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PubMedDate not supplied

Quantitative phenetics and taxonomy of some phlebotomine taxa.

Elucidating the evolution of Phlebotominae is important not only to revise their taxonomy, but also to help understand the origin of the genus Leishmania and its relationship with humans. Our study is a phenetic portrayal of this history based on the genetic relationships among some New Word and Old Word taxa. We used both multilocus enzyme electrophoresis and morphometry on 24 male specimens of the Old Word genus Phlebotomus (with three of its subgenera: Phlebotomus, Spelaeophlebotomus and Australophlebotomus), and on 67 male specimens of the three New World genera, Warileya, Brumptomyia and Lutzomyia, (with three subgenera of Lutzomyia: Lutzomyia, Oligodontomyia and Psychodopygus). Phenetic trees derived from both techniques were similar, but disclosed relationships that disagree with the present classification of sand flies. The need for a true evolutionary approach is stressed.

Animals↗
PubMedDate not supplied

[Growth substance requirements in heterothallic yeast cultures].

Vitamin heterotrophy was studied among the following new yeast genera: Leucosporidium, Rhodosporidium and Filobasidium. The requirement in growth factors of various crossing types was compared among these genera and ascomycetens yeast cultures Saccharomycopsis lipolytica and Metschnikowia pulcherrima. Various crossing types of Filobasidium capsuligenum were found to differ in their requirement in growth factors. Various crossing types of Rhodosporidium and Saccharomycopsis lipolytica were stimulated by different growth substances. These characteristics can be used as markers while selecting the types of crossing.

Ascomycota↗
PubMed1999

The architecture of Mourera fluviatilis (Podostemaceae): developmental morphology of inflorescences, flowers, and seedlings.

Mourera fluviatilis from northern South America is a spectacular member of the Podostemaceae (river-weeds). Its raceme-like inflorescences are up to 64 cm long and have 40-90 flowers arranged in two opposite rows. Inflorescence development starts with the initiation of a double-sheathed (dithecous) bract in a terminal position. All lateral bracts (again dithecous) are initiated in basipetal order along the two flanks of the inflorescence. Each gap between two neighboring bracts contains a single flower. The flowers are bisexual, each with a whorl of 16-20 ligulate tepals and 14-40 stamens, which are arranged in one or two whorls. Floral development starts with the formation of a girdling primordium rim around a two-lobed primordial gynoecium. Stamen and tepal initiation is centrifugal on the girdling primordium. The anthers are introrse or extrorse, depending on stamen position. Seedlings develop two entire, threadlike cotyledons, followed by forked filamentous leaves, which arise from the plumular pole. The radicular pole of the hypocotyl develops into a claw-shaped holdfast that fixes the young plant to the rock. The developmental morphologies of Mourera fluviatilis and other members of the Mourera group (including Lonchostephus and Tulasneantha) fit well with the Podostemoideae bauplan known from other New World genera, such as Apinagia and Marathrum.

Journal Article↗
PubMed1995

Paleobiology of the Mesoproterozoic Billyakh Group, Anabar Uplift, northern Siberia.

Silicified peritidal carbonates of the Mesoproterozoic Kotuikan and Yusmastakh Formations, Anabar Uplift, northeastern Siberia, contain exceptionally well-preserved microfossils. The assemblage is dominated by ellipsoidal akinetes of nostocalean cyanobacteria (Archaeoellipsoides) and problematic spheroidal unicells (Myxococcoides); both are allochthonous and presumably planktonic. The assemblage also includes distinctive mat-forming scytonematacean and entophysalidacean cyanobacteria, diverse short trichomes interpreted as cyanobacterial hormogonia or germinated akinetes, rare longer trichomes, and several types of colonial unicells. Although many taxa in the Kotuikan-Yusmastakh assemblage are long-ranging prokaryotes, the overall character of the assemblage is distinctly Mesoproterozoic, with its major features shared by broadly coeval floras from Canada, China, India, and elsewhere in Siberia. Microfossils also occur in middle to inner shelf shales of the Ust'-Il'ya and lower Kotuikan Formations. Leiosphaerid acritarchs (up to several hundred microns in diameter) characterize this facies. As in other Mesoproterozoic acritarch assemblages, acanthomorphic and other complex forms that typify Neoproterozoic assemblages are absent. The combination in Billyakh assemblages of exceptional preservation and low eukaryotic diversity supports the hypothesis that nucleated organisms diversified markedly near the Mesoproterozoic-Neoproterozoic boundary. The assemblages also demonstrate the antiquity of cyanobacteria capable of cell differentiation and suggest the importance of both changing peritidal substrates and evolving eukaryotes in determining stratigraphic patterns of Proterozoic prokaryotes. The permineralized assemblage contains 33 species belonging to 17 genera. Ten new species or new combinations are proposed: Archaeoellipsoides costatus n. sp., A. elongatus n. comb., A. dolichos n. comb., A. minor n. nom., A. crassus n. comb., A. major n. comb., A. bactroformis n. sp., Veteronostocale medium n. sp., Filiconstrictosus cephalon n. sp., and Partitiofilum yakschinii n. sp.

