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The Amphioxus Model System.
Authors: Kozmik Z Abstract The amphioxus (lancelet) was first described by Pallas in 1774 and incorrectly assigned to mollusks. Since then, amphioxus attracted generations of zoologists. It took however almost one hundred years until Alexander Kowalevsky recognized that the larval stages of amphioxus had much in common with vertebrate embryos. Widely studied around 1900 as the 'elementary vertebrate', amphioxus as a model went out of fashion with the decline of comparative anatomy. Due to the scarcity of taxa at the invertebrate-to-vertebrate transition, amphioxus nevertheless remained the species with a privileged...
Source: International Journal of Developmental Biology - January 12, 2018 Category: Biology Tags: Int J Dev Biol Source Type: research

The ups and downs of amphioxus biology: a history.
Authors: Holland ND, Holland LZ Abstract Humans (at least a select few) have long known about the cephalochordate amphioxus, first as something to eat and later as a subject for scientific study. The rate of publication on these animals has waxed and waned several times. The first big surge, in the late nineteenth century, was stimulated by Darwin's evolutionary ideas and by Kowalevsky's embryologic findings suggesting that an amphioxus-like creature might have bridged the gap between the invertebrates and the vertebrates. Interest declined sharply in the early twentieth century and remained low for the next 50 yea...
Source: International Journal of Developmental Biology - January 12, 2018 Category: Biology Tags: Int J Dev Biol Source Type: research

The dawn of amphioxus molecular biology - a personal perspective.
Authors: Holland P Abstract The cloning and embryonic expression analysis of an amphioxus Hox gene in 1992 marked the start of molecular analysis of cephalochordate development. Other papers quickly followed, including a description of the amphioxus Hox gene cluster in 1994, fuelling a resurgence of interest in a long-forgotten animal. I describe the academic background, laboratory experiments and field work leading to the earliest publications in amphioxus molecular developmental biology and explain their scientific impact. The story of amphioxus biology in the 1990s involved collaboration, team work, opportunisti...
Source: International Journal of Developmental Biology - January 12, 2018 Category: Biology Tags: Int J Dev Biol Source Type: research

Early development of amphioxus links evolutionary events with vertebrates.
Authors: Yasui K Abstract Comparison of early development is a powerful approach to understand how spherical embryos set up the basis for body patterning. Localization of the germ plasm likely couples with the site of gastrulation in many animals including cnidarians. A center of single or complex Wnt signaling pathway(s) is also co-localized with germ plasm and plays a role primarily in antero-posterior patterning in most animals. In addition, a Nodal signaling center appears in deuterostomes perpendicular to Wnt signaling and governs dorso-ventral patterning. Wnt and Nodal signaling pathways function as orthogona...
Source: International Journal of Developmental Biology - January 12, 2018 Category: Biology Tags: Int J Dev Biol Source Type: research

Dorsal-ventral patterning in amphioxus: current understanding, unresolved issues, and future directions.
Authors: Kozmikova I, Yu JK Abstract How the embryonic body axis is generated is a fundamental question in developmental biology. The molecular mechanisms involved in this process have been the subject of intensive studies using traditional model organisms during the last few decades, and the results have provided crucial information for understanding the formation of animal body plans. In particular, studies exploring the molecular nature of Spemann's organizer have revealed the intricate interactions underlying several signaling pathways (namely the Wnt/β-catenin, Nodal and Bmp pathways) that pattern the dor...
Source: International Journal of Developmental Biology - January 12, 2018 Category: Biology Tags: Int J Dev Biol Source Type: research

Left-right asymmetry specification in amphioxus: review and prospects.
Authors: Soukup V Abstract Extant bilaterally symmetrical animals usually show asymmetry in the arrangement of their inner organs. However, the exaggerated left-right (LR) asymmetry in amphioxus represents a true peculiarity among them. The amphioxus larva shows completely disparate fates of left and right body sides, so that organs associated with pharynx are either positioned exclusively on the left or on the right side. Moreover, segmented paraxial structures such as muscle blocks and their neuronal innervation show offset arrangement between the sides making it difficult to propose any explanation or adaptivity...
Source: International Journal of Developmental Biology - January 12, 2018 Category: Biology Tags: Int J Dev Biol Source Type: research

