Heliconius erato Sd NcoI-RAD mapping
Heliconius erato Sd locus - positional cloning
A single locus dubbed Short band (Sd) controls forewing band shape variation in H. erato and H. himera  and was previously assigned to a linkage group {Kapan et al., 2006; Sheppard et al., 1985}. Here we fine-mapped the Sd locus using Restriction-associated Amplified DNA (RAD) mapping {Davey et al., 2011}. In short, this technique generates dense Single Nucleotide Polymorphism (SNP) data on a genome-wide scale using next-generation sequencing, and achieves high coverage using a restriction-based complexity reduction step . In this case, we sequenced two pools of 25 siblings, each corresponding to one of homozygous Sd phenotypes produced in a H. himera x H. erato notabilis F2 brood, and looked for SNPs perfectly associated with each pool.