ABSTRACT
The isolation of a single yeast strain in the clade containing Metschnikowia dekortorum, in the Amazon biome of Brazil, incited us to re-examine the species boundaries within the clade. The strain (UFMG-CM-Y6306) was difficult to position relative to neighbouring species using standard barcode sequences (ITS-D1/D2 rRNA gene region). Mating took place freely with α strains of M. bowlesiae, M. dekortorum, and M. similis, but two-spored asci, indicative of a fertile meiotic progeny, were formed abundantly only with certain strains of M. dekortorum. Accordingly, we examined mating success among every phylotype in the clade and constructed a phylogeny based on a concatenation of 100 of the largest orthologous genes annotated in draft genomes. The analyses confirmed membership of the Amazonian isolate in M. dekortorum, but also indicated that the species should be subdivided into two. As a result, we retain three original members of M. dekortorum in the species, together with the new isolate, and reassign six isolates recovered from Mesoamerican lacustrine habitats to Metschnikowia lacustris sp. nov. The type is UWOPS 12-619.2T (isotype CBS 16250T). MycoBank: MB 833751.
Subject(s)
Metschnikowia/classification , Phylogeny , Brazil , DNA, Fungal/genetics , DNA, Ribosomal Spacer/genetics , Genes, Fungal , Genes, rRNA/genetics , Life Cycle Stages , Metschnikowia/genetics , Metschnikowia/isolation & purification , Mycological Typing Techniques , Saccharomycetales/classificationABSTRACT
A new species of the genus Caecilia (Caeciliidae) from the western foothills of the Serranía de los Yariguíes in Colombia is described. Caecilia pulchraserrana sp. nov. is similar to C. degenerata and C. corpulenta but differs from these species in having fewer primary annular grooves and a shorter body length. With this new species, the currently recognized species in the genus are increased to 35. Mitochondrial DNA sequences, including newly sequenced terminals representing two additional, previously unanalyzed species, corroborate the phylogenetic position of the new species within Caecilia and the monophyly of the genus. This analysis also included newly sequenced terminals of Epicrionops aff. parkeri (Rhinatrematidae) and trans-Andean Microcaecilia nicefori (Siphonopidae). Evidence was found for the non-monophyly of the family Siphonopidae and the siphonopid genera Microcaecilia and Siphonops. The implications of these results for caecilian systematics are discussed and the status of the trans-Andean populations of Caecilia degenerata is commented upon.
ABSTRACT
Monophyly of the genus Leporinus (Characiformes: Anostomidae) was tested by sequencing and analysing a total of 4732 bp, including two mitochondrial [cytochrome oxidase subunit 1 (CO1) and cytochrome b (Cytb)] and three nuclear [myosin heavy chain 6 cardiac muscle alpha (Myh6), recombination activating gene 1 (RAG1) and recombination activating gene 2 (RAG2)] loci for 22 species of Leporinus, or c. 25% of all described species in the genus. Phylogenetic tree analyses (maximum parsimony, maximum likelihood and Bayesian species tree) indicate Leporinus to be paraphyletic, with monophyly being rejected by both Kishino-Hasegawa and Shimodaira-Hasegawa tests. The sequenced species of Leporinus are distributed across five clades that are interleaved among other anostomid genera. Several taxonomic changes are suggested as being necessary to restore monophyly for the group. The clade containing the type species, Leporinus fasciatus, should be considered Leporinus sensu stricto and at least three new genera should be described for other species currently considered part of Leporinus.
Subject(s)
Characiformes/classification , Characiformes/genetics , Genes, Mitochondrial , Phylogeny , Animals , Base Sequence , Bayes Theorem , Cytochromes b/genetics , DNA/chemistry , DNA/isolation & purification , DNA-Binding Proteins/genetics , Electron Transport Complex IV/genetics , Fresh Water , Genetic Markers , Homeodomain Proteins/genetics , Likelihood Functions , Myosin Heavy Chains/genetics , Sequence Alignment/veterinary , Sequence Analysis, DNA/veterinaryABSTRACT
A new species of myxomycete, Perichaena longipes, is described from 56 sporocarp specimens that appeared in moist chamber cultures prepared with samples of decaying plant materials collected in Panama, Costa Rica and Brazil. This new species is distinguished from the morphologically similar species P. pedata on the basis of the much longer stipe, lighter peridium and the unique ornamentation of the capillitium. The nuc 18S ribosomal DNA sequences obtained from four specimens of P. longipes support the distinction of this new taxon and its separation from P. pedata. Furthermore, maximum likelihood phylogeny supports earlier evidence that species currently within the genus Perichaena do not form a monophyletic clade. Instead they appear to form three separate branches within the bright-spored clade. The first clade includes P. longipes together with several species of Trichia and Metatrichia, the second includes P. pedata and P. chrysosperma, and the third clade is composed of P. corticalis, P. depressa and P. luteola.
