Data from: Crossing phenotype heritability and candidate gene expression in grafted black-lipped pearl oyster Pinctada margaritifera, an animal chimera

Grafting mantle tissue of a donor pearl oyster into the gonad of a
recipient oyster results in the formation of a chimera, the pearl sac. The
phenotypic variations of this chimera are hypothesized to be the result of
interactions between the donor and recipient genomes. In this study, the
heritability of phenotypic variation and its association with gene
expression were investigated for the first time during P. margaritifera
pearl production. Genetic variance was evaluated at different levels, 1)
before the graft operation (expression in graft tissue), 2) after grafting
(pearl sac tissue expression in chimera) and 3) on the product of the
graft (pearl phenotype traits) based on controlled bi-parental crosses and
the F1 generation. Donor related genetic parameter estimates clearly
demonstrate heritability for nacre weight and thickness, darkness and
colour, surface defects and grade, which signifies a genetic basis in the
donor oyster. In graft relative gene expression, the value of heritability
was superior to 0.20 in for almost all genes, while in pearl sac,
heritability estimates were low (h² < 0.10) (except for CALC1 and
Aspein). Pearl sac expression seems to be more influenced by residual
variance than the graft, which can be explained by environmental effects
that influence pearls sac gene expression and act as a recipient additive
genetic component. The interactions between donor and recipient are very
complex and further research is required to understand the role of the
recipient oysters on pearl phenotypic and gene expression variances.