Bacteria↗
PubMed1992

Cross-transmission studies with Eimeria arizonensis-like oocysts (Apicomplexa) in New World rodents of the Genera baiomys, Neotoma, Onychomys, Peromyscus, and Reithrodontomys (Muridae).

Cross-transmission experiments were performed using oocysts of an Eimeria arizonensis-like coccidian from Peromyscus leucopus and Peromyscus truei, an E. arizonensis-like coccidian from Reithrodontomys fulvescens, Eimeria baiomysis and Eimeria taylori from Baiomys taylori, Eimeria albigulae from Neotoma albigula, and Eimeria onychomysis from Onychomys spp., between representatives of the above host genera. The E. arizonensis-like coccidian from R. fulvescens infected Reithrodontomys megalotis, Reithrodontomys montanus, and Peromyscus leucopus. Oocysts of E. arizonensis from P. leucopus could be transmitted to both P. leucopus and R. megalotus. Oocysts of E. baiomysis and E. taylori infected only B. taylori. Oocysts of E. arizonensis from P. truei infected P. truei but not Neotoma mexicana or Onychomys leucogaster. Oocysts of E. albigulae from N. albigula were infective for N. mexicana but not for P. truei or O. leucogaster. Oocysts of E. onychomysis from Onychomys spp. infected O. leucogaster but not N. mexicana or P. truei. These results demonstrate that Peromyscus and Reithrodontomys, genera known to be related very closely evolutionarily, are capable of sharing E. arizonensis, whereas morphologically similar coccidians (E. albigulae, E. baiomysis, and E. onychomysis) from more distantly related hosts, are probably distinct and more stenoxenous. This also is the first report of coccidians infecting species of Reithrodontomys.

Animals↗
PubMed2006

Edouard Chatton (1883-1947) and the dinoflagellate protists: concepts and models.

Edouard Chatton contributed to our knowledge of single-celled protoctists, especially ciliates and dinoflagellates, free-living and/or symbiotic, in relation to the marine invertebrate animals in which they reside. More than the description of many new families, genera and species, and of their life cycles, he anticipated several major concepts of cell biology, including the fundamental difference between prokaryote and eukaryote protists, long time before the advent of electron microscopy. These concepts included: the reproductive ability of the kinetosome-centriole system; the homology of the kinetosome with the mitotic centriole of animal cells; and the different kinds of mitotic systems. Chatton trained more than thirty student collaborators, among them Andre Lwoff, who won the 1965 Nobel Prize in Physiology or Medicine. Later, the great cell biologist Hans Ris and I completed Chatton's light microscopy descriptions on syndinian mitosis dinoflagellate. We had at our disposal sophisticated electron microscopes as well as biochemical and molecular techniques and thus succeeded in corroborating the correct interpretation by Chatton of chromosome structure and mitotic cytology.

Animals↗
PubMed2003

A review of recent taxonomic changes in seven genera of bacteria commonly found in foods.

The purpose of this review is to call attention to the new approaches now in use that classify bacteria primarily on the basis of phylogenetic criteria. The primary laboratory methods for ascertaining phylogenetic relationships entail the use of 16S rRNA and DNA sequence comparisons. These methods have been applied to some long-established genera of bacteria of importance in foods, and seven genera (Bacillus, Clostridium, Flavobacterium, Micrococcus, Pseudomonas, Staphylococcus, and Xanthomonas) are summarized in this review. Some 121 species and strains from these seven genera were recently transferred to 36 newly created genera. The new genera consist of general environmental contaminants and some food spoilage species. To date, significant taxonomic changes have not been reported for foodborne pathogens. These taxonomic shifts need to be examined with respect to the utility of widely used microscopic, cultural, and serologic methods for future use in food microbiology. Phylogeny-based detection and identification methods for foodborne bacteria must be further developed for larger numbers of foodborne genera in order to keep up with the current trends in taxonomy.