Metamerism in cephalochordates and the problem of the vertebrate head.
Authors: Onai T, Adachi N, Kuratani S Abstract The vertebrate head characteristically exhibits a complex pattern with sense organs, brain, paired eyes and jaw muscles, and the brain case is not found in other chordates. How the extant vertebrate head has evolved remains enigmatic. Historically, there have been two conflicting views on the origin of the vertebrate head, segmental and non-segmental views. According to the segmentalists, the vertebrate head is organized as a metameric structure composed of segments equivalent to those in the trunk; a metamere in the vertebrate head was assumed to consist of a somite, ...
Source: International Journal of Developmental Biology - January 12, 2018 Category: Biology Tags: Int J Dev Biol Source Type: research

From so simple a beginning - what amphioxus can teach us about placode evolution.
Authors: Schlosser G Abstract Cranial placodes are an evolutionary novelty of vertebrates that give rise to many cranial sense organs and ganglia, as well as to the neurosecretory anterior pituitary. Although amphioxus does not have placodes, it shares with vertebrates several of the ectodermal patterning mechanisms and cell types that are important in placode development. Comparisons between amphioxus, vertebrates and other groups provide us with important insights into what the last common chordate ancestor probably looked like and allow us to propose a scenario for how placodes evolved by rewiring of gene regula...
Source: International Journal of Developmental Biology - January 12, 2018 Category: Biology Tags: Int J Dev Biol Source Type: research

Interpreting amphioxus, and thoughts on ancestral chordate mouths and brains.
Authors: Lacalli T Abstract Amphioxus is increasingly important as a model for ancestral chordates. Nevertheless, it is secondarily modified in various ways, especially in the larva, whose small size has resulted in a rescaling and repositioning of structures. This is especially pronounced in the head region, where the mouth opens asymmetrically on the left side, leading to speculation that the mouth is secondarily derived, e.g. from a gill slit, and is hence not homologous with mouths in other animals. The available evidence does not, in the author's view, support this interpretation. A second issue is raised conc...
Source: International Journal of Developmental Biology - January 12, 2018 Category: Biology Tags: Int J Dev Biol Source Type: research

Origin and evolution of the chordate central nervous system: insights from amphioxus genoarchitecture.
Authors: Albuixech-Crespo B, Herrera-Úbeda C, Marfany G, Irimia M, Garcia-Fernàndez J Abstract The vertebrate brain is arguably the most complex anatomical and functional structure in nature. During embryonic development, the central nervous system (CNS) undergoes a series of morphogenetic processes that eventually obscure the major axes of the early neural plate to our perception. Notwithstanding this complexity, the "genoarchitecture" of the developing neural tube brings into light homologous regions between brains of different vertebrate species, acting as a molecular barcode of each part...
Source: International Journal of Developmental Biology - January 12, 2018 Category: Biology Tags: Int J Dev Biol Source Type: research

Amphioxus photoreceptors - insights into the evolution of vertebrate opsins, vision and circadian rhythmicity.
Authors: Pergner J, Kozmik Z Abstract Studies on amphioxus, representing the most basal group of chordates, can give insights into the evolution of vertebrate traits. The present review of amphioxus research is focused on the physiology of light-guided behavior as well as on the fine structure, molecular biology, and electrophysiology of the nervous system, with special attention being given to the photoreceptive organs. The amphioxus visual system is especially interesting because four types of receptors are involved in light detection - dorsal ocelli and Joseph cells (both rhabdomeric photoreceptors) and the fron...
Source: International Journal of Developmental Biology - January 12, 2018 Category: Biology Tags: Int J Dev Biol Source Type: research

The long and winding path to understanding kidney structure in amphioxus - a review.
Authors: Holland ND Abstract The history of studies on amphioxus kidney morphology is reviewed with special attention to four zoologists who made important early contributions. In 1884, Hatschek described a single anterior nephridial tubule in larval and adult amphioxus. Subsequently, in 1890, Weiss and Boveri independently found multiple branchial nephridia (morphologically similar to Hatschek's nephridium) associated with the pharyngeal gill slits. These initial discoveries set the stage for Goodrich to criticize Boveri repeatedly for the latter's contention that amphioxus nephridia develop from mesoderm and are ...
Source: International Journal of Developmental Biology - January 12, 2018 Category: Biology Tags: Int J Dev Biol Source Type: research

Amphioxus regeneration: evolutionary and biomedical implications.
Authors: Somorjai IML Abstract Regeneration is a variable trait in chordates, with some species capable of impressive abilities, and others of only wound healing with scarring. Regenerative capacity has been reported in the literature for 5 species from two cephalochordate genera, Branchiostoma and Asymmetron. Its cellular and molecular bases have been studied in some detail in only two species: tail regeneration in the European amphioxus B. lanceolatum; and oral cirrus regeneration in the Asian species B. japonicum. Gene expression analyses of germline formation and posterior elongation in cephalochordate embryos ...
Source: International Journal of Developmental Biology - January 12, 2018 Category: Biology Tags: Int J Dev Biol Source Type: research

