Molecular patterning mechanism underlying metamorphosis of the thoracic leg in Manduca sexta

AbstractThe tobacco hornworm Manduca sexta, like many holometabolous insects, makes two versions of its thoracic legs. The simple legs of the larva are formed during embryogenesis, but then are transformed into the more complex adult legs at metamorphosis. To elucidate the molecular patterning mechanism underlying this biphasic development, we examined the expression patterns of five genes known to be involved in patterning the proximal–distal axis in insect legs. In the developing larval leg of Manduca, the early patterning genes Distal-less and Extradenticle are already expressed in patterns comparable to the adult legs of other insects. In contrast, Bric-a-brac and dachshund are expressed in patterns similar to transient patterns observed during early stages of leg development in Drosophila. During metamorphosis of the leg, the two genes finally develop mature expression patterns. Our results are consistent with the hypothesis that the larval leg morphology is produced by a transient arrest in the conserved adult leg patterning process in insects. In addition, we find that, during the adult leg development, some cells in the leg express the patterning genes de novo suggesting that the remodeling of the leg involves changes in the patterning gene regulation

Multispecies Analysis of Expression Pattern Diversification in the Recently Expanded Insect Ly6 Gene Family

The deposited article version is a "MBE Advance Access" published on March 4, 2015" provided by Oxford University Press, and it contains attached the supplementary materials within the pdf.The deposited article is a post-print version.Some supplementary materials are not present in the uploaded version of the article.Gene families often consist of members with diverse expression domains reflecting their functions in a wide variety of tissues. However, how the expression of individual members, and thus their tissue-specific functions, diversified during the course of gene family expansion is not well understood. In this study, we approached this question through the analysis of the duplication history and transcriptional evolution of a rapidly expanding subfamily of insect Ly6 genes. We analyzed different insect genomes and identified seven Ly6 genes that have originated from a single ancestor through sequential duplication within the higher Diptera. We then determined how the original embryonic expression pattern of the founding gene diversified by characterizing its tissue-specific expression in the beetle Tribolium castaneum, the butterfly Bicyclus anynana, and the mosquito Anopheles stephensi and those of its duplicates in three higher dipteran species, representing various stages of the duplication history (Megaselia abdita, Ceratitis capitata, and Drosophila melanogaster). Our results revealed that frequent neofunctionalization episodes contributed to the increased expression breadth of this subfamily and that these events occurred after duplication and speciation events at comparable frequencies. In addition, at each duplication node, we consistently found asymmetric expression divergence. One paralog inherited most of the tissue-specificities of the founder gene, whereas the other paralog evolved drastically reduced expression domains. Our approach attests to the power of combining a well-established duplication history with a comprehensive coverage of representative species in acquiring unequivocal information about the dynamics of gene expression evolution in gene families.IAEA Seibersdorf (Austria); USDA; Duke University; McGill University; DRGC (Kyoto); DSHB (Iowa); Toulouse RIO Imaging Platform; Fundação para a Ciência e a Tecnologia grants: (SFRH/BPD/75139/2010, ANR-13-ISV7-0001-01, ANR-13-ISV7-0001-02, FCT-ANR/BIA-ANM/0003/2013); Fundação Calouste Gulbenkian; Instituto Gulbenkian de Ciência; Agence Nationale de la Recherche (ANR).info:eu-repo/semantics/publishedVersio

Diverse Cis-Regulatory Mechanisms Contribute to Expression Evolution of Tandem Gene Duplicates

