ALBERT

Description:    Daphnids are small crustaceans ubiquitous in fresh water; they have been a subject of study in ecology, evolution, and environmental sciences for decades. To understand data accumulated in daphnid biology at the molecular level, expressed sequence tags and a genome sequence have been determined. However, these discoveries lead to the problem of how to understand the functions of newly discovered genes. Double-stranded RNA (dsRNA)-mediated RNA interference (RNAi) is a useful tool to achieve specific gene silencing in nontransformable species. Hence, we established a technique to inject exogenous materials into ovulated eggs and developed a dsRNA-based RNAi method for Daphnia magna . Eggs were collected just after ovulation and injected with dsRNA specific to the Distal-less ( Dll ) gene, which functions in appendage development in invertebrates and vertebrates. We found that the dsRNA successfully triggered the degradation of Dll mRNAs, which induced the truncation of the second antenna in a dose-dependent manner. This effect was sequence specific in that: (1) an unrelated dsRNA did not induce any morphological abnormalities and (2) two non-overlapping Dll dsRNAs generated the same phenotype. This is the first report of an RNAi technique in D. magna and, together with the emerging genome sequences, will be useful for advancing knowledge of the molecular biology of daphnids. Content Type Journal Article Category Original Article Pages 337-345 DOI 10.1007/s00427-011-0353-9 Authors Yasuhiko Kato, Okazaki Institute for Integrative Bioscience, National Institute for Basic Biology, National Institutes of Natural Sciences, 5-1 Higashiyama, Myodaiji, Okazaki, Aichi 444-8787, Japan Yasuhiro Shiga, School of Life Sciences, Tokyo University of Pharmacy and Life Sciences, 1432-1, Horinouchi, Hachioji, Tokyo 192-0392, Japan Kaoru Kobayashi, Okazaki Institute for Integrative Bioscience, National Institute for Basic Biology, National Institutes of Natural Sciences, 5-1 Higashiyama, Myodaiji, Okazaki, Aichi 444-8787, Japan Shin-ichi Tokishita, School of Life Sciences, Tokyo University of Pharmacy and Life Sciences, 1432-1, Horinouchi, Hachioji, Tokyo 192-0392, Japan Hideo Yamagata, School of Life Sciences, Tokyo University of Pharmacy and Life Sciences, 1432-1, Horinouchi, Hachioji, Tokyo 192-0392, Japan Taisen Iguchi, Okazaki Institute for Integrative Bioscience, National Institute for Basic Biology, National Institutes of Natural Sciences, 5-1 Higashiyama, Myodaiji, Okazaki, Aichi 444-8787, Japan Hajime Watanabe, Okazaki Institute for Integrative Bioscience, National Institute for Basic Biology, National Institutes of Natural Sciences, 5-1 Higashiyama, Myodaiji, Okazaki, Aichi 444-8787, Japan Journal Development Genes and Evolution Online ISSN 1432-041X Print ISSN 0949-944X Journal Volume Volume 220 Journal Issue Volume 220, Numbers 11-12

