Tests to detect and identify mussel larvae by molecular methods (PCR and sequencing).

Information (04/14/11)

Mussels are one of the most collected and disposed of the bivalve molluscs species, as are present along the coasts of many countries in temperate climates, both the Northern Hemisphere and Southern Hemisphere. Mussel production depends on the natural sources where their larvae are found, so these sources are considered a limiting factor crop expansion. Lecos places where seedlings encentran vary spatially and temporally from one year to another, and methods to search and identify new sources of seeds that peritan extend production sites are required.

Mussels produce planktonic larvae in which are dispersed from adults to detect larvae in places of seedbeds. Morphological identification is very difficult and requires enormous experience to differentiate any species of bivalve mollusk larvae receivables that are present.

There are several species: Mytilus edulis, Mytilus galloprovincialis, Mytilus chilensis, Mytilus trosellus, Perna canaliculus, and Perna viridis, which differ in taste and texture, so it is important to identify and authenticate the species marketed to confirm correct labeling of products marketed. It should be borne in mind that although the raw mussels are marketed under their shells, and they help their differentiation, as with the differences in the color of their shells, Mytilus spp. (balvas of black-violet color) and Perna canaliculus (balvas greenish) by the color of the shells, frozen or canned mussels are sold without balvas.

Have developed various molecular methods to differentiate larvae, such as electrophoresis allozymes antigenic differentiation by immunological methods, and methods of DNA as RFLP (Restriction Fragment Length Polymorphism), SSCP (Single Stranded Conformational Polymorphism), and various PCR methods (Polymerase Chain Reaction). Of these, many have applied to differentiate the species Mytilus edulis mussels.

To differentiate using methods DNA analysis nuclear DNA (genomic DNA), or mitochondrial DNA (mtDNA) can be used. Both differentiate between families, genera, species populations. However, it should be noted that the nuclear ribosomal DNA (encoding the ribosomal rRNA). Slower than mtDNA evolves so in principle should be considered more appropriate to make comparisons and phylogenetic analysis of genera and families, while the mtDNA would be more appropriate to differentiate between species and populations. The mtDNA has the advantage over nuclear DNA there is a greater number of copies per cell, and is better when higher sensitivity is required. Ribosomal nuclear genes such as 18S rRNA) are most commonly used for diagnostic purposes and Phylogenetic because they are composed of several similar sequences. However, the mitochondrial genome 16S rRNA (16S rDNA) is preferred, since it has a low mutation rate compared to other genes of mtDNA.

Tests in IVAMI:

Identification of larvae in plankton, or adult individuals, with or without valves, by PCR amplification of gene 18S RNA (16S rDNA) of genomic DNA and gene mitochondrial 16S rRNA (16S rDNA), followed by sequencing and analysis sequence.

Recommended sample:

Plankton sample water (sufficient volume for filtration and collecting plankton, for example 1.000 mL)

Preservation and shipment of sample:

Refrigeration.

Cost of the test:

Consult ivami@ivami.com