the first intron of the H4.1 gene. The H2A and H2B genes are arranged as a gene pair separated by approximately 600 by and are divergently transcribed. The H3 and H4.1 genes are similarly arranged and are separated by approximately 800 bp. The H4.2 gene is not closely linked to either the H2A-H2B or H3-H4.1 gene pairs. Using pulse field gel electrophoresis an electrophoretic karyotype was established forA. nidulans. This karyotype was used to assign the H3–H4.1 gene pair and the H4.2 gene to linkage group VIII and the H2A–H2B gene pair to either linkage group III or VI. The abundance of each of the histone messenger RNAs was determined to be cell cycle regulated but the abundance of the H4.2 mRNA appears to be regulated differently from the others.     

中国萱草属(百合科)的数量细胞分类研究

用数量分类技术比较研究了国产萱草属植物的核型。所研究的分类群是:Hemerocallis citrina, H．dumortieri,H．esculenta,H．forrestii,二倍体和三倍体H．fulva,H．lilioasphodelus,H．mid- dendorffii,H．minor,H．multiflora,H．plicata。结果表明,物种形成已发生在染色体水平,染色体 变异与形态变异基本一致。结果支持将H．citrina和H．minor作为H．lilioasphodelus的亚种,H． esculenta作为H．dumortieri的变种。结果不支持将H．middendorffii作为H．dumortieri的变种,也 没有发现H．multiflora与H．plicata密切相关的证据。     

Expression and purification of recombinant human histones

Nucleosomes reconstituted from bacterially expressed histones are useful for functional and structural analyses of histone variants, histone mutants, and histone post-translational modifications. In the present study, we developed a new method for the expression and purification of recombinant human histones. The human histone H2A, H2B, and H3 genes were expressed well in Escherichia coli cells, but the human histone H4 gene was poorly expressed. Therefore, we designed a new histone H4 gene with codons optimized for the E. coli expression system and constructed the H4 gene by chemically synthesized oligodeoxyribonucleotides. The recombinant human histones were expressed as hexahistidine-tagged proteins and were purified by one-step chromatography with nickel-nitrilotriacetic acid agarose in the presence of 6 M urea. The H2A/H2B dimer and the H3/H4 tetramer were refolded by dialysis against buffer without urea, and the hexahistidine-tags of the histones in the H2A/H2B dimer and the H3/H4 tetramer were removed by thrombin protease digestion. The H2A/H2B dimer and the H3/H4 tetramer obtained by this method were confirmed to be proficient in nucleosome formation by the salt dialysis method. The human CENP-A gene, the centromere-specific histone H3 variant, contains 28 minor codons for E. coli. A new CENP-A gene optimized for the E. coli expression system was also constructed, and we found that the purified recombinant CENP-A protein formed a nucleosome-like structure with histones H2A, H2B, and H4.     

A phylogenetic review of the genus Hexabathynella Schminke, 1972 (Crustacea, Malacostraca, Bathynellacea): with a description of four new species

The genus Hexabathynella (Crustacea, Malacostraca, Bathynellacea) is revised in the sense of the phylogenetic systematics and four new species are described from South Africa ( H. monoaethetasca sp. nov. and H. africana sp. nov. ) and America ( H. schrieveri sp. nov. and H. virginiae sp. nov. ). A comparative analysis of all observable outer structures distributed in 18 known and four new species resulted in a re-evaluation of 18 characters and character states. The phylogenetic analysis using the program PAUP yielded one most-parsimonious tree, which suggests the grouping of ( H. decora (( H. halophila  +  H. aotearoae ) + ( H. pauliani ( H. monoaethetasca  + H. africana )))) + ( H. knoepffleri ( H. nicoleiana ( H. hebrica , H. tenera , H. longiappendiculata , H. breviappendiculata , H. nestica ) +  H. virginiae (( H. minuta ( H. valdecasasi + H. otayana )) + ( H. hessleri + H. muliebris ))) +  H. paranaensis ( H. szidati + H. schrieveri )). The tree is 57 steps long and has a consistency index of 0.6140, a retention index of 0.7982 and a rescaled consistency index of 0.4901. The result does not agree with the previous analyses on the genus. In terms of sampling and coding, the characters used in the previous study are critically assessed.  © 2006 The Linnean Society of London, Zoological Journal of the Linnean Society , 2006, 147 , 71–96.     

