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De Groef S, Ribeiro Lopes M, Winant M, Rosschaert E, Wilms T, Bolckmans L, Calevro F, Callaerts P. Reference genes to study the sex-biased expression of genes regulating Drosophila metabolism. Sci Rep 2024; 14:9518. [PMID: 38664539 PMCID: PMC11045863 DOI: 10.1038/s41598-024-58863-5] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/09/2023] [Accepted: 04/03/2024] [Indexed: 04/28/2024] Open
Abstract
Sex is an important variable in biology. Notable differences have been observed between male and female Drosophila in regulation of metabolism, in response to nutritional challenges, and in phenotypes relevant for obesity and metabolic disorders. The differences between males and females can be expected to result from differences in gene expression. We observed that expression levels of reference genes commonly used for normalization of qRT-PCR results such as GAPDH, β-actin, and 18SrRNA, show prominent sexual dimorphism. Since this will impact relative expression and conclusions related to that, we performed a systematic analysis of candidate reference genes with the objective of identifying reference genes with stable expression in male and female Drosophila. These reference genes (LamCa, βTub60D and βTub97EF) were then used to assess sex-specific differences in expression of metabolism associated genes. Additionally, we evaluated the utility of these reference genes following a nutritional challenge and showed that LamCa and βtub97EF are stably expressed between sexes and under different nutritional conditions and are thus suitable as reference genes. Our results highlight the importance of evaluating the stability of reference genes when sex-specific differences in gene expression are studied, and identify structural genes as a category worth exploring as reference genes in other species. Finally, we also uncovered hitherto unknown sexually dimorphic expression of a number of metabolism-associated genes, information of interest to others working in the field of metabolic disorders.
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Affiliation(s)
- Sofie De Groef
- KU Leuven, Department of Human Genetics, Laboratory of Behavioral and Developmental Genetics, Campus Gasthuisberg O&N1, Herestraat 49 Box 610, 3000, Leuven, Belgium
| | | | - Mattias Winant
- KU Leuven, Department of Human Genetics, Laboratory of Behavioral and Developmental Genetics, Campus Gasthuisberg O&N1, Herestraat 49 Box 610, 3000, Leuven, Belgium
| | - Emily Rosschaert
- KU Leuven, Department of Human Genetics, Laboratory of Behavioral and Developmental Genetics, Campus Gasthuisberg O&N1, Herestraat 49 Box 610, 3000, Leuven, Belgium
| | - Tom Wilms
- KU Leuven, Department of Human Genetics, Laboratory of Behavioral and Developmental Genetics, Campus Gasthuisberg O&N1, Herestraat 49 Box 610, 3000, Leuven, Belgium
| | - Lenz Bolckmans
- KU Leuven, Department of Human Genetics, Laboratory of Behavioral and Developmental Genetics, Campus Gasthuisberg O&N1, Herestraat 49 Box 610, 3000, Leuven, Belgium
| | | | - Patrick Callaerts
- KU Leuven, Department of Human Genetics, Laboratory of Behavioral and Developmental Genetics, Campus Gasthuisberg O&N1, Herestraat 49 Box 610, 3000, Leuven, Belgium.
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2
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Antel M, Simao T, Bener MB, Inaba M. Drosophila CG17003/leaky (lky) is required for microtubule acetylation in early germ cells in Drosophila ovary. PLoS One 2022; 17:e0276704. [PMID: 36342916 PMCID: PMC9639842 DOI: 10.1371/journal.pone.0276704] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/01/2022] [Accepted: 10/11/2022] [Indexed: 11/09/2022] Open
Abstract
Microtubule acetylation is found in populations of stable, long-lived microtubules, occurring on the conserved lysine 40 (K40) residue of α-tubulin by α-tubulin acetyltransferases (αTATs). α-tubulin K40 acetylation has been shown to stabilize microtubules via enhancing microtubule resilience against mechanical stress. Here we show that a previously uncharacterized αTAT, Drosophila CG17003/leaky (lky), is required for α-tubulin K40 acetylation in early germ cells in Drosophila ovary. We found that loss of lky resulted in a progressive egg chamber fusion phenotype accompanied with mislocalization of germline-specific Vasa protein in somatic follicle cells. The same phenotype was observed upon replacement of endogenous α-tubulin84B with non-acetylatable α-tubulin84BK40A, suggesting α-tubulin K40 acetylation is responsible for the phenotype. Chemical disturbance of microtubules by Colcemid treatment resulted in a mislocalization of Vasa in follicle cells within a short period of time (~30 min), suggesting that the observed mislocalization is likely caused by direct leakage of cellular contents between germline and follicle cells. Taken together, this study provides a new function of α-tubulin acetylation in maintaining the cellular identity possibly by preventing the leakage of tissue-specific gene products between juxtaposing distinct cell types.
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Affiliation(s)
- Matthew Antel
- Department of Cell Biology, University of Connecticut Health, Farmington, CT, United States of America
| | - Taylor Simao
- Department of Cell Biology, University of Connecticut Health, Farmington, CT, United States of America
| | - Muhammed Burak Bener
- Department of Cell Biology, University of Connecticut Health, Farmington, CT, United States of America
| | - Mayu Inaba
- Department of Cell Biology, University of Connecticut Health, Farmington, CT, United States of America
- * E-mail:
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3
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Eyres I, Frangedakis E, Fontaneto D, Herniou EA, Boschetti C, Carr A, Micklem G, Tunnacliffe A, Barraclough TG. Multiple functionally divergent and conserved copies of alpha tubulin in bdelloid rotifers. BMC Evol Biol 2012; 12:148. [PMID: 22901238 PMCID: PMC3464624 DOI: 10.1186/1471-2148-12-148] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/19/2012] [Accepted: 08/11/2012] [Indexed: 12/31/2022] Open
Abstract
BACKGROUND Bdelloid rotifers are microscopic animals that have apparently survived without sex for millions of years and are able to survive desiccation at all life stages through a process called anhydrobiosis. Both of these characteristics are believed to have played a role in shaping several unusual features of bdelloid genomes discovered in recent years. Studies into the impact of asexuality and anhydrobiosis on bdelloid genomes have focused on understanding gene copy number. Here we investigate copy number and sequence divergence in alpha tubulin. Alpha tubulin is conserved and normally present in low copy numbers in animals, but multiplication of alpha tubulin copies has occurred in animals adapted to extreme environments, such as cold-adapted Antarctic fish. Using cloning and sequencing we compared alpha tubulin copy variation in four species of bdelloid rotifers and four species of monogonont rotifers, which are facultatively sexual and cannot survive desiccation as adults. Results were verified using transcriptome data from one bdelloid species, Adineta ricciae. RESULTS In common with the typical pattern for animals, monogonont rotifers contain either one or two copies of alpha tubulin, but bdelloid species contain between 11 and 13 different copies, distributed across five classes. Approximately half of the copies form a highly conserved group that vary by only 1.1% amino acid pairwise divergence with each other and with the monogonont copies. The other copies have divergent amino acid sequences that evolved significantly faster between classes than within them, relative to synonymous changes, and vary in predicted biochemical properties. Copies of each class were expressed under the laboratory conditions used to construct the transcriptome. CONCLUSIONS Our findings are consistent with recent evidence that bdelloids are degenerate tetraploids and that functional divergence of ancestral copies of genes has occurred, but show how further duplication events in the ancestor of bdelloids led to proliferation in both conserved and functionally divergent copies of this gene.
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Affiliation(s)
- Isobel Eyres
- Department of Life Sciences, Imperial College London, Silwood Park Campus, Ascot, Berkshire, SL5 7PY, UK
| | - Eftychios Frangedakis
- Department of Life Sciences, Imperial College London, Silwood Park Campus, Ascot, Berkshire, SL5 7PY, UK
- Present address: Department of Plant Sciences, University of Oxford, South Parks Road, Oxford, OX1 3RB, UK
| | - Diego Fontaneto
- Department of Life Sciences, Imperial College London, Silwood Park Campus, Ascot, Berkshire, SL5 7PY, UK
- Current address: Institute of Ecosystem Study, National Research Council, Largo Tonolli 50, 28922, Verbania Pallanza, Italy
| | - Elisabeth A Herniou
- Institut de Recherche sur la Biologie de l’Insecte, CNRS UMR 7261, Université François-Rabelais, 37200, Tours, France
| | - Chiara Boschetti
- Department of Chemical Engineering and Biotechnology, University of Cambridge, New Museums Site, Pembroke Street, Cambridge, CB2 3RA, UK
| | - Adrian Carr
- Department of Genetics, University of Cambridge, Downing Street, Cambridge, CB2 3EH, United Kingdom
| | - Gos Micklem
- Department of Genetics, University of Cambridge, Downing Street, Cambridge, CB2 3EH, United Kingdom
| | - Alan Tunnacliffe
- Department of Chemical Engineering and Biotechnology, University of Cambridge, New Museums Site, Pembroke Street, Cambridge, CB2 3RA, UK
| | - Timothy G Barraclough
- Department of Life Sciences, Imperial College London, Silwood Park Campus, Ascot, Berkshire, SL5 7PY, UK
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4
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Cherbas L, Willingham A, Zhang D, Yang L, Zou Y, Eads BD, Carlson JW, Landolin JM, Kapranov P, Dumais J, Samsonova A, Choi JH, Roberts J, Davis CA, Tang H, van Baren MJ, Ghosh S, Dobin A, Bell K, Lin W, Langton L, Duff MO, Tenney AE, Zaleski C, Brent MR, Hoskins RA, Kaufman TC, Andrews J, Graveley BR, Perrimon N, Celniker SE, Gingeras TR, Cherbas P. The transcriptional diversity of 25 Drosophila cell lines. Genome Res 2010; 21:301-14. [PMID: 21177962 DOI: 10.1101/gr.112961.110] [Citation(s) in RCA: 191] [Impact Index Per Article: 13.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/17/2022]
Abstract
Drosophila melanogaster cell lines are important resources for cell biologists. Here, we catalog the expression of exons, genes, and unannotated transcriptional signals for 25 lines. Unannotated transcription is substantial (typically 19% of euchromatic signal). Conservatively, we identify 1405 novel transcribed regions; 684 of these appear to be new exons of neighboring, often distant, genes. Sixty-four percent of genes are expressed detectably in at least one line, but only 21% are detected in all lines. Each cell line expresses, on average, 5885 genes, including a common set of 3109. Expression levels vary over several orders of magnitude. Major signaling pathways are well represented: most differentiation pathways are "off" and survival/growth pathways "on." Roughly 50% of the genes expressed by each line are not part of the common set, and these show considerable individuality. Thirty-one percent are expressed at a higher level in at least one cell line than in any single developmental stage, suggesting that each line is enriched for genes characteristic of small sets of cells. Most remarkable is that imaginal disc-derived lines can generally be assigned, on the basis of expression, to small territories within developing discs. These mappings reveal unexpected stability of even fine-grained spatial determination. No two cell lines show identical transcription factor expression. We conclude that each line has retained features of an individual founder cell superimposed on a common "cell line" gene expression pattern.
