Whitney Researchers publish article in Science of the Total Environment

Congratulations to Whitney Laboratory researchers who published an article in Science of the Total Environment -"Multicellular species environmental DNA (eDNA) research constrained by overfocus on mitochondrial DNA".

ABSTRACT

Environmental DNA (eDNA) is becoming an established tool across the biological and medical sciences. Despite the evident successes and wide adoption of eDNA approaches, some fundamental questions remain. For instance, there is almost a dogma in the field around the superiority of mitochondrial DNA for use in eDNA studies, however robust comparison with nuclear eDNA is widely lacking. The dominance of mitochondrial-based eDNA for animal and plant studies appears to be largely settled, despite a widespread lack of rigorous nuclear eDNA testing. Outside of the source organism the protections conferred on eDNA by the cell, mitochondrial and nuclear membranes are poorly understood, including the contribution of each to eDNA persistence and degradation. Utilizing shotgun sequencing to unbiasedly assess the level of nuclear and mitochondrial eDNA across samples, we reveal stark differences in nuclear versus mitochondrial eDNA persistence and abundance. By focusing too heavily on mitochondrial DNA alone the field is underutilizing eDNA’s full potential.

Highlights

• With multiple mitochondria (mt) per cell, sequenced tissue has a high ratio of mt to nuclear DNA (genome length adjusted)
• Mitochondrial (mt) to nuclear (nu) ratio of eDNA begins declining immediately after release from the source organism
• The mt to nu ratio continues declining the longer DNA is in the environment, making eDNA fraction an important consideration
• Nu sequences were detected in some eDNA samples when mt sequences were not, with implications for false negatives/ positives
• Shotgun sequencing approaches or nuclear marker incorporation may increase eDNA eukaryotic species detection sensitivity

Multicellular species environmental DNA (eDNA) research constrained by overfocus on mitochondrial DNA