Table 1 The amino acid (aa) and nucleotide states at the sites of the functionally relevant lysines before the Csd/Fem duplication and divergence event (Csd/Fem MRCA) and before the Csd allele divergence (Csd MRCA)
aa/codon of Csd B2–25aa/codon of Csd/Fem MRCA (P > 0.9)aa/codon of Csd MRCA (P > 0.9)aa/codon polymorphisms (frequency %)3)
NLSC1K14RKK (100%)
AAAAGAAAAAAA
K16RKK (100%)
AAAAGAAAAAAA
K24EEE (57%) K (43%)
AAAGAAGAAGAA AAA
C2K243QKK (100%)
AAACAAAAAAAA
K248EKE (7%) K (93%)
AAAGAAAAAGAA AAA
C3K259RKE (14%) K (79%) N (7%) GAG AAG AAC
AAGAGGAAG2)
K280E 1)KK (21%) K (79%)
AAGGAAAAAAAG AAA
  • 1) Ambiguous codon (P < 0.9) due to indels that occurred with outgroup sequence comparison.

  • 2) The predicted codon was R (AGG), P < 0.6 using ANC-GENE (Zhang and Nei 1997), and K (AAG), P > 0.9 using MEGA (Tamura et al. 2011). From the more parsimonious number of mutations required to produce the other polymorphism (GAG and AAC), we suggest that the aa/codon of the csd MRCA is K/AAG.

  • 3) Estimated from a random sample of 14 csd alleles.