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Cite this page: Hill, M.A. (2019, September 23) Embryology Medaka Development. Retrieved from https://embryology.med.unsw.edu.au/embryology/index.php/Talk:Medaka_Development
10 Most Recent Papers
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<pubmed limit=5>Medaka Development</pubmed>
<pubmed limit=5>Medaka Embryology</pubmed>
Generation of a transgenic medaka (Oryzias latipes) strain for visualization of nuclear dynamics in early developmental stages
Dev Growth Differ. 2016 Dec;58(9):679-687. doi: 10.1111/dgd.12324. Epub 2016 Oct 19.
Inoue T1, Iida A2, Maegawa S3, Sehara-Fujisawa A2, Kinoshita M1.
In this study, we verified nuclear transport activity of an artificial nuclear localization signal (aNLS) in medaka fish (Oryzias latipes). We generated a transgenic medaka strain expresses the aNLS tagged enhanced green fluorescent protein (EGFP) driven by a medaka beta-actin promoter. The aNLS-EGFP was accumulated in the nuclei of somatic tissues and yolk nuclei of oocytes, but undetectable in the spermatozoa. The fluorescent signal was observed from immediately after fertilization by a maternal contribution. Furthermore, male and female pronuclei were visualized in fertilized eggs, and nuclear dynamics of pronuclear fusion and subsequent cleavage were captured by time-lapse imaging. In contrast, SV40NLS exhibited no activity of nuclear transport in early embryos. In conclusion, the aNLS possesses a strong nuclear localization activity and is a useful probe for fluorescent observation of the pronuclei and nuclei in early developmental stage of medaka. © 2016 Japanese Society of Developmental Biologists.
KEYWORDS: medaka; nuclear localization signal; pronuclear fusion PMID: 27759163 DOI: 10.1111/dgd.12324
foxl3 is a germ cell-intrinsic factor involved in sperm-egg fate decision in medaka
Science. 2015 Jun 11. pii: aaa2657. [Epub ahead of print]
Nishimura T1, Sato T2, Yamamoto Y3, Watakabe I3, Ohkawa Y4, Suyama M2, Kobayashi S5, Tanaka M6.
Sex determination is an essential step in the commitment of a germ cell to a sperm or egg. However, the intrinsic factors that determine the sexual fate of vertebrate germ cells are unknown. Here we show that foxl3, which is expressed in germ cells but not somatic cells in the gonad, is involved in sperm-egg fate decision in medaka fish. Adult XX medaka with disrupted foxl3 developed functional sperm in the expanded germinal epithelium of a histologically functional ovary. In chimeric medaka, mutant germ cells initiated spermatogenesis in female wild-type gonad. These results indicate that a germ cell-intrinsic cue for the sperm-egg fate decision is present in medaka and that spermatogenesis can proceed in a female gonadal environment. Copyright © 2015, American Association for the Advancement of Science.
YAP is essential for tissue tension to ensure vertebrate 3D body shape
Nature. 2015 May 14;521(7551):217-21. doi: 10.1038/nature14215. Epub 2015 Mar 16.
Porazinski S1, Wang H1, Asaoka Y2, Behrndt M3, Miyamoto T4, Morita H3, Hata S2, Sasaki T5, Krens SF3, Osada Y6, Asaka S2, Momoi A6, Linton S1, Miesfeld JB7, Link BA7, Senga T8, Castillo-Morales A1, Urrutia AO1, Shimizu N5, Nagase H9, Matsuura S4, Bagby S1, Kondoh H10, Nishina H2, Heisenberg CP3, Furutani-Seiki M11.
Vertebrates have a unique 3D body shape in which correct tissue and organ shape and alignment are essential for function. For example, vision requires the lens to be centred in the eye cup which must in turn be correctly positioned in the head. Tissue morphogenesis depends on force generation, force transmission through the tissue, and response of tissues and extracellular matrix to force. Although a century ago D'Arcy Thompson postulated that terrestrial animal body shapes are conditioned by gravity, there has been no animal model directly demonstrating how the aforementioned mechano-morphogenetic processes are coordinated to generate a body shape that withstands gravity. Here we report a unique medaka fish (Oryzias latipes) mutant, hirame (hir), which is sensitive to deformation by gravity. hir embryos display a markedly flattened body caused by mutation of YAP, a nuclear executor of Hippo signalling that regulates organ size. We show that actomyosin-mediated tissue tension is reduced in hir embryos, leading to tissue flattening and tissue misalignment, both of which contribute to body flattening. By analysing YAP function in 3D spheroids of human cells, we identify the Rho GTPase activating protein ARHGAP18 as an effector of YAP in controlling tissue tension. Together, these findings reveal a previously unrecognised function of YAP in regulating tissue shape and alignment required for proper 3D body shape. Understanding this morphogenetic function of YAP could facilitate the use of embryonic stem cells to generate complex organs requiring correct alignment of multiple tissues. Comment in Crumbling under pressure. [Dev Cell. 2015] PMID 25778702
Medaka vasa gene has an exonic enhancer for germline expression
Gene. 2015 Jan 25;555(2):403-8. doi: 10.1016/j.gene.2014.11.039. Epub 2014 Nov 18.
Li M1, Zhao H2, Wei J3, Zhang J1, Hong Y4.