Developmental cell-cell communication pathways in the cephalochordate amphioxus: actors and functions.
Authors: Bertrand S, Le Petillon Y, Somorjai IML, Escriva H Abstract During embryonic development, cells of metazoan embryos need to communicate in order to construct the correct bodyplan. To do so, they use several signals that usually act through interactions between ligands and receptors. Interestingly, only a few pathways are known to be fundamental during animal development, and they are usually found in all the major metazoan clades, raising the following question: how have evolution of the actors and of the functions of these pathways participated in the appearance of the current diversity of animal morpholo...
Source: International Journal of Developmental Biology - January 12, 2018 Category: Biology Tags: Int J Dev Biol Source Type: research

Amphioxus Sp5 is a member of a conserved Specificity Protein complement and is modulated by Wnt/ β-catenin signalling.
Amphioxus Sp5 is a member of a conserved Specificity Protein complement and is modulated by Wnt/β-catenin signalling. Int J Dev Biol. 2017;61(10-11-12):723-732 Authors: Dailey SC, Kozmikova I, Somorjai IML Abstract A cluster of three Specificity Protein (Sp) genes (Sp1-4, Sp5 and Sp6-9) is thought to be ancestral in both chordates and the wider Eumetazoa. Sp5 and Sp6-9 gene groups are associated with embryonic growth zones, such as tailbuds, and are both Wnt/β-catenin signalling pathway members and targets. Currently, there are conflicting reports as to the number and identity of Sp genes in ...
Source: International Journal of Developmental Biology - January 12, 2018 Category: Biology Tags: Int J Dev Biol Source Type: research

CYP26 function is required for the tissue-specific modulation of retinoic acid signaling during amphioxus development.
Authors: Carvalho JE, Lahaye F, Croce JC, Schubert M Abstract During development, morphogens, such as retinoic acid (RA), act as mediators of intercellular communication systems to control patterning and cell fate specification processes. In vertebrates, the tightly regulated production and degradation of RA creates an anterior-posterior (A-P) morphogen gradient that is required for regional patterning of the embryo. RA catabolism in particular, mediated by members of the cytochrome P450 subfamily 26 (CYP26), has been highlighted as a key regulatory component for the formation of this gradient. RA-dependent develop...
Source: International Journal of Developmental Biology - January 12, 2018 Category: Biology Tags: Int J Dev Biol Source Type: research

The origin of dopaminergic systems in chordate brains: insights from amphioxus.
Authors: Zieger E, Lacalli TC, Pestarino M, Schubert M, Candiani S Abstract The basic anatomy of the central nervous system (CNS) is well conserved within the vertebrates and differs in significant ways from that of non-vertebrate chordates. Of the latter, amphioxus is of special interest, being the best available stand-in for the basal chordate condition. Immunohistochemical and gene expression studies on the developing CNS of amphioxus embryos and larvae are now sufficiently advanced that we can begin to assign specific neurotransmitter phenotypes to neurons identified by transmission electron microscopy (TEM), a...
Source: International Journal of Developmental Biology - January 12, 2018 Category: Biology Tags: Int J Dev Biol Source Type: research

The opsin repertoire of the European lancelet: a window into light detection in a basal chordate.
Authors: Pantzartzi CN, Pergner J, Kozmikova I, Kozmik Z Abstract Light detection in animals is predominantly based on the photopigment composed of a protein moiety, the opsin, and the chromophore retinal. Animal opsins originated very early in metazoan evolution from within the G-Protein Coupled Receptor (GPCR) gene superfamily and diversified into several distinct branches prior to the cnidarian-bilaterian split. The origin of opsin diversity, opsin classification and interfamily relationships have been the matter of long-standing debate. Comparative studies of opsins from various Metazoa provide key insight into...
Source: International Journal of Developmental Biology - January 12, 2018 Category: Biology Tags: Int J Dev Biol Source Type: research

Keeping amphioxus in the laboratory: an update on available husbandry methods.
Authors: Carvalho JE, Lahaye F, Schubert M Abstract Cephalochordates, commonly known as amphioxus or lancelets, are small, marine animals that can be found in coastal habitats of temperate, subtropical, and tropical waters. Together with vertebrates and tunicates, the cephalochordates belong to the chordate phylum, whose members are characterized by a number of conserved morphological features, such as a dorsal nerve cord, a notochord, a pharynx, a segmented musculature as well as a post-anal tail. Due to their basal position within the phylum, cephalochordates have become essential models for studying the evolutio...
Source: International Journal of Developmental Biology - January 12, 2018 Category: Biology Tags: Int J Dev Biol Source Type: research