Description:    Fibroblast growth factor receptors (FGFR) are highly conserved receptor tyrosine kinases, and evolved early in metazoan evolution. In order to investigate their functional conservation, we asked whether the Kringelchen FGFR in the freshwater polyp Hydra vulgaris , is able to functionally replace FGFR in fly embryos. In Drosophila , two endogenous FGFR, Breathless (Btl) and Heartless (Htl), ensure formation of the tracheal system and mesodermal cell migration as well as formation of the heart. Using UAS-kringelchen-5xmyc transgenic flies and targeted expression, we show that Kringelchen is integrated correctly into the cell membrane of mesodermal and tracheal cells in Drosophila . Nevertheless, Kringelchen expression driven in tracheal cells failed to rescue the btl LG19 mutant. The Hydra FGFR was able to substitute for Heartless in the htl AB42 null mutant; however, this occurred only during early mesodermal cell migration. Our data provide evidence for functional conservation of this early-diverged FGFR across these distantly related phyla, but also selectivity for the Htl FGFR in the Drosophila system. Content Type Journal Article Category Original Article Pages 1-11 DOI 10.1007/s00427-012-0424-6 Authors Anja Rudolf, Faculty of Biology, Morphology and Evolution of Invertebrates, Philipps-Universität Marburg, Karl-von-Frisch-Str. 8, 35032 Marburg, Germany Christine Hübinger, Faculty of Biology, Morphology and Evolution of Invertebrates, Philipps-Universität Marburg, Karl-von-Frisch-Str. 8, 35032 Marburg, Germany Katrin Hüsken, Faculty of Biology, Morphology and Evolution of Invertebrates, Philipps-Universität Marburg, Karl-von-Frisch-Str. 8, 35032 Marburg, Germany Angelika Vogt, Faculty of Biology, Morphology and Evolution of Invertebrates, Philipps-Universität Marburg, Karl-von-Frisch-Str. 8, 35032 Marburg, Germany Nicole Rebscher, Faculty of Biology, Morphology and Evolution of Invertebrates, Philipps-Universität Marburg, Karl-von-Frisch-Str. 8, 35032 Marburg, Germany Susanne-Filiz Önel, Developmental Biology, Philipps-Universität Marburg, Karl-von-Frisch-Str. 8, 35032 Marburg, Germany Renate Renkawitz-Pohl, Developmental Biology, Philipps-Universität Marburg, Karl-von-Frisch-Str. 8, 35032 Marburg, Germany Monika Hassel, Faculty of Biology, Morphology and Evolution of Invertebrates, Philipps-Universität Marburg, Karl-von-Frisch-Str. 8, 35032 Marburg, Germany Journal Development Genes and Evolution Online ISSN 1432-041X Print ISSN 0949-944X

Description:    Early coelomic development in the abbreviated development of the sea urchin Holopneustes purpurescens is described and then used in a comparison with coelomic development in chordate embryos to support homology between a single arm of the five-armed radial body plan of an echinoderm and the single bilateral axis of a chordate. The homology depends on a positional similarity between the origin of the hydrocoele in echinoderm development and the origin of the notochord in chordate development, and a positional similarity between the respective origins of the coelomic mesoderm and chordate mesoderm in echinoderm and chordate development. The hydrocoele is homologous with the notochord and the secondary podia are homologous with the somites. The homology between a single echinoderm arm and the chordate axis becomes clear when the aboral to oral growth from the archenteron in the echinoderm larva is turned anteriorly, more in line with the anterior–posterior axis of the early zygote. A dorsoventral axis inversion in chordates is not required in the proposed homology. Content Type Journal Article Category Original Article Pages 1-11 DOI 10.1007/s00427-012-0415-7 Authors Valerie B. Morris, School of Biological Sciences A12, University of Sydney, NSW, 2006 Australia Journal Development Genes and Evolution Online ISSN 1432-041X Print ISSN 0949-944X

Description:    Recent advances in both next-generation sequencing and assembly programmes have made the low-cost construction of transcriptome datasets for non-model species feasible, capable of yielding a raft of information even from less well-transcribed genes. Here we present the results of assemblies performed on a 51-bp paired end Illumina dataset derived from a mixed larval sample of the annelid Pomatoceros lamarckii at 24, 48 and 72 h post-fertilization. We used Oases to assemble 36.5 million paired end reads with k -mer sizes from 21 to 29, followed by amalgamation of assemblies, redundancy removal with Vmatch and TGICL and removal of contigs less than 500 bp in length. This resulted in a final assembly of 50,151 contigs, with a mean length of 1,221 bp and covering 61.3 Mbp. A total of 34,846 (69.4 %) of these returned a BlastX hit above a cutoff of 1.0 e −3 , and 17,967 (35.8 %) were assigned at least one GO annotation using Blast2GO. We used the assembly to identify genes belonging to the homeobox superclass and the Fox, Sox and Tbx classes, recovering 37, 16, four and three genes, respectively. This included orthologues of genes previously unidentified in lophotrochozoans and protostomes. Our study illustrates the utility of such transcriptomic assembly methods as a gene discovery tool and greatly expands our knowledge of transcription factor genes in annelids in general and in this species in particular. Content Type Journal Article Category Original Article Pages 1-15 DOI 10.1007/s00427-012-0416-6 Authors Nathan J Kenny, Department of Zoology, University of Oxford, Tinbergen Building, South Parks Road, OX1 3PS Oxford, UK Sebastian M Shimeld, Department of Zoology, University of Oxford, Tinbergen Building, South Parks Road, OX1 3PS Oxford, UK Journal Development Genes and Evolution Online ISSN 1432-041X Print ISSN 0949-944X

