Two Forkhead transcription factors regulate the division of cardiac progenitor cells by a Polo-dependent pathway
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ABSTRACT: The development of a complex organ requires the specification of appropriate numbers of each of its constituent cell types, as well as their proper differentiation and correct positioning relative to each other. During Drosophila cardiogenesis, all three of these processes are controlled by jumeau (jumu) and Checkpoint suppressor homologue (CHES-1-like), two genes encoding forkhead transcription factors that we discovered utilizing an integrated genetic, genomic and computational strategy for identifying novel genes expressed in the developing Drosophila heart. Both jumu and CHES-1-like are required during asymmetric cell division for the derivation of two distinct cardiac cell types from their mutual precursor, and in symmetric cell divisions that produce yet a third type of heart cell. jumu and CHES-1-like control the division of cardiac progenitors by regulating the activity of Polo, a kinase involved in multiple steps of mitosis. This pathway demonstrates how transcription factors integrate diverse developmental processes during organogenesis. GFP-positive and GFP-negative cells were profiled from Stage 11 TinD-GFP Drosophila embryos
Project description:The development of a complex organ requires the proper differentiation and production of appropriate numbers of each of its constituent cell types, as well as their correct positioning within the organ. During Drosophila cardiogenesis, all three of these processes are controlled by jumeau (jumu) and Checkpoint suppressor homologue (CHES-1-like), two genes encoding forkhead transcription factors that were discovered utilizing an integrated genetic, genomic and computational strategy which identified 70 novel genes expressed in the developing Drosophila heart. Both jumu and CHES-1-like are required during asymmetric cell division for the derivation of two distinct cardiac cell types from their mutual precursor, and in symmetric cell division to produce yet a third type of heart cell. jumu and CHES-1-like control the division of cardiac progenitors by regulating the activity of Polo, a kinase involved in multiple steps of mitosis. This pathway demonstrates how transcription factors integrate diverse developmental processes during organogenesis. GFP-positive cells were profiled from Stage 11-12 Drosophila embryos of the following two genotypes: twi-GAL4 UAS-2EGFP/UAS-jumu and twi-GAL4 UAS-2EGFP
Project description:The development of a complex organ requires the specification of appropriate numbers of each of its constituent cell types, as well as their proper differentiation and correct positioning relative to each other. During Drosophila cardiogenesis, all three of these processes are controlled by jumeau (jumu) and Checkpoint suppressor homologue (CHES-1-like), two genes encoding forkhead transcription factors that we discovered utilizing an integrated genetic, genomic and computational strategy for identifying novel genes expressed in the developing Drosophila heart. Both jumu and CHES-1-like are required during asymmetric cell division for the derivation of two distinct cardiac cell types from their mutual precursor, and in symmetric cell divisions that produce yet a third type of heart cell. jumu and CHES-1-like control the division of cardiac progenitors by regulating the activity of Polo, a kinase involved in multiple steps of mitosis. This pathway demonstrates how transcription factors integrate diverse developmental processes during organogenesis.
Project description:The development of a complex organ requires the specification of appropriate numbers of each of its constituent cell types, as well as their proper differentiation and correct positioning relative to each other. During Drosophila cardiogenesis, all three of these processes are controlled by jumeau (jumu) and Checkpoint suppressor homologue (CHES-1-like), two genes encoding forkhead transcription factors that we discovered utilizing an integrated genetic, genomic and computational strategy for identifying novel genes expressed in the developing Drosophila heart. Both jumu and CHES-1-like are required during asymmetric cell division for the derivation of two distinct cardiac cell types from their mutual precursor, and in symmetric cell divisions that produce yet a third type of heart cell. jumu and CHES-1-like control the division of cardiac progenitors by regulating the activity of Polo, a kinase involved in multiple steps of mitosis. This pathway demonstrates how transcription factors integrate diverse developmental processes during organogenesis.
Project description:Two-dimensional patterning of the follicular epithelium in Drosophila oogenesis is required for the formation of three-dimensional eggshell structures. Our analysis of a large number of published gene expression patterns in the follicle cells suggests that they follow a simple combinatorial code based on six spatial building blocks and the operations of union, difference, intersection, and addition. The building blocks are related to the distribution of inductive signals, provided by the highly conserved epidermal growth factor receptor and Decapentaplegic (DPP) pathways. We demonstrate the validity of the code by testing it against a set of patterns obtained in a large-scale transcriptional profiling experiment. Using the proposed code, we distinguish 36 distinct patterns for 81 genes expressed in the follicular epithelium and characterize their joint dynamics over four stages of oogenesis. The proposed combinatorial framework allows systematic analysis of the diversity and dynamics of two-dimensional transcriptional patterns and guides future studies of gene regulation. Keywords: EGFR, BMP, gain/loss-of-function RNA was isolated from hand dissected, stage 9-10 egg chambers. Five genetic backgrounds were profiled including: wild type, EGFR gain of function, EGFR loss of function, BMP gain of function, and BMP loss of function. Three biological replicates were hybridized for each pathway perturbation. The samples were split across two rounds of hybridization. Each round of hybridizations included three biological replicates for wild type: The first round included EGFR gof, EGFR lof, BMP gof, and wild type controls A1-A3 (GSM313514-16). For these 12 arrays the extraction, labeling, and hybridization steps were done in parallel. The second round included the BMP lof and wild type controls B1-B3 (GSM313517-19). For these 6 arrays, the extraction, labeling, and hybridization steps were done in parallel.
