Figure 1.
Geographical distribution of Heliconius melpomene and H. erato.
Colored regions represent focus species/race distributions (each colored area has both H. erato and the co-mimetic H. melpomene), light grey areas represent areas where H. melpomene and H. erato overlap and dark grey areas represent areas where only H. erato occurs. Map based on [37] and [38].
Figure 2.
In a complementation test, alleles are said to complement each other if the F1 offspring exhibits the dominant phenotype (as opposed to parental recessive phenotype). The yellow hindwing bar in each race is caused by a recessive allele (yb) that in some cases interact with the forewing band allele (sd). Here both races are homozygote recessive for alleles known to be involved in color patterning (ybyb sbsb), however the F1 offspring exhibits a modified yellow bar, showing partial complementation. Each backcross exhibits four possible genotypes, alleles from each race are indicated by different colors and superscripts (pet = H. e. petiverana, fav = H. e. favorinus).
Figure 3.
Results of crosses between H. e. petiverana and H. e. favorinus.
Individuals are shown as a composite of the ventral and dorsal side of each wing (left dorsal, right ventral). For the backcrosses, F1 male offspring were mated to female H. e. favorinus (L15 brood) and H. e. petiverana (L14 brood). The outcome of the H. e. petiverana included a third wing phenotype, not present in parental or F1 hybrid (almost completely black hindwing). Both backcross broods had a 1∶1 sex ratio. Numbers below brood indicate number of individuals (#) with each phenotype, results of genotyping for Cr and Sd loci (parental: hybrid) and genotype (or lack of, showed as a crossed genotype) using Fig. 2 notation. In the backcross to H. e. favorinus (L15 brood), all individuals with an F1 like phenotype were hybrid (Fav/Pet alleles) for both Cr and Sd while parental like individuals were homozygotes for at least one locus. In the backcross to H. e. petiverana (L14 brood) all individuals with a full yellow hindwing bar were homozygotes for the H. e. petiverana Cr allele, however the Sd locus genotype did not show an association with wing color pattern.
Figure 4.
Results from crosses between H. m. rosina and H. m. amaryllis.
Individuals are shown as a composite of the ventral and dorsal side of each wing (left dorsal, right ventral). Both F1 and F2 brood had a wing pattern similar to parental races (presence of a full yellow hind wing bar) and a 1∶1 sex ratio.
Figure 5.
Results from crosses between H. m. melpomene and H. m. rosina.
Individuals are shown as a composite of the ventral and dorsal side of each wing (left dorsal, right ventral). Unexpectedly the F1 brood was segregating for presence of yellow hindwing bar (22 out of 44 individuals). Half of the individuals with yellow hindwing bar had a fuzzy bar (n = 11) as show in this picture; the other half had a yellow bar similar to the maternal race (n = 11). Brood sex ratio was skewed towards males (3∶1). Numbers below phenotypes indicate number of individuals (#) with each phenotype and results of Yb locus genotyping (presence of paternal allele a1: presence of paternal allele a2). All individuals with yellow hindwing bar had the paternal allele a1 whereas all individuals with paternal allele a2 had a shadow hindwing bar.
Table 1.
Primer sequences for loci used in Cr and Yb loci genotyping, number of informative SNP positions* and Genbank accession numbers for the F1 sequence.
Table 2.
Diagnostic single nucleotide polymorphism (SNP) positions (based on Genbank sequence, see Table 1) for each locus.