74 research outputs found

    シリヤケイカの繁殖行動

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    The reproductive behavior of the Japanese spineless cuttlefish Sepiella japonica was observed in a tank. The males competed for females before egg-laying and then formed pairs with females. The male then initiated mating by pouncing on the female head, and maintained the male superior head-to-head position during the mating. Before ejaculation, the male moved his right (non-hectocotylized) arm IV under the ventral portion of the female buccal membrane, resulting in the dropping of parts of spermatangia placed there during previous matings. After the sperm removal behavior, the male held spermatophores ejected through his funnel with the base of hectocotylized left arm IV and transferred them to the female buccal area. The spermatophore transfer occurred only once during each mating. The female laid an egg capsule at average intervals of 1.5 min and produced from 36 to more than 408 egg capsules in succession during a single egg-laying bout. Our results also suggested one female produced nearly 200 fertilized eggs without additional mating, implying that the female have potential capacity to store and use active sperm properly. The male continued to guard the spawning female after mating (range=41.8-430.1 min), and repeated matings occurred at an average interval of 70.8 min during the mate guarding. Although the time spent on the sperm removal in S. japonica was shorter than in other sperm-removing cuttlefishes, the shorter sperm removal duration may be compensated by the post-copulatory mate guarding and repeated matings in this species.水槽内でのシリヤケイカSepiella japonicaの繁殖行動を観察した。シリヤケイカの雄は雌が産卵を開始する前に雌をめぐって闘争し,ペアを形成した。ペア雄は雌の頭部に覆い被さる形で交接を始め,雄上位のままで雌雄の頭部が向き合う交接体勢を維持した。雄は自らの精莢を射出する前に,雌の口球周口腹下部で右第IV腕を動かすことによって,過去の交接によってそこに付着させられていた精子塊の一部を落下させた。その精子除去行動後,雄は交接腕である左第IV腕の根元で漏斗から吐き出した精莢をつかみ,雌の口球下部に渡した。この精莢輸送は各交接で1回だけであった。雌は平均1.5分の間隔で産卵基質に卵嚢を1つずつ産みつけ,一連の産卵行動で36から408個以上の卵嚢を産出した。また,本研究では1個体の雌が追加の交接なして200個近くの受精卵を産出することが示され,シリヤケイカの雌は過去の交接によって貯えられた精子を必要な時に受精に使う能力を持つと考えられた。それに対して雄は交接後も産卵雌を他雄からガードし続け(交接後ガード時間の範囲=41.8〜430.1分),そのガード行動中に平均70.8分の間隔で繰り返し交接を行った。シリヤケイカの雄が精子除去に費やす時間は他のコウイカ類のそれらと比べて短かったが,永続的な交接後ガード行動と繰り返し交接が短時間の精子除去から推測された本種の低い精子置換率を補償しているかもしれない

    Sperm removal, ejaculation and their behavioural interaction in male cuttlefish in response to female mating history

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    The removal of previously stored rival sperm and increased ejaculate expenditure are effective male sperm competition tactics to ensure paternity. We examined both behaviours and their interaction for male cuttlefish, Sepia lycidas, as a strategic investment. Males increased the duration of sperm removal and the number of ejaculations per mating when they were not the last male who had mated with the current partner. These responses would decrease the number of rival sperm and increase the male\u27s own sperm in the fertilization area. Recognition of the female\u27s mating history appeared to result from close mate guarding during successive matings. Moreover, when the last mate of the current partner was different from the current mate, there was a significant negative relationship between sperm removal duration and the number of subsequent ejaculations. This interaction suggests both strategic investment allocation and constraints on each mating investment as possible results of mating interruption by other males and spermatophore depletion, respectively. In addition, larger males with high competitive ability prolonged sperm removal when the last mate of the current partner was different from the current mate, whereas smaller males with relatively larger testes ejaculated more times during a mating. Male S. lycidas might adjust the duration of sperm removal at the risk of failing to achieve ejaculation and allocate their finite ejaculate expenditures based on the results (i.e. the increasing proportion of their own sperm)

    New records of Calommata signata (Araneae: Atypidae) from eastern part of Tottori Prefecture, Honshu, Japan.

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    Three new localities of an endangered spider, Calommata signata (Araneae, Atypidae), were discovered from eastern part of Tottori Prefecture, western Honshu, Japan in 2006 and 2007. They are Kugami (Iwami-cho), garden of the Tottori Prefectural Museum, and the campus of Tottori University (Tottori City). Three of the four habitats, including an already-known habitat of the Iwami-Makidani population in the backyard of the Coastal Branch of Tottori Prefectural Museum, were mown turf garden and one was bare ground. All sites are within the residential area. All the records of Calommata signata known from Tottori Prefecture are presented.

