水中音に関する研究-5 : インダス河イルカPlatanista gangeticaの水中鳴音について

Recording of the underwater call and observation of the relative behaviour of the river dolphin (Platanista gangetica) living in the Indus River were carried out. All of the underwater calls emitted by this dolphin were clicks which were continuously emitted. This call was mainly used for echolocation and, when small fishes were thrown into the pond, it was observed that the repetition rate of clicks emitted by the dolphin searching for bait rapidly became higher. The repetition rate was 30-200/sec. (usually 40-100/sec.) The analyzed patterns were monotonous and the particularly strong frequency band was not constant.The clicks emitted by the Indus River Dolphin were very similar to the call of the dolphin living in the Ganges River, but the stratiformed sound, burst, twitter and whistle which the Ganges River Dolphin emitted were not observed with the Indus River Dolphin.!?1. The underwater calls of the Indus River Dolphin were recorded in Pakistan were compared with that of the Ganges River Dolphin of the same species. 2. This dolphin lives at deep places and sinuous places of the Indus River and is always emitting the calls. 3. The emitting interval of underwater calls almost constant all day. 4. All of the calls of the Indus River Dolphin are of the type of so-called "Clicks" and play an important role in echolocation. 5. The analyzed pattern of these calls are monotonous and no special strong frequency band is recognized. 6. The repetition rate is 30-200/sec. (usually 40-100/sec.). 7. Regarding that the Ganges River Dolphin was under the breeding condition, the clicks of the Indus River Dolphin and the Ganges River Dolphin may have no difference at all. 8. Other calls observed in the Ganges River Dolphin were not recognized in the Indus River Dolphin

Fifteen Marseilleviruses Newly Isolated From Three Water Samples in Japan Reveal Local Diversity of Marseilleviridae

The family Marseilleviridae, defined as a group of icosahedral double-stranded DNA viruses with particle size of approximately 250 nm and genome size of 350–380 kbp, belongs to the nucleo-cytoplasmic family of large DNA viruses. The family Marseilleviridae is currently classified into lineages A–E. In this study, we isolated 12 or 15 new members of the family Marseilleviridae from three sampling locations in Japan. Molecular phylogenetic analysis of the MCP genes showed that the new viruses could be further classified into three groups, hokutoviruses, kashiwazakiviruses, and kyotoviruses. Hokutoviruses were closely related to lineage B, kyotoviruses were related to lineage A, and kashiwazakiviruses were also classified into lineage B but a new putative subgroup of lineage B, revealing the diversity of this lineage. Interestingly, more than two viruses with slightly different MCP genes were isolated from a single water sample from a single location, i.e., two hokutoviruses and one kashiwazakivirus were isolated from a small reservoir, five kashiwazakiviruses from the mouth of a river, and five kyotoviruses from fresh water of a river, suggesting that several milliliters of water samples contain several types of giant viruses. Amoeba cells infected with hokutoviruses or kashiwazakiviruses exhibited a “bunch” formation consisting of normal and infected cells similarly to a tupanvirus, whereas cells infected with kyotoviruses or tokyovirus did not. These results suggest the previously unrecognized local diversity of the family Marseilleviridae in aquatic environments

Medusavirus, a Novel Large DNA Virus Discovered from Hot Spring Water

ヒストン遺伝子を全セット持つ巨大ウイルスの発見 --DNA関連遺伝子のウイルス起源に新たな証拠--. 京都大学プレスリリース. 2019-02-08.Recent discoveries of new large DNA viruses reveal high diversity in their morphologies, genetic repertoires, and replication strategies. Here, we report the novel features of medusavirus, a large DNA virus newly isolated from hot spring water in Japan. Medusavirus, with a diameter of 260 nm, shows a T=277 icosahedral capsid with unique spherical-headed spikes on its surface. It has a 381-kb genome encoding 461 putative proteins, 86 of which have their closest homologs in Acanthamoeba, whereas 279 (61%) are orphan genes. The virus lacks the genes encoding DNA topoisomerase II and RNA polymerase, showing that DNA replication takes place in the host nucleus, whereas the progeny virions are assembled in the cytoplasm. Furthermore, the medusavirus genome harbored genes for all five types of histones (H1, H2A, H2B, H3, and H4) and one DNA polymerase, which are phylogenetically placed at the root of the eukaryotic clades. In contrast, the host amoeba encoded many medusavirus homologs, including the major capsid protein. These facts strongly suggested that amoebae are indeed the most promising natural hosts of medusavirus, and that lateral gene transfers have taken place repeatedly and bidirectionally between the virus and its host since the early stage of their coevolution. Medusavirus reflects the traces of direct evolutionary interactions between the virus and eukaryotic hosts, which may be caused by sharing the DNA replication compartment and by evolutionarily long lasting virus-host relationships. Based on its unique morphological characteristics and phylogenomic relationships with other known large DNA viruses, we propose that medusavirus represents a new family, Medusaviridae

Screening of bacterial DNA in bile sampled from healthy dogs and dogs suffering from liver- or gallbladder-associated disease

Although the biliary system is generally aseptic, gallbladder microbiota has been reported in humans and some animals apart from dogs. We screened and analyzed the bacterial deoxyribonucleic acid in canine gallbladders using bile sampled from 7 healthy dogs and 52 dogs with liver- or gallbladder-associated disease. PCR screening detected bacteria in 17.3% of diseased dogs (9/52) and none in healthy dogs. Microbiota analysis of PCR-positive samples showed that the microbial diversity differed between liver- and gallbladder-associated disease groups. Thus, a specific bacterial community appears to occur at a certain frequency in the bile of diseased dogs

ARTICLE Development of radionuclide distribution database and map system on the Fukushima nuclear accident

The Radionuclide distribution database and map system, which provide basic information for evaluations and countermeasures of the accident at Fukushima Daiichi nuclear power plant, are explained. Due to massive earthquake and tsunami, Fukushima Daiichi nuclear power plant had been damaged and spread out radioactive materials around the Fukushima region. In order to meet the various requirements from government, local government, residents, and/or researchers, we developed two systems to provide those data to the public. One of the systems is a database system which is designed to provide quantitative data for detailed analysis. Another is a map system which provides intuitive images for the qualitative estimation. In the two systems, it is possible to provide the information requested by a wide range of people

Morphological and Taxonomic Properties of <i>Tokyovirus</i>, the First <i>Marseilleviridae</i> Member Isolated from Japan

exterior, 196