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Many Developmental Processes (many + developmental_process)
Selected AbstractsActivin/nodal signaling modulates XPAPC expression during Xenopus gastrulationDEVELOPMENTAL DYNAMICS, Issue 3 2008Xin Lou Abstract Gastrulation is the first obligatory morphogenesis during vertebrate development, by which the body plan is established. Nodal signaling is a key player in many developmental processes, including gastrulation. XPAPC has been found to exert its biological function through modifying the adhesion property of cells and interacting with other several important molecules in embryos. In this report, we show that nodal signaling is necessary and sufficient for XPAPC expression during Xenopus gastrulation. Furthermore, we isolated 4.8 kb upstream DNA sequence of Xenopus XPAPC, and proved that this 4.8-kb genomic contig is sufficient to recapitulate the expression pattern of XPAPC from gastrula to tail bud stage. Transgene and ChIP assays indicate that Activin/nodal signaling participates in regulation of XPAPC expression through a Smad binding element within the XPAPC promoter. Concomitant investigation suggests that the canonical Wnt pathway-activated XPAPC expression requires nodal signaling. Developmental Dynamics 237:683,691, 2008. © 2008 Wiley-Liss, Inc. [source] Ptc, Smo, Sufu, and the Hedgehog signaling pathway in amphioxusEVOLUTION AND DEVELOPMENT, Issue 6 2009Yushuang Lin SUMMARY The Hedgehog (Hh) signaling pathway regulates many developmental processes both in vertebrates and in invertebrates. However, little is known about this pathway in the cephalochordate amphioxus. In this paper, we focus on the Ptc, Smo, and Sufu homologs in amphioxus, which are the key members of the Hh signaling pathway. Their genomic structures show their comparability with homologs in vertebrates. In situ hybridization reveals that amphioxus Ptc, Smo, and Sufu have similar expression patterns in embryogenesis. They are expressed in the neural plate at early neurula stage, and then down-regulated in dorsal neural ectoderm. During development, their transcripts appear and persist in the notochord, the wall of the head cavity, the epithelium of the pharynx, and the gut. The data show that the expression patterns of these three genes are overlapping with Hh and Gli during the embryonic development in amphioxus. Moreover, injection of amphioxus Hh RNA into zebrafish-fertilized eggs can expand the expression domains of Ptc1 and Nk2.2a, the target genes of the Hh signaling pathway, which is similar to the injection of zebrafish Sonic hh a (zShha) and Sonic hh b (zShhb). Our results suggest that amphioxus may possess a conserved and functional Hh signaling pathway similar to that of vertebrates. [source] Overexpression of the Wounding-Responsive Gene AtMYB15 Activates the Shikimate Pathway in ArabidopsisJOURNAL OF INTEGRATIVE PLANT BIOLOGY, Issue 9 2006Yanhui Chen Abstract The MYB transcription factor genes play important roles in many developmental processes and various defense responses of plants. The shikimate pathway is a major biosynthetic pathway for the production of three aromatic amino acids and other aromatic compounds that are involved in multiple responses of plants, including protection against UV and defense. Herein, we describe the characterization of the R2R3-MYB gene AtMYB15 as an activator of the shikimate pathway in Arabidopsis. The AtMYB15 protein is nuclear localized and a transcriptional activation domain is found in its C-terminal portion. Northern blots showed that AtMYB15 is an early wounding-inducible gene. Resutls of microarray analysis, confirmed using quantitative real-time polymerase chain reaction, showed that overexpression of AtMYB15 in transgenic plants resulted in elevated expression of almost all the genes involved in the shikimate pathway. Bioinformatics analysis showed that one or more AtMYB15-binding AC elements were detected in the promoters of these upregulated genes. Furthermore, these genes in the shikimate pathway were also found to be induced by wounding. These data suggest an important role of AtMYB15 as a possible direct regulator of the Arabidopsis shikimate pathway in response to wounding. (Managing editor: Ya-Qin Han) [source] An Integrative Analysis of the Effects of Auxin on Jasmonic Acid Biosynthesis in Arabidopsis thalianaJOURNAL OF INTEGRATIVE PLANT BIOLOGY, Issue 1 2006Jun Liu Abstract Auxin and jasmonic acid (JA) are two plant phytohormones that both participate in the regulation of many developmental processes. Jasmonic acid also plays important roles in plant stress response reactions. Although extensive investigations have been undertaken to study the biological functions of auxin and JA, little attention has been paid to the cross-talk between their regulated pathways. In the few available reports examining the effects of auxin on the expression of JA or JA-responsive genes, both synergetic and antagonistic results have been found. To further investigate the relationship between auxin and JA, we adopted an integrative method that combines microarray expression data with pathway information to study the behavior of the JA biosynthesis pathway under auxin treatment. Our results showed an overall down regulation of genes involved in JA biosynthesis, providing the first report of a relationship between auxin and the JA synthesis pathway in Arabidopsis seedlings. (Managing editor: Ya-Qin Han) [source] The ups and downs of signalling between root and shootNEW PHYTOLOGIST, Issue 3 2000Christine Beveridge It is becoming increasingly apparent that the long-distance signalling associated with many developmental processes is complex and that novel hormone-like signals may play substantial roles. The past decades have seen several substances (e.g. brassinosteroids, systemin and other polypeptides, mevalonic and jasmonic acids, polyamines, oligosaccharides, flavonoids, and quinones) vie for a place among the classical plant hormones (e.g. Spaink, 1996). Recent microinjection and grafting studies have also shown that RNA may act as a long-distance signal (Jorgensen et al., 1998; Xoconostle-Cázares et al., 1999). In this issue, Hannah et al. describe long-distance signalling and the regulation of root,shoot partitioning in dwarf lethal or dosage-dependent lethal (DL) mutants of common bean (Shii et al., 1980, 1981), and present evidence indicating that substances in addition to classical plant hormones (e.g. cytokinins) may be involved. As in the report by Hannah et al., much of the evidence for roles of unidentified long-distance signals in the control of plant development is indirect. The possibility that a small number of long-distance signals might control a multitude of developmental processes arises through the potential for differences in tissue sensitivity, fluctuations in hormone levels and differences in the nature of responses of different tissues to the same hormone. Consequently, particular hormones may influence numerous processes seemingly simultaneously, yet independently. Even so, long-distance signalling is involved in processes as diverse as root,shoot balance, senescence, branching, flowering, nodulation, stress responses and nutrient uptake. Through comparison of even a few different developmental processes, progress can be made to reveal the true complexity of plant development. Using this approach it is also clear that many unknown signals may be involved. [source] Wingless can't fly so it hitches a ride with dyneinBIOESSAYS, Issue 10 2001Steven H. Myster Asymmetric RNA localization is required for many developmental processes in a wide range of organisms. For example, wingless and pair-rule transcripts are localized to the apical membrane of polarized cells. It has been unclear, however, if this localization is important for biological activity and, in addition, how the transcripts are transported. Two recent studies(1,2) have identified cis -elements and trans -acting factors that are required for the asymmetric localization of mRNAs. Correct localization is shown to be required for biological activity, and a mechanism of RNA transport involving the microtubule motor dynein has been revealed. BioEssays 23:869,872, 2001. © 2001 John Wiley & Sons, Inc. [source] | ||||||||||