Characterization of an amphioxus heat-shock protein gene promoter and its application in vivo.
Authors: Xing C, Li G, Liu X, Deng X, Wang Y Abstract Amphioxus is a good proxy for studying the evolution and development of mechanisms during the invertebrate to vertebrate transition. However, one of the major limitations of amphioxus as a model organism is the lack of well-developed technical approaches. Promoters of genes encoding heat shock proteins are useful tools for gene function studies. In the present study, we tested heat shock temperatures on 4-cell, 128-cell, late blastula, mid-gastrula and late gastrula amphioxus embryos and optimized the heat shock conditions. We then examined the expression profil...
Source: International Journal of Developmental Biology - January 12, 2018 Category: Biology Tags: Int J Dev Biol Source Type: research

Novel polyclonal antibodies as a useful tool for expression studies in amphioxus embryos.
Authors: Bozzo M, Pergner J, Kozmik Z, Kozmikova I Abstract Cephalochordates, commonly called amphioxus or lancelets, are widely regarded as a useful proxy for the chordate ancestor. In recent decades, expression patterns of important developmental genes have been used extensively to infer homologies between cephalochordate and vertebrate embryos. Such comparisons provided important insight into cephalochordate biology and the origin of vertebrate traits. Most of the developmental expression data are collected using whole-mount in situ hybridization that allows the distributions of specific transcripts to be detect...
Source: International Journal of Developmental Biology - January 12, 2018 Category: Biology Tags: Int J Dev Biol Source Type: research

At the very beginning of life on Earth: the thiol-rich peptide (TRP) world hypothesis.
Authors: Vallee Y, Shalayel I, Ly KD, Rao KVR, De Paëpe G, Märker K, Milet A Abstract Life developed on Earth probably about 3.8 billion years ago, on a planet that was already largely covered by oceans and where the atmosphere was very humid. The reactions, which may have led to the formation of the first polymers, particularly to the first peptides and nucleic acids, must have been compatible with these conditions. This is the case of the reaction of nitriles with aminothiols, such as cysteine and homocysteine. Since aminonitriles are the probable precursors of amino acids, this condensation reaction ha...
Source: International Journal of Developmental Biology - November 16, 2017 Category: Biology Tags: Int J Dev Biol Source Type: research

Beyond the sea: Crepidula atrasolea as a spiralian model system.
Authors: Henry JQ, Lesoway MP, Perry KJ, Osborne CC, Shankland M, Lyons DC Abstract This paper introduces the black-footed slipper snail, Crepidula atrasolea, as a new model for biological studies in the Spiralia. C. atrasolea is a calyptraeid gastropod, and congener of the Atlantic slipper snail, C. fornicata. Like C. fornicata, C. atrasolea shares a sedentary, filter-feeding, protandrous lifestyle, but is preferable as a developmental model because of its short generation time, year-round reproduction, and direct development. In our lab, individuals go from egg to reproductive females in under six months, as comp...
Source: International Journal of Developmental Biology - November 16, 2017 Category: Biology Tags: Int J Dev Biol Source Type: research

Contribution of cranial neural crest cells to mouse skull development.
Authors: Wu T, Chen G, Tian F, Liu HX Abstract The mammalian skull vault is a highly regulated structure that evolutionally protects brain growth during vertebrate development. It consists of several membrane bones with different tissue origins (e.g. neural crest-derived frontal bone and mesoderm-derived parietal bone). Although membrane bones are formed through intramembranous ossification, the neural crest-derived frontal bone has superior capabilities for osteoblast activities and bone regeneration via TGF, BMP, Wnt, and FGF signaling pathways. Neural crest (NC) cells are multipotent, and once induced, will foll...
Source: International Journal of Developmental Biology - November 16, 2017 Category: Biology Tags: Int J Dev Biol Source Type: research

Planar polarity of the extraembryonic epithelia in the preimplantation porcine conceptus.
Authors: Flechon JE Abstract The present review deals with the trophoblast structure during the free intrauterine life of the pig blastocyst. The term trophoblast is used here to describe the association of the first extraembryonic cell layers, the trophectoderm and the primitive endoderm that are polarized epithelia, a fact established by ultrastructural and immunocytochemical data. The aim of this synthesis is to gather the relative works dispersed in the litterature and to explain the implication of the planar polarity of these cell layers on their developmental fate and roles. These epithelia are intricately de...
Source: International Journal of Developmental Biology - November 16, 2017 Category: Biology Tags: Int J Dev Biol Source Type: research

