title: Comparative sperm ultrastructure of twelve leptodactylid frog species with insights into their phylogenetic relationships.
abstract: The spermatozoa of representatives of three Neotropical frog subfamilies, Leiuperinae, Leptodactylinae and Paratelmatobiinae, were observed using Transmission Electron Microscopy, with the aim of identifying ultrastructural traits that provide insights into the phylogenetic relationships among these anurans, which are currently unclear. In the leiuperines, spermatozoa of Physalaemus albifrons, P. cicada, P. deimaticus and P. feioi were characterized by an acrosomal vesicle covering the subacrosomal cone that was not observed in the spermatozoa of Physalaemus centralis and P. cuvieri. The tail of the spermatozoa of P. albifrons, P. centralis, P. cicada, P. cuvieri, P. deimaticus, and P. feioi presented a long undulating membrane, whereas Engystomops petersi and E. freibergi, which form a sister clade to Physalaemus, had an axial fiber, which were absent in Physalaemus. Other leiuperine, E. puyango had an abaxonemal bulb-like swelling distally to the paraxonemal rod, which were also absent in Physalaemus. These differences support the revalidation of Engystomops as a true taxon, distinct from Physalaemus. The tail of the spermatozoa of E. petersi and E. freibergi was similar to that of Paratelmatobius poecilogaster (Paratelmatobiinae). The spermatozoa of Leptodactylus natalenis (Leptodactylinae) had undulating membrane and axial fiber, in contrast with Adenomera marmorata, which lacked these structures. Morphological differences between A. marmorata and L. natalensis sperm cells appeared to validate the allocation of A. marmorata into a genus distinct from Leptodactylus. Overall, dissimilarities in the spermatozoa of the leptodactylids provided an important phylogenetic signal for the understanding of their taxonomic relationships.
authors.affiliation: Departamento de Biologia Estrutural e Funcional, Instituto de Biologia, Universidade Estadual de Campinas - UNICAMP, 13083-863, Campinas, São Paulo, Brazil. Electronic address: juliocezasantos@yahoo.com.br.
authors.forename: Julio Sérgio
authors.initials: JS
authors.lastname: Santos
authors.affiliation: Departamento de Ciências Básicas da Saúde, Universidade Federal de Ciências da Saúde de Porto Alegre - UFCSPA, 90050-170, Porto Alegre, Rio Grande do Sul, Brazil. Electronic address: giseleorlandi@gmail.com.
authors.forename: Gisele Orlandi
authors.initials: GO
authors.lastname: Introíni
authors.affiliation: Departamento de Biologia Estrutural e Funcional, Instituto de Biologia, Universidade Estadual de Campinas - UNICAMP, 13083-863, Campinas, São Paulo, Brazil. Electronic address: anacpveiga@yahoo.com.br.
authors.forename: Ana Cristina Prado
authors.initials: AC
authors.lastname: Veiga-Menoncello
authors.affiliation: Escuela de Ciencias Biológicas, Pontifícia Universidad Católica Del Ecuador, Quito, Ecuador. Electronic address: ailin.blasco.z@gmail.com.
authors.forename: Ailin
authors.initials: A
authors.lastname: Blasco
authors.affiliation: Escuela de Ciencias Biológicas, Pontifícia Universidad Católica Del Ecuador, Quito, Ecuador. Electronic address: MRIVERAI@puce.edu.ec.
authors.forename: Miryan
authors.initials: M
authors.lastname: Rivera
authors.affiliation: Departamento de Biologia Estrutural e Funcional, Instituto de Biologia, Universidade Estadual de Campinas - UNICAMP, 13083-863, Campinas, São Paulo, Brazil. Electronic address: shirlei@unicamp.br.
authors.forename: Shirlei Maria
authors.initials: SM
authors.lastname: Recco-Pimentel
mesh_terms: D000177:Acrosome / Q000648:ultrastructure; D000818:Animals; D001001:Anura / Q000033:anatomy & histology* / Q000145:classification*; D002467:Cell Nucleus / Q000648:ultrastructure; D008297:Male; D046529:Microscopy, Electron, Transmission; D010802:Phylogeny; D013094:Spermatozoa / Q000648:ultrastructure*
keywords: Anura; Leptodactylidae; Sperm structure