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Affiliation(s)
- Lucy Cherbas
- Center for Genomics and Bioinformatics, Indiana University, Bloomington, Indiana 47405, USA.
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5
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Nielsen MG, Gadagkar SR, Gutzwiller L. Tubulin evolution in insects: gene duplication and subfunctionalization provide specialized isoforms in a functionally constrained gene family. BMC Evol Biol 2010; 10:113. [PMID: 20423510 PMCID: PMC2880298 DOI: 10.1186/1471-2148-10-113] [Citation(s) in RCA: 33] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/11/2009] [Accepted: 04/27/2010] [Indexed: 11/26/2022] Open
Abstract
Background The completion of 19 insect genome sequencing projects spanning six insect orders provides the opportunity to investigate the evolution of important gene families, here tubulins. Tubulins are a family of eukaryotic structural genes that form microtubules, fundamental components of the cytoskeleton that mediate cell division, shape, motility, and intracellular trafficking. Previous in vivo studies in Drosophila find a stringent relationship between tubulin structure and function; small, biochemically similar changes in the major alpha 1 or testis-specific beta 2 tubulin protein render each unable to generate a motile spermtail axoneme. This has evolutionary implications, not a single non-synonymous substitution is found in beta 2 among 17 species of Drosophila and Hirtodrosophila flies spanning 60 Myr of evolution. This raises an important question, How do tubulins evolve while maintaining their function? To answer, we use molecular evolutionary analyses to characterize the evolution of insect tubulins. Results Sixty-six alpha tubulins and eighty-six beta tubulin gene copies were retrieved and subjected to molecular evolutionary analyses. Four ancient clades of alpha and beta tubulins are found in insects, a major isoform clade (alpha 1, beta 1) and three minor, tissue-specific clades (alpha 2-4, beta 2-4). Based on a Homarus americanus (lobster) outgroup, these were generated through gene duplication events on major beta and alpha tubulin ancestors, followed by subfunctionalization in expression domain. Strong purifying selection acts on all tubulins, yet maximum pairwise amino acid distances between tubulin paralogs are large (0.464 substitutions/site beta tubulins, 0.707 alpha tubulins). Conversely orthologs, with the exception of reproductive tissue isoforms, show little sequence variation except in the last 15 carboxy terminus tail (CTT) residues, which serve as sites for post-translational modifications (PTMs) and interactions with microtubule-associated proteins. CTT residues overwhelming comprise the co-evolving residues between Drosophila alpha 2 and beta 3 tubulin proteins, indicating CTT specializations can be mediated at the level of the tubulin dimer. Gene duplications post-dating separation of the insect orders are unevenly distributed, most often appearing in major alpha 1 and minor beta 2 clades. More than 40 introns are found in tubulins. Their distribution among tubulins reveals that insertion and deletion events are common, surprising given their potential for disrupting tubulin coding sequence. Compensatory evolution is found in Drosophila beta 2 tubulin cis-regulation, and reveals selective pressures acting to maintain testis expression without the use of previously identified testis cis-regulatory elements. Conclusion Tubulins have stringent structure/function relationships, indicated by strong purifying selection, the loss of many gene duplication products, alpha-beta co-evolution in the tubulin dimer, and compensatory evolution in beta 2 tubulin cis-regulation. They evolve through gene duplication, subfunctionalization in expression domain and divergence of duplication products, largely in CTT residues that mediate interactions with other proteins. This has resulted in the tissue-specific minor insect isoforms, and in particular the highly diverse α3, α4, and β2 reproductive tissue-specific tubulin isoforms, illustrating that even a highly conserved protein family can participate in the adaptive process and respond to sexual selection.
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Affiliation(s)
- Mark G Nielsen
- Department of Biology, University of Dayton, OH 45467, USA.
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6
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Song L, Liu XX, Zhang YA, Zhang QW, Zhao ZW. The cloning and expression of alpha-tubulin in Monochamus alternatus. INSECT MOLECULAR BIOLOGY 2008; 17:495-504. [PMID: 18754809 DOI: 10.1111/j.1365-2583.2008.00818.x] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/26/2023]
Abstract
The Japanese pine sawyer Monochamus alternatus is one of the major forest pests. It damages pine directly and transfers the nematode Bursaphelenchus xylophilus to pine wood; resulting in serious economic losses around the world every year. Alpha-tubulin is one of most important proteins in most species. We cloned a ubiquitously expressed M. alternatus alpha-tubulin gene and analysed its nucleotides and protein structure; its sequence characters are consistent with what have been reported in other insects. The alignment of proteins showed that there is high homology of alpha-tubulin between M. alternatus and other species. Western blot and immunocytochemistry analyses suggested a common epitope of alpha-tubulin between M. alternatus and Strongylcentrotus purpuratus. We also expressed the protein in Escherichia coli for further functional studies.
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Affiliation(s)
- L Song
- Department of Entomology, College of Agronomy and Biotechnology, China Agricultural University, Beijing,China
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7
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Stathopoulos A, Van Drenth M, Erives A, Markstein M, Levine M. Whole-genome analysis of dorsal-ventral patterning in the Drosophila embryo. Cell 2002; 111:687-701. [PMID: 12464180 DOI: 10.1016/s0092-8674(02)01087-5] [Citation(s) in RCA: 231] [Impact Index Per Article: 10.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/15/2022]
Abstract
The maternal Dorsal regulatory gradient initiates the differentiation of several tissues in the early Drosophila embryo. Whole-genome microarray assays identified as many as 40 new Dorsal target genes, which encode a broad spectrum of cell signaling proteins and transcription factors. Evidence is presented that a tissue-specific form of the NF-Y transcription complex is essential for the activation of gene expression in the mesoderm. Tissue-specific enhancers were identified for new Dorsal target genes, and bioinformatics methods identified conserved cis-regulatory elements for coordinately regulated genes that respond to similar thresholds of the Dorsal gradient. The new Dorsal target genes and enhancers represent one of the most extensive gene networks known for any developmental process.
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Affiliation(s)
- Angelike Stathopoulos
- Department of Molecular and Cell Biology, Division of Genetics and Development, 401 Barker Hall, University of California, Berkeley, Berkeley, CA 94720, USA
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8
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Drosopoulou E, Wiebauer K, Yiangou M, Mavragani-Tsipidou P, Domdey H, Scouras ZG. Isolation, characterization, and localization of beta-tubulin genomic clones of three Drosophila montium subgroup species. Genome 2002; 45:604-7. [PMID: 12033631 DOI: 10.1139/g02-020] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
Genomic libraries were constructed from three Drosophila species, namely Drosophila auraria, Drosophila serrata, and Drosophila kikkawai, belonging to the Drosophila montium subgroup of the Drosophila melanogaster species group. Clones containing beta-tubulin specific sequences were isolated, characterized by restriction endonuclease digestions and Southern hybridizations, and mapped by in situ hybridization on the polytene chromosomes of the species studied. The distribution of the beta-tubulin loci was found to be similar in D. montium species and D. melanogaster.
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Affiliation(s)
- Elena Drosopoulou
- Department of Genetics, Development, and Molecular Biology, School of Biology, Faculty of Science, Aristole University of Thessaloniki, Greece.