Description:    Arthropods show two kinds of developmental mode. In the so-called long germ developmental mode (as exemplified by the fly Drosophila ), all segments are formed almost simultaneously from a preexisting field of cells. In contrast, in the so-called short germ developmental mode (as exemplified by the vast majority of arthropods), only the anterior segments are patterned similarly as in Drosophila , and posterior segments are added in a single or double segmental periodicity from a posterior segment addition zone (SAZ). The addition of segments from the SAZ is controlled by dynamic waves of gene activity. Recent studies on a spider have revealed that a similar dynamic process, involving expression of the segment polarity gene (SPG) hedgehog ( hh ), is involved in the formation of the anterior head segments. The present study shows that in the myriapod Glomeris marginata the early expression of hh is also in a broad anterior domain, but this domain corresponds only to the ocular and antennal segment. It does not, like in spiders, represent expression in the posterior adjacent segment. In contrast, the anterior hh pattern is conserved in Glomeris and insects. All investigated myriapod SPGs and associated factors are expressed with delay in the premandibular (tritocerebral) segment. This delay is exclusively found in insects and myriapods, but not in chelicerates, crustaceans and onychophorans. Therefore, it may represent a synapomorphy uniting insects and myriapods (Atelocerata hypothesis), contradicting the leading opinion that suggests a sister relationship of crustaceans and insects (Pancrustacea hypothesis). In Glomeris embryos, the SPG engrailed is first expressed in the mandibular segment. This feature is conserved in representatives of all arthropod classes suggesting that the mandibular segment may have a special function in anterior patterning. Content Type Journal Article Category Original Article Pages 1-11 DOI 10.1007/s00427-012-0413-9 Authors Ralf Janssen, Department of Earth Sciences, Uppsala University, Palaeobiology, Villavägen 16, 75236 Uppsala, Sweden Journal Development Genes and Evolution Online ISSN 1432-041X Print ISSN 0949-944X

Description:    Insect gene function has mainly been studied in the fruit fly Drosophila melanogaster because in this species many techniques and resources are available for gene knock down and the ectopic activation of gene function. However, in order to study biological aspects that are not represented by the Drosophila model, and in order to test to what degree gene functions are conserved within insects and what changes in gene function accompanied the evolution of novel traits, the establishment of respective tools in other insect species is required. While gene knock down can be induced by RNA interference in many insects, methods to misexpress genes are much less developed. In order to allow misexpression of genes in a timely controlled manner in the red flour beetle Tribolium castaneum , we have established a heat shock-mediated misexpression system. We show that endogenous heat shock elements perform better than artificial heat shock elements derived from vertebrates. We carefully determine the optimal conditions for heat shock and define a core promoter for use in future constructs. Finally, using this system, we study the effects of misexpressing the head patterning gene Tc-orthodenticle1 ( Tc-otd1 ), We show that Tc-otd1 suppresses Tc-wingless ( Tc-wg ) in the trunk and to some degree in the head. Content Type Journal Article Category Original Article Pages 1-12 DOI 10.1007/s00427-012-0412-x Authors Johannes Benno Schinko, Institute of Molecular Biology and Biotechnology, Nik. Plastira 100, 71110 Heraklion, Crete, Greece Kathrin Hillebrand, Johann-Friedrich-Blumenbach Institute, Department of Developmental Biology, Georg-August-University Göttingen, Justus-von-Liebig-Weg 11, 37077 Göttingen, Germany Gregor Bucher, Johann-Friedrich-Blumenbach Institute, Department of Developmental Biology, Georg-August-University Göttingen, Justus-von-Liebig-Weg 11, 37077 Göttingen, Germany Journal Development Genes and Evolution Online ISSN 1432-041X Print ISSN 0949-944X

