The development of the enteropneust hemichordate Balanoglossus misakiensis Kuwano

We describe development from fertilization to metamorphosis of the enteropneust hemichordate Balanoglossus misakiensis. This is the first report to describe the complete development of an indirect-developing hemichordate under laboratory conditions. Mature adults were induced to spawn by shifting the temperature of seawater from 23 to 28°C. Eggs (200 μm diameter) were enclosed within a non-mucilaginous membrane, and dispersed readily in seawater. After artificial insemination, a fertilization envelope was elevated from the egg surface beneath the egg membrane; this was followed by the formation of the first and second polar bodies within the envelope. Zygotes cleaved at 20-min intervals to form blastulae, and gastrulation started 9 h after fertilization. Embryos hatched 1 day after fertilization to become typical feeding tornaria larvae. The larvae metamorphosed 7-10 days after fertilization without undergoing the first (Müller) or forth (Krohn) stage of indirect-developing hemichordate development. Larvae that were not fed failed to metamorphose. Juveniles completed adult body formation within a week of settling in sand at the bottom of the culture tube. We discuss heterochronical modifications of B. misakiensis development, and make the case for this species as a potential model organism for the investigation of indirect-developing hemichordates

半索動物門腸鰓綱ミサキギボシムシBalanoglossus misakiensisの発生

取得学位：博士(理学)，学位授与番号：博甲第622号，学位授与年月日：平成16年3月25日,学位授与年：200

パプアニューギニアで食用とされるミナミスナホリガニHippa adactylaの分子的同定

パプアニューギニアのラバウル近郊で現地人により採取されたスナホリガニの一種ミナミスナホリガニHippa adactyla Fabricius, 1787について，核18S及びミトコンドリア16SリボソームRNA遺伝子配列を解析し，近縁種間及び同種内の関係について分子的に比較した。その結果，インド－太平洋域に広く分布するとされる本種において，パプアニューギニア産個体はインド洋産個体と分子的に異なる一方，台湾産個体とは極めて近い関係にあることが示された。あわせて，本種を「グムグム（Gum Gum）」と呼んで食用とする現地の習慣を，他の地域の食習慣とともに紹介した。本稿は，南太平洋域のスナホリガニ類の分子的情報と，同域での食用採取について，初めて報告するものである。A specimen of Hippa adactyla Fabricius, 1787, was collected from Blanche Bay, Papua New Guinea. Nuclear 18S and mitochondrial 16S ribosomal RNA gene sequences were examined for interspecies and intraspecies comparisons. The result suggests some genetic similarity and diversification of this species distributed widely in the Indo-Pacific. We also report a local culture of eating the animal under the name “Gum Gum”. This is a pioneering report on the genetic perspective and fishing of a mole crab in southwest Pacific

WIDGET: System Performance and GRB Prompt Optical Observations

The WIDeField telescope for Gamma-ray burst Early Timing (WIDGET) is used for a fully automated, ultra-wide-field survey aimed at detecting the prompt optical emission associated with Gamma-ray Bursts (GRBs). WIDGET surveys the HETE-2 and Swift/BAT pointing directions covering a total field of view of 62 degree x 62 degree every 10 secounds using an unfiltered system. This monitoring survey allows exploration of the optical emission before the gamma-ray trigger. The unfiltered magnitude is well converted to the SDSS r' system at a 0.1 mag level. Since 2004, WIDGET has made a total of ten simultaneous and one pre-trigger GRB observations. The efficiency of synchronized observation with HETE-2 is four times better than that of Swift. There has been no bright optical emission similar to that from GRB 080319B. The statistical analysis implies that GRB080319B is a rare event. This paper summarizes the design and operation of the WIDGET system and the simultaneous GRB observations obtained with this instrument.Comment: 19 pages, 11 figures, Accepted to appear in PAS

The evolutionally-conserved function of group B1 Sox family members confers the unique role of Sox2 in mouse ES cells.