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9
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Affiliation(s)
- P P D'Avino
- Howard Hughes Medical Institute, Department of Human Genetics, University of Utah, Salt Lake City 84112-5331, USA
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10
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Drosopoulou E, Scouras ZG. The organization of the alpha-tubulin gene family in the Drosophila montium subgroup of the melanogaster species group. Genome 1998; 41:504-9. [PMID: 9796099 DOI: 10.1139/g98-042] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
The alpha 1-, alpha 2-, alpha 3-, and alpha 4-tubulin genes have been mapped by in situ hybridization to the polytene chromosomes of five species representative of the Drosophila montium subgroup geographical distribution. A lambda phage clone containing alpha 1-tubulin specific sequences was isolated from a genomic DNA library of Drosophila auraria and its restriction endonuclease pattern is presented. Both well-characterized heterologous and homologous probes were used to assess orthogonality of gene members between species groups. The in situ hybridization pattern observed in all species studied is consistent with that of Drosophila melanogaster, since alpha 1-, alpha 2-, and alpha 3-tubulin genes are located on the same polytene arm, and the alpha 4-tubulin gene is found on a different arm. Cross-hybridization was observed among alpha 1-, alpha 2-, and alpha 3-tubulin specific sequences in all species studied, using either heterologous or homologous probes. However, unlike D. melanogaster, in all montium species studied, both alpha 1- and alpha 3-tubulin specific probes hybridize to the same polytene band, indicating a clustered organization of the above genes. The chromosomal organization of this gene family would suggest that taxa within the montium subgroup are closer to their common ancestors than are the taxa in the melanogaster species group. A mode of evolution for this gene family in Drosophila is proposed.
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Affiliation(s)
- E Drosopoulou
- Department of Genetics, Development and Molecular Biology, School of Biology, Faculty of Science, Aristotle University of Thessaloniki, Greece
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11
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Rybczynski R, Gilbert LI. Cloning of a beta1 tubulin cDNA from an insect endocrine gland: developmental and hormone-induced changes in mRNA expression. Mol Cell Endocrinol 1998; 141:141-51. [PMID: 9723895 DOI: 10.1016/s0303-7207(98)00083-5] [Citation(s) in RCA: 13] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/20/2022]
Abstract
A rapid increase in ecdysteroid hormone synthesis results when the insect prothoracic gland is stimulated with prothoracicotropic hormone (PTTH), a brain neuropeptide hormone. PTTH also stimulates the specific synthesis of several proteins, one of which is a beta tubulin. To further understand the possible roles of beta tubulin in the prothoracic gland, beta tubulin cDNA clones were isolated from a tobacco hornworm (Manduca sexta) gland cDNA library. Sequence analysis indicated that these clones were assignable to the beta1 tubulin isoform. Gland beta1 tubulin mRNA levels during the last larval instar and early pupal-adult development exhibited peaks that coincided with peaks in ecdysteroid synthesis. Manipulations of the glands hormonal milieu showed that beta1 tubulin mRNA levels respond to 20 hydroxyecdysone and PTTH. The data also support our earlier proposal that the prothoracic gland beta1 tubulin gene is ubiquitously expressed but exhibits tissue- and developmental-specific regulation of transcription and translation.
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Affiliation(s)
- R Rybczynski
- Department of Biology, University of North Carolina at Chapel Hill, 27599, USA.
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12
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Mathe E, Boros I, Josvay K, Li K, Puro J, Kaufman TC, Szabad J. The Tomaj mutant alleles of alpha Tubulin67C reveal a requirement for the encoded maternal specific tubulin isoform in the sperm aster, the cleavage spindle apparatus and neurogenesis during embryonic development in Drosophila. J Cell Sci 1998; 111 ( Pt 7):887-96. [PMID: 9490633 DOI: 10.1242/jcs.111.7.887] [Citation(s) in RCA: 14] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
The three dominant TomajD and their eleven revertant (TomajR) alleles have been localized to the alpha Tubulin67C gene of Drosophila melanogaster. Although the meiotic divisions are normally completed in eggs laid by TomajD/+, TomajD/-, TomajR/- females, embryogenesis arrests prior to the gonomeric division. The arrest is caused by: (1) the failure of prominent sperm aster formation; and (2) a consequent lack of female pronuclear migration towards the male pronucleus. Concomitant with the sperm aster defect, the four female meiotic products fuse (tetra-fusion), similar to what is seen in eggs of wild-type virgin females. In eggs of females heterozygous for weaker TomajR alleles, embryogenesis comes to a cessation before or shortly after cortical migration of cleavage nuclei. The apparent source of embryonic defect is the cleavage spindle apparatus. One of the three TomajD alleles is cold-sensitive and its cold-sensitive period coincides with the completion of female meiosis and pronuclear migration. Disorganized central and peripheral nervous systems are also characteristic of embryos derived from the temperature-sensitive TomajD/+ females. The Tomaj mutant phenotypes indicate an involvement of the normal alpha Tubulin67C gene product in: (1) the formation of the sperm aster; (2) cleavage spindle apparatus formation/function; and (3) the differentiation of the embryonic nervous system. The TomajD alleles encode a normal-sized alpha Tubulin67C isotype. Sequence analyses of the TomajD alleles revealed the replacement in different positions of a single negatively charged or neutral amino acid with a positively charged one. These residues presumably identify important functional sites.
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Affiliation(s)
- E Mathe
- Department of Biology, Albert Szent-Györgyi Medical University, Szeged, Hungary
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13
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Hachouf-Gheras S, Besson MT, Bosquet G. Identification and developmental expression of a Bombyx mori alpha-tubulin gene. Gene 1998; 208:89-94. [PMID: 9479055 DOI: 10.1016/s0378-1119(97)00660-4] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/06/2023]
Abstract
A cDNA clone isolated from the wing discs at the metamorphosis of Bombyx mori during the period of morphogenesis has been characterized. The amino acid sequence predicted for the putative protein is highly homologous to the Drosophila alpha1-tubulin. This is the first alpha-tubulin gene isolated in Bombyx mori and other isotype sequences are present in the Bombyx genome. The transcript is detected in the wing discs at every postembryonic stage examined, and is also expressed in other tissues, but at different levels. Although the mRNA level is maximum when the 20-hydroxyecdysone titre is high, its accumulation is independent of the hormone level both in vivo and in vitro. Significance of the accumulation of the mRNA of an ubiquitous alpha-tubulin in developing wing discs is discussed by comparison with our knowledge of the alpha-tubulin family in Drosophila and in other organisms.
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MESH Headings
- Amino Acid Sequence
- Animals
- Base Sequence
- Blotting, Northern
- Blotting, Southern
- Bombyx/genetics
- Bombyx/growth & development
- Bombyx/metabolism
- Cloning, Molecular
- DNA, Complementary
- Ecdysterone/metabolism
- Ecdysterone/pharmacology
- Gene Expression Regulation, Developmental
- Metamorphosis, Biological
- Molecular Sequence Data
- Organ Specificity
- RNA, Messenger/genetics
- RNA, Messenger/metabolism
- Tubulin/genetics
- Wings, Animal/growth & development
- Wings, Animal/metabolism
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Affiliation(s)
- S Hachouf-Gheras
- Centre de Génétique Moléculaire et Cellulaire-UMR CNRS 5534, Université Lyon-1, 43, boulevard du 11 novembre 1918, 69622, Villeurbanne, Cedex, France
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14
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Casal J, Leptin M. Identification of novel genes in Drosophila reveals the complex regulation of early gene activity in the mesoderm. Proc Natl Acad Sci U S A 1996; 93:10327-32. [PMID: 8816799 PMCID: PMC38383 DOI: 10.1073/pnas.93.19.10327] [Citation(s) in RCA: 32] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/02/2023] Open
Abstract
Two zygotic genes, twist and snail, are indispensable for the correct establishment of the mesoderm primordium in the early Drosophila embryo. They are also needed for morphogenesis and differentiation of the mesoderm. Both genes code for transcription factors with different, albeit complementary, functions. Therefore, to understand the early development of the mesoderm, it will be necessary to identify and study the genes regulated by twist and snail. We have searched for downstream genes using a subtractive cDNA library enriched in sequences expressed in the mesoderm. We have isolated sequences that correspond to 13 novel early mesoderm genes. These novel genes show a variety of expression patterns and also differ in their dependence on twist and snail functions. This indicates that the regulation of early gene activity in the mesoderm is more complex than previously thought.
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Affiliation(s)
- J Casal
- Max-Planck-Institut für Entwicklungsbiologie, Tübingen, Germany
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15
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Demers DM, Metcalf AE, Talbot P, Hyman BC. Multiple lobster tubulin isoforms are encoded by a simple gene family. Gene 1996; 171:185-91. [PMID: 8666270 DOI: 10.1016/0378-1119(96)00006-6] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/01/2023]
Abstract
Microtubule proteins isolated from pleopod tegumental gland (PTG) tissue of the American lobster, Homarus americanus, reveal a complex tubulin (Tub) profile. To determine whether Tub heterogeneity in PTG is due to expression of a large tub gene family or the result of post-translational modification, a PTG cDNA library was constructed. Clones coding for both alpha- and beta-Tub were isolated, sequenced and found to contain open reading frames (ORFs) of 451 amino acids (aa). Alignments reveal phylogenetic clustering with other arthropods and identify unique changes in primary structure which may have functional significance. These clones, when used to probe restriction enzyme-digested lobster genomic DNA in transfer-hybridization experiments, revealed a simple banding pattern indicating a lobster tub gene family of limited complexity. Lobsters appear to make use of a small tub gene family and fulfill the varied functional requirements imposed upon cellular microtubules through post-translational modifications of relatively few gene products.