Bacteria↗
PubMed2005

Parallels in the evolution of the two largest New and Old World seed-beetle genera (Coleoptera, Bruchidae).

This study provides the first phylogenetic analysis of a large sample of the two largest genera of seed-beetles, Acanthoscelides Schilsky and Bruchidius Schilsky, which mostly feed on legumes (Fabaceae). The goal of this study was to investigate evolutionary patterns in relation to biogeography and host-plant associations. We used three mitochondrial molecular markers and parsimony and Bayesian inference methods to reconstruct the phylogeny of 76 species. In addition, we critically reviewed host-plant records in the literature for these two bruchid genera. Our results demonstrated the existence of two major clades, one New World and one largely Old World, which generally correspond to the two genera. Yet, current classification of several species is erroneous, so that both genera as currently defined are paraphyletic. We highlighted a strong trend toward specialization (with high taxonomic conservatism in host-plant use) exhibited by the two studied genera. However, we showed the existence of several host shifts during the evolution of this group of bruchids. Our phylogenetic hypotheses and our evaluation of host-plant associations both suggest that the two genera have undergone parallel evolution, as they have independently colonized similar host plants in their respective areas of distribution. Our estimation of divergence times indicated a more ancient origin for bruchids than that suggested by the fossil records. Interestingly, the suggested timing of diversification is consistent with the hypothesis of a radiation that could have occurred contemporaneously with the diversification of their legume hosts.

Animals↗
PubMed2003

Using AFLP to resolve phylogenetic relationships in a morphologically diversified plant species complex when nuclear and chloroplast sequences fail to reveal variability.

Inferring phylogenetic relationships among closely related plant species is often difficult due to the lack of molecular markers exhibiting enough nucleotide variability at this taxonomic level. Moreover, gene tree does not necessary represent the true species tree because of random sorting of polymorphic alleles in different lineages. A solution to these problems is to use many amplified fragment length polymorphisms (AFLP) distributed throughout the whole genome, to infer cladistic and phenetic among-species relationships. Phylogenetic relationships among interfertile species of Trollius L. (Ranunculaceae) were investigated using nuclear DNA (ITS1+5.8S rRNA+ITS2) and chloroplast DNA (trnL intron and trnL-trnF intergene spacer) sequences, and AFLP markers. ITS sequences were not informative at the intrageneric level, but confirmed the sister relationship between Trollius and Adonis genera, and provided new information on the phylogenetic relationships among five Ranunculaceae genera. Chloroplast DNA was more informative among Trollius species, but not consistent with the sections previously described. AFLP proved to be a powerful tool to resolve the complex genetic relationships between the morphological entities constituting the genus Trollius. Although as much as 76.1% of the total AFLP variability was found within a priori defined morphological groups, the remaining 23.9% variability differentiating groups was sufficient to generate congruent and robust cladistic and phenetic trees. Several morphological traits, independent from those used to define groups, were mapped onto the molecular phylogeny, and their evolution discussed in relation to the absence/presence of pollinator-seed parasite Chiastocheta flies.

Base Sequence↗
PubMed1994

Escherbothrium molinae n. gen. et n. sp. (Eucestoda: Tetraphyllidea: Triloculariidae) in Urotrygon chilensis (Chondrichthyes: Myliobatiformes: Urolophidae) from the Gulf of Nicoya, Costa Rica.

Cestodes collected in spiral valves of the stingray Urotrygon chilensis from the Pacific coast of Costa Rica represent an undescribed species of Tetraphyllidea. By possessing more than 2 loculi as well as an apical sucker on each bothridium, the new species is diagnosably distinct from all other tetraphyllidean genera; therefore, a new genus is proposed for it. The new species also possesses globular structures irregularly arranged on the surface of the bothridia. We found similar structures on the bothridial faces of Trilocularia acanthiaevulgaris, possibly indicating phylogenetic relationships with the new species. This possibility is enhanced by the observation that the bothridia of T. acanthiaevulgaris comprise 2 loculi and an apical sucker, rather than 3 loculi.

