Biomedical subjects

M J Chapela

Publications and source records attributed to M J Chapela.

2 recordsLinked to original sources

PubMed2001

Identification of Hake species (Merluccius Genus) using sequencing and PCR-RFLP analysis of mitochondrial DNA control region sequences.

The use of DNA-based methodologies in identification of hake species belonging to the Merluccius genus was shown to be successful. A short fragment of the left hypervariable domain of the mitochondrial control region was amplified, sequenced, and digested from 11 hake species. The hake-specific PCR product, due to its limited size, was obtained in a variety of tissue samples with different levels of DNA concentration and degradation, including sterilized food products. On the basis of this phylogenetically informative 156-bp sequence were selected four restriction enzymes (ApoI, DdeI, DraIII, and MboII) that allow the hake species discrimination. Species identification by phylogenetic analysis of sequences or by PCR-RFLP methodologies is useful in a variety of scenarios including authentication of thermally processed food, detection of food components, and species determination of individuals whose morphological characters are removed.

Animals↗

PubMed2001

Identification of flatfish (Pleuronectiforme) species using DNA-based techniques.

Identification of flatfish species using a DNA-based methodology was studied. The polymerase chain reaction was employed to obtain a 464 bp amplicon from mitochondrial cytochrome b gene. The sequences from this fragment belonging to 24 species were analyzed using a genetic distance method, and polymorphic sites were determined. The fragment was found to be highly polymorphic (231 sites), and this permitted the differentiation of most of the species. Phylogenetic tree construction was employed to allow the identification of flatfish species. As a result, each species was grouped in a well-differentiated clade, except for two pairs: Limanda ferruginea and L. limanda, and Solea impar and S. lascaris, which could not be differentiated. On the basis of the sequences obtained, restriction enzymes were selected to provide specific restriction profiles, which allow the differentiation of 21 species of flatfish in a faster and less expensive manner than sequencing. This polymerase chain reaction-restriction fragment length polymorphism methodology (PCR-RFLP) was tested using commercial samples.

Animals↗