%0 Journal Article %1 cianchi_et_al_2003 %A Cianchi, R. %A Ungaro, A. %A Marini, M. %A Bullini, L. %D 2003 %J Molecular Ecology %K Papilio differential_introgression hybrids organisms %N 6 %P 1461-1471 %R 10.1046/j.1365-294X.2003.01813.x %T Differential patterns of hybridization and introgression between the swallowtails Papilio machaon and P. hospiton from Sardinia and Corsica islands (Lepidoptera, Papilionidae) %U http://www.blackwell-synergy.com/doi/abs/10.1046/j.1365-294X.2003.01813.x %V 12 %X Abstract Proportions of hybridization and introgression between the swallowtails Papilio hospiton, endemic to Sardinia and Corsica, and the holarctic Papilio machaon, were characterized using nine fully diagnostic and two differentiated allozyme loci and a mitochondrial DNA marker. Very low frequencies of F1 hybrids were detected in both Sardinia (0-4%, average 1.4%) and Corsica (0-3%, average 0.5%), as well as of first generation backcrosses (B1). No F2 were observed, in agreement with the hybrid breakdown detected in laboratory crosses. In spite of this minimal current gene exchange, specimens carrying introgressed alleles were found in high proportions in P. machaon but in lower proportions in P. hospiton. Introgression apparently occurred through past hybridization and repeated backcrossing, as evidenced by hybrid index scores and Bayesian assignment tests. Levels of introgression were low (0-1%) at two sex-linked loci and mitochondrial DNA, limited (0.4-2%) at three autosomal loci coding for dimeric enzymes, and high (up to 43%) at four autosomal loci coding for monomeric enzymes. Accordingly, selective filters are acting against foreign alleles, with differential effectiveness depending on the loci involved. The low levels of introgression at sex-linked loci and mitochondrial DNA are in agreement with Haldane's rule and suggest that introgression in P. machaon proceeds mainly through males, owing to a lower fitness of hybrid females. Papilio machaon populations showed higher levels of introgression in Sardinia than in Corsica. The role of reinforcement in the present reproductive isolation between P. machaon and P. hospiton is examined, as well as the evolutionary effects of introgressive hybridization between the two species.

@article{cianchi_et_al_2003, abstract = { Abstract Proportions of hybridization and introgression between the swallowtails Papilio hospiton, endemic to Sardinia and Corsica, and the holarctic Papilio machaon, were characterized using nine fully diagnostic and two differentiated allozyme loci and a mitochondrial DNA marker. Very low frequencies of F1 hybrids were detected in both Sardinia (0-4%, average 1.4%) and Corsica (0-3%, average 0.5%), as well as of first generation backcrosses (B1). No F2 were observed, in agreement with the hybrid breakdown detected in laboratory crosses. In spite of this minimal current gene exchange, specimens carrying introgressed alleles were found in high proportions in P. machaon but in lower proportions in P. hospiton. Introgression apparently occurred through past hybridization and repeated backcrossing, as evidenced by hybrid index scores and Bayesian assignment tests. Levels of introgression were low (0-1%) at two sex-linked loci and mitochondrial DNA, limited (0.4-2%) at three autosomal loci coding for dimeric enzymes, and high (up to 43%) at four autosomal loci coding for monomeric enzymes. Accordingly, selective filters are acting against foreign alleles, with differential effectiveness depending on the loci involved. The low levels of introgression at sex-linked loci and mitochondrial DNA are in agreement with Haldane's rule and suggest that introgression in P. machaon proceeds mainly through males, owing to a lower fitness of hybrid females. Papilio machaon populations showed higher levels of introgression in Sardinia than in Corsica. The role of reinforcement in the present reproductive isolation between P. machaon and P. hospiton is examined, as well as the evolutionary effects of introgressive hybridization between the two species. }, added-at = {2008-04-02T21:31:03.000+0200}, author = {Cianchi, R. and Ungaro, A. and Marini, M. and Bullini, L.}, biburl = {https://www.bibsonomy.org/bibtex/2cbe8fdf391cf3e4136720da7e17123b4/peter.ralph}, doi = {10.1046/j.1365-294X.2003.01813.x}, eprint = {http://www.blackwell-synergy.com/doi/pdf/10.1046/j.1365-294X.2003.01813.x}, interhash = {b064f5f5ebfb0a26d2f8882f6a441a45}, intrahash = {cbe8fdf391cf3e4136720da7e17123b4}, journal = {Molecular Ecology}, keywords = {Papilio differential_introgression hybrids organisms}, note = {In swallowtails, uses "nine fully diagnostic and two differentiated allozyme loci and a mitochondrial DNA marker" to find that "Levels of introgression were low (0–1%) at two sex-linked loci and mitochondrial DNA, limited (0.4–2%) at three autosomal loci coding for dimeric enzymes, and high (up to 43%) at four autosomal loci coding for monomeric enzymes." Hybrids were identified by morphology. Deduction of introgression was based on seeing mixed types in one species and not the other. }, number = 6, pages = {1461-1471}, timestamp = {2008-04-02T21:31:03.000+0200}, title = {Differential patterns of hybridization and introgression between the swallowtails Papilio machaon and P. hospiton from Sardinia and Corsica islands (Lepidoptera, Papilionidae)}, url = {http://www.blackwell-synergy.com/doi/abs/10.1046/j.1365-294X.2003.01813.x}, volume = 12, year = 2003 }