Studies on Molecular Properties of αs1-κ-Casein Complex by the Hydrodynamical Methods

Some molecular properties of α_s1-κ-casein complex, α_s1- and κ-casein polymers were examined by gel filtration, ultracentrifugation, and viscometry at pH 7.1. The Stoke’s radii of α_s1-κ-casein complex, α_s1- and κ-casein polymers were 99, 44 and 108 Å, respectively. The molecular weight of the above proteins were approximately 45 × 10⁴, 10 × 10⁴ and 80 × 10⁴, respectively. The stokes radius of α_s1-κ casein complex reduced compared with that of κ-casein polymer and the molecular weight of the complex was about half that of κ-casein polymer. These results suggest that κ-casein polymer dissociates into 4 smaller particles when α_s1-κ-casein complex is formed. The frictional coefficient and Scheraga-Mandelkern constants for each protein suggest that the molecular shape of α_s1-casein polymer is globular and that of α_s1-κ-casein complex and κ-casein polymer is rod-like.     

The demise of Leptotheca Thélohan, 1895 (Myxozoa: Myxosporea: Ceratomyxidae) and assignment of its species to Ceratomyxa Thélohan, 1892 (Myxosporea: Ceratomyxidae), Ellipsomyxa K?ie, 2003 (Myxosporea: Ceratomyxidae), Myxobolus Bütschli, 1882 and Sphaerospora Thélohan, 1892 (Myxosporea: Sphaerosporidae)

A revision of Leptotheca Thélohan, 1895 is presented. The boundaries that separate Leptotheca from Ceratomyxa Thélohan, 1892 and Sphaerospora Thélohan, 1892 are vague and have been highlighted as an area of concern within myxosporean classification. A survey of the literature revealed 63 species that are currently assigned to Leptotheca and a further 11 species that have been relegated as synonyms in Ceratomyxa, Sphaerospora or Myxobolus Bütschli, 1882. The placement of some species in the genus is unclear and demonstrates the need for a revision. The type-species of Leptotheca (L. agilis Thélohan 1892) has many Ceratomyxa-like characters, such that a minor amendation of the diagnosis of Ceratomyxa will then accept the type-species of Leptotheca, rendering the latter genus its synonym. We propose the suppression of Leptotheca, with all species currently assigned to that genus reassigned to Ceratomyxa, Ellipsomyxa K?ie, 2003, Myxobolus or Sphaerospora on the basis of appropriate morphological and biological traits. The diagnoses of Ceratomyxa and Ellipsomyxa are amended appropriately. Molecular analysis may change the placement of some species in the future; however, the aim of this review was to eliminate the ambiguity of assignment of species in the genera Leptotheca, Ceratomyxa and Sphaerospora by suppressing Leptotheca.     

小蓬NeMT2基因的克隆及其植物表达载体的构建

该研究利用RACE ( Rapid amplification of cDNA ends)技术从小蓬中成功分离编码金属硫蛋白( Metal-lothionein,MT)的cDNA序列,命名为NeMT2,在GenBank中登录号为KT835290。该基因全长590 bp,开放阅读框为237 bp,编码78个氨基酸,编码的氨基酸序列中含有14个半胱氨酸残基( Cys,C),呈C-C,C-X-C,C-X-X-C排列,集中分布在肽链的N端和C端,基因编码蛋白的分子量为7.6036 kD,等电点为4.71。系统发育分析表明,小蓬金属硫蛋白NeMT2与藜科的海蓬子( AEF01492)和盐穗木( AHI62953)同源性最高,其次是甜菜( XP 010667708.1)。生物信息学分析表明,金属硫蛋白NeMT2无信号肽结构,属于非跨膜亲水性蛋白;疏水性分析表明,NeMT2蛋白的35~45个氨基酸之间有较强的疏水性,其中第41位Asp具最强的疏水性(1.444);结构预测分析该蛋白质二级结构的主要元件是无规则卷曲。通过RT-PCR对NeMT2基因的表达分析发现, NeMT2基因在铜矿区和非铜矿区的小蓬叶片中均有表达,但该基因在铜矿区小蓬叶片的表达量明显高于非铜矿区。将小蓬NeMT2基因定向克隆到植物表达载体pCAMBIA1300的35S 启动子下游,构建该基因的植物超表达载体pCAMBIA1300＋NeMT2。该研究结果为进一步研究该基因的功能和小蓬响应重金属胁迫的分子机制提供了一定基础。     

Characterization of SLFL1, a pollen-expressed F-box gene located in the Prunus S locus