Subject(s)
DNA, Fungal/genetics , Myxomycetes/classification , Myxomycetes/genetics , Microscopy, Electron, Scanning , Myxomycetes/ultrastructure , Panama , RNA, Fungal/genetics , RNA, Ribosomal, 18S/genetics , Species SpecificityABSTRACT
Culex quinquefasciatus Say (Diptera; Culicidae) es un mosquito perteneciente al complejo Pipiens con distribución amplia en el mundo y en Venezuela tanto en zonas urbanas como rurales; es acentuadamente antropofílico y vector de varios virus y parásitos mantenidos en la naturaleza en un ciclo enzoótico ave-mosquito-ave. Dicha distribución y ocupación de hábitats larvales de origen antropogénico podría sugerir la presencia de subpoblaciones geográficas que pudieran participar en forma diferencial en la transmisión de patógenos. Los análisis filogenéticos y redes de haplotipos de éste trabajo, con secuencias de los genes mitocondriales (Subunidad I del Citocromo oxidasa y Subunidad 5 de la NADH deshidrogenasa) de poblaciones de Cx. quinquefasciatus colectadas en nueve localidades (cementerios) de Venezuela sugieren alta homogeneidad genética inter-poblacional y una sola entidad filogenética (monofilia). Se demostró que el fragmento del gen COI tiene mayor resolución en la definición de la filogenia de especies cercanas y a nivel de géneros y ajustado con la clasificación actual. El gen ND5 con alta variación es más útil para estudios poblacionales, sin embargo muestra parafilia entre Cx. corniger y Cx. quinquefasciatus, que representa una evidencia de posible homogenización por entrecruzamiento, introgresión o infección por Wolbachia. Las redes de haplotipos sugieren poblaciones en expansión con alta variabilidad haplotípica y heterogeneidad genética intra poblacional y homogeneidad inter poblacional, con implicaciones evolutivas en la dispersión de sus poblaciones y el éxito en áreas urbanas, así como evidencia de posible cuello de botella en poblaciones producto de marcadas campañas de aplicación de insecticidas, información útil en la planificación de futuras estrategias de control sanitario.
Culex quinquefasciatus Say (Diptera, Culicidae) is a mosquito belonging to the Pipiens complex with wide distribution in the world and in Venezuela, both urban and rural. Besides, it is a markedly anthropophilic vector of several viruses and parasites maintained in nature in a cycle enzootic bird-mosquito-bird. The wide distribution and occupation of larval habitats of anthropogenic origin may suggest the presence of geographical subpopulations, which may differentially participate in the transmission of pathogens. Phylogenetic analysis and haplotype networks with sequences of mitochondrial genes (cytochrome oxidase subunit I and subunit 5 of NADH dehydrogenase) of populations collected in nine locations (cemeteries) of Venezuela showed high interpopulation genetic homogeneity and a single phylogenetic entity (monophyly). It demostrated that the COI gene fragment had a higher resolution in the definition of the phylogeny of closely related species and genera level and correlated with the current classification. The ND5 gene variation is highly useful for population studies. However, this gene showed paraphyly between Cx. corniger and Cx. quinquefasciatus as an evidence of possible homogenization by inbreeding, introgression or infection with Wolbachia. The haplotype networks suggest expanding populations with high haplotype variability and genetic heterogeneity occurred within populations. Moreover, the analysis, showed homogeneity among populations with evolutionary implications in the dispersion of their populations and successful occupation in urban areas, as well as evidence of possible population bottleneck as consequence of insecticide control campaigns.