1. ¹Department of Biology, University of Puerto Rico, PO Box 23360, San Juan 00931, Puerto Rico
2. ²Institute of Cell, Animal & Population Biology, University of Edinburgh, King's Buildings, West Mains Road, Edinburgh EH9 3JT, Scotland, UK
3. ³Department of Entomology, Texas A&M University, College Station, TX 77843, USA
4. ⁴CESAR, Department of Genetics, The University of Melbourne, Parkville, Victoria 3010 Australia

Correspondence: WO McMillan, Department of Biology, University of Puerto Rico, PO Box 23360, San Juan 00931, Puerto Rico. E-mail: wmcmilla@rrpac.upr.clu.edu

⁵Current address: Max Planck Institute of Chemical Ecology, Hans-Knöll-Str. 8, Jena D-07745, Germany.

Received 21 March 2004; Accepted 28 September 2004; Published online 8 December 2004.

Abstract

We report the first genetic linkage map of Heliconius erato, a species that shows remarkable variation in its warningly colored wing patterns. We use crosses between H. erato and its sister species, H. himera, to place two major color pattern genes, D and Cr, on a linkage map containing AFLP, allozyme, microsatellite and single-copy nuclear loci. We identified all 21 linkage groups in an initial genetic screen of 22 progeny from an F1 female male H. himera family. Of the 229 markers, 87 used to identify linkage groups were also informative in 35 progeny from a sibling backcross (H. himera female F1 male). With these, and an additional 33 markers informative in the second family, we constructed recombinational maps for 19 of the 21 linkage groups. These maps varied in length from 18.1 to 431.1 centimorgans (cM) and yielded an estimated total length of 2400 cM. The average distance between markers was 23 cM, and eight of the 19 linkage groups, including the sex chromosome (Z) and the chromosome containing the Cr locus, contained two or more codominant anchor loci. Of the three potential candidate genes mapped here, Cubitus interruptus (Ci), Decapentaplegic (Dpp) and Wingless (Wg), only Ci was linked, although loosely, to a known Heliconius color pattern locus. This work is an important first step for constructing a denser genetic map of the H. erato color pattern radiation and for a comparative genomic study of the architecture of mimicry in Heliconius butterflies.