Rare hybridization and introgression in smooth and palmate newts (Salamandridae:
Triturus vulgaris and T. helveticus)

Arntzen, JW; deWijer, P; Jehle, R; Smit, E; Smit, J

Abstract

This paper describes the occurrence of hybridization and introgression in two species of amphibians (the newts Trifurus helrelicus and Trirurus
culgaris) 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 1 I of those and
most likely to be a F, 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. heltleticus 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,
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.

Citation

Triturus vulgaris and T. helveticus). Journal of Zoological Systematics and Evolutionary Research, 36, 111-122

• Journal Article Type: Article
• Publication Date: Jan 1, 1998
• Deposit Date: Oct 30, 2009
• Journal: Journal of Zoological Systematics and Evolutionary Research
• Print ISSN: 0947-5745
• Publisher: Wiley
• Peer Reviewed: Peer Reviewed
• Volume: 36
• Pages: 111-122
• Keywords: Genetic variation - hybridization - introgression - mitochondrial DNA - multivariate analysis - newts - null alleles - protein; electrophoresis- spatial autocorrelation - Triturus heli~eticu-s Triturus ciulgaris
• Publisher URL: http://www3.interscience.wiley.com/journal/121528405/issue