Planaria: an animal model that integrates development, regeneration and pharmacology.
Authors: Pagán OR Abstract Although planarians are established model organisms in developmental biology and regeneration studies, in the last forty years or so, they have caught the attention of pharmacologists, especially to study the pharmacology of drugs of abuse. This review covers the following topics: some fundamentals of the history of animal models and planarians in biomedical research; an abbreviated story of systematic pharmacology research using planarians as a model organism; an example of how planarians are contributing to the search for compounds against acute cocaine toxicity; an analysis of t...
Source: International Journal of Developmental Biology - November 16, 2017 Category: Biology Tags: Int J Dev Biol Source Type: research

Limitations of the Pax7-creER(T2) transgene for driving deletion of Nf1 in adult mouse muscle.
In this study, we present the characterization of an inducible muscle-specific NF1 knockout strain (Nf1Pax7i f/f ) produced by cross breeding the Pax7-CreER(T2) strain with the conditional Nf1flox/(flox) line. Tamoxifen dosing of 8-week old Nf1Pax7i f/f mice led to recombination of the floxed allele in muscle, as detected by PCR. Detailed phenotypic analysis of treated adult mice over 8 weeks revealed no changes in bodyweight or muscle weight, no histological signs of myopathy, and no functional evidence of distress or impairment. Subsequent analysis using the Ai9 Cre-dependent tdTomato reporter strain was used to analyse ...
Source: International Journal of Developmental Biology - November 16, 2017 Category: Biology Tags: Int J Dev Biol Source Type: research

An empirical model of Onecut binding activity at the sea urchin SM50 C-element gene regulatory region.
In this study, preliminary evidence from biochemical studies towards understanding the role of the Onecut transcription factor during sea urchin skeletogenic mesenchyme cell specification is presented. Based on the evidence, an empirical model is proposed showing how Onecut, together with associated co-factors, may be using the C-element of the SM50 gene regulatory region in advance of the sea urchin Strongylocentrotus purpuratus spicule development. In the model, Onecut recognizes and binds the DNA sequence CATCGATCTC in the C-element without temporal restriction. Onecut then utilizes different sets of co-factors to switc...
Source: International Journal of Developmental Biology - November 16, 2017 Category: Biology Tags: Int J Dev Biol Source Type: research

Neurosphere formation potential resides not in the caudal cell mass, but in the secondary neural tube.
This study showed that neurospheres can be cultured from CCM + 2NT, and the main player in neurosphere formation was the 2NT. The present study has also revealed cephalo-caudal trend in the neural potential of developing CNS. PMID: 29139540 [PubMed - in process] (Source: International Journal of Developmental Biology)
Source: International Journal of Developmental Biology - November 16, 2017 Category: Biology Tags: Int J Dev Biol Source Type: research

Characterization of the Autophagy related gene-8a (Atg8a) promoter in Drosophila melanogaster.
Authors: Bali A, Shravage BV Abstract Autophagy is an evolutionarily conserved process which is upregulated under various stress conditions, including nutrient stress and oxidative stress. Amongst autophagy related genes (Atgs), Atg8a (LC3 in mammals) is induced several-fold during nutrient limitation in Drosophila. The minimal Atg8a cis-regulatory module (CRM) which mediates transcriptional upregulation under various stress conditions is not known. Here, we describe the generation and analyses of a series of Atg8a promoter deletions which drive the expression of an mCherry-Atg8a fusion cassette. Expression studies...
Source: International Journal of Developmental Biology - November 16, 2017 Category: Biology Tags: Int J Dev Biol Source Type: research

Temporal and spatial expression patterns of Hedgehog receptors in the developing inner and middle ear.
In this study, we examined the expression patterns of Gas1, Cdon, and Boc, as well as that of Ptch1, in the developing mouse inner ear from otocyst (embryonic day (E) 9.5) until birth and in the developing middle ear at E15.5. Ptch1, a readout of Hh signaling, was expressed in a graded pattern in response to Shh signaling throughout development. Expression patterns of Gas1, Cdon, and Boc differed from that of Ptch1, and each Hh co-receptor was expressed in specific cells and domains in the developing inner and middle ear. These unique and differential expression patterns of Hh co-receptors suggest their roles in mediating ...
Source: International Journal of Developmental Biology - November 16, 2017 Category: Biology Tags: Int J Dev Biol Source Type: research

