In vitro polymerization of mussel polyphenolic proteins catalyzed by mushroom tyrosinase

The in vitro enzymatic polymerization of the polyphenolic protein purified from the mussels Aulacomya ater, Mytilus edulis chilensis and Choromytilus chorus was studied. Mushroom tyrosinase was used to oxidize the dopa residues present in these proteins, and polymerization was monitored by acid-urea polyacrylamide gel electrophoresis. The protein from A. ater polymerized at a faster rate than the other two. Amino acid analysis of the crosslinked protein showed a notable decrease in the content of dopa, but no significant change of other amino acids. This suggests that crosslink formation may be limited to the oxidized dopa derivatives of the protein molecules.     

A comparative study on the phylogenetic diversity of culturable actinobacteria isolated from five marine sponge species

A cultivation-based approach was employed to compare the culturable actinobacterial diversity associated with five marine sponge species (Craniella australiensis, Halichondria rugosa, Reniochalina sp., Sponge sp., and Stelletta tenuis). The phylogenetic affiliation of the actinobacterial isolates was assessed by 16S rDNA-RFLP analysis. A total of 181 actinobacterial strains were isolated using five different culture media (denoted as M1–M5). The type of medium exhibited significant effects on the number of actinobacteria recovered, with the highest number of isolates on M3 (63 isolates) and the lowest on M1 (12 isolates). The genera isolated were also different, with the recovery of three genera on M2 and M3, and only a single genus on M1. The number of actinobacteria isolated from the five sponge species was significantly different, with a count of 83, 36, 30, 17, and 15 isolates from S. tenuis, H. rugosa, Sponge sp., Reniochalina sp., and C. australiensis, respectively. M3 was the best isolation medium for recovery of actinobacteria from S. tenuis, H. rugosa, and Sponge sp., while no specific medium preference was observed for the recovery of actinobacteria from Reniochalina sp., and C. australiensis. The RFLP fingerprinting of 16S rDNA genes digested with HhaI revealed six different patterns, in which 16 representative 16S rDNAs were fully sequenced. Phylogenetic analysis indicated that 12 strains belong to the group Streptomyces, three strains belong to Pseudonocardia, and one strain belongs to Nocardia. Two strains C14 (from C. australiensis) and N13 (from Sponge sp.) have only 96.26% and 96.27% similarity to earlier published sequences, and are therefore potential candidates for new species. The highest diversity of three actinobacteria genera was obtained from Sponge sp., though the number of isolates was low. Two genera of actinobacteria, Streptomyces, and Pseudonocardia, were isolated from both S. tenuis and C. australiensis. Only the genus of Streptomyces was isolated from H. rugosa and Reniochalina sp. Sponge species have been demonstrated here to vary as sources of culturable actinobacterial diversity, and the methods for sampling such diversity presented may be useful for improved sampling of such diversity.     

Molecular diversity among five different endogenous primate retroviruses.

Genetically transmitted retroviruses of Old and New World monkeys include type C viruses isolated from baboons (M7), macaque (MAC-1), and owl monkeys (OMC-1) and type D viruses from langurs (PO-1-Lu) and squirrel monkeys (SMRV, M534). Each of these isolates is unrelated to the others by nucleic acid hybridization criteria and contains a unique array of virion-associated proteins which can be resolved by agarose gel filtration and polyacrylamide gel electrophoresis under denaturing conditions. The major structural protein of each virus has a distinct primary structure, as determined by two-dimensional tryptic peptide analysis, and is antigenically different from the others. The major virion phosphoproteins of endogenous primate type C viruses (pp15) are also different from those of type D viruses (pp13-pp14). Immunological and structural analyses show that the endogenous langur virus and the horizontally transmitted Mason-Pfizer virus of rhesus monkeys are closely related to one another, consistent with the sequence homology detected in their RNA genomes. Although certain radioimmunoassays detect interspecies antigenic determinants common to either the p30 or gp70 proteins of some of these viruses, no one assay has yet been designed which can detect all groups of endogenous primate retroviridae. The data lead to the conclusion that primates contain a minimum of three different sets of genetically transmitted type C and type D retroviral genes.     

Multi-domain GFP-like proteins from two species of marine hydrozoans

Proteins homologous to Green Fluorescent Protein (GFP) are widely used as genetically encoded fluorescent labels. Many developments of this technology were spurred by discoveries of novel types of GFP-like proteins (FPs) in nature. Here we report two proteins displaying primary structures never before encountered in natural FPs: they consist of multiple GFP-like domains repeated within the same polypeptide chain. A two-domain green FP (abeGFP) and a four-domain orange-fluorescent FP (Ember) were isolated from the siphonophore Abylopsis eschscholtzii and an unidentified juvenile jellyfish (order Anthoathecata), respectively. Only the most evolutionary ancient domain of Ember is able to synthesize an orange-emitting chromophore (emission at 571 nm), while the other three are purely green (emission at 520 nm) and putatively serve to maintain the stability and solubility of the multidomain protein. When expressed individually, two of the green Ember domains form dimers and the third one exists as a monomer. The low propensity for oligomerization of these domains would simplify their adoption as in vivo labels. Our results reveal a previously unrecognized direction in which natural FPs have diversified, suggesting new avenues to look for FPs with novel and potentially useful features.     

