Gut Microbiome Alteration of Cold-adapated Antarctic copepod Tigriopus kingsejongensis with Temperature Changes and Developmental Stages

Abstract

Tigriopus kingsejongensis, a copepod species, reported from the King Sejong Station, Antarctica, serves as a valuable food resource in ecosystems. Some copepods were temperature-sensitive in growth and post-embryonic development. We cultured T. kingsejongensis at three different temperatures (2°C, 8°C, and 15°C) in a laboratory to observe the alterations in the stool microbiome of copepods depending on the cultivation temperature and developmental stages. We observed copepod gut microbiome changes by increasing temperatures: a lower microbial diversity, a higher abundance of aquatic microbes, Vibrio, and a lower abundance of the psychrophilic microbes, Colwellia. Also, the copepod gut microbiome, according to the developmental stage, was changed: a lower microbial diversity in egg-attached copepods than nauplius at 8°C. We further analyzed three shotgun metagenomes from T. kingsejongensis stool samples at different temperatures and obtained 44 metagenome-assembled genomes (MAGs). We noted that MAGs of V. splendidus D contained glycosyl hydrolase (GHs) encoding chitinases and virulence factors with higher relative abundance at 15°C than at lower temperatures. These results that temperature and developmental stages affect the gut microbiome of copepods are helpful to understand the changes in the low-temperature adapted copepod with climate change.

Feeding strategy and dietary preference shape the microbiome of epipelagic copepods in a warm nutrient‐impoverished ecosystem

“…stylifera . Saprospiraceae rarely form associations with copepods (Gerdts et al, 2013; Oh et al, 2021), but we found several ASVs from Saprospiraceae as part of the core microbiome of T . stylifera .…”

“…The metabolic potential of the core microbiota in the seawater and copepod species was predicted from the 16S rRNA amplicon data using Tax4Fun2 (Wemheuer et al, 2020) with the default settings (following tutorial on the GitHub: https://github.com/bwemheu/Tax4Fun2). We searched metabolic pathways that may be relevant to the metabolic interaction between the copepods and the associated microbiota, based on previous studies (De Corte et al, 2018; Oh et al, 2021; Sadaiappan et al, 2021) and performed a PCoA analysis (Bray‐Curtis distances) to assess the specificity of the predicted functions to the specific core ASVs. The differentially abundant metabolic pathways between copepods (mean relative abundance across copepod species) and seawater were determined by the Kruskal‐Wallis test and the p ‐values were adjusted for multiple testing.…”

“…Flavobacteriaceae have been often identified in copepod microbiomes, but unlike previous studies, we showed that Tenacibaculum, Aurantivirga, and Jejudonia genera are associated with T. stylifera. Saprospiraceae rarely form associations with copepods (Gerdts et al, 2013;Oh et al, 2021) Core taxa associated with T. stylifera and C. ponticus exhibited a significant temporal trend in terms of abundance-occurrence. This is in line with previous findings, which suggest that host-associated microbiomes are intrinsically dynamic, varying in their relative abundance and occurrence patterns (Shade & Gilbert, 2015).…”