Chromosome evolution in Lophyohylini (Amphibia, Anura, Hylinae)

SUAREZ, P.; FERRO, JUAN M.; NAGAMICHI, C.Y.; CARDOZO, DARIO E.; BLASCO-ZÚÑIGA, AILIN; SILVA, J.B.; MARCIANO-JR., E.; COSTA, MARCO A.; ORRICO, V.G.D.; SOLÉ, M.; ROBERTO, I. J.; RIVERA, MIRYAN; WILEY, JOHN E.; FAIVOVICH, J.; BALDO, D; PIECZARKA, J.C.

PLOS ONE

PUBLIC LIBRARY SCIENCE

Lugar: San Francisco; Año: 2020 vol. 15 p. 1 - 21

1932-6203

The hyline tribe Lophyohylini includes 87 species of treefrogs, of which cytogenetics aspectshave been studied in less than 20% of them. In order to evaluate the evolution of some of itschromosome characters (NOR position, C-bands, and DAPI/CMA3 bands), we studied thekaryotypes of 21 lophyohylines, 16 of them for the first time, and analyzed them in a phylogeneticcontext. Most species showed similar karyotypes regarding chromosome number(2n = 24) and morphology (FN = 48), excepting Phyllodytes edelmoi and Osteocephalusbuckleyi with 2n = 22 (FN = 44) and 2n = 28 (FN = 50), respectively. The NOR location wasvariable among species and provided valuable phylogenetic information. This marker waslocated in pair 11 in all species of Trachycephalus, Itapotihyla langsdorffii, and Nyctimantisarapapa, representing the plesiomorphic condition of Lophyohylini. Besides, other apomorphicstates were recovered for the clades comprising N. rugiceps and N. siemersi (NORin pair 5), and Dryaderces pearsoni, Osteocephalus, and Osteopilus (NOR in pair 9). Phyllodytespresented variation for NORs position; they were in pair 2 in P. edelmoi, pair 7 in P.melanomystax, and pair 8 in P. gyrinaethes and P. praeceptor. Polymorphisms in size, number,and activity of this marker were observed for N. siemersi, Osteocephalus fuscifacies,and some species of Trachycephalus. Remarkably, in N. siemersi NORs were detected ona single chromosome in the two specimens studied by this technique, raising the question ofhow this complex polymorphism is maintained. Interstitial telomeric sequences were found in P. edelmoi, P. melanomystax, and Osteocephalus buckleyi, and their presence seems tobe not related to the chromosome reorganization events. Finally, some species showedspontaneous rearrangements, possibly as a consequence of an uncommon phenomenon inanuran cytogenetics: the presence of fragile sites or secondary constrictions not associatedwith NORs. We propose that this rare feature would have played an important role in theevolution of this group of frogs. From the evidence obtained in this and previous studies, weconclude that Lophyohylini presents a complex chromosome evolution.