Molecular size diversity of citrate synthases from Pseudomonas species

Two forms of citrate synthase (EC 4.1.3.7) have been found in several species of Pseudomonas, a 'large' form (Mr congruent to 250,000) which is generally inhibited by NADH and reactivated by AMP, and a 'small' form (Mr congruent to 100,000) which is insensitive to these nucleotide effectors. Other species of Pseudomonas were found to contain either the 'large' or the 'small' form. Gel filtration and ion-exchange with the technique of fast protein liquid chromatography were used to resolve the enzymes. Where both citrate synthases were present, there did not appear to be an equilibrium between the two forms. The results reveal a new and complex diversity of citrate synthase within the genus Pseudomonas.     

Molecular weight distribution of ribosomal proteins from several vertebrate species.

Two-dimensional polyacrylamide gel electrophoresis of proteins from the separated ribosomal subunits of rabbit reticulocytes, rabbit liver, mouse liver, rat liver, chicken liver, and toad liver was performed using the "pH 4.5/SDS" system previously described (Martini and Gould, 1975), with internal standards to measure the molecular weight distributions. With few exceptions, the patterns were remarkably similar, indicating a high degree of conservation during evolution of both net charge (largely determining mobility in the first dimension) and size (determining mobility in the second dimension). The aggregate mass (sum of molecular weights) of both small and large subunit proteins, about 0.65 X 10(6) and 0.95 X 10(6) daltons respectively, were invariant. These figures are significantly smaller than the hydrodynamically determined mass of protein in the subunits. The implications of this discrepancy, which is opposite that found in the prokaryotes, is discussed.     

Comparisons of salivary proteins from five aphid (Hemiptera: Aphididae) species

Aphid (Hemiptera: Aphididae) saliva, when injected into host plants during feeding, causes physiological changes in hosts that facilitate aphid feeding and cause injury to plants. Comparing salivary constituents among aphid species could help identify which salivary products are universally important for general aphid feeding processes, which products are involved with specific host associations, or which products elicit visible injury to hosts. We compared the salivary proteins from five aphid species, namely, Diuraphis noxia (Kurdjumov), D. tritici (Gillette), D. mexicana (Baker), Schizaphis graminum (Rondani), and Acyrthosiphon pisum (Harris). A 132-kDa protein band was detected from the saliva of all five species using sodium dodecyl sulfate polyacrylamide gel electrophoresis. Alkaline phosphatase activity was detected from the saliva of all five species and may have a universal role in the feeding process of aphids. The Diuraphis species cause similar visible injury to grass hosts, and nine electrophoretic bands were unique to the saliva of these three species. S. graminum shares mutual hosts with the Diuraphis species, but visible injury to hosts caused by S. graminum feeding differs from that of Diuraphis feeding. Only two mutual electrophoretic bands were visualized in the saliva of Diuraphis and S. graminum. Ten unique products were detected from the saliva of A. pisum, which feeds on dicotyledonous hosts. Our comparisons of aphid salivary proteins revealed similarities among species which cause similar injury on mutual hosts, fewer similarities among species that cause different injury on mutual hosts, and little similarity among species which feed on unrelated hosts.     

Observations on five species of philometrid nematodes from marine fishes in Japan

Five species of philometrid nematodes (subfamily Philometrinae) are redescribed on the basis of newly collected materials from marine fishes from Japan. The species Philometra sciaenae Yamaguti, 1941, considered by Rasheed (1963) a synonym of P. lateolabracis (Yamaguti, 1935), is re-established as a valid species and the male of this nematode, collected from the ovary of the type-host, Argyrosomus argentatus, is described for the first time; the latter is characterised mainly by the length of equally long spicules (0.108–0.126 mm) and the length ratio of the gubernaculum and spicules (1:2.25). Other species redescribed on females include Philometra inimici Yamaguti, 1941 and P. sebastisci Yamaguti, 1941 from the ovary of their type-hosts, Inimicus japonicus and Sebastiscus marmoratus, respectively, and also Philometroides seriolae (Ishii, 1931) from the musculature of Seriola quinqueradiata (type-host), and Clavinema mariae (Layman, 1930) from the subcutaneous tissue of Pleuronectes schrenki and Acanthogobius flavimanus (a new host record). For the first time, cephalic ends of some of these species were studied under the scanning electron microscope (SEM) and the character of their cephalic papillae was described. The importance of a knowledge of male morphology for the taxonomy of philometrids is stressed.     

