Molecular Ecology Notes (2005) 5, 619–621 doi: 10.1111/j.1471-8286.2005.01017.x © 2005 Blackwell Publishing Ltd Blackwell Publishing, Ltd. PRIMER NOTE Microsatellite loci for population and behavioural studies of Horsfield’s bronze-cuckoo (Chalcites basalis: Aves) G. J. ADCOCK,*†‡ N. E. LANGMORE,* R. A. MULDER† and R. M. KILNER‡ *School of Botany and Zoology, Australian National University, Canberra, A.C.T. 0200, Australia, †Department of Zoology, University of Melbourne, Victoria 3010, Australia, ‡ Department of Zoology, University of Cambridge, Downing Street, Cambridge, CB2 3EJ, UK Abstract Eight polymorphic microsatellite loci were identified for Horsfield’s bronze-cuckoo ( Chalcites basalis). These include seven newly isolated loci from cuckoo genomic libraries enriched for GA and GAAA repeat-containing clones. These loci have a mean expected heterozygosity of 0.71, a mean number of alleles of 13.8 and a combined exclusion probability (one parent known) of 0.9999. Two loci (Cba01 and Cba07) showed a significant deficiency of heterozygotes and may therefore have null alleles, although this effect could be the result of nonrandom population sampling. Keywords: Chalcites basalis, Chrysococcyx basalis, enrichment, Horsfield’s bronze-cuckoo, microsatellite Received 9 February 2005; revision accepted 1 April 2005 The first experimental evidence for recognition and desertion of cuckoo chicks by hosts was found for superb fairy- wrens ( Malurus cyaneus ) parasitized by Horsfield’s bronze- cuckoos ( Chalcites basalis ) in Australia (Langmore et al . 2003). These cuckoos lay a highly mimetic egg that fairy- wrens are unable to distinguish from their own in the dark interior of their dome nests (Langmore et al . 2003), which may have led to the evolution of cuckoo chick discrimination by hosts. Further study of this system requires greater knowledge of the poorly defined population and breeding biology of C. basalis. We do not know such elementary details as whether particular females prefer certain hosts for their eggs or if chicks of particular females are more susceptible to rejection by the host. Since this species is partially migratory and widespread over most of the Australian continent (Higgins 1999), there are no data on whether geographical differentiation in this species might promote regional behavioural divergence. Here, we report the isolation of polymorphic microsatellite loci to facilitate the investigation of these issues. Cuckoo DNA was extracted using a salting-out pro- cedure (Bruford et al . 1992) from frozen tissue of dead chicks or blood from chicks and adults from Campbell Park and Black Mountain (35 ° 19 ′ S, 149 ° 12 ′ E), Canberra, Australia. General polymerase chain reaction (PCR) solutions and running conditions were reported in Adcock & Mulder (2002). Genomic libraries enriched for GAAA and GA repeat-containing fragments were created using the method of Gardner et al . (1999) with modifications (Adcock & Mulder 2002). Repeat-containing clones were identified with a PCR-based method and sequenced on both strands using published methods (Adcock & Mulder 2002). The 240 colonies screened in the GAAA and the 192 in the GA- enriched genomic library, yielded respectively, 26 and 39 colonies that were sequenced. Primers were manufactured (Proligo) for the 18 of these that contained eight repeats or more and flanking sequence suitable for primer design. One primer in each pair had a 5 ′ -M13 (TGTAAAACGACG- GCCAGT) tail for use in the universal dye-labelling method described by Schuelke (2000). Primer pairs that gave con- sistent specific products were tested for polymorphism on 30 individuals. Screening reactions (10 μ L) contained an M13 primer (200 n m ), 5 ′ -labelled with an ABI dye ( VIC, FAM or NED), and the locus-specific tailed (15 n m ) and untailed primer (200 n m ), 40 –100 ng of genomic DNA and 2.5 m m MgCl 2 . Amplification began with one cycle at 94 °C at 90 s, followed by 38 cycles at 94 °C for 20 s, 52 °C for 20 s and 73 °C for 90 s. PCR products were electrophoresed on an ABI 3100 automated sequencer together with a Liz-500 size standard Correspondence: G. J. Adcock, Fax: +61 26125 5573; E-mail: gregory.adcock@anu.edu.au