Molecular cloning and expression analysis of Sox3 during gonad and embryonic development in Misgurnus anguillicaudatus.
In this study, a Sox3 homologue, termed MaSox3, was cloned from the brain of M. anguillicaudatus using homology-based cloning and the rapid amplification of cDNA ends method. Sequence analysis reveals that MaSox3 encodes a hydrophilic protein, which contains a characteristic HMG-box DNA-binding domain of 79 amino acids, and shares high homology with Sox3 in other species. Additionally, quantitative real-time reverse transcription PCR and in situ hybridization showed that MaSox3 is consistently expressed during embryogenesis, with peak expression during the neurula stage and broad expression in the central nervous system. M...
Source: International Journal of Developmental Biology - November 16, 2017 Category: Biology Tags: Int J Dev Biol Source Type: research

States of G0 and the proliferation-quiescence decision in cells, tissues and during development.
Authors: Sun D, Buttitta L Abstract While cellular proliferation is fundamental to the development of all multicellular organisms, the slowing or stopping of proliferation at the right places and times is equally important for proper tissue and organ development. The non-cycling state of cellular quiescence or "G0" is relatively understudied compared to proliferation, given its prevalence in nature. It may seem that actively proliferating cells undergo a series of dynamic events, while quiescent cells are in a passive, static state. However, studies over the last 10-15 years suggest that quiescence may be...
Source: International Journal of Developmental Biology - July 12, 2017 Category: Biology Tags: Int J Dev Biol Source Type: research

Regulation of body size in Caenorhabditis elegans: effects of environmental factors and the nervous system.
Authors: Nagashima T, Ishiura S, Suo S Abstract Body size is one of the basic traits of animals and is regulated to adapt to the environment. Animals perceive environmental stimuli with sensory neurons, and signals from the nervous system alter the size of organs, thus regulating body size. The model animal Caenorhabditis elegans is particularly suited for genetic analysis of body size regulation, and has already contributed to the elucidation of various genetic pathways that regulate body size. In this review, we summarize the available literature regarding environmental factors that regulate body size and the rol...
Source: International Journal of Developmental Biology - July 12, 2017 Category: Biology Tags: Int J Dev Biol Source Type: research

Interactions among gibberellins, brassinosteroids and genes regulate stomatal development in the Arabidopsis hypocotyl.
Authors: González D, Fuentes S, Serna L Abstract Stomata are pores on the plant surface that enable gas exchange with the atmosphere. In Arabidopsis thaliana, brassinosteroids, which function upstream of the TTG/bHLHs/MYBs/GL2 transcriptional network, positively regulate stomatal formation in the hypocotyl. Gibberellins also promote stomatal development in the embryonic stem. Here, we investigated the hypothetical interactions between the gibberellin and brassinosteroid signaling pathways during stomatal formation. By combining genetics and gene expression studies, we found that gibberellins promote stomatal...
Source: International Journal of Developmental Biology - July 12, 2017 Category: Biology Tags: Int J Dev Biol Source Type: research

Identification and characterization of the autophagy-related genes Atg12 and Atg5 in hydra.
This study may provide a framework to understand the evolution of autophagy networks in higher eukaryotes. PMID: 28695958 [PubMed - in process] (Source: International Journal of Developmental Biology)
Source: International Journal of Developmental Biology - July 12, 2017 Category: Biology Tags: Int J Dev Biol Source Type: research

Migration behavior of PGCs and asymmetrical gonad formation in pond smelt Hypomesus nipponensis.
Authors: Takahashi E, Shimizu Y, Urushibata H, Kawakami Y, Arai K, Yamaha E Abstract In teleost fish, the gonad originates from primordial germ cells (PGCs) and somatic cells. However, it is not clear whether the final gonadal position is determined by anteroposterior and dextrosinistral differentiation of endodermal organs or by the distribution of PGCs. The pond smelt has a transparent body even after hatching, enabling clear observation of PGC distribution and endodermal differentiation. Here, we first examined normal embryonic development to define the spatio-temporal characteristics of our developmental model....
Source: International Journal of Developmental Biology - July 12, 2017 Category: Biology Tags: Int J Dev Biol Source Type: research

Galectin-1 enhances the generation of neural crest cells.
Authors: Motohashi T, Nishioka M, Kitagawa D, Kawamura N, Watanabe N, Wakaoka T, Kadoya T, Kunisada T Abstract Neural crest (NC) cells are multipotent cells that emerge from the dorsal region of the neural tube. After delaminating from the neural tube, NC cells migrate throughout the developing embryo and differentiate into various cells: neurons and glial cells of the peripheral nervous system, melanocytes of skin, and skeletal elements of the face and head. We previously analyzed the gene expression profile of a NC subpopulation isolated from Sox10-IRES-Venus mice and found that the carbohydrate-binding protein, ...
Source: International Journal of Developmental Biology - July 12, 2017 Category: Biology Tags: Int J Dev Biol Source Type: research

