Systematics of the southern Patagonian-Fueguian endemic Abrothrix lanosus (Rodentia: Sigmodontinae): phylogenetic position, karyotypic and morphological data

FEIJOO, M.; D'ELÍA, G.; PARDIÑAS, U.F.J.; LESSA, E.

MAMMALIAN BIOLOGY

Año: 2008

1616-5047

Abrothrixlanosus (Thomas,1897)ismorphologicallyredescribedonthebasisofnewspecimenscollectedinTierra del Fuego(Argentina).Cranial,mandibular,skeletal,penile,andchromosomalcharacteristicsaredescribedand compared withotherspeciesof Abrothrix, especiallythoseofthePatagonian-Fueguianregion.Itsphylogenetic positionwithinAbrotrichiniisexploredusingDNAsequencesofthemitochondrialcytochrome b (cyt b) andthe nuclear InterphotoreceptorRetinoidBindingProtein(IRBP)genes.Phylogenetically,cyt b places A. lanosus as sister of A. jelskii, whereasIRBPgroups A. lanosus and A. longipilis. Thelattertopologyismostconsistentwith morphologicaldataandtaxonomichistory.Severalcranialandmandibularcharactersdistinguish A. lanosus from the other speciesofthegenus,including A. longipilis, whichisitsmostsimilarspecies. A. lanosus shares withother congenersa2n ¼ 52 karyotypeanddiffersfromotherspeciesof Abrothrix by atleast10%(p-distances)sequence divergenceincyt b. Inconclusion, A. lanosus is avalidspecies,readilydistinguishablefromother Abrothrix in the southernPatagonian-Fueguianregion.Althoughmanydata,includingpenileandskullmorphology,suggestthat A. longipilis is itsclosestlivingrelative, A. jelskii is retainedasaviablealternativeuntiladditionaldataareobtained. r 2008 PublishedbyElsevierGmbHonbehalfofDeutscheGesellschaftfu¨r Sa¨ugetierkunde. (Thomas,1897)ismorphologicallyredescribedonthebasisofnewspecimenscollectedinTierra del Fuego(Argentina).Cranial,mandibular,skeletal,penile,andchromosomalcharacteristicsaredescribedand compared withotherspeciesof Abrothrix, especiallythoseofthePatagonian-Fueguianregion.Itsphylogenetic positionwithinAbrotrichiniisexploredusingDNAsequencesofthemitochondrialcytochrome b (cyt b) andthe nuclear InterphotoreceptorRetinoidBindingProtein(IRBP)genes.Phylogenetically,cyt b places A. lanosus as sister of A. jelskii, whereasIRBPgroups A. lanosus and A. longipilis. Thelattertopologyismostconsistentwith morphologicaldataandtaxonomichistory.Severalcranialandmandibularcharactersdistinguish A. lanosus from the other speciesofthegenus,including A. longipilis, whichisitsmostsimilarspecies. A. lanosus shares withother congenersa2n ¼ 52 karyotypeanddiffersfromotherspeciesof Abrothrix by atleast10%(p-distances)sequence divergenceincyt b. Inconclusion, A. lanosus is avalidspecies,readilydistinguishablefromother Abrothrix in the southernPatagonian-Fueguianregion.Althoughmanydata,includingpenileandskullmorphology,suggestthat A. longipilis is itsclosestlivingrelative, A. jelskii is retainedasaviablealternativeuntiladditionaldataareobtained. r 2008 PublishedbyElsevierGmbHonbehalfofDeutscheGesellschaftfu¨r Sa¨ugetierkunde.