Xanthine oxidase activity in rat serum after administration of homogenized bovine cream preparation

Rats were given a single dose of saline, saline supplemented with xanthine oxidase (XO), half cream and half milk (H/H) and H/H supplemented with XO. XO was determined by a spectrophotometric method at 297 nm in serum at 0, 2, 4 and 6 hours after administration. The method is rapid, reliable and compares favorably with reported assays. No significant difference was obtained between the two saline treatments. The XO activity in serum of animals receiving the H/H increased significantly at 2 hours and then decreased. The H/H supplemented with XO demonstrated a maximum activity in serum at 4 hours and then declined to a value similar to that of the H/H treatment and below the XO level at 0 time. The initial increase in XO activity in serum of rats receiving the H/H treatments may indicate that XO is absorbed in the gastrointestinal tract or that the H/H materials stimulated endogenous XO activity.     

Dodecaploid H1 embryonic stem cells abolished pluripotency in L15F10 medium both with and without leukemia inhibitory factor

Two lines of dodecaploid H1 embryonic stem cells, 12H1 and 12H1(?) cells (mouse-originated cells), were established through polyploidization of two hexaploid H1 cells, 6H1 and 6H1(?) cells, which were cultured in L15F10 (7:3) medium with and without leukemia inhibitory factor (LIF), respectively. The G₁, S, and G₂/M phase fractions of 12H1 and 12H1(?) cells were almost the same as those of 6H1 and 6H1(?) cells, respectively, but the doubling time of cell proliferation was prolonged, suggesting that cell death occurred in 12H1 and 12H1(?)cells. The cell volumes of 12H1 and 12H1(?) cells were about double those of 6H1 and 6H1(?) cells, respectively. 12H1 and 12H1(?) cells showed near-negative activity of alkaline phosphatase and no ability to form teratocarcinomas in mouse abdomen, suggesting that 12H1 and 12H1(?) cells lost pluripotency. The DNA contents of 12H1 and 12H1(?) cells decayed in long-term culturing, suggesting that 12H1 and 12H1(?) cells were DNA-unstable. Possible explanations for the lost pluripotency and for the DNA decay in 12H1 and 12H1(?) cells are presented.     

Prediction of protein secondary structure based on physical theory. Histones

Secondary structures of histones H1, H2A, H2B, H3, H4 and H5 have been calculated by the computer program ALB based on a molecular theory of protein secondary structure. The predicted secondary structures of all histones are predominantly alpha-helical. The calculated secondary structure of linker histones H1 and H5 is close to that previously obtained from two-dimensional NMR data. For each of the core histones (H2A, H2B, H3, H4) one long alpha-helix and several short ones have been predicted. These long helices can be identified with rods in the low-resolution electron density map.     

Histone H1t is not replaced by H1.1 or H1.2 in pachytene spermatocytes or spermatids of H1t-deficient mice

The linker histone gene H1t is exclusively expressed in the mammalian testis. In former experiments we have shown that H1.1 and H1.2 histone gene expression is significantly enhanced in testis of adult H1t deficient mice. In this report we have quantified the mRNA of different H1 genes in 9-day- and 20-day-old wild type and H1t knock out mice. In addition, we have analysed the distribution of H1.1 and H1.2 protein by immunofluorescent staining in spread male germ cells. The aim of this work was to answer the question whether H1t can be replaced during spermatogenesis by H1.1 or H1.2. In our experiments we could not detect elevated levels of H1.1 or H1.2 in pachytene spermatocytes or haploid cells of H1t deficient testis. Therefore, in these cells, H1t seems not to be replaced by H1.1 or H1.2.     

中国萱草属数量分类研究

用聚类分析和主成分分析研究了国产萱草属11个类群的分类。结果发现这些类群形成4簇。第一簇：北黄花菜、黄花菜、小黄花菜和多花萱草。第二簇：小萱草和大苞萱草。第三簇：折叶萱草,西南萱草和矮萱草。第四簇：萱草及其三倍体类型。各簇都有其区别特征。讨论了簇内各类群之间的亲缘关系及属下分组问题。     

Comparative analysis of flagellin sequences from Escherichia coli strains possessing serologically distinct flagellar filaments with a shared complex surface pattern.

