Symbiotic skin bacteria as a source for sex-specific scents in frogs

Amphibians are known to possess a wide variety of compounds stored in their skin glands. While significant progress has been made in understanding the chemical diversity and biological relevance of alkaloids, amines, steroids, and peptides, most aspects of the odorous secretions are completely unknown. In this study, we examined sexual variations in the volatile profile from the skin of the tree frog Boana prasina and combined culture and culture-independent methods to investigate if microorganisms might be a source of these compounds. We found that sesquiterpenes, thioethers, and methoxypyrazines are major contributors to the observed sex differences. We also observed that each sex has a distinct profile of methoxypyrazines, and that the chemical origin of these compounds can be traced to a Pseudomonas sp. strain isolated from the frog´s skin. This symbiotic bacterium was present in almost all individuals examined from different sites and was maintained in captive conditions, supporting its significance as the source of methoxypyrazines in these frogs. Our results highlight the potential relevance of bacteria as a source of chemical signals in amphibians and contribute to increasing our understanding of the role that symbiotic associations have in animals.

Fil: Brunetti, Andrés Eduardo. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Nordeste. Instituto de Biología Subtropical. Instituto de Biología Subtropical - Nodo Posadas | Universidad Nacional de Misiones. Instituto de Biología Subtropical. Instituto de Biología Subtropical - Nodo Posadas; Argentina. Universidade de Sao Paulo; Brasil

Fil: Lucio Lyra, Mariana. Universidade Estadual Paulista Julio de Mesquita Filho; Brasil

Fil: Melo, Weilan G. P.. Universidade de Sao Paulo; Brasil

Fil: Andrade, Laura Elena. Universidade de Sao Paulo; Brasil

Fil: Palacios Rodríguez, Pablo. Universidad de los Andes; Colombia

Fil: Prado, Bárbara M.. Universidade de Sao Paulo; Brasil

Fil: Baptista Haddad, Célio Fernando. Universidade Estadual Paulista Julio de Mesquita Filho; Brasil

Fil: Tallarico Pupo, Monica. Universidade de Sao Paulo; Brasil

Fil: Peporine Lopes, Norberto. Universidade de Sao Paulo; Brasil