Molecular species identification boosts bat diversity

The lack of obvious morphological differences between species impedes the identification of species in many groups of organisms. Meanwhile, DNA-based approaches are increasingly used to survey biological diversity. In this study we show that sequencing the mitochondrial protein-coding gene NADH dehydrogenase, subunit 1 (nd1) from 534 bats of the Western Palaearctic region corroborates the promise of DNA barcodes in two major respects. First, species described with classical taxonomic tools can be genetically identified with only a few exceptions. Second, substantial sequence divergence suggests an unexpected high number of undiscovered species.     

使用RAPD分析辨别印度半岛的五种结鱼

用RAPD分析研究了结鱼种组(黄鳍结鱼Tor putitora,结鱼Tor tor,库德里结鱼Tor khudree,Tor mosalmahanadicus和墨脱四■魮Neolissochilus hexagonolepis)5个物种的遗传关系。在所测试的69个随机引物中,11个引物能够在所有5个物种中扩增出稳定的条带。RAPD带型显示,综合使用这些RAPD标记能够区分这5个物种,但Tor mosal mahanadicus和黄鳍结鱼享有相似的带型。UPGMA分析揭示出3个独特的分支,第一支由黄鳍结鱼、Tor mosal mahanadicus和结鱼组成,第二支是库德里结鱼,第三支是墨脱四■魮。Tor mosal mahanadicus的分类地位在不同学者间存在分歧,被认为是库德里结鱼或结鱼的亚种,但我们的结果表明,相对而言,Mahanadi河中的Tor mosal mahanadicus与黄鳍结鱼的进化关系更近,因此有必要对其系统分类地位进行重新评估。     

Molecular cloning of five GTP-binding protein cDNA species from rat olfactory neuroepithelium

Biochemical studies in vertebrate olfactory tissue indicate that certain odorants stimulate adenylyl cyclase in a GTP-dependent manner. Additionally, immunochemical and toxin-labeling studies demonstrate the presence of several GTP-binding protein (G-protein) species in vertebrate olfactory epithelium. To identify the G-protein(s) responsible for olfactory signal transduction, we screened a rat olfactory cDNA library with an oligonucleotide probe and isolated 32 recombinant clones encoding five distinct types of G-protein alpha subunits. The majority of the clones encoded G alpha s, while the remaining clones encoded G alpha o, G alpha i1, G alpha i2, and a novel species, G alpha i3. Messenger RNA corresponding to each G alpha was detectable in all tissues examined; however, the levels for a given G alpha varied in a tissue-specific manner. In olfactory tissue, G alpha s was the most abundant of these messages and in combination with the biochemical studies suggests that G alpha s is the G-protein component of the olfactory signal transduction cascade.     

Molecular diversity and function of G proteins and calcium channels.

General features of signal transduction by G proteins and structural properties of G-protein-modulated calcium channels are described. Recent results on roles of beta gamma dimers in signal transduction, on the kinetic properties of Gi alpha subunits and structural diversity of Go alpha subunits are discussed, as are the background and current state of our knowledge of the modulation of calcium channels by G proteins.     

Molecular diversity of fungal phylotypes co-amplified alongside nematodes from coastal and deep-sea marine environments

Nematodes and fungi are both ubiquitous in marine environments, yet few studies have investigated relationships between these two groups. Microbial species share many well-documented interactions with both free-living and parasitic nematode species, and limited data from previous studies have suggested ecological associations between fungi and nematodes in benthic marine habitats. This study aimed to further document the taxonomy and distribution of fungal taxa often co-amplified from nematode specimens. A total of 15 fungal 18S rRNA phylotypes were isolated from nematode specimens representing both deep-sea and shallow water habitats; all fungal isolates displayed high pairwise sequence identities with published data in Genbank (99-100%) and unpublished high-throughput 454 environmental datasets (>95%). BLAST matches indicate marine fungal sequences amplified in this study broadly represent taxa within the phyla Ascomycota and Basidiomycota, and several phylotypes showed robust groupings with known taxa in phylogenetic topologies. In addition, some fungal phylotypes appeared to be present in disparate geographic habitats, suggesting cosmopolitan distributions or closely related species complexes in at least some marine fungi. The present study was only able to isolate fungal DNA from a restricted set of nematode taxa; further work is needed to fully investigate the taxonomic scope and function of nematode-fungal interactions.     

