Browsing by Author "Olivares, Gonzalo H."

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    Early-life nutrition interacts with developmental genes to shape the brain and sleep behavior in Drosophila melanogaster
    (2023) Olivares, Gonzalo H.; Nunez-Villegas, Franco; Candia, Noemi; Orostica, Karen; Gonzalez-Ramirez, M. Constanza; Vega-Macaya, Franco; Zuniga, Nolberto; Molina, Cristian; Oliva, Carlos; Mackay, Trudy F. C.; Verdugo, Ricardo A.; Olguin, Patricio
    The mechanisms by which the genotype interacts with nutrition during development to contribute to the variation of complex behaviors and brain morphology of adults are not well understood. Here we use the Drosophila Genetic Reference Panel to identify genes and pathways underlying these interactions in sleep behavior and mushroom body morphology. We show that early-life nutritional restriction effects on sleep behavior and brain morphology depends on the genotype. We mapped genes associated with sleep sensitivity to early-life nutrition, which were enriched for protein-protein interactions responsible for translation, endocytosis regulation, ubiquitination, lipid metabolism, and neural development. By manipulating the expression of candidate genes in the mushroom bodies (MBs) and all neurons, we confirm that genes regulating neural development, translation and insulin signaling contribute to the variable response of sleep and brain morphology to early-life nutrition. We show that the interaction between differential expression of candidate genes with nutritional restriction in early life resides in the MBs or other neurons and that these effects are sex-specific. Natural variations in genes that control the systemic response to nutrition and brain development and function interact with early-life nutrition in different types of neurons to contribute to the variation of brain morphology and adult sleep behavior.
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    Expression of Transposable Elements in Neural Tissues during Xenopus Development
    (2011) Faunes, Fernando; Sanchez, Natalia; Moreno, Mauricio; Olivares, Gonzalo H.; Lee-Liu, Dasfne; Almonacid, Leonardo; Slater, Alex W.; Norambuena, Tomas; Taft, Ryan J.; Mattick, John S.; Melo, Francisco; Larrain, Juan
    Transposable elements comprise a large proportion of animal genomes. Transposons can have detrimental effects on genome stability but also offer positive roles for genome evolution and gene expression regulation. Proper balance of the positive and deleterious effects of transposons is crucial for cell homeostasis and requires a mechanism that tightly regulates their expression. Herein we describe the expression of DNA transposons of the Tc1/mariner superfamily during Xenopus development. Sense and antisense transcripts containing complete Tc1-2_Xt were detected in Xenopus embryos. Both transcripts were found in zygotic stages and were mainly localized in Spemann's organizer and neural tissues. In addition, the Tc1-like elements Eagle, Froggy, Jumpy, Maya, Xeminos and TXr were also expressed in zygotic stages but not oocytes in X. tropicalis. Interestingly, although Tc1-2_Xt transcripts were not detected in Xenopus laevis embryos, transcripts from other two Tc1-like elements (TXr and TXz) presented a similar temporal and spatial pattern during X. laevis development. Deep sequencing analysis of Xenopus tropicalis gastrulae showed that PIWI-interacting RNAs (piRNAs) are specifically derived from several Tc1-like elements. The localized expression of Tc1-like elements in neural tissues suggests that they could play a role during the development of the Xenopus nervous system.
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    Syndecan-1 regulates BMP signaling and dorso-ventral patterning of the ectoderm during early Xenopus development
    (ACADEMIC PRESS INC ELSEVIER SCIENCE, 2009) Olivares, Gonzalo H.; Carrasco, Hector; Aroca, Francisco; Carvallo, Loreto; Segovia, Fabian; Larrain, Juan
    Extracellular regulation of growth factor signaling is a key event for embryonic patterning. Heparan sulfate proteoglycans (HSPG) are among the molecules that regulate this signaling during embryonic development. Here we study the function of syndecan1 (Syn1), a cell-surface HSPG expressed in the non-neural ectoderm during early development of Xenopus embryos. Overexpression of Xenopus Syn1 (xSyn1) mRNA is Sufficient to reduce BMP signaling, induce chordin expression and rescue dorso-ventral patterning in ventrailized embryos. Experiments using chordin morpholinos established that xSyn1 mRNA can inhibit BM P signaling in the absence of chordin. Knockdown of xSyn1 resulted in a reduction of BMP signaling and expansion of the neural plate with the concomitant reduction of the non-neural ectoderm. Overexpression of xSyn1 mRNA in xSyn1 morphant embryos resulted in a biphasic effect, with BMP being inhibited at high concentrations and activated at low concentrations of xSyn1. Interestingly, the function of xSyn1 on dorso-ventral patterning and BMP signaling is specific for this HSPG. In summary, we report that xSyn1 regulates dorso-ventral patterning of the ectoderm through modulation of BMP signaling. (C) 2009 Elsevier Inc. All rights reserved.