Open AccessRare hybridization and introgression in smooth and palmate newts (Salamandridae: Triturus vulgaris and T. helveticus )
Author(s) -
Arntzen J. W.,
Wijer P.,
Jehle R.,
Smit E.,
Smit J.
Publication year - 1998
Publication title -
journal of zoological systematics and evolutionary research
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.769
H-Index - 50
eISSN - 1439-0469
pISSN - 0947-5745
DOI - 10.1111/j.1439-0469.1998.tb00830.x
Subject(s) - salamandridae , biology , triturus , introgression , zoology , evolutionary biology , caudata , genetics , gene
This paper describes the occurrence of hybridization and introgression in two species of amphibians (the newts Triturus helveticus and Triturus vulgaris ) in mid‐Wales, northern France and western France. A single aberrant adult male with intermediate phenotype was found. The multivariate analysis of 14 morphometric and two meristic characters supported its hybrid status. Electrophoretic analysis of 42 protein loci showed a genetic distance of 0.57 ± 0.14 Nei units between the species and revealed 15 diagnostic loci. The aberrant specimen was heterozygous at 11 of those and most likely to be a F 1 hybrid. Four marker loci appeared homozygous, suggesting the presence of enzymatically non‐active (‘null’) alleles. The analysis of (maternally inherited) mitochondrial DNA showed the hybrid to be the offspring of a T. helveticus mother (and a T. vulgaris father). This observation does not conform to expectations based on the species composition in the pond from which the hybrid was collected. No F 1 hybrids were observed in a large sample (n > 5000) of larvae, recently metamorphosed newts and adults using two diagnostic protein loci. Occasionally alleles characteristic for one species were observed in the gene pool of the other species, suggesting the presence of bidirectional introgression. However, the frequency of alien genes was low (maximally 0.07%) which renders it difficult to rule out alternative explanations conclusively. The increase in total genetic variation in T. helveticus and T. vulgaris due to gene flow between them is negligible.