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Affiliation(s)
- D M Demers
- Department of Biology, University of California at Riverside 92521, USA
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16
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The ?-tubulin gene family evolution in theDrosophila montium subgroup of themelanogaster species group. J Mol Evol 1995. [DOI: 10.1007/bf01215176] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/25/2022]
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17
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Fukushige T, Yasuda H, Siddiqui SS. Selective expression of the tba-1 alpha tubulin gene in a set of mechanosensory and motor neurons during the development of Caenorhabditis elegans. BIOCHIMICA ET BIOPHYSICA ACTA 1995; 1261:401-16. [PMID: 7742369 DOI: 10.1016/0167-4781(95)00028-f] [Citation(s) in RCA: 22] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/26/2023]
Abstract
In the nematode Caenorhabditis elegans, a monoclonal antibody 3A5 raised against Drosophila alpha tubulins selectively stains the nervous system immuno-cytochemically. Direct screening of a C. elegans cDNA expression library with 3A5 has allowed cloning of the tba-1 (tubulin alpha-1) gene from C. elegans. The corresponding genomic DNA encodes a protein of 449 amino acid residues that has a high homology with the vertebrate alpha tubulins but a lower homology with yeast alpha tubulins. Interestingly, the carboxyl-terminus sequence EEEGEEY (Glu-Glu-Glu-Gly-Glu-Glu-Tyr) of the nematode tba-1 encoded isotype is identical to these residues in human, mouse, rat, pig and chicken alpha-1 tubulin isotypes that are expressed in the brain. Temporal and spatial expression studies of the tba-1 gene using Northern blot analysis and tba-1::lacZ fusion gene expression analysis during embryonic and the postembryonic development of C. elegans reveal that the tba-1 tubulin is preferentially expressed in the nematode nervous system, especially in a set of mechanosensory neurons and a set of ventral cord motor neurons (DA, DB, VA, and VB) during embryonic and postembryonic development. Our results indicate an inter-species conservation of the alpha tubulin carboxyl-terminal domain in functionally related brain specific isotypes from metazoans as divergent as mammals and nematodes. These results also suggest specificity of the individual alpha tubulin isotypes during neural development.
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Affiliation(s)
- T Fukushige
- Department of Ecological Engineering, Toyohashi University of Technology, Japan
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18
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O'Donnell KH, Wensink PC. GAGA factor and TBF1 bind DNA elements that direct ubiquitous transcription of the Drosophila alpha 1-tubulin gene. Nucleic Acids Res 1994; 22:4712-8. [PMID: 7984422 PMCID: PMC308522 DOI: 10.1093/nar/22.22.4712] [Citation(s) in RCA: 15] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/28/2023] Open
Abstract
Three DNA regions (TE1, TE2 and the intron) regulate the ubiquitous expression of the alpha 1-tubulin gene of Drosophila melanogaster. In this report, we identify two proteins that bind these DNA regions. One is the previously characterized GAGA transcription factor and the other is a newly identified 62 kDa polypeptide, TBF1 (TE1-binding factor 1). Purified GAGA factor binds three sites in TE2 and at least three in the intron. TBF1 was purified from embryos and binds to both TE1 and TE2. Together, the two proteins produce the same DNase I footprints in TE1 and TE2 as does a nuclear extract that transcribes the gene accurately. These footprints cover most of the TE1 and TE2 DNA. Moreover, one binding site for each protein coincides with a site that activates transcription in vitro. The characteristics of the GAGA factor and the genes it regulates suggest roles these two proteins are likely to play in regulating ubiquitous expression.
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Affiliation(s)
- K H O'Donnell
- Department of Biochemistry, Brandeis University, Waltham, MA 02254-9110
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19
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Insulating DNA directs ubiquitous transcription of the Drosophila melanogaster alpha 1-tubulin gene. Mol Cell Biol 1994. [PMID: 8065369 DOI: 10.1128/mcb.14.9.6398] [Citation(s) in RCA: 36] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
We identify DNA regions that are necessary for the ubiquitous expression of the Drosophila melanogaster alpha 1-tubulin (alpha 1t) gene. In vitro transcription showed that two upstream regions, tubulin element 1 (TE1 [29 bp]) and tubulin element 2 (TE2 [68 bp]), and a downstream region activate transcription. Germ line transformation demonstrated that these three regions are sufficient to direct the alpha 1t core promoter to begin transcribing at the stage of cellular blastoderm formation and to continue thereafter at high levels in all tissues and developmental stages. Remarkably, mutation of any one of these regions results in high sensitivity to chromosomal position effects, producing different but reproducible tissue-specific patterns of expression in each transformed line. None of these regions behaves as an enhancer in a conventional germ line transformation test. These observations show that these three regions, two of which bind the GAGA transcription factor, act ubiquitously to insulate from position effects and to activate transcription. The results also provide vectors for ubiquitous expression of gene products and for examining silencer activities.
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20
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O'Donnell KH, Chen CT, Wensink PC. Insulating DNA directs ubiquitous transcription of the Drosophila melanogaster alpha 1-tubulin gene. Mol Cell Biol 1994; 14:6398-408. [PMID: 8065369 PMCID: PMC359165 DOI: 10.1128/mcb.14.9.6398-6408.1994] [Citation(s) in RCA: 22] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/28/2023] Open
Abstract
We identify DNA regions that are necessary for the ubiquitous expression of the Drosophila melanogaster alpha 1-tubulin (alpha 1t) gene. In vitro transcription showed that two upstream regions, tubulin element 1 (TE1 [29 bp]) and tubulin element 2 (TE2 [68 bp]), and a downstream region activate transcription. Germ line transformation demonstrated that these three regions are sufficient to direct the alpha 1t core promoter to begin transcribing at the stage of cellular blastoderm formation and to continue thereafter at high levels in all tissues and developmental stages. Remarkably, mutation of any one of these regions results in high sensitivity to chromosomal position effects, producing different but reproducible tissue-specific patterns of expression in each transformed line. None of these regions behaves as an enhancer in a conventional germ line transformation test. These observations show that these three regions, two of which bind the GAGA transcription factor, act ubiquitously to insulate from position effects and to activate transcription. The results also provide vectors for ubiquitous expression of gene products and for examining silencer activities.
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Affiliation(s)
- K H O'Donnell
- Department of Biochemistry, Brandeis University, Waltham, Massachusetts 02254-9110
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21
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Scouras ZG, Milioni D, Yiangou M, Duchêne M, Domdey H. The beta-tubulin genes of Drosophila auraria are arranged in a cluster. Curr Genet 1994; 25:84-7. [PMID: 8082170 DOI: 10.1007/bf00712973] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/28/2023]
Abstract
When the beta 1-, beta 2- and beta 3-tubulin-specific DNAs from Drosophila melanogaster were used as probes to recognize tubulin-specific sequences in the chromosomes of Drosophila auraria, they were found to hybridize to the same polytene band in region 32C of the 2L polytene chromosome. Three overlapping clones were isolated from a lambda EMBL3 genomic library of D. auraria, and they all contain beta-tubulin-specific sequences based on hybridization and partial-sequencing experiments of subcloned fragments. These clones hybridize in situ to the same polytene chromosome band in region 32C and they represent an approximately 35-kb fragment of genomic DNA.
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Affiliation(s)
- Z G Scouras
- Department of Genetics, School of Biology, Faculty of Science, Aristotelian University of Thessaloniki, Greece
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22
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Buttgereit D, Renkawitz-Pohl R. Expression of beta 1 tubulin (beta Tub56D) in Drosophila testis stem cells is regulated by a short upstream sequence while intron elements guide expression in somatic cells. MOLECULAR & GENERAL GENETICS : MGG 1993; 241:263-70. [PMID: 8246879 DOI: 10.1007/bf00284677] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/29/2023]
Abstract
Stem cell differentiation to mature spermatozoa is a morphogenetic process that is highly dependent on microtubular arrays. In the early, mitotically active stages of spermatogenesis, only the beta 1 tubulin isotype is expressed. Analysis of transgenic flies containing beta 1-lacZ gene fusions revealed that this expression is regulated by sequences located between positions -45 and -191 upstream of the transcription initiation site. Furthermore, beta 1 tubulin is a major component of cyst cells. Expression in these cells is driven by enhancer elements located in the beta 1 tubulin gene intron. These enhancer elements also guide expression in combination with the hsp70 basal promoter. In addition, redundant enhancer elements in the intron drive expression in the testis wall. Our data show that within a single tissue, the male gonad, expression of the beta 1 tubulin gene is under cell-type-specific control mediated by independent cis-acting elements. Therefore in the germ line, control of beta 1 tubulin expression is strictly governed by promoter-proximal elements, while for the somatic parts of the testis, enhancer elements confer less stringent expression control.
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Affiliation(s)
- D Buttgereit
- Fachbereich Biologie, Philipps-Universität Marburg, Germany
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23
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Chapel S, Sobrier ML, Montpied P, Micard D, Bruhat A, Couderc JL, Dastugue B. In Drosophila Kc cells 20-OHE induction of the 60C beta3 tubulin gene expression is a primary transcriptional event. INSECT MOLECULAR BIOLOGY 1993; 2:39-48. [PMID: 9087542 DOI: 10.1111/j.1365-2583.1993.tb00124.x] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/22/2023]
Abstract
In Drosophila Kc cells, the 60C beta3 tubulin transcription unit, whose expression is induced by 20-hydroxyecdysone (20-OHE), has the same structure as in Drosophila. This gene is characterized by an unusual 5' intron of regulating importance, by an alternatively spliced second intron and by a long 3' transcribed but untranslated region. This gene codes for two beta3 tubulin isoforms with one amino acid difference. We have established that beta3 tubulin gene expression is transcriptionally regulated by the steroid hormone in a time and hormonal concentration-dependent fashion, without requirement of protein synthesis. This implies that this transcriptional induction is a primary event and that this gene is probably a direct target for the 20-OHE receptor.
