Molecular characterization of larval development from fertilization to metamorphosis in a reef-building coral

Marie E. Strader,Mikhail V. Matz,Galina V. Aglyamova

doi:10.1186/s12864-017-4392-0

Marie E. Strader, Mikhail V. Matz + Show 1 more

Open Access

https://doi.org/10.1186/s12864-017-4392-0

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Journal: BMC Genomics	Publication Date: Jan 4, 2018
Citations: 42	License type: open-access

Affiliation: The University of Texas at Austin

Abstract

BackgroundMolecular mechanisms underlying coral larval competence, the ability of larvae to respond to settlement cues, determine their dispersal potential and are potential targets of natural selection. Here, we profiled competence, fluorescence and genome-wide gene expression in embryos and larvae of the reef-building coral Acropora millepora daily throughout 12 days post-fertilization.ResultsGene expression associated with competence was positively correlated with transcriptomic response to the natural settlement cue, confirming that mature coral larvae are “primed” for settlement. Rise of competence through development was accompanied by up-regulation of sensory and signal transduction genes such as ion channels, genes involved in neuropeptide signaling, and G-protein coupled receptor (GPCRs). A drug screen targeting components of GPCR signaling pathways confirmed a role in larval settlement behavior and metamorphosis.ConclusionsThese results gives insight into the molecular complexity underlying these transitions and reveals receptors and pathways that, if altered by changing environments, could affect dispersal capabilities of reef-building corals. In addition, this dataset provides a toolkit for asking broad questions about sensory capacity in multicellular animals and the evolution of development.

Highlights

Molecular mechanisms underlying coral larval competence, the ability of larvae to respond to settlement cues, determine their dispersal potential and are potential targets of natural selection
The possible reason for this unusual competence profile was the unintended variation in light-dark cycle and/or moving the cultures to another room on day 10, numerous other unknown factors may have caused this brief reduction in competence
Effect of drugs modulating G-protein coupled signaling receptor (GPCR) signaling Overall, our neuropharmacological screen supports the results of gene expression analysis suggesting a role of GPCR pathway in competence: we find that drugs inhibiting GPCR signaling suppress settlement and metamorphosis (Fig. 4b)

Summary

Introduction

Molecular mechanisms underlying coral larval competence, the ability of larvae to respond to settlement cues, determine their dispersal potential and are potential targets of natural selection. Quantifying the extent and spatial scale of marine larval dispersal are critical for designing effective management strategies [4]. Competence is the capacity of an individual to metamorphose in response to specific environmental cues where metamorphosis is the irreversible commitment to transition from a larval to juvenile stage [5, 6]. Being competent is a state in which a larva delays metamorphosis until the appropriate habitat selection cues are detected and is considered a form of developmental plasticity [5]. The biology of larval competence is quite complex and it is imperative to unravel the molecular mechanisms responsible for this critical developmental state

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