Project description:Homeodomain (HD) proteins comprise a large family of evolutionarily conserved transcription factors (TFs) having diverse developmental functions, yet they paradoxically recognize very similar DNA sequences. To investigate how HDs control cell-specific gene expression patterns, we determined the DNA binding specificities of a broad range of HDs critical for Drosophila embryonic mesoderm development. These studies revealed particular sequences that are bound by one HD and not by others. Such HD-preferred binding sites are overrepresented in the noncoding regions of genes that are regulated by the corresponding HD. Moreover, we show at single-cell resolution in intact embryos that the HD Slouch (Slou) controls myoblast gene expression through unique DNA sequences that are preferentially bound by Slou. These findings demonstrate that the sequence of a HD-binding site dictates which HD family member binds to and regulates a particular enhancer. This represents a novel mechanism for how cell type-specific TFs induce the distinct genetic programs of individual embryonic cells. Mesodermal cells were profiled from wild type, slou gain-of-function and msh gain-of-function backgrounds.
Project description:Comparison of wild type and heterozygote and homozygote chico mutants ( Clancy, et al. Extension of Life-Span by Loss of CHICO, a Drosophila Insulin Receptor Substrate Protein. Science 292 (5514), 104.) on Affymetrix Drosophila2 GeneChip. The flies (Drosophila melanogaster) are 7 day old adult females.
Project description:Investigation of whole genome gene expression level changes in zebrafish TIF1g-deficient, cdc73 deficient and double-deficient embryos, compared to the wild-type ebryos. A twelve-chip study using total RNA isolated from gata1-GFP positive cells (sorted by FACS) from 12 somite-stage wild type embryos, TIF1g morholino injected, Cdc73 morpholino injected and double morpholino injected embryos.
Project description:Forkhead box (Fox) transcription factors (TFs) mediate multiple conserved cardiogenic processes in both mammals and Drosophila. Our prior work identified the roles of two Drosophila Fox genes, jumeau (jumu) and Checkpoint suppressor 1-like (CHES-1-like), in cardiac progenitor cell specification and division, and in the proper positioning of cardiac cell subtypes. Fox TF binding sites are also significantly enriched in the enhancers of genes expressed in the heart, suggesting that these genes may play a core regulatory role in one or more of these cardiogenic processes. We identified downstream targets of Jumu by comparing transcriptional expression profiles of flow cytometry-sorted mesodermal cells from wild-type embryos and embryos completely lacking the jumu gene and found that genes with functional annotation and ontological features suggesting roles in cell division were overrepresented among Jumu targets. Phenotypic analysis of a subset of these targets identified 21 jumu-regulated genes that mediate cardiac progenitor cell division, one of which, Retinal Homeobox (Rx), was characterized in more detail. Finally, the observation that many of these 21 genes and/or their orthologs exhibit genetic or physical interactions among themselves indicates that Jumu is a master regulator acting as a hub of a cardiac progenitor cell division-mediating network.
Project description:The adult mammalian heart has little regenerative capacity after myocardial infarction (MI) while neonatal mouse heart regenerates without scarring or dysfunction. However, the underlying pathways are poorly defined. We sought to derive insights into the pathways regulating neonatal development of the mouse heart and cardiac regeneration post-MI. Total RNA-seq of mouse heart through the first 10 days of postnatal life (referred to as P3, P5, P10) revealed a previously unobserved transition in microRNA expression between P3 and P5 associated specifically with altered expression of protein-coding genes on the focal adhesion pathway and cessation of cardiomyocyte cell division. We found profound changes in the coding and non-coding transcriptome after neonatal MI, with evidence of essentially complete healing by P10. Over two thirds of each of the mRNAs, lncRNAs and microRNAs that were differentially expressed in the post-MI heart were differentially expressed during normal postnatal development, suggesting a common regulatory pathway for normal cardiac development and post-MI cardiac regeneration. We selected exemplars of miRNAs implicated in our data set as regulators of cardiomyocyte proliferation. Several of these showed evidence of a functional influence on mouse cardiomyocyte cell division. In addition, a subset of these microRNAs, miR-144-3p, miR-195a-5p, miR-451a and miR-6240 showed evidence of functional conservation in human cardiomyocytes. The sets of mRNAs, miRNAs and lncRNAs that we report here merit further investigation as gatekeepers of cell division in the postnatal heart and as targets for extension of the period of cardiac regeneration beyond the neonatal period.