Spatiotemporal Dynamics of Genetic Variation in the Iberian Lynx along Its Path to Extinction Reconstructed with Ancient DNA

There is the tendency to assume that endangered species have been both genetically and demographically healthier in the past, so that any genetic erosion observed today was caused by their recent decline. The Iberian lynx (Lynx pardinus) suffered a dramatic and continuous decline during the 20th century, and now shows extremely low genome- and specieswide genetic diversity among other signs of genomic erosion. We analyze ancient (N¼10), historical (N¼245), and contemporary (N¼172) samples with microsatellite and mitogenome data to reconstruct the species’ demography and investigate patterns of genetic variation across space and time. Iberian lynx populations transitioned from low but significantly higher genetic diversity than today and shallow geographical differentiation millennia ago, through a structured metapopulation with varying levels of diversity during the last centuries, to two extremely genetically depauperate and differentiated remnant populations by 2002. The historical subpopulations show varying extents of genetic drift in relation to their recent size and time in isolation, but these do not predict whether the populations persisted or went finally extinct. In conclusion, current genetic patterns were mainly shaped by genetic drift, supporting the current admixture of the two genetic pools and calling for a comprehensive genetic management of the ongoing conservation program. This study illustrates how a retrospective analysis of demographic and genetic patterns of endangered species can shed light onto their evolutionary history and this, in turn, can inform conservation actions

Major components in oils obtained from Amazonian palm fruits

Native palm trees belong to the <i>Arecaceae</i> family and are among the most useful plant resources in the Amazons. Despite its great diversity and various uses, few species have been study in detail, which makes it necessary to perform more comprehensive studies on the quality and composition of species not yet explored.&#13; This study deals with the characterization of the major compounds in the oils obtained from the mesocarp of fruits of the main palm species from the State of Amapá, Brasil, i.e. bacaba (<i>Oenocarpus bacaba</i>), buriti (<i>Mauritia flexuosa</i>), inajá (<i>Maximiliana maripa</i>), pupunha (<i>Bactris gasipaes</i>) and tucumã (<i>Astrocaryum vulgare</i>). Physicochemical characteristics, fatty acids and triacylglycerol (TAG) contents were analyzed by HPLC and GC. The proximate composition of the fruits was also analyzed.&#13; The results relating to acidity, peroxide value and polar compounds indicate good quality of the oils obtained. Oleic acid ranging from 39.2 to 71.6% and palmitic acid ranging from 20.8 to 39.6% were the two major fatty acids in all the samples. The oils from inajá were characterized by the presence of significant amounts of lauric (4.6%) and miristic (10.7%) acids while in bacaba, buriti, pupunha and tucumã, as in most edible vegetable oils, only the fatty acids of 16 and 18 carbon atoms were present. Accordingly, the major TAG species in all the samples were POP, POO and OOO. The mesocarp of the palm fruit had a high content in lipids ranging from 17.0% for pupunha to 38.3% for bacaba, expressed as dry basis.<br><br>Las palmeras nativas de la familia <i>Arecaceae</i> constituyen recursos alimentarios de gran importancia en la región amazónica. A pesar de su diversidad y utilidad, muchas especies son poco conocidas por lo que son de interés los estudios dirigidos a conocer la calidad y composición de las especies menos exploradas para evaluar su potencial económico. &#13; El objetivo de este estudio fue la caracterización de los aceites obtenidos del mesocarpio de frutos de especies de bacaba (<i>Oenocarpus bacaba</i>), buriti (<i>Mauritia flexuosa</i>), inajá (<i>Maximiliana maripa</i>), pupunha (<i>Bactris gasipaes</i>) y tucumã (<i>Astrocaryum vulgare</i>), de importante producción en el Estado de Amapá, Brasil. Se analizaron sus características físicoquímicas, composición de ácidos grasos y composición de triglicéridos (TAG) mediante cromatografías líquida y de gases. Se determinó igualmente la composición proximal de los mesocarpios de los frutos.&#13; Los resultados indicaron que los aceites obtenidos eran todos de buena calidad. Por otra parte, el ácido oleico, entre 39.2 y 71.6%, y el ácido palmítico, entre 20.8 y 39.6%, fueron los dos ácidos mayoritarios en todos los aceites. El aceite de inajá fue el único con cantidades significativas de ácido laurico (4.6%) y mirístico (10.7%) ya que los demás contenían sólo ácidos grasos de 16 y 18 átomos de carbono. De acuerdo con su composición, las especies mayoritarias de TAG en todas las muestras fueron POP, POO y OOO. Finalmente, el contenido en aceite de los frutos fue elevado, oscilando entre 17.0% en la especie de pupunha hasta el 38.3% en la de bacaba, expresados sobre base seca

Retention of functional variation despite extreme genomic erosion: MHC allelic repertoires in the Lynx genus

[Background] Demographic bottlenecks erode genetic diversity and may increase endangered species’ extinction risk via decreased fitness and adaptive potential. The genetic status of species is generally assessed using neutral markers, whose dynamic can differ from that of functional variation due to selection. The MHC is a multigene family described as the most important genetic component of the mammalian immune system, with broad implications in ecology and evolution. The genus Lynx includes four species differing immensely in demographic history and population size, which provides a suitable model to study the genetic consequences of demographic declines: the Iberian lynx being an extremely bottlenecked species and the three remaining ones representing common and widely distributed species. We compared variation in the most variable exon of the MHCI and MHCII-DRB loci among the four species of the Lynx genus.[Results] The Iberian lynx was characterised by lower number of MHC alleles than its sister species (the Eurasian lynx). However, it maintained most of the functional genetic variation at MHC loci present in the remaining and genetically healthier lynx species at all nucleotide, amino acid, and supertype levels.[Conclusions] Species-wide functional genetic diversity can be maintained even in the face of severe population bottlenecks, which caused devastating whole genome genetic erosion. This could be the consequence of divergent alleles being retained across paralogous loci, an outcome that, in the face of frequent gene conversion, may have been favoured by balancing selection.Funding for this project was provided by the Spanish Dirección General de Investigación Científica y Técnica (CGL2010–21540/BOS and CGL2013–47755-P), project "Adaptive variation in declining species: Survey of MHC variation in Eurasian lynx populations at the western edge of its range" funded by the internal EBD proposal call “Microproyectos” financed by the Spanish Ministry of Economy and Competitiveness, through the Severo Ochoa Program for Centres of Excellence in R + D + I (SEV-2012-0262), and project 2014/15/B/NZ8/00212 funded by the National Science Center, Poland. Elena Marmesat received a JAE predoctoral grant from CSIC (Spanish National Research Council). We acknowledge support of the publication fee by the CSIC Open Access Publication Support Initiative through its Unit of Information Resources for Research (URICI).Peer reviewe