Escherichia coli morphotype E flagellar filaments have a characteristic surface pattern of short-pitch loops when examined by electron microscopy. Seven of the 50 known E. coli H (flagellar antigen) serotypes (H1, H7, H12, H23, H45, H49, and H51) produce morphotype E filaments. Polymerase chain reaction was used to amplify flagellin structural (fliC) genes from E. coli strains producing morphotype E flagellar filaments and from strains with flagellar filaments representing other morphotypes. A single DNA fragment was obtained from each strain, and the size of the amplified DNA correlated with the molecular mass of the corresponding flagellin protein. This finding and hybridization data suggest that these bacteria are monophasic. fliC genes from three E. coli serotypes (H1, H7, and H12) possessing morphotype E flagellar filaments were sequenced in order to assess the contribution of conserved flagellin primary sequence to the characteristic filament architecture. The H1 and H12 fliC sequences were identical in length (1,788 bp), while the H7 fliC sequence was shorter (1,755 bp). The deduced molecular masses of the FliC proteins were 60,857 Da (H1), 59,722 Da (H7), and 60,978 Da (H12). The H1, H7, and H12 flagellins demonstrated 98 to 99% identity over the amino-terminal region (190 amino acid residues) and 89% (H7) to 99% (H1 and H12) identity in the carboxy-terminal region (100 amino acid residues). The complete primary amino acid sequences for H1 and H12 flagellins differed by only 10 amino acids, accounting for previously reported serological cross-reactions. However, the central region of H7 flagellin had only 38% identity with H1 and H12 flagellins.The characteristic morphology of morphotype E flagellar filaments is therefore not dependent on a highly conserved primary sequence within the exposed central region. Comparison of morphotype E E. coli flagellins with those from E. coli K-12, Serratia marcescens, and several Salmonella serovars supported the established concept of highly conserved terminal regions flanking a variable central region.     

Steryl glycosides: a characteristic feature of the Helicobacter spp.?

The lipids of different species of Helicobacter (H.felis, H. muridarum, H. mustelae, H. fennelliae, and H. cinaedi) were studied. Different types of cholesteryl glucosides were found in all of the species studied except H. cinaedi. The total amount of cholesteryl glucosides varied from 14.8% of total lipids in H. mustelae to 33.1% of total lipids in H. felis. The different types of cholesteryl glucosides and their species distribution are cholesteryl-6-O-acyl-alpha-D-glucopyranoside (cholesteryl-6-O-tetradecanoyl-alpha-D-glucopyranoside in H. felis and cholesteryl-6-O-dodecanoyl-alpha-D-glucopyranoside in H. muridarum), cholesteryl-alpha-D-glucopyranoside (H. felis, H. muridarum, H. mustelae, and H. fennelliae), and cholesteryl-6-O-phosphatidyl-alpha-D-glucopyranoside (H. fennelliae). The neutral lipid fractions showed a high percentage of cholesterol, with selective accumulation of free cholesterol. The study thus shows that the characteristic presence of steryl glycosides in Helicobacter spp. may be an important chemotaxonomic marker for many of the species, and the helicobacters show a selective accumulation of free cholesterol from the media.     

Oxidation-reduction potentials and ionization states of extracellular peroxidases from the lignin-degrading fungus Phanerochaete chrysosporium

The oxidation-reduction potentials of lignin peroxidase isozymes H1, H2, H8, and H10 as well as the Mn-dependent peroxidase isozymes H3 and H4 are reported. The potentiometric titrations involving the ferrous and ferric states of the enzyme had Nernst plots indicating single-electron transfer. The Em7 values of lignin peroxidase isozymes H1, H2, H8, and H10 are -142, -135, -137, and -127 mV versus standard hydrogen electrode, respectively. The Em7 values for the Mn-dependent peroxidase isozymes H3 and H4 are -88 and -93 mV versus standard hydrogen electrode, respectively. The midpoint potential of H1, H8, and H4 remained unchanged in the presence of their respective substrates, veratryl alcohol and Mn(II). The midpoint potential between the ferric and ferrous forms of isozymes H1 and H4 exhibited a pH-dependent change between pH 3.5 and pH 6.5. These results indicate that the reductive half-reaction of the enzymes is the following: ferric peroxidase + le- + H+----ferrous peroxidase. Above pH 6.5, the effect of pH on the midpoint potential is diminished and indicates that an ionization with an apparent pKa equal to approximately 6.6-6.7 occurs in the reduced form of the enzymes. A heme-linked ionization group in the ferrous form of the enzymes was confirmed by studying the effect of pH on the absorption spectra of isozymes H1 and H4. These spectrophotometric pH titration experiments confirmed the electrochemical results indicating pKa values of 6.59 and 6.69 for reduced isozymes H1 and H4, respectively. These results indicate the presence of a heme-linked ionization of an amino acid in the reduced form of the lignin peroxidase isozymes similar to that of other plant peroxidases.