Організаційно-педагогічні умови підготовки майбутнього педагога-музиканта в системі неперервної освіти

У статті досліджуються організаційно-педагогічні умови підготовки майбутнього педагога-музиканта в системі неперервної освіти.В статье исследуются организационно-педагогические условия подготовки будущего педагога-музыканта в системе непрерывного образования

Editorial: Evolution of Postembryonic Development

info:eu-repo/semantics/publishedVersio

Function and Evolution of highly conserved head genes in the red flour beetle Tribolium castaneum

Die anterior-posterior Achse von bilateral symmetrischen Organismen (Bilateria) ist unterteilt in eine posteriore Region, die durch die Expression der hoch konservierten HOX-Cluster Gene gekennzeichnet ist und eine anteriore Region, die frei von deren Expression ist. Dennoch sind einige hoch konservierte Gene in der anterioren Region von Vertebraten und Insekten exprimiert und an der Musterung dieser Region beteiligt. Diese Beobachtung lässt vermuten, dass grundlegende Prinzipien der Kopfentwicklung innerhalb der Bilateria konserviert sind. Bisher fehlt jedoch ein ausführlicher Vergleich von Genen, die an der anterioren Musterung von Vertebraten und Insekten beteiligt sind.Um mehr Kandidatengene des hoch konservierten Grundnetzwerkes der anterioren Musterung zu identifizieren, habe ich systematisch die Expression und Funktion der Orthologen von Neuralplattengenen aus Vertebraten im Reismehlkäfer Tribolium castaneum analysiert. Basierend auf diesen Daten schlage ich Bestandteile des Regulatorischen Netzwerkes vor, das der anterioren Musterung in Tribolium zugrunde liegt. Einige dieser hypothetischen Interaktionen wurden daraufhin experimentell bestätigt. Um Einblicke in die Konservierung des Regulatorischen Netzwerkes zu erlangen, wurden einige der gefundenen Interaktionen im Vertebraten-Model Xenopus laevis getestet. Dabei zeigte sich, dass das Potential von six3 die Expression von wnt1 und pax6 zu reprimieren konserviert zu sein scheint. Der Vergleich der Expressionsdaten im Käfer und in Vertebraten zeigt, dass die Okkular/Preokkulare Region des embryonalen Insektenkopfes sehr viele Ähnlichkeiten zur Vorder-/Mittelhirn Region der Vertebraten aufweist. Weiterhin lässt der Vergleich vermuten, dass der letzte gemeinsame Vorfahre von Insekten und Vertebraten ein wichtiges Signalzentrum im anterioren Kopf besessen hat.Die Etablierung der anterior-posterior Achse in Vertebraten ist abhängig von der Funktion des kanonischen Wnt-Signalweges. Einige kürzlich veröffentlichte Daten aus verschiedenen Arthropoden lassen vermuten, dass die Beteiligung des Wnt-Signalweges bei der Bildung posteriorer Strukturen innerhalb der Bilateria konserviert ist. Um die Beteiligung des Wnt-Signalweges an der anterior-posterior Achsen-Bildung weiter zu bestätigen, habe ich mit Hilfe von Tc-axin RNAi ektopische Wnt Signale in der anterioren Region aktiviert. Die Resultate zeigen, dass ektopische Wnt Signale zur Posteriorisierung des frühen Embryos führen, was für eine essentielle Funktion des Wnt-Signalweges in der anterior-posterior Achsenbildung in Tribolium spricht. Zusätzlich sind bisher einige weitere Aspekte der Insektenkopfentwicklung ungeklärt geblieben. Zum Beispiel ist nicht bekannt, welcher Teil der starren Kopfkapsel der Larvenstadien vom Interkalarsegment gebildet wird. Deshalb habe ich die Funktion des Interkalarsegment-Markers Tc-labial/Hox1 in Tribolium analysiert. Die Daten zeigen, dass der Verlust von Tc-labial/Hox1 zum Verlust des Interkalarsegments führt. Weiterhin konnte gezeigt werden, dass das Interkalarsegment laterale Bestandteile der Kopfkapsel bildet

Changes in anterior head patterning underlie the evolution of long germ embryogenesis