Apolipoprotein C-I mediates Wnt/Ctnnb1 signaling during neural border formation and is required for neural crest development.
Authors: Yokota C, Åstrand C, Takahashi S, Hagey DW, Stenman JM Abstract In vertebrates, the neural crest and placodes originate in the neural border, which is located between the neural plate and epidermal ectoderm. The neural crest and placodes give rise to a vast array of cell types. Formation of neural crest is a multi-step process, in which Wnt signals are used reiteratively, but it is currently not clear if a Wnt signal is required for neural border formation. Here, we have identified apolipoprotein C-I (apoc1) in a screen for genes regulated by Wnt/Ctnnb1 signaling in late blastula stage Xenopus tropic...
Source: International Journal of Developmental Biology - July 12, 2017 Category: Biology Tags: Int J Dev Biol Source Type: research

Gdf11/Smad signalling and Cdx proteins cooperate to activate the Hoxc8 early enhancer in HepG2 cells.
Authors: Gaunt SJ Abstract Developing anatomy along the head-tail axis of bilaterian embryos is specified, to a large extent, by the overlapping patterns of expression of the Hox genes. Hox gene enhancers respond to a variety of signals in order to regulate these discreet domains of expression. For mouse Hoxc8, the 399bp "early enhancer" plays a major role. Activation of this enhancer is now examined using luciferase expression constructs transfected into HepG2 cells. Constructs are activated by the combined actions of Gdf11/Smad and Cdx protein signalling pathways, both of which are functional in early e...
Source: International Journal of Developmental Biology - July 12, 2017 Category: Biology Tags: Int J Dev Biol Source Type: research

Differential regulation of cumulus cell transcription during oocyte maturation in vivo and in vitro.
This study confirms and extends previous data on gene expression dysregulation during IVM and indicates that the size of follicles from which immature oocytes are retrieved can be an independent factor of differential transcriptional regulation. PMID: 28695963 [PubMed - in process] (Source: International Journal of Developmental Biology)
Source: International Journal of Developmental Biology - July 12, 2017 Category: Biology Tags: Int J Dev Biol Source Type: research

Segmentation gene expression patterns in Bactrocera dorsalis and related insects: regulation and shape of blastoderm and larval cuticle.
Authors: Suksuwan W, Cai X, Ngernsiri L, Baumgartner S Abstract The oriental fruit fly, Bactrocera dorsalis, is regarded as a severe pest of fruit production in Asia. Despite its economic importance, only limited information regarding the molecular and developmental biology of this insect is known to date. We provide a detailed analysis of B. dorsalis embryology, as well as the expression patterns of a number of segmentation genes known to act during patterning of Drosophila and compare these to the patterns of other insect families. An anterior shift of the expression of gap genes was detected when compared to Dro...
Source: International Journal of Developmental Biology - July 12, 2017 Category: Biology Tags: Int J Dev Biol Source Type: research

Role of Mad2 expression during the early development of the sea urchin.
Authors: Bronchain O, Jdey W, Caraty L, Ciapa B Abstract Mitotic arrest deficient 2 (Mad2) belongs to the spindle assembly checkpoint (SAC), a mechanism that blocks progression of the cell cycle until microtubule attachment to kinetochores is complete. It has been found to be involved in the resistance of cancer cells to "anti-mitotic" drugs such as paclitaxel. Mad2 controls meiotic progression, but its role during sea urchin development had never been investigated. Furthermore, the existence of a SAC in this species had never been proved. The present data show that a Mad2 protein, highly homologous to th...
Source: International Journal of Developmental Biology - July 12, 2017 Category: Biology Tags: Int J Dev Biol Source Type: research

DYRK2 displays muscle fiber type specific function during zebrafish early somitogenesis.
Authors: Sun W, Jiao S, Tan X, Zhang P, You F Abstract Dual specificity tyrosine-phosphorylation regulated kinase 2 (DYRK2) is a serine/threonine kinase. In zebrafish, DYRK2 is expressed in the lateral somites and adaxial cells at the early stage of embryo development. However, its role in early myogenesis had not been elucidated yet. Here, we report that DYRK2 mRNA and MyoD mRNA were colocalized in the muscle progenitor cells in somites, including both the posterior compartment of the lateral somites and adaxial cells. Knockdown of DYRK2 reduced the levels of MyoD transcripts in the muscle progenitor cells in somi...
Source: International Journal of Developmental Biology - July 12, 2017 Category: Biology Tags: Int J Dev Biol Source Type: research