High concentrations of methemoglobin in five species of temperate marine teleosts

Blood samples from five species of marine teleosts were assayed for methemoglobin (metHb) levels during winter and summer acclimatization. There was at least 7% total hemoglobin in the met-form in all species, and as high as 27% in one species, the Atlantic cod (Gadus morhua). There was significant seasonal variation in metHb levels for three of the five species, the highest values occurring during the winter months; cunners (Tautogolabrus adspersus) 15.6% in winter and 10.1% in the summer, shorthorn sculpin (Myoxocephalus scorpius) 20.0% in the winter and 8.19% in the summer, longhorn sculpin (Myoxocephalus octodecemspinosus) 17.3-21.6% in the winter and 8.12% in the summer. The winter flounder (Pseudopleuronectes americanus) and the Atlantic cod maintained metHb concentrations constant throughout the year: 13% and 27%, respectively. There does not appear to be any relationship between the activity of a fish and the level of metHb in its blood.     

Geographical variation in species diversity: A comparison of marine polychaetes and nematodes

The aim of this study was to determine if marine species diversity was influenced by geographical location and whether it was higher at lower latitudes. Artificial collectors (made of nylon pan scourers) were employed as a standard substratum for the colonisation of marine invertebrates inhabiting subtidal (12 to 15 m) hard, rocky bottom substrata. These artificial substrate units (ASUs) were deployed at different latitudes including northern and southern temperate (South West England, UK and New Zealand), tropical (Trinidad and Tobago, West Indies) and polar (Signy Island, Antarctica) areas. The polychaetes, representative of the macrofauna and the nematodes, representative of the meiofauna fractions of the total invertebrate fauna collected were analysed.Neither polychaete nor nematode species diversity showed a trend based on latitude and each taxon showed a different pattern of diversity variation in relation to location. Polychaete diversity varied from area to area with highest species diversity occurring in the southern temperate (New Zealand). Nematode species diversity however was similar for the northern and southern temperate (UK and New Zealand) and the tropical area (Trinidad and Tobago). Thus, although the number of locations studied was limited, these data do not conform to a gradient in species diversity with latitude as has been previously supposed. The success of ASUs to compare species diversities in standardised habitat units augurs well for their future use in other ecological areas such as biogeographical or pollution studies.     

The phylogeny and chemical diversity of quinone-tanned glues and varnishes

1. 3,4-Dihydroxyphenyl-L-alanine (DOPA)-containing proteins are widely distributed throughout the animal kingdom and appear to serve chiefly as waterproof adhesives and varnishes. 2. The unique chemical and physical stability of these adhesives and varnishes is imparted by quinone-tanning, an oxidative process that leads to the polymerization of DOPA-containing and other proteins. 3. Recent advances in the biochemistry of DOPA-containing proteins suggest that most consist of tandemly repeated sequence motifs. Each motif contains DOPA, a basic amino acid (usually lysine), and abundant glycine or proline. 4. The DOPA residues undergo catechol oxidase-catalyzed conversion to o-quinones at the onset of quinone-tanning. 5. The complexity of quinone chemistry is discussed with regard to quinone-tanning.     

Molecular polymorphism of ciliary proteins from different species of the ciliate Tetrahymena

Ciliary proteins from five different Tetrahymena species were analyzed by means of SDS-polyacrylamide gel electrophoresis. Of at least 32 different polypeptides, only 2 were found to have identical molecular weights in all species. In any comparison of 2 species, a maximum of 60% and at least 20% of the proteins had indistinguishable molecular weights, depending on the combination examined. Extensive codominance of ciliary proteins was found in a F₁ hybrid. No interspecific cross-reactions occurred in double-diffusion tests involving the cilia from different species and antisera produced against them in rabbits.Supported by grants from the U.S. Public Health Service (AG-00010 and GM-07779 to D. L. Nanney and AG-00248 to J.H.W.). H.M.S. was sponsored by a postdoctoral fellowship from the Deutsche Forschungsgemeinschaft to work in D. L. Nanney's laboratory.     

Molecular phylogenetic assessment of host range in five Dermanyssus species

Given that 14 out of the 25 currently described species of Dermanyssus Dugès, 1834, are morphologically very close to each another, misidentifications may occur and are suspected in at least some records. One of these 14 species is the red fowl mite, D. gallinae (De Geer, 1778), a blood parasite of wild birds, but also a pest in the poultry industry. Using molecular phylogenetic tools we aimed to answer two questions concerning host specificity and synanthropicity: (1) is D. gallinae the only species infesting European layer farms?, and (2) can populations of D. gallinae move from wild to domestic birds and vice versa? Mitochondrial cytochrome oxidase I gene sequences were obtained from 73 Dermanyssus populations collected from nests of wild European birds and from poultry farms and these were analyzed using maximum parsimony and Bayesian inference. Mapping of the observed host range on the obtained topology and correlation with behavioural observations revealed that (1) host range is strongly dependent on some ecological parameters (e.g. nest hygiene, exposure to pesticides and predators), that (2) out of five species under test, synanthropic populations were found only in lineages of D. gallinae, and that (3) at least some haplotypes found in wild birds were very close to those found in association with domestic birds.