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.将供体珍珠贝的外套膜组织移植至受体贝的生殖腺中，可形成嵌合体——珍珠囊（pearl sac）。该嵌合体的表型变异被假设为供体与受体基因组相互作用的结果。本研究首次在P. margaritifera珍珠生产过程中，探究了表型变异的遗传力及其与基因表达的关联。研究基于控制性双亲杂交及F1代群体，从三个不同层面评估了遗传变异：1）移植操作前（供体外套膜组织的基因表达水平）；2）移植完成后（嵌合体的珍珠囊组织基因表达水平）；3）移植产物的珍珠表型性状层面。供体的遗传参数估计结果清晰证实，珍珠层重量、厚度、色泽深度与色调、表面瑕疵及品级均存在遗传力，这表明供体贝中存在对应的遗传基础。在供体外套膜的相对基因表达分析中，几乎所有基因的遗传力值均高于0.20；而在珍珠囊组织中，除CALC1和Aspein外，遗传力估计值均较低（h² < 0.10）。相较于供体组织，珍珠囊的基因表达似乎更易受剩余方差影响，这可由影响珍珠囊基因表达的环境效应，以及作为受体加性遗传组分的因素共同解释。供体与受体间的相互作用极为复杂，未来仍需开展进一步研究，以阐明受体贝对珍珠表型及基因表达变异的作用机制。