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Affiliation(s)
- S Chapel
- Laboratoire de Biochemie Médicale, Faculté de Médecine, Clermont Ferrand, France
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24
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Tourmente S, Chapel S, Dreau D, Drake ME, Bruhat A, Couderc JL, Dastugue B. Enhancer and silencer elements within the first intron mediate the transcriptional regulation of the beta 3 tubulin gene by 20-hydroxyecdysone in Drosophila Kc cells. INSECT BIOCHEMISTRY AND MOLECULAR BIOLOGY 1993; 23:137-143. [PMID: 8485515 DOI: 10.1016/0965-1748(93)90092-7] [Citation(s) in RCA: 24] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/22/2023]
Abstract
We have studied the transcriptional regulation of the beta 3 tubulin gene by the steroid hormone 20-hydroxyecdysone (20-E) in Drosophila Kc cells. A series of hybrid genes, with different fragments of the beta 3 tubulin gene driving the bacterial chloramphenicol acetyl transferase (CAT) gene were constructed. The promoter activity was assayed after transient expression in Kc cells, in the presence and the absence of 20-E. Constructs with 0.91 kb upstream from the transcription start site and 360 bp from the first large intron allowed the hormonal regulation, i.e. a repression in the absence of 20-E and a derepression-activation in the presence of the hormone. This 360 bp fragment contains several enhancers and silencer(s) sequences. The regulation of the expression of the beta 3 tubulin gene results from the combined activity of all the positive and negative regulatory sequences of the first intron, and a dialogue with the promoter sequences. The nucleotide sequence of this intronic regulatory-fragment has been established and we have identified several EcRE (ecdysone responsive element) consensus sequences.
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Affiliation(s)
- S Tourmente
- Laboratoire de Biochemie Médicale, CJF INSERM 88.06, UFR de Médecine, Clermont-Ferrand, France
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25
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Theurkauf WE. Behavior of structurally divergent alpha-tubulin isotypes during Drosophila embryogenesis: evidence for post-translational regulation of isotype abundance. Dev Biol 1992; 154:205-17. [PMID: 1426627 DOI: 10.1016/0012-1606(92)90060-t] [Citation(s) in RCA: 51] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/27/2022]
Abstract
Two major alpha-tubulin isotypes are present during Drosophila embryogenesis: an evolutionarily divergent maternal isotype that is synthesized only in the ovary and deposited in the oocyte and a highly conserved constitutive isotype that is both maternally supplied and zygotically synthesized. A maternal isotype-specific antibody and a monoclonal antibody that recognizes both the maternal and constitutive isotypes were characterized and used to determine the distribution and abundance of alpha-tubulins during embryogenesis. Both isotypes are abundant and assemble into all classes of microtubules from the syncytial blastoderm stage until completion of germ band retraction. During subsequent development, however, the maternal isotype is retained only in the developing CNS, and later in a subset of connective fibers within the CNS. In contrast, total alpha-tubulin levels remain high in essentially all tissues throughout embryogenesis, indicating that most tissues selectively accumulate the constitutive isotype. To determine if selective accumulation of the constitutive isotype requires zygotic synthesis of this protein, mutant embryos that do not contain functional constitutive alpha-tubulin genes were examined. In these embryos, as in wild type, the maternal isotype decreases to background levels in tissues that retain high levels of the constitutive isotype. The constitutive isotype therefore appears to be more stable than the maternal isotype in most tissues. Differences in isotype stability may play an important role in determining the developmental pattern of isotype accumulation in Drosophila embryos.
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Affiliation(s)
- W E Theurkauf
- Department of Biochemistry and Biophysics, University of California, San Francisco 94143-0448
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26
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Guénette S, Prichard RK, Matlashewski G. Identification of a novel Brugia pahangi beta-tubulin gene (beta 2) and a 22-nucleotide spliced leader sequence on beta 1-tubulin mRNA. Mol Biochem Parasitol 1992; 50:275-84. [PMID: 1741015 DOI: 10.1016/0166-6851(92)90225-9] [Citation(s) in RCA: 14] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/28/2022]
Abstract
We have examined the expression of beta-tubulin genes in the parasitic nematode, Brugia pahangi. A genomic library was constructed and screened by hybridization with a Haemonchus contortus beta-tubulin cDNA fragment which recognizes several B. pahangi beta-tubulin sequences, including sequences which correspond to the previously characterized beta 1-tubulin gene. The B. pahangi beta 2-tubulin gene was isolated by selecting clones which hybridize to the H. contortus beta-tubulin gene but which do not hybridize to the beta 1-tubulin gene. A partial sequence of the beta 2-tubulin gene confirms that it codes for a distinct beta-tubulin. Southern hybridization analyses show that the beta 2-tubulin sequence exists as a single copy gene within the B. pahangi genome. Expression of the beta 2-tubulin gene is developmentally regulated and the message is found predominantly in adult male worms, whereas the beta 1-tubulin gene is expressed in microfilariae and approximately equal levels of the transcript are found in male and female adult worms. During mRNA maturation the beta 1-tubulin mRNA of microfilariae and adult worms acquires a trans-spliced leader identical to the SL1 of Caenorhabditis elegans.
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Affiliation(s)
- S Guénette
- Institute of Parasitology, McGill University, Ste-Anne de Bellevue, Quebec, Canada
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27
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Natzle JE, Robertson JP, Majumdar A, Vesenka GD, Enlow B, Clark KE. Sequence and expression of IMP-L1, an ecdysone-inducible gene expressed during Drosophila imaginal disc morphogenesis. DEVELOPMENTAL GENETICS 1992; 13:331-44. [PMID: 1292892 DOI: 10.1002/dvg.1020130504] [Citation(s) in RCA: 16] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/26/2022]
Abstract
Drosophila imaginal discs are induced by the steroid hormone 20-hydroxyecdysone to initiate morphogenesis leading to formation of the adult appendages and thoracic epidermis at the end of the third larval instar. Ecdysone-dependent transcriptional activation of a set of genes that encode imaginal disc transcripts found on membrane-bound polysomes precedes and may be responsible for some aspects of the cellular changes that mediate epithelial morphogenesis in this system. A 1.35 kb transcript from one of these genes, IMP-L1, is first observed in vivo at or just prior to pupariation, as ecdysone titers are peaking and beginning to decline. Expression is initiated in proximal areas of the antennal disc, later spreading to a more widespread but nonuniform distribution throughout other thoracic imaginal discs. IMP-L1 is not, however, expressed in other ecdysone target tissues such as salivary glands or fat body. The IMP-L1 gene encodes a novel protein product containing a signal peptide, a possible transmembrane domain, two highly charged domains and a proline rich C-terminal domain. We suggest that the delayed timing of expression of this secondary response gene is necessary for proper ordering of cellular events associated with disc morphogenesis.
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Affiliation(s)
- J E Natzle
- Department of Zoology, University of California, Davis 95616-8755
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28
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Langdon CM, Rafiee P, MacRae TH. Synthesis of tubulin during early postgastrula development of Artemia: isotubulin generation and translational regulation. Dev Biol 1991; 148:138-46. [PMID: 1718798 DOI: 10.1016/0012-1606(91)90324-v] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/28/2022]
Abstract
Isotubulin diversity and the synthesis of tubulin were examined during development of the brine shrimp, Artemia. It was found, by Northern and dot-blot analyses, that Artemia possess constant amounts of one size class of mRNA each for alpha- and beta-tubulin during the first 24 hr of postgastrula development. Two-dimensional gel electrophoresis and fluorography, following the in vitro translation of developmentally staged poly(A)+ mRNA, yielded one alpha- and one beta-tubulin. Clearly, the isotubulin diversity seen on Coomassie blue-stained two-dimensional gels of Artemia tubulin is not generated by differential gene transcription during postgastrula growth, nor is development accompanied by synthesis of novel isotubulins resolvable by the methods employed. Characterization of polysomal poly(A)+ mRNA, and of proteins synthesized in vivo, indicated very little tubulin was synthesized in Artemia as they developed from gastrula to first instar larvae. The results suggest control of tubulin synthesis in Artemia by a mechanism that restricts binding of the message to ribosomes. Of general significance, it appears that a complex metazoan animal is able to undergo extensive growth with limited tubulin synthesis and in the absence of differential expression of tubulin genes. Moreover, the capacity of microtubules to assume changing and/or increased functions associated with cellular development is seemingly not dependent on the synthesis of new tubulin isoforms.
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Affiliation(s)
- C M Langdon
- Department of Biology, Dalhousie University, Halifax, Nova Scotia, Canada
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29
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Michiels F, Wolk A, Renkawitz-Pohl R. Further sequence requirements for male germ cell-specific expression under the control of the 14 bp promoter element (beta 2UE1) of the Drosophila beta 2 tubulin gene. Nucleic Acids Res 1991; 19:4515-21. [PMID: 1909432 PMCID: PMC328643 DOI: 10.1093/nar/19.16.4515] [Citation(s) in RCA: 20] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/29/2022] Open
Abstract
We have investigated a 14 bp promoter element (beta 2UE1) that is required for testis-specific expression of the Drosophila beta 2 tubulin gene. To further elucidate the role of the 14 bp element, we fused different promoter constructs to the E. coli lacZ gene and established transgenic strains with the aid of the Drosophila P-element transformation system. Germ line transformation experiments with constructs in which the element in the beta 2 tubulin gene promoter was exchanged for a related sequence from the promoter region of the Drosophila beta 3 tubulin gene led to a dramatic reduction in the expression of the lacZ gene in the testis. Exchanging the 14 bp promoter element for a similar sequence from the distal promoter of the Drosophila alcohol dehydrogenase gene abolished expression. This might indicate that the sequence differences between the beta 2UE1 and the beta 2UE1-related elements reflect functional differences between these elements. Constructs in which the beta 2UE1 was fused to the hsp70 promoter revealed that testis-specific expression of a marker gene is obtained only when the element is located at the correct distance from the transcription initiation site. However, constructs in which the beta 2UE1 was inserted at about the correct position (between -41 and -54 bp) upstream of a truncated beta 3 tubulin gene promoter did not show any expression. By making beta 2-beta 3 gene promoter fusions it was found that both the region surrounding the beta 3 transcription initiation site as well as the first 116 b of beta 3 leader sequences independently reduce testis-specific expression. These findings suggest that the testis-specific expression of the Drosophila beta 2 tubulin gene underlies a unique regulatory mechanism.
