Detection of telomere length and oxidative stress in Chondrichthyes     

Hori  Misaki  Kimura  Satoko S.  Mizutani  Yuichi  Miyagawa  Yoshimi  Ito  Konomi  Arai  Nobuaki  Niizuma  Yasuaki 《Fisheries Science》2022,88(6):741-750

Telomeres, repeating TTAGGG sequences at the ends of eukaryotic chromosomes, increase genomic stability. Telomere shortening occurs not only during DNA replication associated with cell division but also under oxidative stress, where reactive oxygen species damage DNA. Therefore, changes in telomere length can be used to evaluate chronic cost or stress responses incurred by individuals. The phylogenetically unique Chondrichthyes are among the least-studied groups of marine vertebrates. Telomere data are limited and have only been reported in a few Chondrichthyes species. In this study, we measured telomere length and quantified oxidative stress and antioxidant power in 17 Chondrichthyes species whose telomere length has not been measured before. The presence of telomere sequences?>?30 bp and lower values of oxidative stress were confirmed in most species. Average telomere length was not correlated with oxidative stress and antioxidant power in 15 species for which both measurements were available. It would be desirable in the future to elucidate the nature of telomeres in Chondrichthyes, and their direct relationship with reactive oxygen species.

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Similarity of GATA-3 Expression between Rat and Human Mammary Glands     

Yuichi Kinoshita  Katsuhiko Yoshizawa  Yuko Emoto  Michiko Yuki  Takashi Yuri  Nobuaki Shikata  Airo Tsubura 《Journal of toxicologic pathology》2014,27(2):159-162

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Rescue In Vitro Fertilization Method for Legacy Stock of Frozen Mouse Sperm     

Naomi NAKAGATA  Toru TAKEO  Kiyoko FUKUMOTO  Yukie HARUGUCHI  Tomoko KONDO  Yumi TAKESHITA  Yuko NAKAMUTA  Tomoko UMENO  Shuuji TSUCHIYAMA 《The Journal of reproduction and development》2014,60(2):168-171

Sperm cryopreservation has been widely adopted for maintenance of the genetically engineered mouse (GEM). The cryopreserved sperm are being exchanged among many institutes worldwide. However, the recipients are not always able to obtain high fertilization rates with the frozen sperm shipped from senders. In this study, we cryopreserved mouse sperm via various methods and performed in vitro fertilization (IVF) in which the combination of methyl-beta-cyclodextrin for sperm preincubation and reduced glutathione for insemination was used (the MBCD-GSH IVF). In addition, frozen sperm sent from the Jackson Laboratory (USA) were thawed and used for IVF in the same manner. The fertilization rates of both the sperm cryopreserved via the methods applied in some countries and the cryopreserved GEM sperm improved when used with the MBCD-GSH IVF method. Therefore, we strongly believe that the MBCD-GSH IVF method brings about relatively high fertilization rates with any strain of frozen mouse sperm.  相似文献   

Molecular attempt to identify prey organisms of lobster phyllosoma larvae   总被引：2，自引：0，他引：2  

Nobuaki Suzuki  Keisuke Murakami  Haruko Takeyama  Seinen Chow 《Fisheries Science》2006,72(2):342-349

ABSTRACT:   A molecular approach was adopted to investigate the natural diets of palinurid and scyllarid lobster phyllosoma larvae. The central domain of the 18S rDNA gene was amplified using nested polymerase chain reaction (PCR) and genomic DNA extracted from the larval hepatopancreas. The resulting 18S rDNA clones were screened using restriction fragment length polymorphism (RFLP) analysis, and then FASTA homology search and phylogenetic analysis were performed on the nucleotide sequences to identify the source of the eukaryotic organisms. The feasibility of this method was confirmed using the laboratory-reared phyllosoma larvae of the Japanese spiny lobster Panulirus japonicus that were fed either with common mussel Mytilus edulis gonads or with Artemia nauplii exclusively. Among the 804 clones isolated from five wild-caught mid- to late-stage phyllosoma larvae (three palinurids and two scyllarids), 0–132 clones per sample possessed restriction profiles distinct from those of the hosts. The Cnidaria and Urochordata DNA were identified from both the palinurid and the scyllarid larvae, which were thought to be prey animals for the mid- to late-stage phyllosoma larvae.  相似文献   

Comparison of behavioral characteristics of hatchery-reared and wild red tilefish Branchiostegus japonicus released in Maizuru Bay by using acoustic biotelemetry     

Takashi Yokota  Hiromichi Mitamura  Nobuaki Arai  Reiji Masuda  Yasushi Mitsunaga  Masashi Itani  Hiroyuki Takeuchi  Tatsuo Tsuzaki 《Fisheries Science》2006,72(3):520-529

