title: Sex reversal of the newt Triturus cristatus reared at extreme temperatures.
abstract: Crested newt larvae were reared at defined temperatures, either from uncleaved eggs or from early feeding larvae, until metamorphosis when sexual differentiation had occurred. Trials at 18-24 degrees C showed a 1:1 sex ratio. A higher temperature trial produced more males than females, including some XX neomales. Lower temperatures resulted in a significant excess of females, including XY neofemales. Sex reversal only occurred in about half the possible cases on average. Extreme temperatures must perturb the normal XX/XY system of sex determination, to reveal either an ancestral ZZ/ZW system or a still more primitive environmental control. It is suggested that neofemales (but not neomales) could occur in nature.
authors: School of Biosciences, University of Birmingham, Edgbaston, United Kingdom. H.Wallace@bham.ac.uk
authors: H
authors: H
authors: Wallace
authors: B M
authors: BM
authors: Wallace
mesh_terms: D000818:Animals; D002871:Chromosome Banding; D003080:Cold Temperature; D012734:Disorders of Sex Development; D005260:Female; D005838:Genotype; D006358:Hot Temperature; D008297:Male; D019849:Sex Determination Processes; D012737:Sex Factors; D013696:Temperature; D014319:Triturus / Q000196:embryology / Q000235:genetics* / Q000502:physiology*