Reliability of non-invasive tissue sampling methods for DNA extraction in rabbits (Oryctolagus cuniculus)

[EN] Deoxyribonucleic acid (DNA) can be extracted from different tissue sources. The most common is blood, but in some situations it can be easier to take a biopsy. In some cases when it is difficult to capture animals, especially in wild populations, faeces and hairs can be considered as a source of DNA. This paper presents a pilot study conducted to compare the applicability of invasive and non-invasive sampling methods for extracting DNA for use in genetic studies of rabbits (Oryctolagus cuniculus). The study included 24 rabbits from the INRA 1001 strain. Blood, hair, ear biopsies and faeces were collected and used as DNA sources. Our aim was to verify the quantity of DNA obtained from different tissues using two or three types of extraction. DNA was obtained for all tissue types and all extraction methods. DNA extraction was shown to be optimal with the LGC (Laboratory of Cellular Genetics) blood extraction method. With regard to non-invasive methods, DNA extraction for hair using the LGC protocol and QIAamp¿ DNA mini kit gave very low quantities of DNA that could not be used for PCR reactions. The Chelex extraction protocol gave good results for PCR but could not be quantified. DNA extracted from faeces is a viable source of DNA for determining individual genotypes. The use of such non-invasive samples as a source of genetic material is a recent and very promising technique, especially for the study of endangered species, but these techniques are still too unreliable and costly to altogether replace invasive techniques when the latter are possible.Ben Larbi, M.; Tircazes, A.; Feve, K.; Tudela, F.; Bolet, G. (2012). Reliability of non-invasive tissue sampling methods for DNA extraction in rabbits (Oryctolagus cuniculus). World Rabbit Science. 20(2):117-124. doi:10.4995/wrs.2012.1077SWORD11712420

Nuevos enfoques sobre los vertebrados del Pérmico y Triásico de la Península Ibérica, con énfasis en las cuencas Pirenaica y Catalana

Few studies paid attention to the Permian and Triassic vertebrates from the Iberian Peninsula and a re-evaluation of these faunas is needed in order to compare them with other European basins. As a first step, we present here the available data from the Catalonian and Pyrenean basins (NE of the Iberian Peninsula), offering new insights on the diversity and temporal distribution of their vertebrate faunas. The two basins have yielded unexpectedly abundant and diverse vertebrate assemblages, including fishes, amphibians and reptiles from continental and marine environments. The revision of classical finds and the analysis of new material provide data towards an understanding of the evolutionary and palaebiogeographical history of the Permian and Triassic vertebrate Iberian faunas. Permian remains mainly correspond to footprints recovered from alluvial deposits; the osteological record is scarce in the Iberian Peninsula. Early Triassic vertebrate localities are unknown. Middle Triassic faunas are abundant and reflect the change from continental environments to a wide diversity of coastal and marine depositional environments. During the Anisian, faunas are represented by footprints and skeletal remains of amphibians (capitosaurs) and terrestrial reptiles (archosauromorphs and procolophonoids). Ichthyofauna, sauropterygians, thalattosaurs and protorosaurians are known through the late Anisian and Ladinian. Finally, Late Triassic localities representing coastal environments have also yielded marine reptiles (sauropterygians) and a diverse ichthyofauna.Se han realizado hasta el momento pocos estudios de los vertebrados del Pérmico y el Triásico de la Península Ibérica y por este motivo, una re-evaluación de estas faunas es necesaria para compararlas con las halladas en otras cuencas europeas. Como primer paso, aquí presentamos la información disponible de las cuencas Catalana y Pirenaica (NE de la Península Ibérica), ofreciendo nuevos puntos de vista sobre la diversidad y distribución temporal de las faunas de vertebrados. Las dos cuencas muestran una inesperada abundancia y diversidad de faunas de vertebrados, incluyendo peces, anfibios y reptiles de ambientes continentales y marinos. La revisión de hallazgos clásicos y el análisis de nuevo material proporcionan nuevos datos para la comprensión de la historia evolutiva y paleobiogeográfica de las faunas de vertebrados durante el Pérmico y el Triásico en la Península Ibérica. Los hallazgos en el Pérmico corresponden mayoritariamente a pisadas encontradas en depósitos aluviales, siendo el registro osteológico muy escaso en la Península Ibérica. Se desconocen localidades de vertebrados del Triásico inferior. Las faunas del Triásico medio son abundantes y reflejan el cambio desde ambientes continentales hasta una amplia diversidad de ambientes deposicionales costeros y marinos. Durante el Anisiense, las faunas están representadas por pisadas y restos esqueléticos de anfibios (capitosaurios) y reptiles terrestres (arcosauriformes y procolofonoideos). De finales del Anisiense y el Ladiniense se conoce ictiofauna, sauropterigios, talattosaurios y protorosaurios. Finalmente, las localidades del Triásico superior están representadas por ambientes costeros conservando reptiles marinos (sauropterigios) y una diversa ictiofauna