ABSTRACT:   In order to establish techniques for the stock enhancement of red tilefish Branchiostegus japonicus , it is important to understand the behavioral characteristic of both hatchery-reared and wild fish. Four hatchery-reared and six wild fish were released and tracked using acoustic biotelemetry in Maizuru Bay, Kyoto, Japan, from August 2003 to February 2004. Data for the four wild fish released and tracked from January 2003 to May 2003 were also referred to for analysis. The released fish moved around in relatively large areas within about 10 days after the release, and then three hatchery-reared and two wild fish settled and stayed within limited areas. Fish of both origins showed strong site fidelity and diel activity patterns, i.e. they were detectable in the day but not at night, probably due to hiding behavior in their burrows at night. However, some discrepancies between fish of both origins were detected by comparing their track terms and activity patterns in detail. These discrepancies are probably attributable to the differences in environmental conditions that the fish had experienced before release.  相似文献   

Directed movements and diel burrow fidelity patterns of red tilefish <Emphasis Type="Italic">Branchiostegus japonicus</Emphasis> determined using ultrasonic telemetry     

Hiromichi?MitamuraEmail author  Nobuaki?Arai  Yasushi?Mitsunaga  Takashi?Yokota  Hiroyuki?Takeuchi  Tatsuo?Tsuzaki  Masashi?Itani 《Fisheries Science》2005,71(3):491-498

ABSTRACT:   Wild red tilefish Branchiostegus japonicus were tracked and/or monitored for up to nearly 3 months in Western Wakasa Bay and Maizuru Bay, Japan, using ultrasonic telemetry to examine their movements and burrow fidelity patterns. In Western Wakasa Bay, it is guessed that fish released in relatively shallow waters, about 30 m deep, actively moved into more suitable deeper habitats after their release. In Maizuru Bay, the fish did not undertake large-scale movements and showed burrow fidelity about 1 month after their release. That is, the fish primarily remained in the burrow, which was constructed in the sea-bottom, during the night and moved outside the burrow during the day. The marked circadian rhythm from Fourier analysis indicated a clear diel movement pattern of the red tilefish.  相似文献   

A genetic linkage map of the Japanese flounder, Paralichthys olivaceus     

Maria R. M. Coimbra  Kazunobu Kobayashi  Shinrokuro Koretsugu  Osamu Hasegawa  Eriko Ohara  Akiyuki Ozaki  Takashi Sakamoto  Kyoshi Naruse  Nobuaki Okamoto   《Aquaculture (Amsterdam, Netherlands)》2003,220(1-4):203-218

We report the first genetic linkage map of the Japanese flounder (Paralichthys olivaceus) constructed with 111 microsatellite markers and 352 AFLP fragments. The parental male linkage map consisted of 25 linkage groups while the female map consisted of 27 groups, with an average resolution of 8 and 6.6 cM, respectively. We have identified linkage among 96% of the markers and the total map length was estimated to be around 1000–1200 cM. This study reports the first low-density linkage map for the Japanese flounder and describes differences in sex recombination. Recombination rates were higher in male flounder compared to the female (7.4:1), a rare condition among vertebrates. This map is a starting point for the mapping of single loci and quantitative traits in flatfish species.  相似文献   

Seasonal changes and controlling factors of gross N transformation in an evergreen plantation forest in central Japan     

Naoko Tokuchi  Satomi Yoneda  Nobuhito Ohte  Nobuaki Usui  Keisuke Koba  Megumi Kuroiwa  Hiroto Toda  Yuichi Suwa 《Journal of Forest Research》2014,19(1):77-85

We conducted a year-round measurement of gross N transformation rates using the ¹⁵N dilution method, and analyzed seasonal changes and the mechanisms regulating gross N transformation in the Kiryu Experimental Forest in central Japan. While soil microbial biomass C (SMB-C) decreased from the dormant to growing seasons at the organic (O) horizon, no significant trend was observed in SMB-N. This resulted in SMB-C/N being high in the dormant season and low in the growing season, and suggests that the microbial composition changed seasonally. No clear seasonal trend was found in gross NH₄ ⁺ production rates at either the O or surface mineral soil horizons. In contrast, the NH₄ ⁺ consumption rate varied seasonally, with high values in January and April during the dormant season and low values in July and October during the growing season. There was no clear trend in seasonal fluctuation of net NH₄ ⁺ production rates. Gross NH₄ ⁺ production and gross NH₄ ⁺ consumption rates were 10 times greater than the gross nitrification rate. Almost all of the produced NH₄ ⁺ was immobilized, indicating that N tightly cycles at this study site. Considered together with results of the gross N transformation rates, the dominance of high SMB-C/N microbes might stimulate immobilization in the dormant season. At this study site, the change in microbial composition likely influences gross N transformation through immobilization efficiency.  相似文献   

中日传统家具结构形式的比较     

戴向东  曾献  李敏秀  服部顺昭 《木材工业》2007,21(6):34-36,40

受传统木结构建筑的影响,中日两国传统家具都以榫卯结构为主要接合方式.中国传统家具品类众多,又兼具独树一帜的"硬木"文化情结,因此,不仅中国家具榫结构的类型比日本的多,结构形式也复杂;制作技术水平优于日本传统家具.  相似文献   

Suppression of the whistling noise in circular saws using “Silentalloy”     

Nobuaki Hattori  Masami Noguchi 《Wood Science and Technology》1992,26(6):449-459

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