The S locus and its flanking regions in the genus Prunus (Rosaceae) contain four pollen-expressed F-box genes. These genes contain the S locus F-box genes with low allelic sequence polymorphism genes 1, 2, and 3 (SLFL1, SLFL2, and SLFL3) as well as the putative pollen S gene, named the S haplotype-specific F-box protein gene (SFB). As much less information is available on the function of SLFLs than that of SFB, we analyzed the SLFLs of six S haplotypes of sweet cherry (Prunus avium) in this study. Genomic DNA blot analysis and the isolation of SLFL1 showed that the SLFL1 gene in a functional self-incompatible S ³ haplotype is deleted and only a partial sequence resembling SLFL1 is left in the S ³ locus region, suggesting that SLFL1 by itself is not directly involved in either the GSI reaction or pollen-tube growth. Genomic DNA blot analysis showed that there was no substantial modification or mutation in SLFL2 and SLFL3. A phylogenic analysis of F-box genes in the rosaceous S locus and its border regions showed that Prunus SLFLs were more closely related to maloid S locus F-box brothers than to Prunus SFBs. The functions of SLFLs and the evolution of self-incompatibility in Prunus are discussed based on these results. Electronic supplementary material  The online version of this article (doi:) contains supplementary material, which is available to authorized users. The nucleotide sequence data reported appear in the DDBJ, EMBL, and GenBank Nucleotide Sequence Databases under the accession numbers, AB360339, AB360340, AB360341, and AB360342, for SLFL1-S ¹ , SLFL1-S ² , SLFL1-S ⁵ , and SLFL1-S ⁶ , respectively.     

Analisi citologica di alcune specie del genere Vicia

Abstract

Karyology of some species of Vicia. The species studied are: Vicia articulata, Vicia monantha, Vicia narbonensis and Vicia ervilia.

The chromosome number 2n = 14 counted for the first three species agrees with that reported in literature; that of Vicia monantha (2n=14) agrees with that quoted by Heitz, while Senn finds 2n=12.

Karyotypes of V. narbonensis and V. ervilia show appreciable differences from those reported in literature.     

The Evolution of RecD Outside of the RecBCD Complex

The common understanding of the function of RecD, as derived predominantly from studies in Escherichia coli, is that RecD is one of three enzymes in the RecBCD double-stranded break repair DNA recombination complex. However, comparative genomics has revealed that many organisms possess a recD gene even though the other members of the complex, recB and recC, are not present. Further, bioinformatic analyses have shown that there is substantial sequence dissimilarity between recD genes associated with recB and recC (recD1), and those that are not associated with recBC (recD2). Deinococcus radiodurans, known for its extraordinary DNA repair capability, is one such organism that does not possess either recB or recC, and yet does possess a recD gene. The recD of D. radiodurans was deleted and this mutant was shown to have a capacity to repair double-stranded DNA breaks equivalent to wild-type. The phylogenetic history of recD was studied using a dataset of 120 recD genes from 91 fully sequenced species. The analysis focused upon the role of gene duplication and functional genomic context in the evolution of recD2, which appears to have undergone numerous independent events resulting in duplicate recD2 genes. The role of RecD as part of the RecBCD complex appears to have a divergence from an earlier ancestral RecD function still preserved in many species including D. radiodurans.     

Asexual reproductive organ-specific expression of the glyceraldehyde-3-phosphate dehydrogenase 2 gene of Pilobolus crystallinus

Pilobolus crystallinus has three putative glyceraldehyde-3-phosphate dehydrogenase (gapdh) genes (pcgapdh1, pcgapdh2 and pcgapdh3). The results of this study demonstrate that expression of pcgapdh2 was increased by irradiation and that this increased expression was correlated with the formation of asexual reproductive organs (trophocysts). Interestingly, expression of pcgapdh2 was restricted to trophocysts. The formation of trophocysts was likely promoted by light, and the expression of pcgapdh2 was increased as a result of trophocyst formation. This is the first report that shows the regulation of a gapdh gene in an organ-specific manner in fungi.     