Animals↗
PubMed2006

Ultrastructural and molecular phylogenetic delineation of a new order, the Rhizophydiales (Chytridiomycota).

In the order Chytridiales, Rhizophydium is a morphologically defined genus based upon the production of a monocentric, inoperculate, epibiotic sporangium, an endobiotic rhizoidal axis which branches, and an epibiotic resting spore. Despite its simple morphology, over 220 species of Rhizophydium have been described. Recent phylogenetic analyses using nuLSU rRNA (28 S rRNA) gene sequences of a geographically diverse sampling of Rhizophydium cultures revealed that the classical genus Rhizophydium is genetically more variable than previously understood and actually represents multiple genera. In the present study, we use zoospore ultrastructural characters and 28 S rRNA and 5.8 S ribosomal gene sequences of 96 isolates in culture to circumscribe the monophyletic Rhizophydium clade as a new order, Rhizophydiales. Correspondingly, zoospores of members of the Rhizophydiales exhibit a unique suite of ultrastructural character states that further define the order and distinguish it from the order Chytridiales. Molecular analyses reveal several strongly supported clades within the Rhizophydiales. Three of those clades encompass a broad range of isolates and are defined as new families Rhizophydiaceae, Terramycetaceae, and Kappamycetaceae. To resolve close relationships within Terramycetaceae, combined 28 S rRNA and ITS1-5.8 S-ITS2 sequences were analysed and details of zoospore ultrastructural character states determined, with two new genera, Terramyces and Boothiomyces, described. Two species formerly classified in Rhizophydium are transferred to the new genera. This work provides a framework for additional taxonomic revisions within the new order Rhizophydiales and compares genetic variation useful in defining genera, species, and populations within this lineage of chytrids. A broader sampling of representatives is needed before taxonomic decisions can be made for remaining clades within the Rhizophydiales.

Base Sequence↗
PubMed1976

New early tertiary primates and a reappraisal of some Plesiadapiformes.

A new study of specimens of paromomyid and microsyopid primates clarifies evolution in these primates and reuslts in new concepts of each family. The paromomyid Phenacolemur and its former synonym, Ignacius, are distinct genera, each with new Early Wasatchian species, Plesiolestes, Palaechthon, Torrejonia, Palenochtha, Navajovius, Micromomys, and Tinimomys are removed from the Paromomyidae and transferred to the Microsyopidae. The Plesiadapiformes are classified in three groups which may be differentiated on incisor and molor structure: Plesiadapoidea (Plesiadapidae, Carpolestidae, and Saxonellidae), Microsyopidae, and Paromomyidae. The Paromomyidae, Microsyopidae (and its two subfamilies), and several genera are rediagnosed in the light of new comparative evidence.

Animals↗
PubMed2006

On the classification and nomenclature of baculoviruses: a proposal for revision.

Recent evidence from genome sequence analyses demands a substantial revision of the taxonomy and classification of the family Baculoviridae. Comparisons of 29 baculovirus genomes indicated that baculovirus phylogeny followed the classification of the hosts more closely than morphological traits that have previously been used for classification of this virus family. On this basis, dipteran- and hymenopteran-specific nucleopolyhedroviruses (NPV) should be separated from lepidopteran-specific NPVs and accommodated into different genera. We propose a new classification and nomenclature for the genera within the baculovirus family. According to this proposal the updated classification should include four genera: Alphabaculovirus (lepidopteran-specific NPV), Betabaculovirus (lepidopteran-specific Granuloviruses), Gammabaculovirus (hymenopteran-specific NPV) and Deltabaculovirus (dipteran-specific NPV).

Baculoviridae↗
PubMed2003

Volatile components of selected species of the liverwort genera Frullania and Schusterella (Frullaniaceae) from New Zealand, Australia and South America: a chemosystematic approach.

The volatile components of 25 taxa of the liverwort family Frullaniaceae from New Zealand, Australia and South America have been analyzed by GC-MS. The present Frullania species are chemically divided into five major types: (1) sesquiterpene lactones, (2) sesquiterpene lactones-bibenzyls, (3) bibenzyls, (4) 2-alkanone and (5) triterpene types; the latter two chemo-types are newly proposed for the genus. Schusterella chevalierii, belonging to the Frullaniaceae, is closely related chemically to the sesquiterpene lactone type of the Frullania species since it elaborates two eudesmanolides, beta-cyclocostunolide and dihydro-beta-cyclocostunolide as major components.

