Eastern oyster transcriptomic response to different Perkinsus marinus exposure methods and infection intensities

Authors: Proestou, Dina; SULLIVAN, MARY - University Of Rhode Island

Submitted to: Meeting Abstract
Publication Type: Abstract Only
Publication Acceptance Date: 12/9/2020
Publication Date: N/A
Citation: N/A

Interpretive Summary: N/A

Technical Abstract: In controlled lab challenges, Perkinsus marinus dosing method and infection intensity affect oyster responses. Exploring how oyster survival and gene expression vary with exposure method and parasite load can broaden our understanding of this host-parasite interaction. We compared response traits and global expression patterns over time in an Eastern oyster family exposed to P. marinus through suspension feeding and direct injection. All exposed oysters received a dose of 5 × 106 P. marinus cells g-1 wet tissue weight, but oysters in the injected group had higher initial infection intensity and reduced survival probability compared to the fed group. Using RNAseq, we identified differentially expressed transcripts between fed and control animals 6 h after exposure and between fed and injected groups at 36 h, 7 d, and 28 d post exposure. Immediately after infection, caspase-8 and transcripts associated with mediating cell damage from reactive oxygen species were upregulated in the fed group compared to unchallenged controls. Early in the infection process, increased innate immune activity and upregulation of transcripts involved in proinflammatory cytokine pathways (e.g. toll-like receptor 4 and TNF receptor-associated factor 6-like protein) were observed in the injected relative to the fed group. By 28 d post-exposure, the fed group expressed transcripts associated with growth, specifically microtubule-based processes, at a higher level than the injected group. This study demonstrates that dosing method impacts initial parasite load, survival, and transcriptomic response to infection with Perkinsus marinus and highlights the importance of considering dosing method when interpreting interactions between parasite and host.