Guenons (tribe Cercopithecini) are one of the most diverse groups of primates. They occupy all of sub-Saharan Africa and show great variation in ecology, behavior, and morphology. This variation led ...to the description of over 60 species and subspecies. Here, using next-generation DNA sequencing (NGS) in combination with targeted DNA capture, we sequenced 92 mitochondrial genomes from museum-preserved specimens as old as 117 years. We infer evolutionary relationships and estimate divergence times of almost all guenon taxa based on mitochondrial genome sequences. Using this phylogenetic framework, we infer divergence dates and reconstruct ancestral geographic ranges. We conclude that the extraordinary radiation of guenons has been a complex process driven by, among other factors, localized fluctuations of African forest cover. We find incongruences between phylogenetic trees reconstructed from mitochondrial and nuclear DNA sequences, which can be explained by either incomplete lineage sorting or hybridization. Furthermore, having produced the largest mitochondrial DNA data set from museum specimens, we document how NGS technologies can "unlock" museum collections, thereby helping to unravel the tree-of-life.
The amphisbaenian Monopeltis schoutedeni is reported for the first time from Gabon based on a single individual from the extreme southeastern part of the country. The species was formerly known only ...from the Republic of Congo and the Democratic Republic of Congo. It is the 4th amphisbaenian and the 123rd reptile species recorded from Gabon. An identification key to Gabon amphisbaenians is provided.
Cercopithecus solatus is a recently discovered monkey endemic to Gabon, present in parts of the Lopé National Park and the Forêt des Abeilles in the center of the country. It is listed as Vulnerable ...on the IUCN Red List (2010) due to its restricted extent of occurrence and continuing decline in population caused by high hunting pressure. All known field observations of this species are compiled here. Data collected since 1999 show that C. solatus occurs further to the south, east, and west than was previously known, and that its extent of occurrence almost certainly includes three national parks, rather than one.
Lenglet Georges, Coppois Guy. Description du crâne et de quelques ossements d'un genre nouveau éteint de Cricetidae géant des Galapagos : Megaoryzomys (gen. nov.). In: Bulletin de la Classe des ...sciences, tome 65, 1979. pp. 632-648.
The light microscope observations on the oesophagus and the buccal cavity of the African (Schübe mystus L.) and the Asian (Pangasius micronemus BLKR.) freshwater catfishes revealed that the ...stratified squamous epithelium was made up of three kinds of cells. Two cell-types are well-known, e.g. undifferen¬ tiated and mucus-secreting cells. The third cell-type («barrel-shaped») was abundant and of an unusual giant size (25-30μm x 15-20 μm). These cells were not mucoid in nature. In contrast they stained reddish-brown with the coupled tetrazonium method according to DANIELLI, which allows the authors to ensure their protein content. Furthermore their particular binding of fluorescent lectin from Arachis hypogaea (PNA) indicated that ß-D-galactosyl residues were abundant in the cytoplasm. The occurence of similar cells (club cells) in the skin of both siluroid and cyprinoid fishes is well documented. They were claimed to be involved in alarm substance secretion. Their presence, however, in the oesophageal and buccal mucosa has never been reported. Thus, the present work embodies an original observation on the histology of the anterior part of the alimentary tract of the catfishes.
Since scientists regard the main role of buccal cavity and oesophagus as gustation and mucus production, the function of these giant cells in this part of the alimentary tract remains conjectural.
L'examen microscopique de la cavité buccale et de l'œsophage des silures d'eau douce africain (Schübe mystus L.) et asiatique (Pangasius micronemus BLKR) révèle que leur épithélium stratifié est composé de trois types cellulaires. Deux d'entre eux sont bien connus, ce sont les cellules indifférenciées et muqueuses. Le troisième type (cellules en forme de «tonnelet») est de grande taille (25-30 μm X 1 5-20 μm). Ce type cellulaire est riche en protéines comme le montre sa positivité à la tetrazoréaction de DANIELLI. En outre, ces cellules réagissent avec la lectine d 'Arachis hypogaea (PNA) liée à un fluorochrome, ce qui indique la présence d'abondants résidus ß-D-galactosyl. Des cellules semblables ont été décrites dans la peau des poissons siluriformes et cypriniformes où elles sécréteraient une substance d'alarme. Leur présence dans la cavité buccale et l'œsophage n'a, à notre connaissance, jamais été clairement mentionnée et le présent travail rapporte donc une observation originale sur la région antérieure du tractus digestif des poissons-chats.
La fonction de ces cellules géantes à ce niveau du tube digestif reste toutefois obscure et mériterait d'autres recherches.
Danguy André J., Kiss Robert, Lenglet Georges. The oesophageal and buccal histology of two freshwater siluriformes (Schübe mystus L. and Pangasius micronemus Blkr.) with reference to an unsual cell type. In: Bulletin de la Classe des sciences, tome 72, 1986. pp. 62-72.
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