Australia↗
PubMed1990

Actinobacillus rossii sp. nov., Actinobacillus seminis sp. nov., nom. rev., Pasteurella bettii sp. nov., Pasteurella lymphangitidis sp. nov., Pasteurella mairi sp. nov., and Pasteurella trehalosi sp. nov.

Evidence from numerical taxonomic analysis and DNA-DNA hybridization supports the proposal of new species in the genera Actinobacillus and Pasteurella. The following new species are proposed: Actinobacillus rossii sp. nov., from the vaginas of postparturient sows; Actinobacillus seminis sp. nov., nom. rev., associated with epididymitis of sheep; Pasteurella bettii sp. nov., associated with human Bartholin gland abscess and finger infections; Pasteurella lymphangitidis sp. nov. (the BLG group), which causes bovine lymphangitis; Pasteurella mairi sp. nov., which causes abortion in sows; and Pasteurella trehalosi sp. nov., formerly biovar T of Pasteurella haemolytica, which causes septicemia in older lambs.

Abscess↗
PubMed1996

Phylogenetic analysis reveals new relationships among members of the genera Microtetraspora and Microbispora.

The 16S rRNA gene sequences of 7 Microbispora strains, 14 Microtetraspora species, 9 Streptosporangium species, and 12 Actinomadura species were determined. A phylogenetic analysis showed that Microtetraspora fusca, Microtetraspora glauca, and Microtetraspora niveoalba formed a coherent cluster with the members of the genus Microbispora. This cluster is distantly related to two other clusters, one of which consists of the Microtetraspora species transferred from the former Actinomadura pusilla group and one of which consists of members of the genus Streptosporangium. Our results show that it is necessary to review the taxonomic definitions of the genera Microtetraspora and Microbispora, which have been separated by a single morphological characteristic, the number of spores on spore chains.

Actinomycetales↗
PubMed1993

Molecular phylogeny of the New World monkeys (Platyrrhini, primates).

Phylogenetic relationships among the 16 extant genera of Ceboidea (the New World monkeys) were examined using aligned epsilon-globin gene sequences from 19 New World monkeys (representing all 16 extant ceboid genera), and seven catarrhines (one Old World monkey and six hominoids) and tarsier as the outgroups. The consensus maximum parsimony tree found for these epsilon-globin sequences and the levels of support from parsimony and bootstrap analyses, for the clades in this tree, provided strong evidence for a cladistic classification with the following clusters. Subtribes Callitrichina (Callithrix, Cebuella), Callimiconina (Callimico), Leontopithecina (Leontopithecus), and Saguina (Saguinus) constitute subfamily Callitrichinae, and subfamilies Callitrichinae, Aotinae (Aotus), Saimiriinae (Saimiri), and Cebinae (Cebus) constitute family Cebidae. In turn, subtribes Chiropotina (Chiropotes, Cacajao) and Pitheciina (Pithecia) constitute tribe Pithecini, tribes Pitheciini and Callicebini (Callicebus) constitute subfamily Pitheciinae, tribes Atelini (Brachyteles, Lagothrix, Ateles) and Alouattini (Alouatta) constitute subfamily Atelinae, and subfamilies Pitheciinae and Atelinae constitute family Atelidae. The two families (Cebidae and Atelidae) constitute the Ceboidea, the only extant superfamily of infraorder Platyrrhini. The sister-group relationships of Brachyteles and Lagothrix, Saguinus and Leontopithecus, and Callimico with a Cebuella/Callithrix clade is not as well supported by the parsimony and bootstrap analyses. Therefore, these relationships are not incorporated in the proposed cladistic classification. On determining branch lengths for the ceboid phylogenetic tree from only the more freely evolving noncoding sequences at the epsilon-globin locus and taking the reference age of 35 million years ago (MYA) for the New World monkey-catarrhine branch point, we estimated the age of the atelid-cebid branch point as about 20 MYA, and the ages of the next branch points, those between the subfamilies in each family, as 19-16 MYA.

Animals↗