DNA from mollusc shell: a valuable and underutilised substrate for genetic analyses.

Area of Science:

• Paleogenetics
• Molecular Biology
• Marine Biology

Background:

• Mollusc shells are abundant, ancient archives of ecological and evolutionary history.
• Their potential as a source for molecular genetic analysis remains largely untapped.
• Previous studies have not extensively explored DNA viability in diverse shell conditions.

Purpose of the Study:

• To investigate the utility of various mollusc shell types (fresh, aged, beach-cast, cooked) for molecular genetic analysis.
• To determine the quantity and quality of DNA recoverable from these shells.
• To assess the success rate of PCR amplification for mitochondrial and nuclear genes from shell DNA.

Main Methods:

• DNA extraction from fresh, aged (13 months post-mortem), beach-cast, and cooked *Perna canaliculus* shells.
• Quantification of extracted DNA using spectrophotometry.
• Polymerase Chain Reaction (PCR) amplification of mitochondrial and nuclear gene fragments (chitin synthase).
• Success rate assessment of PCR amplification across different shell treatments.

Main Results:

• Significant DNA quantities (0.002-21.48 ng/mg) were recovered from aged, beach-cast, and cooked shells.
• High success rates for mitochondrial DNA amplification (96.5% from aged, 93.75% from cooked shells).
• Moderate success for nuclear DNA amplification (80% from fresh, decreasing with age; 75% from cooked shells).

Conclusions:

• Mollusc shells are a promising, underutilized substrate for ancient DNA research.
• DNA from aged, beach-cast, and cooked shells can support PCR-based genetic analyses.
• This method expands possibilities for paleogenetic studies using readily available mollusc shell material.