菘蓝IiEMF基因的克隆与功能分析

该研究以菘蓝(Isatis indigotica Fort.)转录组数据为基础,克隆得到菘蓝EMF基因的cDNA全长,命名为IiEMF。(1)序列分析表明,IiEMF基因开放阅读框长度为1896 bp,编码631个氨基酸。进化树分析表明,菘蓝IiEMF蛋白与甘蓝(Brassica oleracea)EMF蛋白亲缘关系最为接近。(2)实时定量PCR结果显示,IiEMF在菘蓝不同器官中均有表达,且在叶中表达量最高,果实中表达量最低;IiEMF基因在菘蓝抽薹开花过程中叶内的表达量呈先升后降的趋势,并于初花期表达量达到最高后逐渐降低回落;在花/果期IiEMF基因表达量较花蕾中明显降低。(3)成功构建了超表达载体pCAMBIA1300-EMF,经农杆菌介导侵染拟南芥,PCR鉴定表明,有7株为超表达转IiEMF基因植株。(4)表型观察发现,在长日照和短日照条件下,与野生型相比2个转IiEMF基因拟南芥株系的开花时间都明显较早(提前6~10 d),且转IiEMF基因株系的莲座叶数比野生型多10片以上,叶片也比野生型大而肥厚。(5)qRT-PCR检测结果显示,在拟南芥营养生长过程中,过表达IiEMF显著抑制了拟南芥AtAP1、AtCO和AtLFY的表达,而促进了AtFLC的表达;当拟南芥开花时,转基因株系中的AtAP1和AtFLC表达量均高于野生型,AtCO和AtLFY的表达量显著低于野生型。研究表明,过量表达IiEMF基因能够促使拟南芥提前开花,且IiEMF可能是通过影响多种开花途径来共同调节促进拟南芥的早花。     

Phylogenetic relationships in Blumea (Asteraceae: Inuleae) as evidenced by molecular and morphological data

The present study, based on sequences of cpDNA (trnL-F & psbA-trnH) and nrDNA (ITS) and morphology, examined the evolutionary relationships in Blumea and its position among related genera. The results confirmed that the closest relatives of Blumea are Caesulia, Duhaldea and Pentanema p.p., and showed that the monotypic genera Blumeopsis and Merrittia are nested within Blumea. In Blumea s.l., two major, well-supported clades were recognised and a single species, the widespread Blumea balsamifera, that could not be placed with certainty relative to the two main clades. The two main clades differ in habit, ecology and distribution. The Blumea densiflora clade contains shrubs and subshrubs of evergreen forests, distributed from continental Asia to New Guinea and Polynesia, whereas the Blumea lacera clade is a widespread paleotropical group that comprises mostly annual, weedy herbs of open forests and fields.     

High-Resolution Genetic and Physical Mapping of Modifier-of-deafwaddler (mdfw) and Waltzer (Cdh23)

Modifier-of-deafwaddler (mdfw) and waltzer (Cdh23^v) are loci on mouse chromosome 10 encoding factors that are essential for the function of auditory hair cells. The BALB/cByJ-specific mdfw allele encodes a necessary and sufficient modifier that induces progressive early onset hearing loss in CBy-dfw^2J heterozygotes. Recessive mutations in the waltzer locus result in circling behavior and congenital deafness. In this report we present a high-resolution integrated genetic and physical map of mdfw and Cdh23^v. Our genetic analyses localize mdfw between markers D10Mit60 and 148M13T7 within a 1.01-cM region. The Cdh23^v critical interval is fully contained within the mdfw region and localizes between markers 146O23T7 and 148M13T7 within a 0.35-cM interval that is represented in an ≈500-kb BAC contig. Our data suggest that mdfw and Cdh23^v are allelic.     

The size distribution of insertions and deletions in human and rodent pseudogenes suggests the logarithmic gap penalty for sequence alignment

The size distributions of deletions, insertions, and indels (i.e., insertions or deletions) were studied, using 78 human processed pseudogenes and other published data sets. The following results were obtained: (1) Deletions occur more frequently than do insertions in sequence evolution; none of the pseudogenes studied shows significantly more insertions than deletions. (2) Empirically, the size distributions of deletions, insertions, and indels can be described well by a power law, i.e., f _k = Ck ^–b , where f _k is the frequency of deletion, insertion, or indel with gap length k, b is the power parameter, and C is the normalization factor. (3) The estimates of b for deletions and insertions from the same data set are approximately equal to each other, indicating that the size distributions for deletions and insertions are approximately identical. (4) The variation in the estimates of b among various data sets is small, indicating that the effect of local structure exists but only plays a secondary role in the size distribution of deletions and insertions. (5) The linear gap penalty, which is most commonly used in sequence alignment, is not supported by our analysis; rather, the power law for the size distribution of indels suggests that an appropriate gap penalty is w _k = a + b ln k, where a is the gap creation cost and blnk is the gap extension cost. (6) The higher frequency of deletion over insertion suggests that the gap creation cost of insertion (a _i ) should be larger than that of deletion (a _d ); that is, a _i – a _d = In R, where R is the frequency ratio of deletions to insertions. Correspondence to: W.-H. Li     