Enhancers are DNA sequences that enhance gene transcription in a position- and orientation-independent manner. Many enhancers controlling somatic gene expression have been described. Enhancers controlling germline expression have remained rare. Here we report the identification of V35 as a first exonic germline enhancer in vertebrates. V35 constitutes the first 35bp of exon 1 of the medaka vasa gene. V35 is required for vasa promoter function and sufficient to increase transcriptional activity of a heterologous promoter by ~13 fold in either forward or reverse orientation. V35 contains CAGCAGCACGAG for two paired E box-like motifs. Upon incubation with nuclear extract from spermatogonial cells, V35 formed three DNA-protein complexes. We show that complex formation is inhibited partially by oligos containing an E box or E box-like motif but completely by V35 and oligos that contain overlapped E box and E box-like motifs. Most importantly, V35 is sufficient to drive transgene expression in germ cells of developing embryos. These results establish V35 as the first exonic germline enhancer in a lower vertebrate, and provide evidence for the importance of exonic sequences in controlling germ gene expression. Copyright © 2014 Elsevier B.V. All rights reserved. KEYWORDS: Exonic enhancer; Gene transcription; Germline; V35; Vasa PMID 25447919
The Effects of Rearing Density, Salt Concentration, and Incubation Temperature on Japanese Medaka (Oryzias latipes) Embryo Development
Zebrafish. 2012 Dec;9(4):185-90. doi: 10.1089/zeb.2012.0744.
Rosemore BJ, Welsh CA. Source Cloquet Senior High School , Cloquet, Minnesota.
Abstract Environmental stressors are often present when an aquatic species, such as the Japanese medaka (Oryzias latipes) fish, are developing. This study examined the effects of some of these environmental stressors (variation in rearing density, salinity, and incubation temperature) on medaka embryo development. The hypotheses are if rearing density is increased, then hatching success will also be improved, while having no effect on embryo development; if the salt concentration is increased to 20 parts per thousand (ppt), then the rate of development will also be increased; if temperature is increased to 32°C, then the rate of development will also be increased. To determine the effects of variations in rearing density (1, 2, 3, and 4 eggs per well), the time of hatch was observed and noted. When testing variations in temperature (24°, 28°, and 32°C) and salinity (0.3, 10, 15, and 20 ppt), the onset of heartbeat and onset of retina pigmentation were observed. The original hypotheses were not all supported: as rearing density increased, success of hatch decreased; as salinity increased, only the rate of development for heartbeat increased; as temperature increased, the rate of development for both onset of the heartbeat and retina pigmentation also increased.
Snail gene expression in the medaka, Oryzias latipes
Gene Expr Patterns. 2010 Nov 19. [Epub ahead of print] Liedtke D, Erhard I, Schartl M.
Physiological Chemistry I, University of Würzburg, Biozentrum, Am Hubland, Würzburg, Germany. Abstract Snail transcription factors have prominent roles during embryonic development of vertebrates. They are often involved in cell migration processes during neural crest development, epithelial-mesenchymal transition and cancer progression. Comparative expression studies of snai gene family members in different vertebrate species are expected to contribute to a better understanding of their roles during development and reflect their evolutionary history. To investigate and to compare the expression patterns of snai genes in a second main fish model we used the medaka fish (Oryzias latipes), a complementary teleost model to zebrafish. We identified three snai gene family members, snai1a, snai1b and snai2. Phylogenetic and synteny analysis show a close relatedness of all family members to other vertebrate snai genes. Surprisingly, no homologue of snai3 could be identified in medaka, although this gene is present in zebrafish and the pufferfishes. Here we demonstrate that while most expression domains of medaka snai genes are comparable to zebrafish, the contribution of the individual paralogs to the overall pattern differs between the two teleosts and indicate lineage specific expression shuffling.
Copyright © 2010. Published by Elsevier B.V. PMID: 21094700
The National BioResource Project Medaka (NBRP Medaka): an integrated bioresource for biological and biomedical sciences
Exp Anim. 2010;59(1):13-23.
Sasado T, Tanaka M, Kobayashi K, Sato T, Sakaizumi M, Naruse K.
Laboratory of Bioresources, National Institute for Basic Biology, Okazaki, Japan. Abstract Medaka (Oryzias latipes) is a small freshwater teleost fish that serves as a model vertebrate organism in various fields of biology including development, genetics, toxicology and evolution. The recent completion of the medaka genome sequencing project has promoted the use of medaka as a comparative and complementary material for research on other vertebrates such as zebrafish, sticklebacks, mice, and humans. The Japanese government has supported the development of Medaka Bioresources since 2002. The second term of the Medaka Bioresource Project started in 2007. The National Institute for Basic Biology and Niigata University were selected as the core organizations for this project. More than 400 strains including more than 300 spontaneous and induced mutants, 8 inbred lines, 21 transgenic lines, 20 medaka-related species and 66 wild stock lines of medaka are now being provided to the scientific community and educational non-profit organizations. In addition to these live fish, NBRP Medaka is also able to provide cDNA/EST clones such as full-length cDNA and BAC/fosmid clones covering 90% of the medaka genome. All these resources can be found on the NBRP Medaka website (http://shigen.lab.nig.ac.jp/medaka/), and users can order any resource using the shopping cart system. We believe these resources will facilitate the further use of medaka and help to promote new findings for this vertebrate species.