The deposited article is a post-print version and has peer review. The deposited article version contains attached the supplementary materials within the pdf.Pairs of duplicated genes generally display a combination of conserved expression patterns inherited from their unduplicated ancestor and newly acquired domains. However, how the cis-regulatory architecture of duplicated loci evolves to produce these expression patterns is poorly understood. We have directly examined the gene-regulatory evolution of two tandem duplicates, the Drosophila Ly6 genes CG9336 and CG9338, which arose at the base of the drosophilids between 40 and 60 million years ago. Comparing the expression patterns of the two paralogs in four Drosophila species with that of the unduplicated ortholog in the tephritid Ceratitis capitata, we show that they diverged from each other as well as from the unduplicated ortholog. Moreover, the expression divergence appears to have occurred close to the duplication event and also more recently in a lineage-specific manner. The comparison of the tissue-specific cis-regulatory modules (CRMs) controlling the paralog expression in the four Drosophila species indicates that diverse cis-regulatory mechanisms, including the novel tissue-specific enhancers, differential inactivation, and enhancer sharing, contributed to the expression evolution. Our analysis also reveals a surprisingly variable cis-regulatory architecture, in which the CRMs driving conserved expression domains change in number, location, and specificity. Altogether, this study provides a detailed historical account that uncovers a highly dynamic picture of how the paralog expression patterns and their underlying cis-regulatory landscape evolve. We argue that our findings will encourage studying cis-regulatory evolution at the whole-locus level in order to understand how interactions between enhancers and other regulatory levels shape the evolution of gene expression.Fundação Calouste Gulbenkian/Instituto Gulbenkian de Ciência; Toulouse RIO Imaging platform; Bloomington Drosophila Stock Center (Indiana, USA); Developmental Studies Hybridoma Bank (Iowa, USA); Drosophila Genomics Resource Center (Indiana, USA); NIH grant: (2P0OD010949); Agence Nationale de la Recherche grant: (ANR-13-ISV7-0001-01); Fundação para a Ciência e a Tecnologia grants: (SFRH/BPD/75139/2010, FCT-ANR/BIA-ANM/0003/2013, FCT-EXPL/BEX-GMG/2197/2013).info:eu-repo/semantics/acceptedVersio

Active Enhancement of Rat Cardiac Allografts by Donor-Specific B Lymphocytes

In an attempt to induce the active enhancement of the cardiac allografts, recipient rats were injected intravenously with 1 x 107 donor-specific spleen cells or an equal number of their T or B cell subpopulations on each of 7 days before transplantation. Mean survival times (MST) in the group pretreated with donor-specific spleen cells (MST 27.5 ± 7.8 days) and the group pretreated with donor-specific B cells (MST 37.5 ± 15.5 days) were significantly prolonged (p<0.01) compared with the untreated control (MST 11.6 ± 2.0 days) and the group pretreated with donor-specific T cells. To investigate the mechanisms of the beneficial effect of donor-specific B cells on rat cardiac allografts, inhibition assay of mixed lymphocyte reaction (MLR) were carried out by the addition of recipient rat sera or spleen cells harvested 7 days following the intravenous administration of donor-specific spleen cells or their T and B cell subpopulations. Recipient rat sera harvested 7 days following the intravenous administration of donor-specific B cells showed significant inhibition of MLR; this inhibition was correlated to the prolonged survival of histoincompatible rat cardiac allografts. In contrast, MLR suppressor cells could not be detected in any experimental group. Thus, donor-specific B cell given 7 days before transplantation may possibly have beneficial effect on rat cardiac allografts and MLR inhibition induced by the intravenous administration of donor-specific B cells may be essential for prolonged allograft survival

Beneficial effect of donor-specific blood transfusions (DST) on living-related kidney allograft survival.

The survival rate of 19 patients who underwent living-related kidney transplantation after donor-specific blood transfusions (DST) was compared with that of 32 historical controls receiving transplants without DST. The graft survival rate of the DST group was 82% after two and three years. The graft survival rate of the DST group was significantly better than the 53% rate after two years obtained with the 32 historical controls (p less than 0.05). We tested sera from 16 DST-treated recipients to study the beneficial effect of DST on kidney allograft survival using the mixed lymphocyte culture (MLC) serum inhibition test. The results demonstrated that MLC inhibitory factors were induced in the serum of the recipient after completion of DST. This inhibition of MLC was observed by treatment of responder lymphocytes with serum obtained three weeks after DST plus rabbit complement. The inhibitory effect was also specific for responder cells in anti-donor MLC. Regarding the correlation with rejection episodes, these MLC inhibitory factors were often observed in the non-rejection group (p less than 0.05). The data suggest that such factors may be anti-idiotypic antibodies and be associated with prolonged graft survival.</p

