pubmed.ncbi.nlm.nih.gov

The genetics of colony form and function in Caribbean Acropora corals - PubMed

  • ️Wed Jan 01 2014

The genetics of colony form and function in Caribbean Acropora corals

Elizabeth M Hemond et al. BMC Genomics. 2014.

Abstract

Background: Colonial reef-building corals have evolved a broad spectrum of colony morphologies based on coordinated asexual reproduction of polyps on a secreted calcium carbonate skeleton. Though cnidarians have been shown to possess and use similar developmental genes to bilaterians during larval development and polyp formation, little is known about genetic regulation of colony morphology in hard corals. We used RNA-seq to evaluate transcriptomic differences between functionally distinct regions of the coral (apical branch tips and branch bases) in two species of Caribbean Acropora, the staghorn coral, A. cervicornis, and the elkhorn coral, A. palmata.

Results: Transcriptome-wide gene profiles differed significantly between different parts of the coral colony as well as between species. Genes showing differential expression between branch tips and bases were involved in developmental signaling pathways, such as Wnt, Notch, and BMP, as well as pH regulation, ion transport, extracellular matrix production and other processes. Differences both within colonies and between species identify a relatively small number of genes that may contribute to the distinct "staghorn" versus "elkhorn" morphologies of these two sister species.

Conclusions: The large number of differentially expressed genes supports a strong division of labor between coral branch tips and branch bases. Genes involved in growth of mature Acropora colonies include the classical signaling pathways associated with development of cnidarian larvae and polyps as well as morphological determination in higher metazoans.

PubMed Disclaimer

Figures

Figure 1
Figure 1

Branch morphology of A. cervicornis (A) and A. palmata (B), with insets showing branch tips. Regions of sampling for branch tips (red boxes) and bases (white boxes).

Figure 2
Figure 2

nMDS for all samples and transcripts expressed at > 100 total normalized counts (n = 23,554). Dashed lines delineate groups of samples.

Figure 3
Figure 3

Number of DE genes for factors (colony position and species) and their interaction. Venn diagrams include results for all coral transcripts (A), annotated transcripts (B), and annotated transcripts with greater than 2-fold difference between treatments (C).

Figure 4
Figure 4

Scatter plots of gene expression for all genes in the dataset (n = 22,320). Species (A) and colony position (B) comparisons with DE transcripts in red (Padj < 0.05). Filtering of transcripts expressed at < 100 total normalized counts results in the loss of points around the origin.

Figure 5
Figure 5

Heat map of transcripts DE for both factors or the interaction between factors (*). Includes only transcripts with fold change > 2, except for transcripts with a significant interaction effect.

Figure 6
Figure 6

GO term summary of DE genes for colony position. Values represent the number of transcripts with > 2-fold change in gene expression for selected ‘enriched’ GO Biological Process terms. N is the total number of transcripts in the dataset annotated with the given GO term.

Figure 7
Figure 7

Heat map of selected transcripts DE by colony position (but not species). Transcripts include those putatively involved in signaling, pH regulation or ion transport, or ECM with > 2-fold DE between branch bases and tips.

Similar articles

Cited by

References

    1. Mackie GO. From aggregates to integrates: physiological aspects of modularity in colonial animals. Phil Trans R Soc B. 1986;313:175–196. doi: 10.1098/rstb.1986.0032. - DOI
    1. Pearse VB, Muscatine L. Role of symbiotic algae (zooxanthellae) in coral calcification. Biol Bull. 1971;141:350–363. doi: 10.2307/1540123. - DOI
    1. Cartwright P. The development and evolution of hydrozoan polyp and colony form. Hydrobiologia. 2004;530:309–317.
    1. Siebert S, Robinson MD, Tintori SC, Goetz F, Helm RR, Smith SA, Shaner N, Haddock SHD, Dunn CW. Differential gene expression in the siphonophore Nanomia bijuga (Cnidaria) assessed with multiple next-generation sequencing workflows. PLoS One. 2011;6:e22953. doi: 10.1371/journal.pone.0022953. - DOI - PMC - PubMed
    1. Gladfelter EH. Skeletal development in Acropora cervicornis: I. Patterns of calcium carbonate accretion in the axial corallite. Coral Reefs. 1982;1:45–51. doi: 10.1007/BF00286539. - DOI

Publication types

MeSH terms

Substances

LinkOut - more resources