Akodon polopi Jayat et al., 2010 is a senior subjective synomym of Akodon viridescens Braun et al., 2010

Two new taxa of species level were recently named for grass mice of the genus Akodon (Cricetidae, Sigmodontinae) from central Argentina: Akodon polopi Jayat, Ortiz, Salazar-Bravo, Pardiñas et D’Elía, 2010 and Akodon viridescens Braun, Mares, Coyner et Van Den Bussche, 2010. Several lines of evidence show that both taxa refer to the same biological species. Various morphologic characters enumerated by the two research teams for A. polopi and A. viridescens are coincident. The brownish coloration of the dorsal pelage, the chin with a small but distinguishable white patch, the tail of approximately 70% of head and body length, and the broad rostrum are among the diagnostic characters cited for both forms. Other additional characters mentioned in the diagnosis of only one of the nominal forms are also enumerated in the general description of the other. These include the size intermediate for the genus, the hour-glass shaped interorbital region with sharply squared posterior margins in older individuals, the anterior border of mesopterygoid fossa rounded with sides parallel or slightly diverging backward, and the parapterygoid fossae with straight and gradually divergent sides. Many additional features are mentioned for both nominal forms in their general descriptions.Fil: D' Elía, Guillermo. Universidad Austral de Chile. Instituto de Ecología y Evolución; ChileFil: Jayat, Jorge Pablo. Universidad Nacional de Tucumán. Facultad de Ciencias Naturales e Instituto Miguel Lillo. Laboratorio de Investigaciones Ecológicas de Las Yungas; ArgentinaFil: Ortiz, Pablo Edmundo. Universidad Nacional de Tucumán. Facultad de Ciencias Naturales e Instituto Miguel Lillo. Cátedra de Paleontología; ArgentinaFil: Salazar-bravo, Jorge. Texas Tech University. Department of Biological Sciences; Estados UnidosFil: Pardiñas, Ulises Francisco J.. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Nacional Patagónico; Argentin

Analyse des remaniements du protéome associés à la levée de dormance d’une graine imbibée

National audienc

Revision and analysis of the chromosome variability in the speciose genus Akodon (Rodentia, Sigmodontinae), including new data from Argentina

Abstract Rodentia has a high species number and chromosomal variability. The South American genus Akodon is one of the most speciose muroids, with more than 40 species included in several species groups. Here, we characterize cytogenetically specimens of Akodon from central-western Argentina. Subsequently, we reviewed and analyzed the cytogenetic data for this genus, build a phylogeny and mapped chromosome changes to interpret its evolution. Specimens of A. dolores from central-western Argentina have 2n=42-44/FNa=44 (46, 48) due to a Robertsonian rearrangement. Our data expand the distribution range known for this polymorphism and confirm its geographic structure. Other specimens had 2n=40/FNa=40, representing populations of A. oenos, A. polopi, and A. spegazzinii. All karyotypes have a low amount of heterochromatin, concentrated in centromeres and sex chromosomes, as in other rodents. The complement with 2n=40/FNa=40 is the most frequent in Akodon and is shared by most species in some groups. Chromosome numbers are very diverse. The FNa shows less variability; FNa=42 was recovered as ancestral, excluding A. mimus, which was connected at the base of the Akodon tree and has FNa=44. This indicates a complex chromosome evolution in Akodon, and suggests that reductions and increases in the 2n and FNa evolved independently in some lineages

Taxonomy based on science is necessary for global conservation

Peer reviewe

Significant range extension for the Foch’s tuco tuco (Ctenomys fochi Thomas, 1919; Rodentia, Ctenomyidae)

