The neuston layer in tropical seas provides a good model to study the effects of increased levels of different stressors (e.g., temperature, ultraviolet radiation and Trichodesmium blooms). Here, we use a comparative in situ metatranscriptomics approach to reveal the functional genomic composition of metabolically active neustonic mesozooplankton community in response to the summer conditions in the Red Sea. The neustonic population exhibited changes in composition and abundance with a significant decline in copepods and appendicularia in July, when Trichodesmium cells were more abundant along with high temperatures and UV-B radiation. Nearly 23,000 genes were differentially expressed at the community level when the metatranscriptomes of the neustonic zooplankton were compared in April, July, and October. On a wider Phylum level, the genes related to oxidative phosphorylation, carbon, nucleotides, amino acids, and lipids were significantly overrepresented in both arthropods and chordates in April and October. On organism level for copepods, expression of genes responsive to oxidative stress, defense against bacteria, immune response, and virus reproduction were increased along with the observed increased appearance of copepod carcasses in the samples collected during July. The differences in expression correspond either to secondary effects of the Trichodesmium bloom or more likely to the increased UV-B radiation in July. Given the dearth of information on the zooplankton gene expression in response to environmental stimuli, our study provides the first transcriptome landscape of the mesozooplankton community during a period of increased mortality of the copepod and appendicularia population.
|Original language||English (US)|
|Number of pages||12|
|Journal||Limnology and Oceanography|
|State||Published - Oct 20 2016|
Bibliographical noteKAUST Repository Item: Exported on 2020-10-01
Acknowledgements: We thank the captain and crew of the KAUST research vessel operated by the Coastal and Marine Resources Core lab (CMOR) at King Abdullah University of Science and Technology (KAUST) for their technical support during sampling. We are also thankful to the Analytical Core Lab and the Bioscience Core Lab at KAUST for their support and services. We also thank the two anonymous reviewers for their helpful comments. This research was supported by baseline funding provided by KAUST to Prof. Xabier Irigoien.