Description:    Cephalization and seamless fusion of the anterior body segments during development obscure the segmental boundaries of the insect head. Most of the visible seams are thought to reflect cuticular infolding for structural reinforcement rather than a merger of cuticular plate borders. Incomplete fusions and other modifications of the adult head found in eight Tribolium mutations indicate that the frontal and gular sutures likely are true sutures that mark borders between adjacent cuticular plates, and suggest that the anterior facial shelf is a composite of three independent cuticular surfaces: ocular, antennal, and clypeo-labral. Additionally, midline splits of the clypeo-labrum and gula, and membranous lesions on the lateral head capsule reveal probable borders of adjacent cuticular plates where visible sutures are normally absent. The anterior lateral lesions seen in the Lucifer mutation mark a border between ocular and antennal plates and appear to identify part of the postfrontal sutures. While revealing or clarifying possible intersegmental borders between ocular, antennal, and clypeo-labral plates, the various modified or unfused surfaces of the head neither reveal an additional acronal plate nor support the view that the clypeo-labrum is segmentally associated with ocular cuticle. Content Type Journal Article Category Original Article Pages 1-13 DOI 10.1007/s00427-012-0397-5 Authors Merrilee Susan Haas, Agricultural Research Service, Center for Grain and Animal Health Research, USDA-ARS-CGAHR, 1515 College Avenue, Manhattan, KS 66502, USA Richard W. Beeman, Agricultural Research Service, Center for Grain and Animal Health Research, USDA-ARS-CGAHR, 1515 College Avenue, Manhattan, KS 66502, USA Journal Development Genes and Evolution Online ISSN 1432-041X Print ISSN 0949-944X

Description:    In the present study, we found that different ecdysone-responsive transcription factors were expressed differentially in different regions of the epidermis at around pupation. βFTZ-F1 transcripts were strongly but E74A transcripts were barely observed in the thoracic region of the epidermis, and vice versa in the abdominal region. Transcripts of all the examined transcription factors were observed in wing disc. Transcript of a cuticular protein gene, BMWCP4 , which does not have a βFTZ-F1 binding site in the 2-kb upstream region, was not observed in the thoracic region of the epidermis. Transcript of BMWCP9 , which does not have an E74 binding site in the 2-kb upstream region, was not observed in the abdominal region of the epidermis. BMWCP2 has all the transcription factor binding sites examined and was expressed in the thoracic and abdominal region of the epidermis. Thus, it is suggested that ecdysone-responsive transcription factors determined the space where the cuticular protein genes were expressed, which, in turn, determined the character of the cuticle that was characterized by the combination of cuticular proteins. Content Type Journal Article Category Original Article Pages 1-9 DOI 10.1007/s00427-012-0392-x Authors Md. Saheb Ali, Faculty of Agriculture, Utsunomiya University, 350 Mine, Utsunomiya, Tochigi 321-8505, Japan Masashi Iwanaga, Faculty of Agriculture, Utsunomiya University, 350 Mine, Utsunomiya, Tochigi 321-8505, Japan Hideki Kawasaki, Faculty of Agriculture, Utsunomiya University, 350 Mine, Utsunomiya, Tochigi 321-8505, Japan Journal Development Genes and Evolution Online ISSN 1432-041X Print ISSN 0949-944X

