DOI: 10.5061/dryad.qjq2bvqcb
title: Data from: Multiple mating in the context of interspecific hybridization between two Tetramorium ant species

description: In eusocial Hymenoptera, haplodiploidy and polyandry may facilitate
 selection for hybridization. Interspecific hybridization is widespread in
 ants and can lead to hybrid inviability as well as the formation of new
 species through hybrid speciation. However, in ants, polyandry is
 uncommon. By analyzing microsatellite markers on 15 ant workers per
 colony, we show that the mating system of 28 pure colonies of Tetramorium
 immigrans, 15 pure colonies of Tetramorium caespitum and 27 hybrid
 colonies is a monogyne/polyandrous mating system, with a higher mating
 rate in T. caespitum (mean = 2.4 males vs. 1.7 in T. immigrans). Hybrid
 queens, but no hybrid fathers, were deduced from workers’ genotypes, in
 accordance to Haldane’s rule extended to haplodiploid organisms, which
 states that the haploid sex should more often be sterile or inviable. In
 five colonies, hybridization and multiple mating allowed the simultaneous
 production of both hybrid and nonhybrid offspring. Although rare, these
 situations hinted at asymmetrical, larger contributions of T. immigrans
 vs. T. caespitum males to offspring production. Together, these findings
 point towards a complex and dynamic mating system in T. immigrans and T.
 caespitum and contribute to better understand interspecific hybridization
 mechanisms and their consequences on genetic and taxonomic diversity. The
 study of polyandry within a hybrid zone is unprecedented and opens new
 opportunities to better understand interspecific hybridization mechanisms
 and their short- to long-term consequences.
description: DNA was extracted from
 whole individuals, which were crushed and then mixed with 150 μL of
 Chelex® 100 and 10 μL of proteinase K (15 mg.mL-1) at room temperature;
 the solution was incubated at 55°C overnight. The 17 microsatellites
 developed for T. immigrans or T. tsushimae by Steiner et al. (2008) were
 organized in three multiplex PCR mixes. All three mixes had a total volume
 of 10 μL with 1X MasterMix (kit type-it microsatellite PCR Qiagen
 n°206246) and 2 μL DNA. Mix1 contained 0.08 μM of tspE53a primers, and 0.2
 μM of tspE52b, tspE52d, tspE52k, ttsU55a and ttsU56d primers. Mix2
 contained 0.15 μM of tspE51oR3 primers, 0.2 μM of tspE51a, tspE51b,
 tspE51d, ttsU58i and ttsU59j primers, and 0.3 μM of tspE51i primers. Mix 3
 contained 0.08 μM of ttsU54e, 0.15 μM of tspE52a, and 0.2 μM of tspE53b
 and ttsU57l primers. Amplifications consisted in 5 min at 95°C, then 32
 cycles (30 s at 95°C, 90 s at 60°C, 30 s at 72°C), and 30 min at 60°C. All
 PCR products were analyzed with an ABI 3730xl sequencer. Electropherograms
 were read and interpreted with Genemarker v.1.95 (SoftGenetics). One
 marker was discarded because it presented risks of misinterpretation at
 the reading stage. In addition, workers where alleles were not clearly
 legible for at least 12 markers were removed from the analysis, and
 colonies with less than 12 (pure T. immigrans or T. caespitum) or 14
 (hybrids colonies) legible worker genotypes were discarded. The dataset
 included genotypes for 16 microsatellite markers (Tspe52d, Tspe52b,
 Tspe52k, Ttsu56d, Tspe53a, Ttsu55a, Ttsu59j, Tspe51i, Ttsu58i, Tspe51a,
 Tspe51o, Tspe51b, Tspe51d, Tspe52a, Tspe53b, Ttsu57l) for 28 putative T.
 immigrans colonies, 15 putative T. caespitum colonies, and 27 putative
 hybrid colonies (14 F1 and 13 backcrosses) with an average of 14.8 worker
 genotypes per colony, and a total 1038 genotypes for 16 markers. Based on
 the worker genotypes, the genotypes of queens and their mates have been
 inferred in each colony. At each locus two alleles shared by all the
 workers were assigned to the queen, while haploid fathers’ genotypes were
 determined by the alleles unassigned to the mother. This pattern was then
 iterated over the 16 markers until reaching a minimal number of sires per
 queen.
description: Localities : X,Y coordinates of the sampled families
 Microsatellites data : Table of the microsatellites; Missing data
 coded as -9; Family : name of the family sampled; Cast: F = female, M =
 male, W = worker; Tspe52d, Tspe52b, Tspe52k, Ttsu56d, Tspe53a, Ttsu55a,
 Ttsu59j, Tspe51i, Ttsu58i, Tspe51a, Tspe51o, Tspe51b, Tspe51d, Tspe52a,
 Tspe53b, Ttsu57l: names of the microsatellites developed for
 <i>Tetramorium immigrans</i> or <i>T. tsushimae
 </i>by Steiner et al. (2008).