Expression of the ALK1 family of type I BMP/ADMP receptors during gastrula stages in Xenopus embryos.
Authors: Leibovich A, Steinbeißer H, Fainsod A Abstract Multiple members of the transforming growth factor beta (TGFβ) family of secreted factors play central inductive and patterning roles during embryogenesis. During gastrulation in vertebrates, the bone morphogenetic protein (BMP) sub-family is linked to formation of the embryonic organizer, Spemann's organizer in Xenopus, and dorsal-ventral mesoderm patterning. Our knowledge regarding the BMP receptors mediating this signaling is still very incomplete. The BMPR1A (ALK3) and BMPR1B (ALK6) receptors are known to mediate the BMP4 signal. These receptors...
Source: International Journal of Developmental Biology - July 12, 2017 Category: Biology Tags: Int J Dev Biol Source Type: research

A "Brief History" of Developmental Biology in Israel.
A "Brief History" of Developmental Biology in Israel. Int J Dev Biol. 2017;61(3-4-5):115-120 Authors: Sela-Donenfeld D, Frank D Abstract While the history of developmental biology in Israel is relatively short, its impact is far-reaching, so we wanted to present a concise perspective on the Israeli developmental biology community, past-present-future. This community has undergone a wonderful, nearly exponential growth over the last three decades. How exactly did this happen? There are approximately fifty research groups that focus on developmental biology questions in Israel today that are me...
Source: International Journal of Developmental Biology - June 19, 2017 Category: Biology Tags: Int J Dev Biol Source Type: research

Hefzibah Eyal-Giladi (1925-2017): over fifty years of embryological research in Israel.
Authors: Khaner O Abstract Hefzibah Eyal-Giladi was a creative and innovative pioneering scientist in the creation of the field of early chick embryo development. She had a sharp thinking and enthusiastic attitude, which enabled her to make a deep impression that was highly valued by the general scientific community. Notably, she was a highly successful female researcher in an era which was dominated by male scientists. Her unique personality and keen intellect enabled her to break these borders in a most successful manner. The experiments conducted by her personally, her students and her collaborators served to pr...
Source: International Journal of Developmental Biology - June 19, 2017 Category: Biology Tags: Int J Dev Biol Source Type: research

The Leo Sachs' legacy: a pioneer's journey through hematopoiesis.
Authors: Lotem J, Groner Y Abstract Leo Sachs spent almost his entire scientific career in Israel, at the Weizmann Institute of Science, and became a worldwide renowned scientist for his pioneering studies in normal hematopoiesis, its breakdown in leukemia and the suppression of malignancy by inducing differentiation, thereby bypassing genetic defects that give rise to malignancy. The cell culture system he established in the early 1960s for the clonal development of normal hematopoietic cells, made it possible to discover the proteins that regulate the viability, proliferation and differentiation of different bloo...
Source: International Journal of Developmental Biology - June 19, 2017 Category: Biology Tags: Int J Dev Biol Source Type: research

Annotating the genome by DNA methylation.
Authors: Cedar H, Razin A Abstract DNA methylation plays a prominent role in setting up and stabilizing the molecular design of gene regulation and by understanding this process one gains profound insight into the underlying biology of mammals. In this article, we trace the discoveries that provided the foundations of this field, starting with the mapping of methyl groups in the genome and the experiments that helped clarify how methylation patterns are maintained through cell division. We then address the basic relationship between methyl groups and gene repression, as well as the molecular rules involved in contr...
Source: International Journal of Developmental Biology - June 19, 2017 Category: Biology Tags: Int J Dev Biol Source Type: research

The not-so-long history of zebrafish research in Israel.
Authors: Blechman J, Levkowitz G, Gothilf Y Abstract The zebrafish has become a model of choice in fundamental and applied life sciences and is widely used in various fields of biomedical research as a human disease model for cancer, metabolic and neurodegenerative diseases, and regenerative medicine. The transparency of the zebrafish embryo allows real-time visualization of the development and morphogenesis of practically all of its tissues and organs. Zebrafish are amenable to genetic manipulation, for which innovative genetic and molecular techniques are constantly being introduced. These include the study of ge...
Source: International Journal of Developmental Biology - June 19, 2017 Category: Biology Tags: Int J Dev Biol Source Type: research