Morphological variation among the inner ears of extinct and extant baleen whales (Cetacea: Mysticeti)

Living mysticetes (baleen whales) and odontocetes (toothed whales) differ significantly in auditory function in that toothed whales are sensitive to high‐frequency and ultrasonic sound vibrations and mysticetes to low‐frequency and infrasonic noises. Our knowledge of the evolution and phylogeny of cetaceans, and mysticetes in particular, is at a point at which we can explore morphological and physiological changes within the baleen whale inner ear. Traditional comparative anatomy and landmark‐based 3D‐geometric morphometric analyses were performed to investigate the anatomical diversity of the inner ears of extinct and extant mysticetes in comparison with other cetaceans. Principal component analyses (PCAs) show that the cochlear morphospace of odontocetes is tangential to that of mysticetes, but odontocetes are completely separated from mysticetes when semicircular canal landmarks are combined with the cochlear data. The cochlea of the archaeocete Zygorhiza kochii and early diverging extinct mysticetes plot within the morphospace of crown mysticetes, suggesting that mysticetes possess ancestral cochlear morphology and physiology. The PCA results indicate variation among mysticete species, although no major patterns are recovered to suggest separate hearing or locomotor regimes. Phylogenetic signal was detected for several clades, including crown Cetacea and crown Mysticeti, with the most clades expressing phylogenetic signal in the semicircular canal dataset. Brownian motion could not be excluded as an explanation for the signal, except for analyses combining cochlea and semicircular canal datasets for Balaenopteridae. J. Morphol. 277:1599–1615, 2016. © 2016 Wiley Periodicals, Inc.     

Ein Elasmosaurierzahn aus der oberen Kreide des St. Pietersberges bei Maastricht,Süd-Limburg,Niederlande

An elasmosaurian tooth is described and figured from the St. Pietersberg near Maastricht (Netherlands), well-known for its classical mosasaur finds. The tooth shows lingually a remarkable grinding trace. The preserved sediment allowed a determination of the stratigraphical position by analysis of bioclasts.     

Moraxella catarrhalis Expresses a Cardiolipin Synthase That Impacts Adherence to Human Epithelial Cells

The major phospholipid constituents of Moraxella catarrhalis membranes are phosphatidylglycerol, phosphatidylethanolamine, and cardiolipin (CL). However, very little is known regarding the synthesis and function of these phospholipids in M. catarrhalis. In this study, we discovered that M. catarrhalis expresses a cardiolipin synthase (CLS), termed MclS, that is responsible for the synthesis of CL within the bacterium. The nucleotide sequence of mclS is highly conserved among M. catarrhalis isolates and is predicted to encode a protein with significant amino acid similarity to the recently characterized YmdC/ClsC protein of Escherichia coli. Isogenic mclS mutant strains were generated in M. catarrhalis isolates O35E, O12E, and McGHS1 and contained no observable levels of CL. Site-directed mutagenesis of a highly conserved HKD motif of MclS also resulted in a CL-deficient strain. Moraxella catarrhalis, which depends on adherence to epithelial cells for colonization of the human host, displays significantly reduced levels of adherence to HEp-2 and A549 cell lines in the mclS mutant strains compared to wild-type bacteria. The reduction in adherence appears to be attributed to the absence of CL. These findings mark the first instance in which a CLS has been related to a virulence-associated trait.     

Purification and characterization of the lipoprotein-associated coagulation inhibitor from human plasma

The lipoprotein-associated coagulation inhibitor (LACI) has been isolated from human plasma using a combination of hydrophobic, ion-exchange, and affinity chromatography. The final purification required was greater than 500,000-fold with a yield of 13%. Plasma LACI, on sodium dodecyl sulfate-polyacrylamide gel electrophoresis, contains major bands at 40 and 46 kDa and minor bands at 55, 65, 75, 90, and approximately 130 kDa. All of the molecular weight forms are recognized by antibodies to LACI's amino and carboxyl termini and are able to inhibit the factor VII(a)-tissue factor complex and factor Xa. Plasma LACI, reduced with beta-mercaptoethanol, migrates on sodium dodecyl-sulfate-polyacrylamide gel electrophoresis as a doublet at 42 kDa and has an amino-terminal sequence essentially identical to that of HepG2 LACI. The difference in size between reduced plasma LACI (42 kDa) and HepG2 LACI (47 kDa) may be related to differing degrees of N-linked glycosylation. The 46-kDa and larger forms of unreduced plasma LACI are associated with apolipoprotein A-II (apoA-II) in mixed disulfide linkages. Studies using isolated lipoproteins show that low density lipoprotein (LDL) contains primarily the 40-kDa form of LACI, whereas high density lipoprotein (HDL) contains primarily the 46-kDa form of LACI (LACI/apoA-II complexes). Gel filtration of a fresh plasma sample showed approximately 50% of plasma LACI to be associated with LDL/very low density lipoprotein, 44% with HDL, and the remaining 6% to not be associated with lipoproteins.     

Hadrosauroid Dinosaurs from the Late Cretaceous of the Sultanate of Oman

Fragmentary post-cranial remains (femora, tibia, vertebrae) of ornithischian dinosaurs from the Late Cretaceous of the Sultanate of Oman are described and referred to hadrosauroids. The specimens come from the Al-Khod Conglomerate, of latest Campanian to Maastrichtian age, in the north-eastern part of the country. Although the fragmentary condition of the fossils precludes a precise identification, various characters, including the shape of the fourth trochanter of the femur and the morphology of its distal end, support an attribution to hadrosauroids. With the possible exception of a possible phalanx from Angola, this group of ornithopod dinosaurs, which apparently originated in Laurasia, was hitherto unreported from the Afro-Arabian plate. From a paleobiogeographical point of view, the presence of hadrosauroids in Oman in all likelihood is a result of trans-Tethys dispersal from Asia or Europe, probably by way of islands in the Tethys shown on all recent paleogeographical maps of that area. Whether hadrosauroids were widespread on the Afro-Arabian landmass in the latest Cretaceous, or where restricted to the « Oman island » shown on some paleogeographical maps, remains to be determined.