BACKGROUND: In mouse ES cells, the function of Sox2 is essential for the maintenance of pluripotency. Since the Sox-family of transcription factors are well conserved in the animal kingdom, addressing the evolutionary origin of Sox2 function in pluripotent stem cells is intriguing from the perspective of understanding the origin of pluripotency. RESULTS: Here we approach this question using a functional complementation assay in inducible Sox2-null ES cells. Assaying mouse Sox proteins from different Groups, we found that only Group B1 and Group G proteins were able to support pluripotency. Interestingly, invertebrate homologs of mammalian Group B1 Sox proteins were able to replace the pluripotency-associated function of mouse Sox2. Moreover, the mouse ES cells rescued by the Drosophila SoxNeuro protein are able to contribute to chimeric embryos. CONCLUSIONS: These data indicate that the function of mouse Sox2 supporting pluripotency is based on an evolutionally conserved activity of the Group B1 Sox family. Since pluripotent stem cell population in developmental process could be regarded as the evolutional novelty in vertebrates, it could be regarded as a co-optional use of their evolutionally conserved function

Jamun seed and orange peel extracts protects effects of microcystin LR on serum calcium and phosphate of rats

Wistar rats were treated as Group A: Control; Group B: microcystin LR (MCLR); Group C: microcystin LR and jamun seed extract (MCLR+JSE); Group D: microcystin LR and orange peel extract (MCLR+OPE); Group E: orange peel extract (OPE); Group F: jamun seed extract (JSE). MCLR dose was 10 µg/kg body wt/day whereas OPE and JSE dose was 200 mg/kg body wt/day. Serum calcium and phosphate were analyzed on 15 and 30 day. Serum calcium of rat exposed  for 15 day to MCLR; MCLR+JSE and MCLR+OPE decreased. Although there is little increase in levels of group C and group D  but treatment with OPE and JSE is not able to completely restore decreased calcium levels caused by MCLR. After 30 day calcium decreased after MCLR; MCLR+JSE and MCLR+OPE treatment. Levels in group E and F remain unaltered. Levels in group C and D exhibit elevation as compared to group B which indicates that treatment with OPE and JSE recovered calcium. Serum phosphate decreased after 15 day in MCLR; MCLR+JSE and MCLR+OPE  treated rats. Phosphate levels of group C (compared with group F) and group D (compared with group E) show decrease. After 30 day exposure to MCLR; MCLR+JSE and MCLR+OPE phosphate levels decreased. Levels of group C and D when compared with group B are increased. Phosphate levels of group C (compared with group F) and D (compared with group E) are decreased. This indicates that OPE and JSE treatment provoked some recovery of phosphate levels. DOI: http://dx.doi.org/10.5281/zenodo.394065

The Hox8 of the hemichordate Balanoglossus misakiensis

金沢大学理工研究域自然システム学系Deuterostomes comprise a monophyletic group of animals that include chordates, xenoturbellids, and the Ambulacraria, which consists of echinoderms and hemichordates. The ancestral chordate probably had 14 Hox genes aligned linearly along the chromosome, with the posterior six genes showing an independent duplication compared to protostomes. In contrast, ambulacrarians are characterized by a duplication of the posterior Hox genes, resulting in three genes known as Hox11/13a, Hox11/ 13b, and Hox11/13c. Here, we isolated 12 Hox genes from the hemichordate Balanoglossus misakiensis and found an extra Hox gene that has not been reported in hemichordates. The extra B. misakiensis gene was suggested to be Hox8 from paralog-characteristic residues in its hexapepetide motif and homeodomain and a comparison with Strongylocentrotus purpuratus Hox genes. Our data suggest that the ancestor of echinoderms and hemichordates may have had a full complement of 12 Hox genes. © Springer-Verlag 2009

シイクカ ニ オケル ナメクジウオ ヨウセイ ノ セイチョウ

We are successfully maintaining a laboratory colony of the lancelet Branchiostoma belcheri bred in the laboratory. Based on living individuals in this mass culture, morphological characteristics from the seven-day larval to benthic juvenile stages have been studied. Most striking was that later larval development of B. belcheri showed great individual variation even in a rather stable culture environment. Metamorphosis first occurred on 60 days post fertilization (dpf) and was continuously observed throughout the present study up to 100 dpf. Morphological traits such as the number of primary gill slits and body size at the start of metamorphosis are apparently affected by culture condition. Body size measured in the largest individuals showed nearly linear growth at 0.087 mm/day. The variability found in larval development calls for caution when developmental stages and chronological ages are compared between populations. However, the developmental flexibility of this animal also raises the possibility that growth and sexual maturation could be controlled artificially in captivity