Environmental DNA monitoring of oncogenic viral shedding and genomic profiling of sea turtle fibropapillomatosis reveals unusual viral dynamics

摘要

a Green sea turtle inguinal external FP tumor, infested with leeches. Upon patient intake FP-afflicted tumors frequently harbor marine leeches, as was the case for this patient 02-2021-Cm “Broccoli”. Leeches from “Broccoli’s” tumors were used for the ChHV5 analysis in (e). Leeches are commonly found within the crevasses of external FP tumors (right image). b Detailed view of a marine leech removed from the surface of a fibropapillomatosis tumor, with gills and with dark red blood pellet (after feeding on a C. mydas turtle) visible. c Detection and quantification of ChHV5 UL30 gene DNA by qPCR, using leeches as proxy eDNA samples (whole leech lysis and DNA extraction). Error bars denote the standard deviation of three technical replicates. Amplification ratio for leeches from the FP-free loggerhead turtle (09-2015-Cc) was 0, and the amplification ratio for both the FP-tumor leech and FP-tumor tissue samples (green turtle, 07-2015-Cm) was 1.0. d Quantification of ChHV5 UL30 gene DNA by qPCR, from leeches removed from FP-afflicted green turtles from either FP tumors or non-tumor locations. Individual turtle denoted by rd—36-2020-Cm “Richard Dawkins”, bh—52-2020-Cm “Bruno Hofer”, or rg—78-2020-Cm “Ruth Gates”. Approximately ten leeches were pooled for each of the 12 DNA extraction samples. Error bars denote the standard deviation of six technical replicates. e Quantification of ChHV5 UL30 gene DNA by qPCR, from leeches (individual leech DNA extractions) removed from FP tumors of green sea turtle patient 02-2021-Cm “Broccoli” (a). Amplification ratios for leech samples are provided in Supplementary Table 1. Error bars denote the standard deviation of six technical replicates.