AbstractEarly embryonic stages differ significantly among related animal taxa while subsequent development converges at the conserved phylotypic stage before again diverging. Although this phenomenon has long been observed, its underlying genetic mechanisms remain enigmatic. The dipteran Drosophila melanogaster develops as a long germ embryo where the head anlagen form a cap at the anterior pole of the blastoderm. Consequently, the anterior and terminal maternal systems give crucial input for head patterning. However, in the short germ beetle Tribolium castaneum, as in most insects, the head anlagen is located at a ventral position distant from the anterior pole of the blastoderm. In line with these divergent embryonic anlagen, several differences in the axis formation between the insects have been discovered. We now ask to what extent patterning and morphogenesis of the anterior median region (AMR) of the head, including clypeolabral and stomodeal anlagen, differ among these insects. Unexpectedly, we find that Tc-huckebein is not a terminal gap gene and, unlike its Drosophila ortholog, is not involved in Tribolium head development. Instead, Tc-six3 acts upstream of Tc-crocodile and Tc-cap'n'collar to pattern posterior and anterior parts of the AMR, respectively. We further find that instead of huckebein, Tc-crocodile is required for stomodeum development by activating Tc-forkhead. Finally, a morphogenetic movement not found in Drosophila shapes the embryonic head of Tribolium. Apparently, with anterior displacement of the head anlagen during long germ evolution of Drosophila, the ancestral regulation by the bilaterian anterior control gene six3 was replaced by the anterior and terminal maternal systems, which were further elaborated by adding bicoid, tailless and huckebein as anterior regionalization genes

Origin and consequences of chromosomal inversions in the virilis group of Drosophila

In Drosophila, large variations in rearrangement rate have been reported among different lineages and among Muller’s elements. Nevertheless, the mechanisms that are involved in the generation of inversions, their increase in frequency, as well as their impact on the genome are not completely understood. This is in part due to the lack of comparative studies on species distantly related to Drosophila melanogaster. Therefore, we sequenced and assembled the genomes of two species of the virilis phylad (Drosophila novamexicana [15010-1031.00] and Drosophila americana [SF12]), which are diverging from D. melanogaster for more than 40 Myr. Based on these data, we identified the precise location of six novel inversion breakpoints. A molecular characterization provided clear evidence that DAIBAM (a miniature inverted–repeat transposable element) was involved in the generation of eight out of the nine inversions identified. In contrast to what has been previously reported for D. melanogaster and close relatives, ectopic recombination is thus the prevalent mechanism of generating inversions in species of the virilis phylad. Using pool-sequencing data for three populations of D. americana, we also show that common polymorphic inversions create a high degree of genetic differentiation between populations for chromosomes X, 4, and 5 over large physical distances. We did not find statistically significant differences in expression levels between D. americana (SF12) and D. novamexicana (15010-1031.00) strains for the three genes surveyed (CG9588, Fig 4, and fab1) flanking three inversion breakpoints.This article is a result of the project Norte-01-0145-FEDER-000008—Porto Neurosciences and Neurologic Disease Research Initiative at I3S, supported by Norte Portugal Regional Operational Programme (NORTE 2020), under the PORTUGAL 2020 Partnership Agreement, through the European Regional Development Fund (FEDER). N.P. and M.R. are funded by the Emmy Noether Programme of the Deutsche Forschungsgemeinschaft (Grant Number: PO 1648/3-1 to N.P.). We would like to thank the Transcriptome Analysis Lab (TAL) (University Medical Center Göttingen, UMG) in Göttingen for the Illumina sequencing

Probing the Drosophila retinal determination gene network in Tribolium (II): The Pax6 genes eyeless and twin of eyeless

