A New Late Miocene Odobenid (Mammalia: Carnivora) from Hokkaido,Japan Suggests Rapid Diversification of Basal Miocene Odobenids

The modern walrus, Odobenus rosmarus, is specialized and only extant member of the family Odobenidae. They were much more diversified in the past, and at least 16 genera and 20 species of fossil walruses have been known. Although their diversity increased in the late Miocene and Pliocene (around 8–2 Million years ago), older records are poorly known. A new genus and species of archaic odobenid, Archaeodobenus akamatsui, gen. et sp. nov. from the late Miocene (ca. 10.0–9.5 Ma) top of the Ichibangawa Formation, Hokkaido, northern Japan, suggests rapid diversification of basal Miocene walruses. Archaeodobenus akamatsui is the contemporaneous Pseudotaria muramotoi from the same formation, but they are distinguishable from each other in size and shape of the occipital condyle, foramen magnum and mastoid process of the cranium, and other postcranial features. Based on our phylogenetic analysis, A. akamatsui might have split from P. muramotoi at the late Miocene in the western North Pacific. This rapid diversification of the archaic odobenids occurred with a combination of marine regression and transgression, which provided geological isolation among the common ancestors of extinct odobenids.     

Cloning and analysis of the MNN4 gene required for phosphorylation of N-linked oligosaccharides in Saccharomyces cerevisiae

The Saccharomyces cerevisiae MNN4 gene, which is involved inmannosylphosphate transfer from GDP-mannose to N-linked oligosaccharide,has been cloned from a lambda phage containing a yeast chromosomeXI DNA fragment The MNN4 ORF encodes a protein of 1178 aminoacids. The deduced amino acid sequence shows a topology of typeII membrane proteins and has a unique repeated sequence of lysineand glutamic acid at the C-terminus. Disruption and overexpressionof MNN4 led to a decrease and increase, respectively, of themannosylphosphate content in cell wall mannans prepared fromboth mnn4 and wild type strains. A dramatic decrease of mannosylphosphateoccurs in     

Sleep‐related behaviors in zoo‐housed giraffes (Giraffa camelopardalis reticulata): Basic characteristics and effects of season and parturition

Despite increasing interest in the behavior of zoo animals, studies of nocturnal behavior of zoo animals are limited. In this study, we investigated the relationship between parturition, season, and the sleep‐related behaviors in captive reticulated giraffes to better understand the nocturnal life in giraffes. The subjects were two adult reticulated giraffes living in Kyoto City Zoo, Japan. Observations were made via an infrared camera that was mounted in the indoor enclosure between June 2007 and August 2009. We analyzed video clips that were recorded between 16:30 and 09:00 the next morning, over a total of 199 days. Sleep‐related behaviors were classified into two categories based on the posture of the giraffes; recumbent posture and paradoxical sleep. We also recorded the laterality of recumbent posture, which was coded based on the direction of the legs against the torso (right or left). Seasonal differences in sleep behaviors between summer and winter were observed in both individuals. They tended to start to lie down earlier in the winter than in the summer. Parturition also affected the behaviors as both individuals decreased the behaviors before and after the parturition of the female. Additionally, the female lay on her left side less frequently than her right when resuming a recumbent posture in the pre‐parturition period, while such laterality was not observed in the baseline and post‐parturition period. These results suggested that season and parturition are important factors for determining the sleep‐related behaviors in giraffes. Further studies are needed to understand how these changes in sleep affect other welfare parameters.     

Molecular and Biochemical Characterization of Three Anthocyanin Synthetic Enzymes from Gentiana triflora

Full length cDNA clones of flavonoid 3',5'-hydroxylase, dihydroflavonol4-reductase and flavonoid 3-glucosyltransferase were clonedfrom petals of Gentiana triflora. Their sequences were homologousto counterparts from other plants. Flavonoid 3',5'-hydroxylaseand flavonoid 3-glucosyltransferase were enzymatically characterizedby expressing cDNAs in heterologous expression systems. (Received May 21, 1996; Accepted June 4, 1996)     

Impaired tetramer assembly of variant medium-chain acyl-coenzyme A dehydrogenase with a glutamate or aspartate substitution for lysine 304 causing instability of the protein.

