Genetic variation in the massive coral Porites lobata

Do reef corals age?

“…Soong et al (1999) may comprise many ramets that become widely dispersed, for example during storms, leading to a high degree of clonality within the population (Baums, Miller & Hellberg, 2006;Pinzon et al, 2012;Japaud et al, 2015). Genetic mosaicism has been recorded across the colony due to somatic mutations (van Oppen et al, 2011;Barfield, Aglyamova & Matz, 2016) and chimeric colonies may form by fusion of adjacent, non-clonal colonies, particularly by fusion of juveniles before the immune system is fully developed (Schweinsberg, Tollrian & Lampert, 2016). This implies that cell turnover and migration across the colony, if it occurs (van Oppen et al, 2011), is not extensive or rapid enough to mask the genetic differentiation of the individual polyp lineage.…”

“…Phenotypically observable mutation rate is similarly high, with 300-500 mutations estimated to accumulate over the lifetime of the colony in Orbicella faveolata (Barfield et al, 2016). High frequencies of somatic mutations have also been proposed to explain significant intra-colonial variability observed in other coral species (Maier et al, 2012;Schweinsberg et al, 2015Schweinsberg et al, , 2016. In addition, significant levels of somatic mutation have been reported in microsatellite loci between ramets within the genet of A. palmata from sites across the Caribbean (Devlin-Durante et al, 2016).…”

Peer Review #1 of "Divergent evolutionary histories of DNA markers in a Hawaiian population of the coral Montipora capitata (v0.1)"

“…Given the existing hypotheses of current and historic coral chimerism [10,21,22, e.g., Fig. 5A], mosaicism, and hybridization based on population data [13], the major goal of our study was to elucidate the nature and sources of genetic variation in the coral host. Our approach examined the intra and inter-colony genetic structure in M. capitata, which is the dominant reef builder in Hawai'i.…”

“…The MTC region was amplified from sperm DNA using the primers Ms_FP2 (5'-TAG ACA GGG CCA AGG AGA AG-3') and MON_RP2 (5'GAT AGG GGC TTT TCA TTT GTT TG-3') [13]. The ITS1 region was amplified using the primers ZITS1 (5'-TAA AAG TCG TAA CAA GGT TTC CGT A-3') and ZITS2 (5'-CCT CCG CTT ATT GAT ATG CTT AAA T-3") [17].…”

“…Another source of variation is the maintenance of multiple copies of genes either through heteroplasmy of organelles or replication of genes within the genome. Furthermore, genetic variation can accumulate through mutations in somatic tissues (mosaicism) that differentiate in individual polyps [12,13], propagate in the somatic tissue, and may be transferred to subsequent generations if the germline is not segregated [8,9]. However, an independently segregating germline has been suggested in the coral Orbicella faveolata, which could protect gametes from propagating these mutations [14].…”