title: Evolution of Courtship Songs in Xenopus : Vocal Pattern Generation and Sound Production.
abstract: The extant species of African clawed frogs (Xenopus and Silurana) provide an opportunity to link the evolution of vocal characters to changes in the responsible cellular and molecular mechanisms. In this review, we integrate several robust lines of research: evolutionary trajectories of Xenopus vocalizations, cellular and circuit-level mechanisms of vocalization in selected Xenopus model species, and Xenopus evolutionary history and speciation mechanisms. Integrating recent findings allows us to generate and test specific hypotheses about the evolution of Xenopus vocal circuits. We propose that reduced vocal sex differences in some Xenopus species result from species-specific losses of sexually differentiated neural and neuromuscular features. Modification of sex-hormone-regulated developmental mechanisms is a strong candidate mechanism for reduced vocal sex differences.
authors.affiliation: Biology Department and Cross-Disciplinary Neurosciences Program, St. Mary's College of Maryland, St. Mary's City, Md., USA.
authors.forename: Elizabeth C
authors.initials: EC
authors.lastname: Leininger
authors.forename: Darcy B
authors.initials: DB
authors.lastname: Kelley
mesh_terms: D000200:Action Potentials; D000818:Animals; D005075:Biological Evolution; D063226:Central Pattern Generators / Q000502:physiology; D003380:Courtship; D005260:Female; D012739:Gonadal Steroid Hormones / Q000502:physiology; D007821:Laryngeal Muscles / Q000502:physiology / Q000648:ultrastructure; D007830:Larynx / Q000033:anatomy & histology; D008297:Male; D009046:Motor Neurons / Q000502:physiology; D018656:Muscle Fibers, Fast-Twitch / Q000502:physiology; D018995:Myosin Heavy Chains / Q000502:physiology; D009991:Oscillometry; D010802:Phylogeny; D011898:Ranidae / Q000033:anatomy & histology / Q000502:physiology; D015656:Respiratory Mechanics; D012249:Rhombencephalon / Q000033:anatomy & histology / Q000502:physiology; D012727:Sex Characteristics; D013018:Sound Spectrography; D013045:Species Specificity; D014828:Vocalization, Animal / Q000502:physiology*; D014981:Xenopus / Q000033:anatomy & histology / Q000502:physiology*
chemical_list: D012739:Gonadal Steroid Hormones; D018995:Myosin Heavy Chains