Description:    The central complex of the grasshopper ( Schistocerca gregaria ) brain comprises a modular set of neuropils, which develops after mid-embryogenesis and is functional on hatching. Early in embryogenesis, Repo-positive glia cells are found intermingled among the commissures of the midbrain, but then redistribute as central complex modules become established and, by the end of embryogenesis, envelop all midbrain neuropils. The predominant glia associated with the central body during embryogenesis are glutamine synthetase-/Repo-positive astrocyte-like glia, which direct extensive processes (gliopodia) into and around midbrain neuropils. We used intracellular dye injection in brain slices to ascertain whether such glia are dye-coupled into a communicating cellular network during embryogenesis. Intracellular staining of individual cells located at any one of four sites around the central body revealed a population of dye-coupled cells whose number and spatial distribution were stereotypic for each site and comparable at both 70 and 100 % of embryogenesis. Subsequent immunolabeling confirmed these dye-coupled cells to be astrocyte-like glia. The addition of n -heptanol to the bathing saline prevented all dye coupling, consistent with gap junctions linking the glia surrounding the central body. Since dye coupling also occurred in the absence of direct intersomal contacts, it might additionally involve the extensive array of gliopodia, which develop after glia are arrayed around the central body. Collating the data from all injection sites suggests that the developing central body is surrounded by a network of dye-coupled glia, which we speculate may function as a positioning system for the developing neuropils of the central complex. Content Type Journal Article Category Original Article Pages 1-14 DOI 10.1007/s00427-012-0394-8 Authors George S. Boyan, Developmental Neurobiology Group, Biocenter, Ludwig-Maximilians-Universität, Grosshadernerstrasse 2, 82152 Martinsried, Germany Yu Liu, Developmental Neurobiology Group, Biocenter, Ludwig-Maximilians-Universität, Grosshadernerstrasse 2, 82152 Martinsried, Germany Michael Loser, Developmental Neurobiology Group, Biocenter, Ludwig-Maximilians-Universität, Grosshadernerstrasse 2, 82152 Martinsried, Germany Journal Development Genes and Evolution Online ISSN 1432-041X Print ISSN 0949-944X

Description:    The transcriptional repressor snail was first discovered in Drosophila melanogaster , where it initially plays a role in gastrulation and mesoderm formation, and later plays a role in neurogenesis. Among arthropods, this role of snail appears to be conserved in the insects Tribolium and Anopheles gambiae , but not in the chelicerates Cupiennius salei and Achaearanea tepidariorum , the myriapod Glomeris marginata , or the Branchiopod crustacean Daphnia magna . These data imply that within arthropoda, snail acquired its role in gastrulation and mesoderm formation in the insect lineage. However, crustaceans are a diverse group with several major taxa, making analysis of more crustaceans necessary to potentially understand the ancestral role of snail in Pancrustacea (crustaceans + insects) and thus in the ancestor of insects as well. To address these questions, we examined the snail family in the Malacostracan crustacean Parhyale hawaiensis . We found three snail homologs, Ph-snail1 , Ph-snail2 and Ph-snail3 , and one scratch homolog, Ph-scratch . Parhyale snail genes are expressed after gastrulation, during germband formation and elongation. Ph-snail1 , Ph-snail2 , and Ph-snail3 are expressed in distinct patterns in the neuroectoderm. Ph-snail1 is the only Parhyale snail gene expressed in the mesoderm, where its expression cycles in the mesodermal stem cells, called mesoteloblasts. The mesoteloblasts go through a series of cycles, where each cycle is composed of a migration phase and a division phase. Ph-snail1 is expressed during the migration phase, but not during the division phase. We found that as each mesoteloblast division produces one segment’s worth of mesoderm, Ph-snail1 expression is linked to both the cell cycle and the segmental production of mesoderm. Content Type Journal Article Category Original Article Pages 1-13 DOI 10.1007/s00427-012-0396-6 Authors Roberta L. Hannibal, Department of Molecular and Cell Biology, University of California, 519A LSA #3200, Berkeley, CA 94720-3200, USA Alivia L. Price, Department of Molecular and Cell Biology, University of California, 519A LSA #3200, Berkeley, CA 94720-3200, USA Ronald J. Parchem, Department of Molecular and Cell Biology, University of California, 519A LSA #3200, Berkeley, CA 94720-3200, USA Nipam H. Patel, Department of Molecular and Cell Biology, University of California, 519A LSA #3200, Berkeley, CA 94720-3200, USA Journal Development Genes and Evolution Online ISSN 1432-041X Print ISSN 0949-944X