Electronic versions

DOI

  • Edina Nemesházi
    Lendület Centre for Agricultural Research, Budapest
  • Zoltán Gál
    NARIC Agricultural Biotechnology Institute
  • Nikolett Ujhegyi
    Lendület Centre for Agricultural Research, Budapest
  • Viktória Verebélyi
    Lendület Centre for Agricultural Research, Budapest
  • Zsanett Mikó
    Lendület Centre for Agricultural Research, Budapest
  • Bálint Üveges
    Lendület Centre for Agricultural Research, Budapest
  • Kinga Katalin Lefler
    Szent István University
  • Daniel Lee Jeffries
    University of Lausanne
  • Orsolya Ivett Hoffmann
    NARIC Agricultural Biotechnology Institute
  • Veronika Bókony
    Lendület Centre for Agricultural Research, Budapest

Populations of ectothermic vertebrates are vulnerable to environmental pollution and climate change because certain chemicals and extreme temperatures can cause sex reversal during early ontogeny (i.e. genetically female individuals develop male phenotype or vice versa), which may distort population sex ratios. However, we have troublingly little information on sex reversals in natural populations, due to unavailability of genetic sex markers. Here, we developed a genetic sexing method based on sex-linked single nucleotide polymorphism loci to study the prevalence and fitness consequences of sex reversal in agile frogs (Rana dalmatina). Out of 125 juveniles raised in laboratory without exposure to sex-reversing stimuli, 6 showed male phenotype but female genotype according to our markers. These individuals exhibited several signs of poor physiological condition, suggesting stress-induced sex reversal and inferior fitness prospects. Among 162 adults from 11 wild populations in North-Central Hungary, 20% of phenotypic males had female genotype according to our markers. These individuals occurred more frequently in areas of anthropogenic land use; this association was attributable to agriculture and less strongly to urban land use. Female-to-male sex-reversed adults had similar body mass as normal males. We recorded no events of male-to-female sex reversal either in the laboratory or in the wild. These results support recent suspicions that sex reversal is widespread in nature, and suggest that human-induced environmental changes may contribute to its pervasiveness. Furthermore, our findings indicate that sex reversal is associated with stress and poor health in early life, but sex-reversed individuals surviving to adulthood may participate in breeding.

Keywords

  • Adult, Animals, Breeding, Female, Genetic Markers, Genotype, Humans, Male, Ranidae/genetics, Sex Ratio
Original languageEnglish
Pages (from-to)3607-3621
Number of pages15
JournalMolecular Ecology
Volume29
Issue number19
Early online date16 Aug 2020
DOIs
Publication statusPublished - 1 Oct 2020
Externally publishedYes
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