The Jurassic rise of squamates as supported by lepidosaur disparity and evolutionary rates

The squamates (lizards, snakes, and relatives) today comprise more than 10,000 species, and yet their sister group, the Rhynchocephalia, is represented by a single species today, the tuatara. The explosion in squamate diversity has been tracked back to the Cretaceous Terrestrial Revolution, 100 million years ago (Ma), the time when flowering plants began their takeover of terrestrial ecosystems, associated with diversification of coevolving insects and insect-eating predators such as lizards, birds, and mammals. Squamates arose much earlier, but their long pre-Cretaceous history of some 150 million years (Myr) is documented by sparse fossils. Here, we provide evidence for an initial radiation of squamate morphology in the Middle and Late Jurassic (174-145 Ma), and show that they established their key ecological roles much earlier than had been assumed, and they have not changed them much since

Enigmatic amphibians in mid-Cretaceous amber were chameleon-like ballistic feeders

Albanerpetontids are tiny, enigmatic fossil amphibians with a distinctive suite of characteristics, including scales and specialized jaw and neck joints. Here we describe a new genus and species of albanerpetontid, represented by fully articulated and three-dimensional specimens preserved in amber. These specimens preserve skeletal and soft tissues, including an elongated median hyoid element, the tip of which remains embedded in a distal tongue pad. This arrangement is very similar to the long, rapidly projecting tongue of chameleons. Our results thus suggest that albanerpetontids were sit-and-wait ballistic tongue feeders, extending the record of this specialized feeding mode by around 100 million years

Estimation of genetic variation in residual variance in female and male broiler chickens

In breeding programs, robustness of animals and uniformity of end product can be improved by exploiting genetic variation in residual variance. Residual variance can be defined as environmental variance after accounting for all identifiable effects. The aims of this study were to estimate genetic variance in residual variance of body weight, and to estimate genetic correlations between body weight itself and its residual variance and between female and male residual variance for broilers. The data sets comprised 26 972 female and 24 407 male body weight records. Variance components were estimated with ASREML. Estimates of the heritability of residual variance were in the range 0.029 (s.e.50.003) to 0.047 (s.e.50.004). The genetic coefficients of variation were high, between 0.35 and 0.57. Heritabilities were higher in females than in males. Accounting for heterogeneous residual variance increased the heritabilities for body weight as well. Genetic correlations between body weight and its residual variance were 20.41 (s.e.50.032) and 20.45 (s.e.50.040), respectively, in females and males. The genetic correlation between female and male residual variance was 0.11 (s.e.50.089), indicating that female and male residual variance are different traits. Results indicate good opportunities to simultaneously increase the mean and improve uniformity of body weight of broilers by selection

A new Early Cretaceous lizard in Myanmar amber with exceptionally preserved integument

We here report on a well-preserved juvenile lizard specimen in Albian amber (ca. 110 mya) from the Hkamti site (Myanmar). This new taxon is represented by an articulated skull and the anterior portion of the trunk, including the pectoral girdle and forelimbs. The scleral ossicles and eyelid are also visible, and the specimen exhibits pristine detail of the integument (of both head and body). In a combined molecular and morphological analysis, it was consistently recovered as a scincoid lizard (Scinciformata), as sister to Tepexisaurus + Xantusiidae. However, the phylogenetic position of the new taxon should be interpreted with caution as the holotype is an immature individual. We explored the possibility of miscoding ontogenetically variable characters by running alternative analyses in which these characters were scored as missing data for our taxon. With the exception of one tree, in which it was sister to Amphisbaenia, the specimen was recovered as a Pan-xantusiid. Moreover, we cannot rule out the possibility that it represents a separate lineage of uncertain phylogenetic position, as it is the case for many Jurassic and Cretaceous taxa. Nonetheless, this fossil offers a rare opportunity to glimpse the external appearance of one group of lizards during the Early Cretaceous