Ninety percent of variant medium-chain acyl-CoA dehydrogenase (MCAD) alleles in patients with MCAD deficiency carry a 985 A-->G transition which causes glutamate substitution for lysine 329 in precursor (p) MCAD (K-304 in mature MCAD). We have used site-directed mutagenesis to produce three variant cDNAs encoding variant pMCAD with glutamate (Kp329E2), aspartate (Kp329D), or arginine (Kp329R) substitution for Kp329. We carried out in vitro expression of cDNAs, and incubated the translation products with isolated rat liver mitochondria. Kp329E was imported into mitochondria and processed into the mature subunit as efficiently as wild-type. Gel filtration analysis of the mitochondria revealed that at 10 min after import, markedly more K304E eluted as a monomer than did wild-type, and the amount of K304E tetramer formed was distinctly less than wild-type at any point up to 60 min after import, indicating that the assembly of K304E is defective. After further incubation, K304E decayed more rapidly than did wild-type, indicating a reduced stability. In similar studies, K304R behaved like the wild-type, while K304D closely resembled K304E, indicating that the presence of a basic residue at 304 is essential for tetramer formation and intramitochondrial stability of mature MCAD.     

Carotenoid synthesis in Streptomyces setonii ISP5395 is induced by the gene crtS, whose product is similar to a sigma factor

In many species of actinomycetes, carotenogenesis can be photoinduced. The capacity to respond to photoinduction is, however unstable and, in various strains of Streptomyces, is lost at a relatively high frequency. In Streptomyces setonii ISP5395, which normally produces no carotenoids, carotenoid-producing mutants can be obtained following protoplast regeneration. We report here the characterization of a gene, crtS, which was isolated from one such mutant and can confer on wild-type S. setonii ISP5395 cells the capacity to synthesize carotenoids. Sequence analysis of crtS reveals an open reading frame, which shows homology to genes that encode alternative sigma factors in Bacillus subtilis. We propose that crtS encodes a sigma factor which is necessary for the expression of a cryptic gene(s) for carotenoid biosynthesis in S. setonii ISP5395.     

Ibaraki Virus,an Agent of Epizootic Disease of Cattle Resembling Bluetongue

Replication of Ibaraki virus was not inhibited by 5-iodo-2′-deoxyuridine, indicating that the virus is an RNA virus. The virus was resistant to ether, chloroform and deoxycholate, sensitive to trypsin, very labile at acidic pH but stable at pH 6.4 or higher, and was resistant to repeated freezing and thawing. The virus was readily inactivated at 56 C or higher, was fairly stable at 37 C, and very stable at 4 C, while it rapidly lost infectivity when stored frozen at —20 C. The virus was readily sedimented by centrifugation at 40 000Xg for 60 min. It readily passed through membrane filters of 200 mμ pore size, passed through 100 μfilters but only with some titer loss and did not through 50 mμ filters. In these tests, the bluetongue virus used as a control behaved in the same manner as Ibaraki virus. These findings provide additional evidence for the similarity of Ibaraki virus to bluetongue virus which had been previously demonstrated on the basis of seasonal incidence, symptomatology and pathology of the diseases caused by these viruses and the behavior of the viruses in cell cultures, embryonated eggs and laboratory animals. The present study, however, provided no evidence for any serological relation between these two viruses. More Information is needed to reach a final decision on the classification of Ibaraki virus, particularly regarding the morphology of the virion, the doublestrandedness of the viral RNA and other basic features.     

IOP1 Protein Is an External Component of the Human Cytosolic Iron-Sulfur Cluster Assembly (CIA) Machinery and Functions in the MMS19 Protein-dependent CIA Pathway

The emerging link between iron metabolism and genome integrity is increasingly clear. Recent studies have revealed that MMS19 and cytosolic iron-sulfur cluster assembly (CIA) factors form a complex and have central roles in CIA pathway. However, the composition of the CIA complex, particularly the involvement of the Fe-S protein IOP1, is still unclear. The roles of each component are also largely unknown. Here, we show that MMS19, MIP18, and CIAO1 form a tight “core” complex and that IOP1 is an “external” component of this complex. Although IOP1 and the core complex form a complex both in vivo and in vitro, IOP1 behaves differently in vivo. A deficiency in any core component leads to down-regulation of all of the components. In contrast, IOP1 knockdown does not affect the level of any core component. In MMS19-overproducing cells, other core components are also up-regulated, but the protein level of IOP1 remains unchanged. IOP1 behaves like a target protein in the CIA reaction, like other Fe-S helicases, and the core complex may participate in the maturation process of IOP1. Alternatively, the core complex may catch and hold IOP1 when it becomes mature to prevent its degradation. In any case, IOP1 functions in the MMS19-dependent CIA pathway. We also reveal that MMS19 interacts with target proteins. MIP18 has a role to bridge MMS19 and CIAO1. CIAO1 also binds IOP1. Based on our in vivo and in vitro data, new models of the CIA machinery are proposed.