Mutation percentages (≥5%) emerged in HA and NA of X-181 viruses passaged in eggs.

Notes: The percentages obtained from RNA library followed by HiSeq sequencing are presented without parentheses or brackets. The percentages obtained from RNA library followed by MiSeq sequencing are presented in parentheses. The percentages obtained from DNA library followed by HiSeq sequencing are presented in brackets. These mutation percentages were calculated per comparison with the corresponding expanded progenitor. (See accession numbers in Materials and Methods.) aa: Amino-acid, nt: Nucleotide.