Ctenomys fochi es una de las especies menos estudiada del género. Hasta el momento solo ha sido documentada en dos localidades en Argentina, Chumbicha (Provincia de Catamarca) y Estancia La Providencia (Provincia de Córdoba). Sobre la base del estudio de caracteres morfológicos y genéticos de materiales depositados en la colección de mamíferos del Museo Argentino de Ciencias Naturales, en esta nota reportamos el primer registro de la especie para la provincia de Santiago del Estero (Finca Zorro Pozo, aproximadamente 8,6 km al OSO de Isca Yacu, Dpto. Giménez) y discutimos las implicancias de la extensión del rango distribucional en el contexto de su estatus de conservación.Ctenomys fochi is one of the less studied species of the genus. Until the present, it has been documented for only two Argentinean localities, Chumbicha (Catamarca Province) and Estancia La Providencia (Córdoba Province). On the base of the study of morphologic and genetic characters of materials housed in the mammal collection of the Museo Argentino de Ciencias Naturales, in this note we report the first record for the species in Santiago del Estero (Zorro Pozo, approximately 8.6 km WSW of Isca Yacu, Giménez Department) and we discuss the implications of the extension of the range in the context of its conservation status.Fil: Jayat, Jorge Pablo. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico - Tucumán. Unidad Ejecutora Lillo; Argentina. Universidad Nacional de Chilecito. Departamento de Ciencias Basicas y Tecnologicas; ArgentinaFil: D' Elía, Guillermo. Universidad Austral de Chile; ChileFil: Teta, Pablo Vicente. Consejo Nacional de Investigaciones Científicas y Técnicas. Oficina de Coordinación Administrativa Parque Centenario. Museo Argentino de Ciencias Naturales "Bernardino Rivadavia"; Argentin

Taxonomic status of the nominal forms assigned to Necromys lactens (Rodentia, Cricetidae) as revealed by molecular and morphometric evidence

Necromys is a genus of sigmodontine rodent that inhabits grasslands and scrublands in South America. Eight extant species are recognized in the genus; one of these is Necromys lactens, which inhabits high-elevation grasslands in the Yungas from south-central Bolivia to northwestern Argentina. Morphological variation in N. lactens has been recognized by the description of three nominal forms. Geographically structured genetic diversity also has been observed, but a thorough revision of these nominal forms within an integrative framework has yet to be performed. We conducted a phylogeographic assessment based on an 801 base-pair fragment of the cytochrome-b gene that guided morphometric analyses (univariate and multivariate comparisons) of patterns of geographic variation in the species, and the distinction of its nominal forms. Haplotypes of N. lactens form a well-supported and geographically structured clade. Within it, there are two main clades; haplotypes from the northern range form a well-supported clade, sister and allopatric to a weakly supported southern clade, which includes variants collected at or near the type localities of three nominal forms. In turn, both main clades are composed by two allopatric subclades. Morphometric analyses indicated no differences in shape of the skull among the three nominal forms or between the recovered clades and subclades. Taking together all the available evidence, we consider N. lactens to be a monotypic species. Necromys es un género de roedor sigmodontino que habita los pastizales y arbustales de América del Sur. Se reconocen ocho especies actualmente en existencia en el género; una de ellas, Necromys lactens, habita pastizales de altura en las Yungas, desde el centro-sur de Bolivia hasta el noroeste de Argentina. Se ha reconocido variación morfológica en N. lactens con base en descripciones de tres formas nominales; también se ha observado diversidad genética geográficamente estructurada, pero una revisión exhaustiva de esas formas nominales dentro de un esquema integrativo aún no se ha llevado a cabo. Realizamos una evaluación filogeográfica basada en un fragmento de 801 pares de bases del gen citocromo b que orientó análisis morfométricos (comparaciones univariadas y multivariadas) respecto al patrón geográfico de variación de la especie y la distinción de sus formas nominales. Los haplotipos de N. lactens forman un clado bien apoyado y geográficamente estructurado. Dentro de este clado, los haplotipos del norte de su área de distribución forman un clado bien apoyado que es hermano y alopátrico con respecto de un clado austral débilmente apoyado, el cual incluye variantes colectadas en las localidades tipo de las tres formas nominales o sus cercanías. A su vez, ambos clados principales están compuestos por dos sub-clados alopátricos. Los análisis morfométricos no revelaron diferencias en la forma del cráneo entre las tres formas nominales ni entre los clados y sub-clados recuperados. Teniendo en cuenta toda la evidencia disponible, consideramos que N. lactens es una especie monotípica.Fil: Jayat, Jorge Pablo. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico - Tucumán. Unidad Ejecutora Lillo; ArgentinaFil: Ortiz, Pablo Edmundo. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Tucumán. Instituto Superior de Correlación Geológica. Universidad Nacional de Tucumán. Facultad de Ciencias Naturales e Instituto Miguel Lillo. Departamento de Geología. Cátedra Geología Estructural. Instituto Superior de Correlación Geológica; ArgentinaFil: D' Elía, Guillermo. Instituto de Ciencias Ambientales y Evolutivas; ChileFil: Salazar Bravo, Jorge. Department Of Biological Sciences, Texas Tech Universit; Estados UnidosFil: Patterson, Bruce D.. Integrative Research Center, Field Museum Of Natural Hi; Estados Unido