Spm and I element changes with the a-m2 8004 allele in maize

Summary Among the mobile element systems in maize, the En (Spm) system (En — the regulatory element and I the receptive element — a nonfunctional En) has several interesting aspects of control of gene expression (En and Spm are homologous in structure and activity). One of the alleles arising from the Spm group included the a-m2 8004 allele that has a low spotting pattern and unique ringed areas. The interest in this allele is that Spm or En will induce it to co-express the A phenotype and mutability. Several exceptions of the allele were analyzed. Two are Spm changes and two are I changes. The analysis shows that the heritable changes include I changes that are co-expressed in various grades of color and different degrees of mutability. All these changes occur with I at the locus. The Spm changes also include changes in mutability patterns and a mottling pattern.Journal Paper No., J-11792 of the Iowa Agriculture and Home Economics Experiment Station, Ames, Iowa, Project No. 2381     

Increased tolerance to salt stress in the phosphate-accumulating <Emphasis Type="Italic">Arabidopsis</Emphasis> mutants <Emphasis Type="Italic">siz1</Emphasis> and <Emphasis Type="Italic">pho2</Emphasis>

High salinity is an environmental factor that inhibits plant growth and development, leading to large losses in crop yields. We report here that mutations in SIZ1 or PHO2, which cause more accumulation of phosphate compared with the wild type, enhance tolerance to salt stress. The siz1 and pho2 mutations reduce the uptake and accumulation of Na⁺. These mutations are also able to suppress the Na⁺ hypersensitivity of the sos3-1 mutant, and genetic analyses suggest that SIZ1 and SOS3 or PHO2 and SOS3 have an additive effect on the response to salt stress. Furthermore, the siz1 mutation cannot suppress the Li⁺ hypersensitivity of the sos3-1 mutant. These results indicate that the phosphate-accumulating mutants siz1 and pho2 reduce the uptake and accumulation of Na⁺, leading to enhanced salt tolerance, and that, genetically, SIZ1 and PHO2 are likely independent of SOS3-dependent salt signaling.     

The ret oncogene can induce melanogenesis and melanocyte development in W/W mice

We recently reported the establishment of transgenic mouse lines carrying the mouse metallothionein/ret fusion gene in which severe melanosis and melanocytic tumors developed. In the present study, we demonstrate that a significant number of pigmented hairs developed in W^v/W^v mice crossed to one of the transgenic mouse lines. The pigmented hair of W^v/W^v mice carrying the ret oncogene did not lose color during aging and reappeared after shaving, indicating that the melanocytes in the hair follicle function. The melanocytic tumors also developed in these mice, although the incidence was lower than that in the wild transgenic mice. Furthermore, the neural tube culture of mouse embryos indicated that neural crest cells of the transgenic mice gave rise to a cell population that autonomously produced melanin even in the absence of melanocyte stimulating hormone. These results strongly suggested that the introduced ret oncogene could compensate for the defect of c-kit in W^v mice during both embryogenesis and postnatal life and induce a high level of melanin synthesis in the process of melanocyte development.     

CLAUSA restricts tomato leaf morphogenesis and GOBLET expression

Leaf morphogenesis and differentiation are highly flexible processes. The development of compound leaves is characterized by an extended morphogenesis stage compared with that of simple leaves. The tomato mutant clausa (clau) possesses extremely elaborate compound leaves. Here we show that this elaboration is generated by further extension of the morphogenetic window, partly via the activity of ectopic meristems present on clau leaves. Further, we propose that CLAU might negatively affect expression of the NAM/CUC gene GOBLET (GOB), an important modulator of compound‐leaf development, as GOB expression is elevated in clau mutants and reducing GOB expression suppresses the clau phenotype. Expression of GOB is also elevated in the compound leaf mutant lyrate (lyr), and the remarkable enhancement of the clau phenotype by lyr suggests that clau and lyr affect leaf development and GOB in different pathways.     

