LONG-TERM VIABILITY OF MICRORNAS IN MARINE MAMMAL ARCHIVED SAMPLES

MicroRNAs (miRNAs) are conserved short non-coding RNAs that regulate gene expression in nearly all eukaryotes. These epigenetic markers have been extensively used in disease and organ injury diagnosis in humans but their use in wildlife studies has been limited; little is known about their resilience in samples collected under non-sterile conditions post-mortem. Here, we assessed long-term miRNA viability in marine mammal skin tissues using two approaches: (1) conducting time-series experiments with freshly dead stranded dolphins using various preservatives for over a two-year period and (2) comparing miRNA extracts from samples obtained from live animal biopsies and post-mortem/ stranded skin tissues, in samples archived in formalin, ETOH and salt- saturated DMSO archived for 2-6 years. These approaches revealed that, with the exception of formalin, high quality miRNA extracts can be consistently obtained from dolphin skin biopsies or stranded specimen irrespective of preservative and length of preservation. We observed that freeze-thaw cycles ( greater than 3 cycles) can significantly negatively impact sample viability so we recommend sub-sampling prior to preservation whenever possible. Our study confirms previous reports using human sampling studies that miRNAs are remarkably resilient to degradation, particularly in comparison to messenger RNAs (mRNA). The increased resilience of miRNAs, largely due to their coupling with Argonaute proteins, make them promising markers for wildlife studies.

Presentation Preference: Oral

Primary Presenter: Halia Morris, Hampton University (halia.morris@my.hamptonu.edu)

Authors:

Halia Morris, Hampton University  (halia.morris@my.hamptonu.edu)

Carolina Lewallen, Hampton University  (carolina.lewallen@hamptonu.edu)