    ‘Protected DNA Probes’ capable of strong hybridization without removal of base protecting groups

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    We propose a new strategy called the ‘Protected DNA Probes (PDP) method’ in which appropriately protected bases selectively bind to the complementary bases without the removal of their base protecting groups. Previously, we reported that 4-N-acetylcytosine oligonucleotides (ac4C) exhibited a higher hybridization affinity for ssDNA than the unmodified oligonucleotides. For the PDP strategy, we created a modified adenine base and synthesized an N-acylated deoxyadenosine mimic having 6-N-acetyl-8-aza-7-deazaadenine (ac6az8c7A). It was found that PDP containing ac4C and ac6az8c7A exhibited higher affinity for the complementary ssDNA than the corresponding unmodified DNA probes and showed similar base recognition ability. Moreover, it should be noted that this PDP strategy could guarantee highly efficient synthesis of DNA probes on controlled pore glass (CPG) with high purity and thereby could eliminate the time-consuming procedures for isolating DNA probes. This strategy could also avoid undesired base-mediated elimination of DNA probes from CPG under basic conditions such as concentrated ammonia solution prescribed for removal of base protecting groups in the previous standard approach. Here, several successful applications of this strategy to single nucleotide polymorphism detection are also described in detail using PDPs immobilized on glass plates and those prepared on CPG plates, suggesting its potential usefulness

    Huge splenic epidermoid cyst with elevation of serum CA19-9 level

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    A 30-year-old female was referred to our hospital for further examination of liver dysfunction. A huge, soft mass was noted in her left upper quadrant on physical examination. Abdominal ultrasonography and computed tomography revealed a huge cystic tumor of 20 cm in the hilus of the spleen. Serum CA19-9 was 491 U/ml, and splenectomy was performed under suspicion of a malignant cystic tumor. The inner surface of the cyst was lined by squamous epithelial cells that were immunohistochemically positive for CA19-9. Serum CA19-9 level was normalized after the surgery. Our case of a very rare, huge epidermoid cyst of the spleen suggests that measurement of the serum CA19-9 level is useful for evaluating therapeutic efficacy of a splenic epidermoid cyst

    Successful pregnancy and delivery after a vitrified-warmed embryo transfer in a woman with Kallmann syndrome: A case report and literature review

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    Kallmann syndrome, a congenital disorder of idiopathic hypogonadotropic hypogonadism associated with anosmia, results in infertility because of anovulation. Assisted reproductive technology (ART) is considered when optimal ovulation induction therapy is difficult or when several cycles of ovulation induction therapy do not result in pregnancy. However, evidence is lacking regarding the optimal ART treatment for Kallmann syndrome. We report the case of a 33-year-old woman who successfully achieved pregnancy and delivery after ART treatment. At 29 years old, she was diagnosed with Kallmann syndrome due to hypothalamic amenorrhea and anosmia. At 33 years old, she revisited the hospital, desiring a child after one year of infertility. Due to anovulation, she was treated with gonadotropin therapy, but controlling follicular development was difficult, and thus ART treatment was initiated. The controlled ovarian stimulation (COS) protocol for ART treatment employed gonadotropins, recombinant follicular stimulating hormone/human menopausal gonadotropin plus human chorionic gonadotropin, to promote follicular growth. Four oocytes were retrieved, and two cleaved embryos were vitrified and cryopreserved. After vitrified-warmed embryo transfer of a morula stage embryo in a hormone replacement cycle, pregnancy was achieved but resulted in a miscarriage. A second oocyte retrieval was performed under the same COS; four oocytes were retrieved, and two cleaved embryos were vitrified and cryopreserved. Further, a pregnancy was achieved through the vitrified warmed embryo transfer. At 40 weeks and 6 days of gestation, a baby boy weighing 3,344 g with an Apgar score of 7/8 was delivered vaginally. The mother's postpartum course and neonate were free from adverse events. For women with Kallmann syndrome, ART treatment and selective embryo cryopreservation may be a reasonable and safe option

    ショクブツ シキソ アントシアニン ノ ヒドロキシルラジカル ショウキョカッセイ ヲ カシカ シタ リカジッケン キョウザイ カイハツ ト ソノ キョウイク コウカ

