Full-Length Transcriptome Sequencing of the Scleractinian Coral Montipora foliosa Reveals the Gene Expression Profile of Coral-Zooxanthellae Holobiont.

Yunqing Liu,Zuhong Lu,Xin Liao,Zhuojun Guo,Na Lu,Tingyu Han,Ao Su,Chunpeng He

doi:10.3390/biology10121274

Yunqing Liu, Zuhong Lu + Show 6 more

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https://doi.org/10.3390/biology10121274

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Journal: Biology	Publication Date: Dec 5, 2021
Citations: 3	License type: CC BY 4.0

Affiliation: Southeast University, Guangxi Mangrove Research Center

Abstract

Simple SummaryCoral bleaching (the disintegration of coral–zooxanthellae symbionts) is one of the important factors leading to coral death. However, we still lack an understanding of the mechanism of coral–zooxanthellae symbiosis. One of the reasons is the lack of reliable transcriptome sequence data. In this paper, through PacBio Sequel II sequencing technology polished with the Illumina RNA-seq platform, the Montipora foliosa transcriptome was obtained. The function and isoform of symbiosis-related genes were analyzed. This study provides a valuable resource for the study of coral symbiosis.Coral–zooxanthellae holobionts are one of the most productive ecosystems in the ocean. With global warming and ocean acidification, coral ecosystems are facing unprecedented challenges. To save the coral ecosystems, we need to understand the symbiosis of coral–zooxanthellae. Although some Scleractinia (stony corals) transcriptomes have been sequenced, the reliable full-length transcriptome is still lacking due to the short-read length of second-generation sequencing and the uncertainty of the assembly results. Herein, PacBio Sequel II sequencing technology polished with the Illumina RNA-seq platform was used to obtain relatively complete scleractinian coral M. foliosa transcriptome data and to quantify M. foliosa gene expression. A total of 38,365 consensus sequences and 20,751 unique genes were identified. Seven databases were used for the gene function annotation, and 19,972 genes were annotated in at least one database. We found 131 zooxanthellae transcripts and 18,829 M. foliosa transcripts. A total of 6328 lncRNAs, 847 M. foliosa transcription factors (TFs), and 2 zooxanthellae TF were identified. In zooxanthellae we found pathways related to symbiosis, such as photosynthesis and nitrogen metabolism. Pathways related to symbiosis in M. foliosa include oxidative phosphorylation and nitrogen metabolism, etc. We summarized the isoforms and expression level of the symbiont recognition genes. Among the membrane proteins, we found three pathways of glycan biosynthesis, which may be involved in the organic matter storage and monosaccharide stabilization in M. foliosa. Our results provide better material for studying coral symbiosis.

Highlights

Introduction conditions of the Creative CommonsCorals are marine invertebrates within the class Anthozoa of the phylum Cnidaria that first appeared in the Cambrian approximately 535 million years ago
Scleractinia is the key component of coral reef ecosystems, and it can extract calcium and carbonate to construct aragonite, which provides a habitat for other creatures
Some corals can catch plankton and small fish using stinging cells on their tentacles, scleractinian corals obtain most of their energy and nutrients from photosynthetic unicellular dinoflagellates of the genus Symbiodinium that live within their cells

Summary

Introduction

Introduction conditions of the Creative CommonsCorals are marine invertebrates within the class Anthozoa of the phylum Cnidaria that first appeared in the Cambrian approximately 535 million years ago. Many corals in the order Scleractinia are hermatypic, meaning that they are involved in building reefs [1]. They secrete calcium carbonate to form hard skeletons that become the framework of a reef [2]. Scleractinia is the key component of coral reef ecosystems, and it can extract calcium and carbonate to construct aragonite (biomineralization), which provides a habitat for other creatures. Some corals can catch plankton and small fish using stinging cells on their tentacles, scleractinian corals obtain most of their energy and nutrients from photosynthetic unicellular dinoflagellates of the genus Symbiodinium that live within their cells. The genus Symbiodinium is commonly known as zooxanthellae and provides coral its color. Zooxanthellae benefit from a safe place to live and consume the polyps’ carbon dioxide, phosphate, and nitrogenous waste

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