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Affiliation(s)
- F Michiels
- Genzentrum am MPI für Biochemie, Martinsried, FRG
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30
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Buttgereit D, Leiss D, Michiels F, Renkawitz-Pohl R. During Drosophila embryogenesis the beta 1 tubulin gene is specifically expressed in the nervous system and the apodemes. Mech Dev 1991; 33:107-18. [PMID: 1903298 DOI: 10.1016/0925-4773(91)90077-j] [Citation(s) in RCA: 30] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/29/2022]
Abstract
We determined the in vivo distribution of the beta 1 tubulin from D. melanogaster using isotype specific antibodies. Maternally expressed beta 1 tubulin is incorporated into mitotic spindles. Later in development a strong expression in the CNS is observed. Furthermore, all chordotonal organs and the apodemes are marked by beta 1 tubulin. Nuclear run-on assays and stage specific in vitro transcription showed a zygotic expression of the beta 1 tubulin gene from the extended germ-band stage onwards. Using the P-element system, we identified several elements; upstream between -2.2 kb and the transcription initiation site, elements for low level expression in the CNS are present. In the intron between +0.44 kb and +2.5 kb enhancer elements are located that drive the expression in the chordotonal organs and the apodemes. Between the start site and +0.44 kb (273 bp) and +2.5 kb and the second exon (315 bp), maternal and CNS enhancers result in full level expression of a lacZ-beta 1 reporter gene. We show, that the beta 1 tubulin gene is very early effector gene starting its expression shortly after the commitment of neuroblast cell fate. This gene offers an excellent model system for the identification of neural and apodeme specific transcription factors.
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Affiliation(s)
- D Buttgereit
- Gentechnologische Arbeitsgruppe am MPI für Biochemie, Martinsried/München, F.R.G
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31
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Abstract
We have tested the functional capacity of different beta tubulin isoforms in vivo by expressing beta 3-tubulin either in place of or in addition to beta 2-tubulin in the male germ line of Drosophila melanogaster. The testes-specific isoform, beta 2, is conserved relative to major metazoan beta tubulins, while the developmentally regulated isoform, beta 3, is considerably divergent in sequence. beta 3-tubulin is normally expressed in discrete subsets of cells at specific times during development, but is not expressed in the male germ line. beta 2-Tubulin is normally expressed only in the postmitotic germ cells of the testis, and is required for all microtubule-based functions in these cells. The normal functions of beta 2-tubulin include assembly of meiotic spindles, axonemes, and at least two classes of cytoplasmic microtubules, including those associated with the differentiating mitochondrial derivatives. A hybrid gene was constructed in which 5' sequences from the beta 2 gene were joined to protein coding and 3' sequences of the beta 3 gene. Drosophila transformed with the hybrid gene express beta 3-tubulin in the postmitotic male germ cells. When expressed in the absence of the normal testis isoform, beta 3-tubulin supports assembly of one class of functional cytoplasmic microtubules. In such males the microtubules associated with the membranes of the mitochondrial derivatives are assembled and normal mitochondrial derivative elongation occurs, but axoneme assembly and other microtubule-mediated processes, including meiosis and nuclear shaping, do not occur. These data show that beta 3 tubulin can support only a subset of the multiple functions normally performed by beta 2, and also suggest that the microtubules associated with the mitochondrial derivatives mediate their elongation. When beta 3 is coexpressed in the male germ line with beta 2, at any level, spindles and all classes of cytoplasmic microtubules are assembled and function normally. However, when beta 3-tubulin exceeds 20% of the total testis beta tubulin pool, it acts in a dominant way to disrupt normal axoneme assembly. In the axonemes assembled in such males, the doublet tubules acquire some of the morphological characteristics of the singlet microtubules of the central pair and accessory tubules. These data therefore unambiguously demonstrate that the Drosophila beta tubulin isoforms beta 2 and beta 3 are not equivalent in intrinsic functional capacity, and furthermore show that assembly of the doublet tubules of the axoneme imposes different constraints on beta tubulin function than does assembly of singlet microtubules.
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Affiliation(s)
- H D Hoyle
- Institute for Molecular and Cellular Biology, Indiana University, Bloomington 47405
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32
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Abstract
In this review, the types of mRNAs found in oocytes and eggs of several animal species, particularly Drosophila, marine invertebrates, frogs, and mice, are described. The roles that proteins derived from these mRNAs play in early development are discussed, and connections between maternally inherited information and embryonic pattern are sought. Comparisons between genetically identified maternally expressed genes in Drosophila and maternal mRNAs biochemically characterized in other species are made when possible. Regulation of the meiotic and early embryonic cell cycles is reviewed, and translational control of maternal mRNA following maturation and/or fertilization is discussed with regard to specific mRNAs.
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33
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Bruhat A, Tourmente S, Chapel S, Sobrier ML, Couderc JL, Dastugue B. Regulatory elements in the first intron contribute to transcriptional regulation of the beta 3 tubulin gene by 20-hydroxyecdysone in Drosophila Kc cells. Nucleic Acids Res 1990; 18:2861-7. [PMID: 2349088 PMCID: PMC330811 DOI: 10.1093/nar/18.10.2861] [Citation(s) in RCA: 39] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/31/2022] Open
Abstract
We have studied the transcriptional regulation of the beta 3 tubulin gene by the steroid hormone 20-hydroxyecdysone (20-OH-E) in Drosophila Kc cells. A series of hybrid genes with varying tubulin gene lengths driving the bacterial chloramphenicol acetyl transferase (CAT) gene were constructed. The promoter activity was assayed after transient expression in Kc cells, in the presence or absence of 20-OH-E. We find that 0.91Kb upstream from the transcription start site contain one or several hormone independent positive cis-acting elements, responsible for the constitutive expression of the beta 3 tubulin gene. In the large (4.5 Kb) first intron of this gene, we identified additional hormone dependent negative and positive regulatory elements, which can act in both directions and in a position-independence manner. Then, the negative intron element(s), which repress the transcription in the absence of 20-OH-E has characteristics of silencer.
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Affiliation(s)
- A Bruhat
- Laboratoire de Biochimie Médicale, CJF INSERM 88.06, Clermont-Ferrand, France
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34
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Hortsch M, Bieber AJ, Patel NH, Goodman CS. Differential splicing generates a nervous system-specific form of Drosophila neuroglian. Neuron 1990; 4:697-709. [PMID: 1693086 DOI: 10.1016/0896-6273(90)90196-m] [Citation(s) in RCA: 144] [Impact Index Per Article: 4.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/28/2022]
Abstract
We recently described the characterization and cloning of Drosophila neuroglian, a member of the immunoglobulin superfamily. Neuroglian contains six immunoglobulin-like domains and five fibronectin type III domains and shows strong sequence homology to the mouse neural cell adhesion molecule L1. Here we show that the neuroglian gene generates at least two different protein products by tissue-specific alternative splicing. The two protein forms differ in their cytoplasmic domains. The long form is restricted to the surface of neurons in the CNS and neurons and some support cells in the PNS; in contrast, the short form is expressed on a wide range of other cells and tissues. Thus, whereas the mouse L1 gene appears to encode only one protein that functions largely as a neural cell adhesion molecule, its Drosophila homolog, the neuroglian gene, encodes at least two protein forms that may play two different roles, one as a neural cell adhesion molecule and the other as a more general cell adhesion molecule involved in other tissues and imaginal disc morphogenesis.
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MESH Headings
- Amino Acid Sequence
- Animals
- Antibodies, Monoclonal/immunology
- Base Sequence
- Cell Adhesion Molecules, Neuronal/genetics
- Cell Adhesion Molecules, Neuronal/immunology
- Cell Adhesion Molecules, Neuronal/metabolism
- Central Nervous System/cytology
- Central Nervous System/metabolism
- Cloning, Molecular
- Cytoplasm/metabolism
- DNA, Recombinant/genetics
- DNA, Recombinant/metabolism
- Drosophila/genetics
- Drosophila Proteins
- Embryo, Nonmammalian/metabolism
- Epitopes/immunology
- Gene Expression Regulation
- Immunoglobulins/genetics
- Immunoglobulins/metabolism
- Immunohistochemistry
- Larva/metabolism
- Larva/physiology
- Molecular Sequence Data
- Neuroglia/cytology
- Neuroglia/metabolism
- Neurons/cytology
- Neurons/metabolism
- Peripheral Nerves/cytology
- Peripheral Nerves/metabolism
- RNA, Messenger/genetics
- RNA, Messenger/metabolism
- Transcription, Genetic
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Affiliation(s)
- M Hortsch
- Howard Hughes Medical Institute, University of California, Berkeley 94720
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35
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Moore JT, Fristrom D, Hammonds AS, Fristrom JW. Characterization of IMP-E3, a gene active during imaginal disc morphogenesis in Drosophila melanogaster. DEVELOPMENTAL GENETICS 1990; 11:299-309. [PMID: 2128624 DOI: 10.1002/dvg.1020110409] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/30/2022]
Abstract
The steroid hormone 20-hydroxyecdysone (20-HE) induces imaginal discs to form adult appendages in Drosophila. We have isolated a set of six ecdysone-responsive genes that apparently encode disc cell-surface or secreted proteins. Transcripts from one of these genes, IMP-E3, accumulate rapidly within 1-2 h in response to hormone. Developmentally, IMP-E3 transcripts reach maximum levels during the first stages of metamorphosis (white prepupae, WPP) and are primarily limited to imaginal tissues. Transcripts are also present during embryogenesis (0-3 h and 12-18 h). Two different-sized transcripts (1.2 and 1.4 kb) result from differential polyadenylation, with the larger transcript predominating in WPP. The conceptual IMP-E3 protein contains a signal peptide, an RGD sequence, and a potential glycosylphosphatidylinositol anchor. We speculate that the protein provides a transient cue important for imaginal disc morphogenesis.
