Online Resource 1
Eighteen microsatellite markers were assayed initially using primers developed for the roseate
tern (Sterna dougallii; Szczys et al. 2005), red-billed gull (Larus novaehollandiae; Given et al.
2002), and black-legged kittiwake (Rissa tridactyla; Tirard et al. 2002). These primers have been
used successfully in population genetic studies of other tern species including the South
American tern (Sterna hirundinacea; Faria et al. 2010) and the common tern (S. hirundo; Sruoga
et al. 2006). Initial tests of these loci in a subset of Caspian terns failed to yield reliable products
for seven loci (K6, K56, K67, K71, RBG20, RBG28, RBG39) and five other loci were not
polymorphic (K16, K31, K32, RBG13, Sdaat27). The six remaining loci were PCR amplified
either individually (Scaac20, RBG18) or in di-locus multiplexes (RBG27/RBG29 and
Sdaat20/Sdaat46). The reaction conditions for most PCRs were identical to those outlined in
Taylor et al. (2010). For locus Scaac20, only 0.06 μM WellRED D4 labelled M13 was used and
the number of PCR cycles was increased by ten. Allele sizes were determined on a BeckmanCoulter (Mississauga, ON) CEQ 8000 genetic analysis system following the protocols of Sun et
al. (2009). Due to difficulties interpreting the stutter pattern of locus Sdaat46, it was excluded
from all further analysis.
Approximately 490 base pairs of the mitochondrial cytochrome b gene was amplified
from each individual using general avian primers b5 (5'TTCCACCCCTACTTCTCACTAAAAGA-3'; T. Birt, unpublished data) and b6 (5'GTCTTCAGTTTTTGGTTTACAAGAC-3'; T. Birt, unpublished data). PCRs contained
approximately 5 ng of DNA, 1 x Multiplex Mix (Qiagen, Mississauga, Ontario), and 0.7 mM of
each primer under standard conditions with annealing at 50 °C for 30 seconds. PCR products
were sequenced with both primers on a 3730XL DNA Analyzer (Applied Biosystems, Foster
City, California) at the Genome Quebec Innovation Centre (McGill University, Montreal,
Quebec). Chromatograms were verified manually and sequences were aligned using ClustalW
(Thompson et al. 1994) as implemented in BioEdit (Version 7.0.5.3; Hall 1999).
Literature Cited
Given AD, Mills JA, Baker AJ (2002) Isolation of polymorphic microsatellite loci from the redbilled gull (Larus novaehollandiae scopulinus) and amplification in related species. Mol Ecol
Notes 2:416-418
Faria PJ, Campos FP, Branco JO, Musso CM, Morgante JS, Bruford MW (2010) Population
structure in the South American tern Sterna hirundinacea in the South Atlantic: two populations
with distinct breeding phenologies. J Avian Biol 41:378-387
Sruoga A, Butkauskas D, Prakas P, Paulauskas A (2006) Evaluation of the genetic structure of
the breeding common tern (Sterna hirundo) population by means of microsatellite markers.
Biologija 1:47-52
Sun Z, Gomez-Diaz E, Bailie A, Friesen V (2009) Isolation and characterization of microsatellite
loci for storm-petrels. Mol Ecol Res 9: 913-915
Taylor SA, Morris-Pocock JA, Sun Z, Friesen VL (2010) Isolation and characterization of ten
microsatellite loci in Blue-footed (Sula nebouxii) and Peruvian Boobies (Sula variegata). J
Ornithol 151:525-528
Thompson JD, Higgins DG, Gibson TJ (1994) CLUSTALW: improving the sensitivity of
progressive multiple sequence alignment through sequence weighting, position-specific gap
penalties, and weight matrix choice. Nucleic Acids Res 22: 4673-80
Tirard C, Helfenstein F, Danchin E (2002) Polymorphic microsatellites in the black-legged
kittiwake Rissa tridactyla. Mol Ecol Notes 2:431-433