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    本研究は,植物色素が光合成のみならず酸素毒性から細胞や種を守る抗酸化物質としても働いてきたことを,進化的側面から植物色素の存在意義について再考察させるための実験開発と教材開発を行った。実験開発では,過酸化水素と2価鉄から生じる最も酸化力の高いヒドロキシルラジカルによるDNA分解が,植物色素であるアントシアニンにより防ぐことができることを可視化するための最適実験条件を明らかにした。また,高校生を対象とした授業実践から,本実験教材を用いた授業の教育効果を検証し,高等学校生物への発展的導入について考察を行った。授業実践の事前・事後アンケートの比較の結果,本教材のアントシアニンによる抗酸化能を可視化した実験により,植物色素の抗酸化能について理解しやすい教材であることが明らかとなった。また,授業解説と実験を行うことで,植物色素の抗酸化能が,紫外線や光合成から生じる活性酸素の毒性に対する防御機構として,植物の細胞機能の維持に重要な働きをしていることを,進化的側面から理解させることのできる効果的な教材であることも明らかとなった。よって本研究は,光合成以外の働きとして重要な植物色素の抗酸化能に着目した新たな実験としてだけでなく,光合成とバイオテクノロジーで学ぶ知識と実験技術を融合したバイオテクノロジーの発展的教材として,生徒に生命進化の観点から植物色素を多面的に理解させるための探究活動として,高校生物への今後の導入が期待された。This study aims to reorient a foundation of the existing teaching material and experiment in school education toward putting more focus on the evolutionarily preserved implication that plant pigments function not only as photosynthesis but also as anti-oxidant to protect living cells and plant seeds from oxidative toxicity. A developed experiment was designed for high school students to visualize the anti-oxidant potential of anthocyanin preventing DNA decomposition from hydroxyl radicals (ROS) derived from hydrogen peroxide and ferrous iron through electrophoresis as showing the indicative optimum condition. In addition, to the educational practice conducted for high school students, the study considered the validation of educational effectiveness of the teaching material together with a view to ushering in a developmental approach to high school biology class.It is also indicative that the posteriori survey revealed that students clearly understand the anti-oxidant ability of plant pigments, and it is effective for students to associate the biological importance of plant pigments in the course of evolution by teaching this function as anti-oxidant material of plant pigments for species preservation against ROS toxicity resulting from ultraviolet rays and photosynthesis. The study suggests that hands on experimental teaching material elicits students’ multifaceted understanding of plant pigments and the evolutionary implication, in high school education. Furthermore, the study material could be utilized as an exploratory activity to fulfill the requirement of biotechnology class, which is supported by techniques of scientific experiment and knowledge taught through unit learning of photosynthesis and biotechnology. Thus, the experimental teaching material is encouraged to be introduced to high school biology class as part of progressive educational material

    In vitro generation of cytotoxic and regulatory T cells by fusions of human dendritic cells and hepatocellular carcinoma cells

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    <p>Abstract</p> <p>Background</p> <p>Human hepatocellular carcinoma (HCC) cells express WT1 and/or carcinoembryonic antigen (CEA) as potential targets for the induction of antitumor immunity. In this study, generation of cytotoxic T lymphocytes (CTL) and regulatory T cells (Treg) by fusions of dendritic cells (DCs) and HCC cells was examined.</p> <p>Methods</p> <p>HCC cells were fused to DCs either from healthy donors or the HCC patient and investigated whether supernatants derived from the HCC cell culture (HCCsp) influenced on the function of DCs/HCC fusion cells (FCs) and generation of CTL and Treg.</p> <p>Results</p> <p>FCs coexpressed the HCC cells-derived WT1 and CEA antigens and DCs-derived MHC class II and costimulatory molecules. In addition, FCs were effective in activating CD4<sup>+ </sup>and CD8<sup>+ </sup>T cells able to produce IFN-γ and inducing cytolysis of autologous tumor or semiallogeneic targets by a MHC class I-restricted mechanism. However, HCCsp induced functional impairment of DCs as demonstrated by the down-regulation of MHC class I and II, CD80, CD86, and CD83 molecules. Moreover, the HCCsp-exposed DCs failed to undergo full maturation upon stimulation with the Toll-like receptor 4 agonist penicillin-inactivated <it>Streptococcus pyogenes</it>. Interestingly, fusions of immature DCs generated in the presence of HCCsp and allogeneic HCC cells promoted the generation of CD4<sup>+ </sup>CD25<sup>high </sup>Foxp3<sup>+ </sup>Treg and inhibited CTL induction in the presence of HCCsp. Importantly, up-regulation of MHC class II, CD80, and CD83 on DCs was observed in the patient with advanced HCC after vaccination with autologous FCs. In addition, the FCs induced WT1- and CEA-specific CTL that were able to produce high levels of IFN-γ.</p> <p>Conclusion</p> <p>The current study is one of the first demonstrating the induction of antigen-specific CTL and the generation of Treg by fusions of DCs and HCC cells. The local tumor-related factors may favor the generation of Treg through the inhibition of DCs maturation; however, fusion cell vaccination results in recovery of the DCs function and induction of antigen-specific CTL responses in vitro. The present study may shed new light about the mechanisms responsible for the generation of CTL and Treg by FCs.</p
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