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Affiliation(s)
- J T Moore
- Department of Molecular and Cell Biology, University of California, Berkeley 94720
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36
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37
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Abstract
An internal 1.4-kb Bst EII fragment was used to disrupt the benA gene and establish heterokaryons. The heterokaryons demonstrated that the molecular disruption of benA results in a recessive benA null mutation. Conidia from a heterokaryon swell and germinate but cannot undergo nuclear division and are thus inviable. A chimeric beta-tubulin gene was constructed with the benA promoter driving the tubC structural gene. This chimeric gene construction was placed on a plasmid containing a selectable marker for Aspergillus transformation and the gene disrupting fragment of benA. Integration of this plasmid at benA by the internal gene disrupting fragment of benA simultaneously disrupts the benA gene and replaces it with the chimeric beta-tubulin gene, rescuing the benA null generated by the integration. Strains generated by this procedure contain only tubC beta-tubulin for all beta-tubulin functions. Strains having only tubC beta-tubulin are viable and exhibit no detectable microtubule dysfunction though they are more sensitive than wild-type strains to the antimicrotubule drug benomyl. It is concluded that the two beta-tubulin genes of Aspergillus nidulans, though highly divergent, are interchangeable.
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Affiliation(s)
- G S May
- Department of Cell Biology, Baylor College of Medicine, Houston, Texas 77030
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38
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Sobrier ML, Chapel S, Couderc JL, Micard D, Lecher P, Somme-Martin G, Dastugue B. 20-OH-ecdysone regulates 60 C beta tubulin gene expression in Kc cells and during Drosophila development. Exp Cell Res 1989; 184:241-9. [PMID: 2507336 DOI: 10.1016/0014-4827(89)90382-0] [Citation(s) in RCA: 14] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/01/2023]
Abstract
Cultured Kc cells of Drosophila melanogaster are sensitive to the insect moulting hormone, 20-hydroxy-ecdysone (20-OH-E). Morphological changes of Kc-treated cells were observed and electron microscopic analysis of pseudopodia shows a large increase in the number of microtubules, all arranged in the same orientation. The 60 C beta tubulin gene which is expressed only in 20-OH-E-treated cells encodes a 2.6-kb mRNA which is essentially cytoplasmic and polyadenylated. The corresponding premessenger is 7 kb in length and is absent in untreated cells. Two peaks of expression of the 60 C beta tubulin gene are observed during Drosophila development: at midembryogenesis (stage 8-13 h) and at the late third instar larvae-early pupae stage. By use of the Ecdysone 1 mutant, 60 C beta tubulin gene expression was demonstrated to be regulated in part by 20-OH-E during Drosophila development. Through these two complementary biological models of study, the mode and role of beta tubulin gene regulation are discussed.
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Affiliation(s)
- M L Sobrier
- Laboratoire de Biochimie Médicale, UFR de Médecine, Clermont-Ferrand, France
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39
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Interacting proteins identified by genetic interactions: a missense mutation in alpha-tubulin fails to complement alleles of the testis-specific beta-tubulin gene of Drosophila melanogaster. Mol Cell Biol 1989. [PMID: 2498648 DOI: 10.1128/mcb.9.3.875] [Citation(s) in RCA: 34] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
In this paper we demonstrate that failure to complement between mutations at separate loci can be used to identify genes that encode interacting structural proteins. A mutation (nc33) identified because it failed to complement mutant alleles of the gene encoding the testis-specific beta 2-tubulin of Drosophila melanogaster (B2t) did not map to the B2t locus. We show that this second-site noncomplementing mutation is a missense mutation in alpha-tubulin that results in substitution of methionine in place of valine at amino acid 177. Because alpha- and beta-tubulin form a heterodimer, our results suggest that the genetic interaction, failure to complement, is based on the structural interaction between the protein products of the two genes. Although the nc33 mutation failed to complement a null allele of B2t (B2tn), a deletion of the alpha-tubulin gene to which nc33 mapped complemented B2tn. Thus, the failure to complement appears to require the presence of the altered alpha-tubulin encoded by the nc33 allele, which may act as a structural poison when incorporated into either the tubulin heterodimer or microtubules.
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40
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Gasch A, Hinz U, Renkawitz-Pohl R. Intron and upstream sequences regulate expression of the Drosophila beta 3-tubulin gene in the visceral and somatic musculature, respectively. Proc Natl Acad Sci U S A 1989; 86:3215-8. [PMID: 2654939 PMCID: PMC287100 DOI: 10.1073/pnas.86.9.3215] [Citation(s) in RCA: 44] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/02/2023] Open
Abstract
The morphogenetic programs involved in the differentiation of internal organs, such as the muscle system, during Drosophila embryogenesis have remained largely obscure. beta 3-tubulin has proved to be a good marker for mesoderm development as this tubulin isotype is detectable soon after mesoderm formation and during the process of mesoderm differentiation. The beta 3-tubulin gene is expressed in the somatic and pharyngeal musculature, the dorsal vessel, and the visceral musculature. To learn more about the programs underlying mesodermal differentiation, we have started to dissect the regulatory elements of the beta 3-tubulin gene by means of P-element-mediated transformation experiments. We show that expression of the beta 3-tubulin gene in the somatic muscles, the pharyngeal muscles, and the dorsal vessel is mediated by far upstream sequences. We also demonstrate that the first intron of the beta 3-tubulin gene bears a tissue-specific enhancer element that is required for expression in the visceral muscles and that also functions efficiently when cloned downstream of an indicator gene. The separability of elements driving beta 3-tubulin expression in the somatic and visceral mesoderm facilitates the investigation of the different programs involved in regulating the early differentiation of this germ layer.
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Affiliation(s)
- A Gasch
- Gentechnologische Arbeitsgruppe am Max-Planck-Institute für Biochemie, Martinsried, Federal Republic of Germany
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41
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Michiels F, Gasch A, Kaltschmidt B, Renkawitz-Pohl R. A 14 bp promoter element directs the testis specificity of the Drosophila beta 2 tubulin gene. EMBO J 1989; 8:1559-65. [PMID: 2504583 PMCID: PMC400987 DOI: 10.1002/j.1460-2075.1989.tb03540.x] [Citation(s) in RCA: 91] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/08/2022] Open
Abstract
To analyze the regulation of gene expression during male germ cell development, we investigated the testis-specific expression of the Drosophila beta 2 tubulin gene. Germ line transformation experiments with the upstream region of the D.melanogaster beta 2 tubulin gene fused to the Escherichia coli lacZ gene resulted in the correct tissue specific expression of the reporter gene. Furthermore, we showed that the upstream sequences of the beta 2 tubulin gene of the distantly related species D.hydei can drive the expression of the lacZ gene testis specifically in D.melanogaster flies. A detailed deletion analysis showed that 53 bp of upstream and 23 bp (D.melanogaster) or 29 bp (D.hydei) of leader sequences are sufficient to confer tissue specificity. The short promoter regions contain a 14 bp motif at identical positions in both species, which acts as a position-dependent promoter element. In vitro mutagenesis and subsequent germline transformation experiments revealed that this sequence is the only element necessary for the testis-specific transcription of the beta 2 tubulin gene in Drosophila.
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Affiliation(s)
- F Michiels
- Gentechnologische Arbeitsgruppen am MPI für Biochemie, Martinsried, FRG
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42
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Hays TS, Deuring R, Robertson B, Prout M, Fuller MT. Interacting proteins identified by genetic interactions: a missense mutation in alpha-tubulin fails to complement alleles of the testis-specific beta-tubulin gene of Drosophila melanogaster. Mol Cell Biol 1989; 9:875-84. [PMID: 2498648 PMCID: PMC362676 DOI: 10.1128/mcb.9.3.875-884.1989] [Citation(s) in RCA: 25] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/01/2023] Open
Abstract
In this paper we demonstrate that failure to complement between mutations at separate loci can be used to identify genes that encode interacting structural proteins. A mutation (nc33) identified because it failed to complement mutant alleles of the gene encoding the testis-specific beta 2-tubulin of Drosophila melanogaster (B2t) did not map to the B2t locus. We show that this second-site noncomplementing mutation is a missense mutation in alpha-tubulin that results in substitution of methionine in place of valine at amino acid 177. Because alpha- and beta-tubulin form a heterodimer, our results suggest that the genetic interaction, failure to complement, is based on the structural interaction between the protein products of the two genes. Although the nc33 mutation failed to complement a null allele of B2t (B2tn), a deletion of the alpha-tubulin gene to which nc33 mapped complemented B2tn. Thus, the failure to complement appears to require the presence of the altered alpha-tubulin encoded by the nc33 allele, which may act as a structural poison when incorporated into either the tubulin heterodimer or microtubules.
