Fig. 6

Depth-dependent and seasonal variations in gene coverages of Ca. Regnicoccus frigidus MAGs. Volcano plots showing variations in MAG-AL1 (a, c, e, g, i, k) and MAG-AL2 (b, d, f, h, j, l) gene coverages in samples from different lake depths (oxic, interface, anoxic) or seasons (summer, winter, spring). Each dot in a plot represents a MAG gene. The y-axes indicate the statistical significance (− log10 of P-value) of the change in gene coverage, with significance increasing from bottom to top: red dots, genes with fold change > 1 or <  − 1 and P ≤ 0.05; blue dots, genes with fold change between − 1 and 1 and P ≤ 0.05; black dots, genes with P > 0.05. The y-axis scale varies for each plot to enhance data visibility. See Additional file 4: Dataset S3 for a list of genes with significant fold changes. The x-axes indicate the magnitude of change (log2 of fold change) in gene coverage: positive fold change, gene coverage higher in samples taken as numerator; negative fold change, gene coverage higher in samples taken as denominator. For example, in the oxic vs anoxic plots (a) and (b), the oxic zone samples were considered as numerator, while the anoxic zone samples were taken as denominator. Therefore, the MAG-AL1 genes represented by red dots in a have significantly higher relative coverage in oxic zone samples, whereas the MAG-AL2 genes depicted by red dots in b have significantly higher relative coverage in anoxic zone samples. g–l No significant gene coverage variations were observed during comparison of seasonal samples (see further description in supplementary text)