The steroid-hormone ecdysone coordinates parallel pupariation neuromotor and morphogenetic subprograms via epidermis-to-neuron Dilp8-Lgr3 signal induction

Funding Information: We thank Drs. Carlos Ribeiro, Christen Mirth, Elio Sucena, Filip Port, Frank Schnorrer, Julien Colombani, Maria Dominguez, Maria Luisa Vasconcelos, Pierre Leopold, Simon Bullock, Rita Teodoro, Gerald Rubin, Melissa Harrison, Kate O’Connor-Giles, Jill Wildonger, Mariana Melani, Pablo Wappner, and Christian Wegener for fly stocks and reagents. We thank Ryohei Yagi and Konrad Basler for the LHV2 plasmid and Brain McCabe for the mhc-Gateway destination plasmid. We thank Carlos Ribeiro and Dennis Goldschmidt for help in designing and constructing one of the pupariation arenas and Mariana Melani, Pablo Wappner, Arash Bashirullah, and Filip Port for sharing resources and unpublished data. We thank Arash Bashirullah, Fillip Port, and Carlos Ribeiro for discussions and/or comments on the manuscript, and Jim Truman for discussions on Fraenkel’s pupariation factors. Stocks obtained from the Bloomington Drosophila Stock Center (NIH P40OD018537) were used in this study. Work in the Integrative Biomedicine Laboratory was supported by the European Commission FP7 (PCIG13-GA-2013-618847), by the FCT (IF/00022/2012; Congento LISBOA-01-0145-FEDER-022170, cofinanced by FCT/Lisboa2020; UID/Multi/04462/2019; PTDC/BEXBCM/1370/2014; PTDC/MED-NEU/30753/2017; PTDC/BIA-BID/31071/2017; FCT SFRH/BPD/94112/ 2013; SFRH/BD/94931/2013), the MIT Portugal Program (MIT-EXPL/BIO/0097/2017), and FAPESP (16/09659-3, 16/10342-4, and 17/17904-0). AG is a CONICET researcher, YV holds a CONICET postdoctoral fellowship and FPS and MJD hold a PhD fellowship from CONICET. Work in the Garelli lab was supported by ANPCyT (Agencia Nacional para la Promoción de la Ciencia y la Tecnología, PICT 2014-2900 and PICT 2017-0254) and CONICET (PIP11220150100182CO). Publisher Copyright: © 2021, The Author(s). Copyright: Copyright 2021 Elsevier B.V., All rights reserved.Innate behaviors consist of a succession of genetically-hardwired motor and physiological subprograms that can be coupled to drastic morphogenetic changes. How these integrative responses are orchestrated is not completely understood. Here, we provide insight into these mechanisms by studying pupariation, a multi-step innate behavior of Drosophila larvae that is critical for survival during metamorphosis. We find that the steroid-hormone ecdysone triggers parallel pupariation neuromotor and morphogenetic subprograms, which include the induction of the relaxin-peptide hormone, Dilp8, in the epidermis. Dilp8 acts on six Lgr3-positive thoracic interneurons to couple both subprograms in time and to instruct neuromotor subprogram switching during behavior. Our work reveals that interorgan feedback gates progression between subunits of an innate behavior and points to an ancestral neuromodulatory function of relaxin signaling.publishersversionpublishe

Evolution of Sex-Specific Traits through Changes in HOX-Dependent doublesex Expression

Analysis in Drosophila suggests that evolutionary changes in the spatial regulation of the transcription factor doublesex play a key role in the origin, diversification, and loss of sex-specific structures