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Affiliation(s)
- T S Hays
- Department of Molecular, Cellular and Developmental Biology, University of Colorado, Boulder 80309-0347
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43
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Heino TI. Polytene chromosomes from ovarian pseudonurse cells of the Drosophila melanogaster otu mutant. I. Photographic map of chromosome 3. Chromosoma 1989; 97:363-73. [PMID: 2498045 DOI: 10.1007/bf00292763] [Citation(s) in RCA: 20] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/01/2023]
Abstract
Certain mutant alleles of the otu locus in Drosophila melanogaster produce abnormal nurse cells in the ovaries. These cells are called pseudonurse cells (PNC), since they generate polytene chromosomes instead of endopolyploid ones and do not normally have an oocyte to nurse. The banding pattern of polytene chromosome 3 from the salivary glands (SG) and from PNCs of homozygous otu1 females was compared and a detailed photomap of PNC chromosomes with different degrees of polyteny is presented. The banding pattern was found to be strikingly similiar in the two tissues. The puffing pattern of the PNC chromosomes is discussed. No constrictions or breaks were found in the PNC chromosomes which seems to indicate that these sites, which are known to be underreplicated in the SG chromosomes, are equally replicated along with the rest of the chromosomes in the PNC nuclei.
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Affiliation(s)
- T I Heino
- Department of Genetics, University of Helsinki, Finland
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44
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Matthews KA, Miller DF, Kaufman TC. Developmental distribution of RNA and protein products of the Drosophila alpha-tubulin gene family. Dev Biol 1989; 132:45-61. [PMID: 2492961 DOI: 10.1016/0012-1606(89)90203-0] [Citation(s) in RCA: 71] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/01/2023]
Abstract
The developmental pattern of gene expression of the Drosophila melanogaster alpha-tubulin family has been examined in detail at both the mRNA and protein levels. Northern data from 16 stages of development have been quantified to produce estimates of pool sizes of each of the alpha-tubulin transcripts through development. The in situ pattern of alpha 67C RNA localization in developing oocytes and early embryos has also been determined. At the protein level, two of the three previously unidentified products of alpha-tubulin genes (alpha 67C and alpha 85E) have been identified. Evidence that protein from the fourth gene comigrates with the ubiquitously expressed alpha 84B is presented. In addition to the primary translational products of the alpha-tubulin genes, an elaborate series of post-translationally modified alpha-tubulins has been resolved. The developmental profiles of both synthesis and accumulation of these alpha-tubulin proteins are described.
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Affiliation(s)
- K A Matthews
- Department of Biology, Indiana University, Bloomington 47405
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45
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Kimble M, Incardona JP, Raff EC. A variant beta-tubulin isoform of Drosophila melanogaster (beta 3) is expressed primarily in tissues of mesodermal origin in embryos and pupae, and is utilized in populations of transient microtubules. Dev Biol 1989; 131:415-29. [PMID: 2492243 DOI: 10.1016/s0012-1606(89)80014-4] [Citation(s) in RCA: 52] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/01/2023]
Abstract
The beta 3-tubulin gene of Drosophila melanogaster codes for a variant tubulin isoform which is expressed at two distinct times during development: (1) during midembryogenesis from 8-16 hr postfertilization, and (2) during the 4 days of pupal development. We have determined the spatial pattern of beta 3-tubulin expression by localizing the beta 3 mRNA in paraffin sections using a 3' message-specific RNA probe and by localizing the beta 3 protein using a polyclonal antibody specific for Drosophila beta 3-tubulin. During embryogenesis beta 3 is restricted to and is expressed in all of the developing muscles. During pupal development beta 3 is also expressed at high levels in developing adult muscles. In addition, early in pupal development beta 3 is expressed in the imaginal discs, while at later times beta 3 is expressed in the epidermal cells of the wing blade, the optic lobe, the ovaries, and the testes. The expression of beta 3 tubulin ceases by the end of pupal development in all of these tissues except the ovaries and testes where expression persists into the adult. In both developing muscles and wings our results indicate that beta 3-tubulin is utilized in populations of specialized but transient cytoskeletal microtubules which are involved in establishing the final form of the tissue.
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Affiliation(s)
- M Kimble
- Department of Biology, Indiana University, Bloomington 47405
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46
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Natzle JE, Fristrom DK, Fristrom JW. Genes expressed during imaginal disc morphogenesis: IMP-E1, a gene associated with epithelial cell rearrangement. Dev Biol 1988; 129:428-38. [PMID: 2458289 DOI: 10.1016/0012-1606(88)90390-9] [Citation(s) in RCA: 33] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/01/2023]
Abstract
A unique set of genes that encodes hormone-inducible transcripts found on membrane-bound polysomes is expressed during ecdysone-dependent morphogenesis of Drosophila imaginal discs cultured in vitro. The pattern of expression of one of these genes, IMP-E1, was analyzed in tissues from late third instar larvae and white prepupae by hybridization of asymmetric RNA probes to tissue sections. The IMP-E1 transcript was detected in all anterior and posterior imaginal discs except the ommatidial region of the imaginal eye disc. Within the imaginal leg disc, the IMP-E1 transcript is expressed more abundantly in the proximal than in the distal portions of the epithelium. The distribution of transcripts is consistent with the hypothesis that the IMP-E1 gene product is involved in the cell rearrangements associated with morphogenesis of the disc epithelium. The IMP-E1 transcript is also expressed at pupariation in glial cell layers that ensheath the brain. This glial cell transcript is the same size (7.5 kb) and polarity as the imaginal disc transcript, and is also transcribed in response to 20-hydroxyecdysone. Similarities between the morphogenetic changes in imaginal disc and glial cell layers during metamorphosis are discussed.
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Affiliation(s)
- J E Natzle
- Department of Genetics, University of California, Berkeley 94720
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47
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48
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Montpied P, Sobrier ML, Chapel S, Couderc JL, Dastugue B. 20-Hydroxyecdysone induces the expression of one beta-tubulin gene in Drosophila Kc cells. BIOCHIMICA ET BIOPHYSICA ACTA 1988; 949:79-86. [PMID: 2825814 DOI: 10.1016/0167-4781(88)90057-7] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/02/2023]
Abstract
The expression of 56D and 60C beta-tubulin genes has been examined in Drosophila melanogaster Kc cells in response to the insect moulting hormone, 20-hydroxyecdysone (20-OH-E). Northern blots probed with beta-tubulin subclones show that the 56D beta-tubulin gene encodes a 1.8 kb mRNA whose abundance is not affected by 20-OH-E. The 60C gene probe detects two mRNAs: one of 1.8 kb present in untreated and 20-OH-E-treated cells, and one of 2.6 kb present only in 20-OH-E-treated cells; using a 60C 3'-specific probe, only the 2.6 kb is revealed. Hybrid selection translation experiment demonstrates that a 20-OH-E-inducible mRNA homologous to the 60C gene encodes a beta-tubulin subunit (P4); this subunit is the so-called beta 3-tubulin. Translation of size-fractionated mRNA shows that the 20-OH-E-induced beta 3-tubulin subunit is encoded, in treated cells, by the 2.6 kb mRNA.
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Affiliation(s)
- P Montpied
- Laboratoire de Biochimie Médicale, U.A. C.N.R.S. 360, Faculté de Médecine, Clermont-Ferrand, France
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49
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Regan CL, Fuller MT. Interacting genes that affect microtubule function: the nc2 allele of the haywire locus fails to complement mutations in the testis-specific beta-tubulin gene of Drosophila. Genes Dev 1988; 2:82-92. [PMID: 3128461 DOI: 10.1101/gad.2.1.82] [Citation(s) in RCA: 44] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/04/2023]
Abstract
A mutation that fails to complement certain alleles of the testis-specific beta 2-tubulin gene (B2t) of Drosophila melanogaster maps to a separate locus, haywire, located at 3-34.4 map units in polytene region 67E3-F3. Second-site non-complementing mutations such as haync2 and B2t alleles could identify genes that encode products that participate in the same functions or that interact in the same structure. Consistent with a structural interaction between the hay gene product and beta 2-tubulin, the genetic interaction between haync2 and B2t requires the presence of the mutant hay gene product; a deficiency for the hay region complements the same alleles of B2t that haync2 fails to complement. haync2 is a recessive male sterile mutation in a genetic background that is wild type at the B2t locus. Homozygous males have defects in meiosis, flagellar elongation and nuclear shaping, the three major microtubule-based processes in which the testis-specific beta 2-tubulin participates. The haync2 allele also has effects outside of spermatogenesis. It is a temperature-sensitive semilethal mutation, and homozygous haync2 females have reduced fertility. These phenotypes are consistent with a role for the haywire gene product in general microtubule function. Analysis of second-site non-complementing mutations such as haync2 offers a genetic tool for analysis of interacting proteins in complex assemblies.
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Affiliation(s)
- C L Regan
- Department of Molecular, Cellular and Developmental Biology, University of Colorado at Boulder 80309
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50
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Davis MTB, Miller SG. Expression of a testis β-tubulin gene in Heliothis virescens during spermatogenesis. ACTA ACUST UNITED AC 1988. [DOI: 10.1016/0020-1790(88)90054-6] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/27/2022]
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