Table 3.

Mutations in the HA gene of egg-adapted virusesa

VirusNA insertionMutation(s) in:
HA1HA2
0EAYES95Asn→Asp72Asn→Lys
21EAYES135Val→Ile
2EANO146Ser→Gly106Arg→Lys
262Arg→Lys
  • a For each adapted strain, HA cDNA was synthesized by reverse transcriptase PCR followed by cDNA sequencing as described in Materials and Methods.