Population structure and genetic connectivity of the scalloped hammerhead shark (Sphyrna lewini) across nursery grounds from the Eastern Tropical Pacific: Implications for management and conservation.

Defining demographically independent units and understanding patterns of gene flow between them is essential for managing and conserving exploited populations. The critically endangered scalloped hammerhead shark, Sphyrna lewini, is a coastal semi-oceanic species found worldwide in tropical and subtropical waters. Pregnant females give birth in shallow coastal estuarine habitats that serve as nursery grounds for neonates and small juveniles, whereas adults move offshore and become highly migratory.

A multiplex qPCR TaqMan-assay to detect fungal antagonism between (Hypocreaceae) and (Sclerotiniaceae) in blackberry fruits using a tef1-α- and an IGS-sequence based probes.

The aim of this study was to design a -specific qPCR oligo set, evaluate its specificity, and standardize a methodology that quantifies antagonism against in blackberry fruits ( Schltdl.). Primers and probe were designed based on the nuclear translation elongation factor 1-alpha (tef1-α) of .

Phenolic variation among Chamaecrista nictitans subspecies and varieties revealed through UPLC-ESI(-)-MS/MS chemical fingerprinting.

Introduction: Comparative analysis of metabolic features of plants has a high potential for determination of quality control of active ingredients, ecological or chemotaxonomic purposes. Specifically, the development of efficient and rapid analytical tools that allow the differentiation among species, subspecies and varieties of plants is a relevant issue. Here we describe a multivariate model based on LC-MS/MS fingerprinting capable of discriminating between subspecies and varieties of the medicinal plant Chamaecrista nictitans, a rare distributed species in Costa Rica.

Genetic Diversity of Xylella fastidiosa Strains from Costa Rica, São Paulo, Brazil, and United States.

ABSTRACT The diversity of 42 Xylella fastidiosa strains from Costa Rica, São Paulo, Brazil, and the United States were analyzed using the sequence of the 16S rRNA gene by variable number of tandem repeat (VNTR) fragment analysis and by restriction fragment length polymorphisms (RFLP) of a specific polymerase chain reaction (PCR)-amplification product using enzyme CfoI. Limited variability in the sequence of the 16S rRNA gene was observed and, although the separation was not absolute, most strains from Costa Rica clustered with strains from the United States and not with strains from São Paulo. The PCR-RFLP produced different patterns of DNA bands.

Molecular data indicate that Rhytidhysteron rufulum (ascomycetes, Patellariales) in Costa Rica consists of four distinct lineages corroborated by morphological and chemical characters.

Rhytidhysteron rufulum is a poorly known, common, pantropical species, capable of utilizing different substrata and occupying diverse habitats, and is the only species of its genus in Costa Rica. We have employed molecular, morphological, and chemical data to assess the variability and differentiation of R. rufulum in Costa Rica, including sites from the Pacific and Atlantic coast.

Partial characterization of Maize rayado fino virus isolates from Ecuador: phylogenetic analysis supports a Central American origin of the virus.

Maize rayado fino virus (MRFV) infects maize and appears to be restricted to, yet widespread in, the Americas. MRFV was previously unreported from Ecuador. Maize plants exhibiting symptoms of MRFV infection were collected at the Santa Catalina experiment station in Quito, Ecuador.

Scientific publications about DNA structure-function and PCR technique in Costa Rica: a historic view (1953-2003).

The spreading of knowledge depends on the access to the information and its immediate use. Models are useful to explain specific phenomena. The scientific community accepts some models in Biology after a period of time, once it has evidence to support it.

HBx M130K and V131I (T-A) mutations in HBV genotype F during a follow-up study in chronic carriers.

Background: Around 400 million people worldwide are chronically infected with Hepatitis B virus (HBV). An estimated 10% of these chronic patients develop progressive liver damage including cirrhosis and Hepatocellular Carcinoma (HCC). The HBx gene encodes a protein of 154 amino acids which is a transactivator and has been associated with HBV pathogenesis.

Characterization of a photosynthetic Euglena strain isolated from an acidic hot mud pool of a volcanic area of Costa Rica.

Abstract Conspicuous green patches on the surface of an acidic hot mud pool located near the Rincón de la Vieja volcano (northwestern Costa Rica) consisted of apparently unialgal populations of a chloroplast-bearing euglenoid. Morphological and physiological studies showed that it is a non-flagellated photosynthetic Euglena strain able to grow in defined mineral media at temperatures up to 40 degrees C and exhibiting higher thermotolerance than Euglena gracilis SAG 5/15 in photosynthetic activity analyses. Molecular phylogeny studies using 18S rDNA and GapC genes indicated that this strain is closely related to Euglena mutabilis, another acid-tolerant photosynthetic euglenoid, forming a clade deeply rooted in the Euglenales lineage.