A kinetic study of the genetic control of hemopoietic progenitor cells assayed in culture and in vivo

The kinetics of growth of bone marrow cells from normal or genetically anemic mice (Sl/Sl^d and W/W^v) were studied in irradiated normal and genetically anemic hosts. The parameters followed included total cellularity, the number of peroxidase positive cells, and the number of cells capable of forming colonies in vivo (CFU-S) or in culture (CFU-C). The results of these experiments demonstrate that W and Sl defects alter the growth of CFU-C and peroxidase-positive cells to a modest degree; that the defects are more obvious when studied in spleen rather than in bone marrow; and that there is no additivity of W and Sl defects. Nineteen irradiated recipients of marrow from W/W^v mice were studied after three to six months. Of these, 18 showed host-type erythrocytes, while in one mouse the erythrocytes had the size distribution of W/W^v cells. This finding indicated that occasionally genetically defective stem cells may repopulate irradiated hosts.     

Evolutionary relationship of the Bacillus licheniformis macrolide-lincosamide-streptogramin B resistance elements

Summary Naturally occurring erythromycin (Em) resistance was found in 11 of the 18 Bacillus licheniformis isolates tested but was absent from a wide variety of other Bacillus strains. The Em resistance elements confer inducible macrolide-lincosamide-streptogramin B (MLS) resistance and are related to ermD an MLS resistance element previously cloned from the chromosome of B. licheniformis 749. The MLS sensitive B. licheniformis strains and the other sensitive Bacillus strains tested, lack sequences with detectable homology to ermD. The sensitive B. licheniformis strains do exhibit homology to sequences which flank ermD in B. licheniformis 749. The relative sizes of the homologous DNA fragments suggest that the sensitive strains are lacking a 3.6 kb segment which contains ermD. It is shown that ermD is homologous to chromosomal DNA from Streptomyces erythreus ATCC 11635, an Em producing organism. These observations suggest to us that MLS resistance may have arisen in the Streptomyces and spread to B. licheniformis another gram positive bacterium found in soil. It is further proposed that ermD is or was located on a transposon-like element and has spread and evolved further to yeild a variety of related Staphylococcal and Streptococcal MLS determinants.     

Surface display of human lactoferrin using a glycosylphosphatidylinositol-anchored protein of <Emphasis Type="Italic">Saccharomyces cerevisiae</Emphasis> in <Emphasis Type="Italic">Pichia pastoris</Emphasis>

A cell surface display system was developed in Pichia pastoris using the gene TIP1, encoding the glycosylphosphatidylinositol (GPI)-anchored protein of Saccharomyces cerevisiae (ScTIP). Human lactoferrin cDNA (hLf) was fused to a full-length TIP1 DNA (ScTIP ₆₃₀ ) or a short-TIP1 fragment (ScTIP ₁₂₀ ) encoding the 40 C-terminal amino acids of ScTIP. Both hLf-ScTIP fusion genes were expressed in P. pastoris SMD 1168. The fused protein was detected by western blotting after extraction of the lysed recombinant cells with Triton X-100, urea, and Triton X-100 plus urea, suggesting that the hLf is associated with the membrane. The localization of surface-displayed hLf was confirmed by immunofluorescence confocal microscopy and flow cytometric analysis using FITC-labeled anti-hLf antibody, suggesting that hLf was successfully located at the surface of P. pastoris. The intact recombinant cells and cell lysates showed antibacterial activity against target microorganisms, meaning that the expressed hLf was biologically active. The results indicated that the ScTIP anchoring motif is useful for cell surface display of foreign proteins in P. pastoris.     

DNA data and morphology reveal the existence of Kentrochrysalis streckeri Staudinger, 1880 (Lepidoptera: Sphingidae) instead of K. consimilis in South Korea

In the present study, we determined that specimens of Kentrochrysalis consimilis collected from South Korea were K. streckeri, rather than K. consimilis, based on morphology, DNA barcodes and nuclear elongation factor 1 alpha (EF‐1α) sequences. The major morphological differences between K. streckeri and K. consimilis include the shape of forewing and hind‐wing pattern elements and male and female genitalia. The DNA barcode analysis of the South Korean specimens and the Russia‐originated K. streckeri showed a maximum sequence divergence of only 0.659% (4 bp), whereas that of the South Korean specimens and Japan‐originated K. consimilis showed a minimum sequence divergence of 2.965% (18 bp), indicating that the Korean specimens are, in fact, K. streckeri and not K. consimilis. Phylogenetic analyses both by Bayesian inference and maximum likelihood methods strongly clustered the South Korean specimens and Russian K. streckeri into one group, excluding K. consimilis. The EF‐1α‐based sequence and phylogenetic analyses of the two species also supported data from the DNA barcode, indicating the distribution of K. streckeri in South Korea, instead of K. consimilis.