AbstractThe Pax6 genes eyeless (ey) and twin of eyeless (toy) are upstream regulators in the retinal determination gene network (RDGN), which instructs the formation of the adult eye primordium in Drosophila. Most animals possess a singleton Pax6 ortholog, but the dependence of eye development on Pax6 is widely conserved. A rare exception is given by the larval eyes of Drosophila, which develop independently of ey and toy. To obtain insight into the origin of differential larval and adult eye regulation, we studied the function of toy and ey in the red flour beetle Tribolium castaneum. We find that single and combinatorial knockdown of toy and ey affect larval eye development strongly but adult eye development only mildly in this primitive hemimetabolous species. Compound eye-loss, however, was provoked when ey and toy were RNAi-silenced in combination with the early retinal gene dachshund (dac). We propose that these data reflect a role of Pax6 during regional specification in the developing head and that the subsequent maintenance and growth of the adult eye primordium is regulated partly by redundant and partly by specific functions of toy, ey and dac in Tribolium. The results from embryonic knockdown and comparative protein sequence analysis lead us further to conclude that Tribolium represents an ancestral state of redundant control by ey and toy

Six3 demarcates the anterior-most developing brain region in bilaterian animals.

BACKGROUND: The heads of annelids (earthworms, polychaetes, and others) and arthropods (insects, myriapods, spiders, and others) and the arthropod-related onychophorans (velvet worms) show similar brain architecture and for this reason have long been considered homologous. However, this view is challenged by the 'new phylogeny' placing arthropods and annelids into distinct superphyla, Ecdysozoa and Lophotrochozoa, together with many other phyla lacking elaborate heads or brains. To compare the organisation of annelid and arthropod heads and brains at the molecular level, we investigated head regionalisation genes in various groups. Regionalisation genes subdivide developing animals into molecular regions and can be used to align head regions between remote animal phyla. RESULTS: We find that in the marine annelid Platynereis dumerilii, expression of the homeobox gene six3 defines the apical region of the larval body, peripherally overlapping the equatorial otx+ expression. The six3+ and otx+ regions thus define the developing head in anterior-to-posterior sequence. In another annelid, the earthworm Pristina, as well as in the onychophoran Euperipatoides, the centipede Strigamia and the insects Tribolium and Drosophila, a six3/optix+ region likewise demarcates the tip of the developing animal, followed by a more posterior otx/otd+ region. Identification of six3+ head neuroectoderm in Drosophila reveals that this region gives rise to median neurosecretory brain parts, as is also the case in annelids. In insects, onychophorans and Platynereis, the otx+ region instead harbours the eye anlagen, which thus occupy a more posterior position. CONCLUSIONS: These observations indicate that the annelid, onychophoran and arthropod head develops from a conserved anterior-posterior sequence of six3+ and otx+ regions. The six3+ anterior pole of the arthropod head and brain accordingly lies in an anterior-median embryonic region and, in consequence, the optic lobes do not represent the tip of the neuraxis. These results support the hypothesis that the last common ancestor of annelids and arthropods already possessed neurosecretory centres in the most anterior region of the brain. In light of its broad evolutionary conservation in protostomes and, as previously shown, in deuterostomes, the six3-otx head patterning system may be universal to bilaterian animals.RIGHTS : This article is licensed under the BioMed Central licence at http://www.biomedcentral.com/about/license which is similar to the 'Creative Commons Attribution Licence'. In brief you may : copy, distribute, and display the work; make derivative works; or make commercial use of the work - under the following conditions: the original author must be given credit; for any reuse or distribution, it must be made clear to others what the license terms of this work are

Candidate Gene Screen in the Red Flour Beetle Tribolium Reveals Six3 as Ancient Regulator of Anterior Median Head and Central Complex Development

Several highly conserved genes play a role in anterior neural plate patterning of vertebrates and in head and brain patterning of insects. However, head involution in Drosophila has impeded a systematic identification of genes required for insect head formation. Therefore, we use the red flour beetle Tribolium castaneum in order to comprehensively test the function of orthologs of vertebrate neural plate patterning genes for a function in insect head development. RNAi analysis reveals that most of these genes are indeed required for insect head capsule patterning, and we also identified several genes that had not been implicated in this process before. Furthermore, we show that Tc-six3/optix acts upstream of Tc-wingless, Tc-orthodenticle1, and Tc-eyeless to control anterior median development. Finally, we demonstrate that Tc-six3/optix is the first gene known to be required for the embryonic formation of the central complex, a midline-spanning brain part connected to the neuroendocrine pars intercerebralis. These functions are very likely conserved among bilaterians since vertebrate six3 is required for neuroendocrine and median brain development with certain mutations leading to holoprosencephaly