Fig. 1: Genetic diversity across the TSHR region in spring- and autumn-spawning Atlantic herring.

a Genome scan based on 6.06 million SNPs for the identification of divergent genomic regions between seven spring- and seven autumn-spawning populations (based on data from Han et al.¹⁶). The y-axis represents the significance value (-log₁₀P-value) per SNP in a X² test comparing the allele frequencies in spring- and autumn-spawning populations. Each dot corresponds to a single SNP, and different shades of gray were used to distinguish SNPs in consecutive chromosomes. The horizontal red line indicates the significance threshold based on Bonferroni correction. b Genome-wide diversity statistics π and Tajima’s D, and absolute allele frequency differences (dAF) of seven spring- and seven autumn-spawning herring pools in chr 15: 8–10 Mbp. The location of TSHR is denoted with a shadowed gray area (chr 15: 8.85–8.95 Mbp). Each line corresponds to a single pool, and the two colors distinguish autumn- and spring-spawning populations. c Comparison of the π and Tajima’s D distributions between SNPs on chromosome 15 located outside (214 635 SNPs) and inside (8.85–8.95 Mbp, 215 SNPs) the TSHR region. The P-values were obtained from the Wilcoxon test applied to estimate the statistical significance of the mean differences between SNPs inside and outside the TSHR region for the spring- and autumn-spawning populations.