Genetic variation of the Chilean endemic long-haired mouseAbrothrix longipilis(Rodentia, Supramyomorpha, Cricetidae) in a geographical and environmental context

Abstract

Quaternary climate and associated vegetational changes affected the fauna of the Chilean Mediterranean ecosystem. Here we studied the genetic variation of the long-haired mouse, Abrothrix longipilis, a sigmodontine rodent endemic to this area. Within an environmentally explicit context, we examined the geographic distribution of the genetic diversity and demographic history of the species based on sequences of the mitochondrial Cytochrome-b gene of 50 individuals from 13 localities and a large panel of single nucleotide polymorphisms of 17 individuals from 6 localities. The gene genealogy of A. longipilis revealed three intraspecific lineages that are allopatric and latitudinally segregated (northern, central, and southern lineages) with an estimated crown age for the whole species clade of 552.3 kyr B.P. A principal component analysis based on 336,596 SNP loci is in line with the information given by the the mitochondrial gene genealogy. Along its complete distributional range, A. longipilis showed patterns of isolation by distance and also isolation by environment. The general pattern of historical demography showed stability for most intraspecific lineages of A. longipilis. Northern and central lineages showed signals of historical demographic stability, while the southern lineage showed contrasting signals. In agreement with this, the niche models performed showed that in the northern range of A. longipilis, areas of high suitability for this species increased towards the present time; areas of central range would have remained relatively stable, while southern areas would have experienced more change through time. In summary, our study shows three distinct allopatric lineages of A. longipilis, each showing slightly different demographic history.

A comprehensive overview of the genetic diversity in Thylamys elegans (Didelphimorphia: Didelphidae): establishing the phylogeographic determinants

“…Probably with the creation of the Arid Diagonal and the periodic climate oscillation which changed the landscape several times in the last 1.5 Mya, the different ancestors of each lineage were adapted to xeric environment (clades A and northern part of clade B), mesic (clades C, D,E and southern part of clade B) or humid environment (Clade F) favoring even more the differentiation not drove by barriers. A similar scenario was reported in Abrothrix longipilis with lineages restricted to different bioclimate [26,47]. Therefore, although today some rivers as the Quilimarí or even the Aconcagua seems to be barriers, that they could be only delimitating the current distribution of the lineages but not promoted divergence by vicariance as suggest the topology and phylogenetic relationships of our results because T. e. coquimbensis and Aconcagua lineage from opposite banks of Quilimarí and Aconcagua lineage and T. e. elegans from opposite banks of Aconcagua river are not sister clades (Fig.…”

“…Indeed, some rivers can act as barriers to gene flow and/or geographic boundary of distribution structuring genetic diversity in different taxa from Chile [36,[41][42][43][44][45][46]. However, none of these papers discussed in detail if the riverine divergence would be a primary or secondary differentiation [47]. On the other hand, the historical and recent effects of other rivers different to Maipo river on the differentiation of T. elegans lineages are still unknown, being necessary to evaluate if the role of rivers was for primary diversification, secondary contact or dispersal [4].…”

Genetic Diversity and Demographic History of the Shaggy Soft-Haired Mouse Abrothrix hirta (Cricetidae; Abrotrichini)

“…However, the northern limit of its distribution remains unclear. As a result of our field work, here we extend the known distribution of the species toward the norther up Constitución, Maule Región include (locality 1; Table 1 and Figure 1 ) where it almost reaches the southern known locality of A. longipilis (see Valdez et al, 2020 ). A. hirta inhabits highly contrasting environmental conditions, including sclerophyllous forests, the humid temperate Valdivian and Magellan rainforest, and the arid Patagonian steppe.…”

Diferencias en el ensamble de micromamíferos entre áreas con distinto grado de protección del sitio Prioritario los Molles-Pichidangui

“…La urgencia de proteger la franja costera adyacente al parque se hace más notoria al ser en esta área donde se registró exclusivamente a dos de las especies endémicas capturadas en este La variabilidad genética también es parte de la biodiversidad y respecto a algunas de las especies registradas en este estudio corresponderían a los siguientes linajes genéticos: T. elegans al linaje Aconcagua (Boric-Bargetto, 2015; Boric-Bargetto et al, en revisión), A. longipilis al linaje norte (Valdez et al, 2020), P. darwini al linaje B (Gutiérrez-Tapia & Palma, 2016), O. degus al linaje norte (Valladares, 2009), A. o. olivacea (Rodríguez-Serrano et al, 2006 y O. l. longicaudatus (Palma et al, 2012). Además, en los alrededores del sitio prioritario para la conservación Los Molles-Pichidangui se han reportado especies híbridas de plantas y animales (Correa et al, 2013;Frías, 2005;Schulte et al, 2010).…”