Abstract
Maternal effects have been well documented for offspring morphology and
life history traits in plants and terrestrial animals, yet little is
known about maternal effects in corals. Further, few studies have
explored maternal effects in gene expression. In a previous study, F1
interspecific hybrid and purebred larvae of the coral species
Acropora tenuis and A. loripes were settled and exposed to
ambient or elevated temperature and pCO2
conditions for seven months. At this stage, the hybrid coral recruits
from both ocean conditions exhibited strong maternal effects in several
fitness traits. We conducted RNA-sequencing on samples from the same
experiment and showed that gene expression of the hybrid Acropora
also showed clear maternal effects. Only 40 genes were differentially
expressed between hybrids and their maternal progenitor. In contrast,
~2000 differentially expressed genes were observed
between hybrids and their paternal progenitors, and between the
reciprocal F1 hybrids. These results indicate that maternal effects in
coral gene expression can be long-lasting. Unlike findings from most
short-term stress experiments in corals, no genes were differentially
expressed in the hybrid nor purebred offspring after seven months of
exposure to elevated temperature and pCO2
conditions.