Fig. 5.

Characterization of environmentally responsive genes with selective signals associated with lipid and ATP metabolisms and related phenotypes. (a) Heatmaps for genes with selective signals that are highly expressed at northern (up) and southern (bottom) environments. (b) F_ST and Tajima’s D values of acod along the coding (marked in green), upstream and downstream noncoding regions. F_ST values and Tajima’s D values are plotted using a 10-kb sliding window. Numbers along the x axis indicate positions in the corresponding scaffold. Dashed line indicates top 5% significance level of F_ST values, where F_ST is 0.22. (c) Divergence for genotype frequency of SNPs in coding (marked in green), upstream and downstream noncoding regions of acod between the two species. The y axis represents log(10) transformed P value of χ² test. (d) Linkage disequilibrium (LD) blocks in acod flanking regions (as depicted in b) in the southern Crassostrea angulata (left) and northern C. gigas (right). The red boxes indicate transcription start site (TSS). (e) ATP and free fatty acid (FFA) content of two species cultured at northern and southern habitats. Red and blue dashed lines indicate the northern and southern oyster species, and circles and diamonds indicate the content of ATP and FFA, respectively. Error bars represent SD values. Ca, C. angulata; Cg, C. gigas; N, northern habitat; S, southern habitat. Cg_N and Ca_S indicate oysters in their native habitats.