Ultrastructure variation in the spermatozoa of Pseudopaludicola frogs (Amphibia, Anura, Leptodactylidae), with brief comments on its phylogenetic relevance.
The taxonomic history of the small frogs of the genus Pseudopaludicola from South America has been controversial. Phylogenetic inferences based on molecular data have identified four Pseudopaludicola clades, correlating with the known variation in karyotypes (2n = 22, 20, 18, and 16). In this study, the ultrastructure of the spermatozoa was analyzed in 12 species of the Pseudopaludicola, with the aim of describing their morphology and identifying characters that may contribute to a better understanding of the phylogenetic relationships. The spermatozoa presented marked differences in tail structures. The tails of the spermatozoa of the species with 2n = 22 chromosomes (Pseudopaludicola sp. 1 [P. pusilla group], Pseudopaludicola falcipes, P. mineira, and Pseudopaludicola saltica), as well as Pseudopaludicola ameghini and Pseudopaludicola ternetzi (2n=20), have juxta-axonemal fibers, undulating membranes and axial fibers. In contrast, in the species with 2n = 18 (P. facureae, P. giarettai, Pseudopaludicola canga, P. atragula, and Pseudopaludicola sp. 2) and 2n = 16 (Pseudopaludicola mystacalis), there are no evident axial or juxta-axonemal fibers, but a paraxonemal rod with a thick undulating membrane, which is shorter than that found among Pseudopaludicola species. The ultrastructural morphological differences observed in the spermatozoa of these species may be phylogenetically informative, given that they coincide with the consensus phylogeny of the group and appear to represent a progressive simplification of the spermatozoon.
Departamento de Biologia Estrutural e Funcional, Instituto de Biologia, Universidade Estadual de Campinas (UNICAMP), 13083-863 Campinas, São Paulo, Brazil.
Julio Sérgio
JS
dos Santos
Departamento de Biologia Estrutural e Funcional, Instituto de Biologia, Universidade Estadual de Campinas (UNICAMP), 13083-863 Campinas, São Paulo, Brazil.|Departamento de Ciências Básicas da Saúde, Universidade Federal de Ciências da Saúde de Porto Alegre (UFCSPA), 245, Porto Alegre, Rio Grande do Sul, 90050-170, Brazil.
Gisele Orlandi
GO
Introíni
Departamento de Biologia Estrutural e Funcional, Instituto de Biologia, Universidade Estadual de Campinas (UNICAMP), 13083-863 Campinas, São Paulo, Brazil.
Ana Cristina Prado
AC
Veiga-Menoncello
Departamento de Biologia Estrutural e Funcional, Instituto de Biologia, Universidade Estadual de Campinas (UNICAMP), 13083-863 Campinas, São Paulo, Brazil.
Shirlei Maria
SM
Recco-Pimentel
D000818:Animals; D008297:Male; D010802:Phylogeny; D011898:Ranidae / Q000033:anatomy & histology* / Q000145:classification; D013020:South America; D013094:Spermatozoa / Q000648:ultrastructure*
anura; electron microscopy; sperm; structure