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2012
Deleury Emeline, Dubreuil Géraldine, Elangovan Namasivayam, Wajnberg Eric, Reichhart Jean-Marc, Gourbal Benjamin, Duval David, Baron Olga Lucia, Gouzy Jérôme, Coustau Christine
Specific versus non-specific immune responses in an invertebrate species evidenced by a comparative de novo sequencing study Journal Article
In: PLoS ONE, vol. 7, no. 3, pp. e32512, 2012, ISSN: 1932-6203.
Abstract | Links | BibTeX | Tags: Animals, Biomphalaria, Calmodulin, Cluster Analysis, Complementary, DNA, Expressed Sequence Tags, Ferritins, Gene Expression Profiling, Gene Expression Regulation, High-Throughput Nucleotide Sequencing, Immunity, Innate, M3i, messenger, Pattern Recognition, Phylogeny, Receptors, reichhart, RNA, Signal Transduction, Zinc Fingers
@article{deleury_specific_2012,
title = {Specific versus non-specific immune responses in an invertebrate species evidenced by a comparative de novo sequencing study},
author = {Emeline Deleury and Géraldine Dubreuil and Namasivayam Elangovan and Eric Wajnberg and Jean-Marc Reichhart and Benjamin Gourbal and David Duval and Olga Lucia Baron and Jérôme Gouzy and Christine Coustau},
doi = {10.1371/journal.pone.0032512},
issn = {1932-6203},
year = {2012},
date = {2012-01-01},
journal = {PLoS ONE},
volume = {7},
number = {3},
pages = {e32512},
abstract = {Our present understanding of the functioning and evolutionary history of invertebrate innate immunity derives mostly from studies on a few model species belonging to ecdysozoa. In particular, the characterization of signaling pathways dedicated to specific responses towards fungi and Gram-positive or Gram-negative bacteria in Drosophila melanogaster challenged our original view of a non-specific immunity in invertebrates. However, much remains to be elucidated from lophotrochozoan species. To investigate the global specificity of the immune response in the fresh-water snail Biomphalaria glabrata, we used massive Illumina sequencing of 5'-end cDNAs to compare expression profiles after challenge by Gram-positive or Gram-negative bacteria or after a yeast challenge. 5'-end cDNA sequencing of the libraries yielded over 12 millions high quality reads. To link these short reads to expressed genes, we prepared a reference transcriptomic database through automatic assembly and annotation of the 758,510 redundant sequences (ESTs, mRNAs) of B. glabrata available in public databases. Computational analysis of Illumina reads followed by multivariate analyses allowed identification of 1685 candidate transcripts differentially expressed after an immune challenge, with a two fold ratio between transcripts showing a challenge-specific expression versus a lower or non-specific differential expression. Differential expression has been validated using quantitative PCR for a subset of randomly selected candidates. Predicted functions of annotated candidates (approx. 700 unisequences) belonged to a large extend to similar functional categories or protein types. This work significantly expands upon previous gene discovery and expression studies on B. glabrata and suggests that responses to various pathogens may involve similar immune processes or signaling pathways but different genes belonging to multigenic families. These results raise the question of the importance of gene duplication and acquisition of paralog functional diversity in the evolution of specific invertebrate immune responses.},
keywords = {Animals, Biomphalaria, Calmodulin, Cluster Analysis, Complementary, DNA, Expressed Sequence Tags, Ferritins, Gene Expression Profiling, Gene Expression Regulation, High-Throughput Nucleotide Sequencing, Immunity, Innate, M3i, messenger, Pattern Recognition, Phylogeny, Receptors, reichhart, RNA, Signal Transduction, Zinc Fingers},
pubstate = {published},
tppubtype = {article}
}
Our present understanding of the functioning and evolutionary history of invertebrate innate immunity derives mostly from studies on a few model species belonging to ecdysozoa. In particular, the characterization of signaling pathways dedicated to specific responses towards fungi and Gram-positive or Gram-negative bacteria in Drosophila melanogaster challenged our original view of a non-specific immunity in invertebrates. However, much remains to be elucidated from lophotrochozoan species. To investigate the global specificity of the immune response in the fresh-water snail Biomphalaria glabrata, we used massive Illumina sequencing of 5'-end cDNAs to compare expression profiles after challenge by Gram-positive or Gram-negative bacteria or after a yeast challenge. 5'-end cDNA sequencing of the libraries yielded over 12 millions high quality reads. To link these short reads to expressed genes, we prepared a reference transcriptomic database through automatic assembly and annotation of the 758,510 redundant sequences (ESTs, mRNAs) of B. glabrata available in public databases. Computational analysis of Illumina reads followed by multivariate analyses allowed identification of 1685 candidate transcripts differentially expressed after an immune challenge, with a two fold ratio between transcripts showing a challenge-specific expression versus a lower or non-specific differential expression. Differential expression has been validated using quantitative PCR for a subset of randomly selected candidates. Predicted functions of annotated candidates (approx. 700 unisequences) belonged to a large extend to similar functional categories or protein types. This work significantly expands upon previous gene discovery and expression studies on B. glabrata and suggests that responses to various pathogens may involve similar immune processes or signaling pathways but different genes belonging to multigenic families. These results raise the question of the importance of gene duplication and acquisition of paralog functional diversity in the evolution of specific invertebrate immune responses.
2003
Kambris Zakaria, Bilak Hana, D'Alessandro Rosalba, Belvin Marcia, Imler Jean-Luc, Capovilla Maria
DmMyD88 controls dorsoventral patterning of the Drosophila embryo Journal Article
In: EMBO reports, vol. 4, no. 1, pp. 64–69, 2003, ISSN: 1469-221X.
Abstract | Links | BibTeX | Tags: Adaptor Proteins, Alleles, Animals, Antigens, Base Sequence, Cell Surface, Complementary, Developmental, Differentiation, DNA, DNA Transposable Elements, Egg Proteins, Embryo, Exons, Female, Gene Expression Regulation, Genetically Modified, Genotype, imler, Immunity, Immunologic, Innate, Insertional, M3i, Male, messenger, Morphogenesis, Mutagenesis, Myeloid Differentiation Factor 88, Nonmammalian, Oocytes, Protein Biosynthesis, Protein Structure, Receptors, Reverse Transcriptase Polymerase Chain Reaction, RNA, Signal Transducing, Tertiary, Toll-Like Receptors, Zygote
@article{kambris_dmmyd88_2003,
title = {DmMyD88 controls dorsoventral patterning of the Drosophila embryo},
author = {Zakaria Kambris and Hana Bilak and Rosalba D'Alessandro and Marcia Belvin and Jean-Luc Imler and Maria Capovilla},
doi = {10.1038/sj.embor.embor714},
issn = {1469-221X},
year = {2003},
date = {2003-01-01},
journal = {EMBO reports},
volume = {4},
number = {1},
pages = {64--69},
abstract = {MyD88 is an adapter protein in the signal transduction pathway mediated by interleukin-1 (IL-1) and Toll-like receptors. A Drosophila homologue of MyD88 (DmMyD88) was recently shown to be required for the Toll-mediated immune response. In Drosophila, the Toll pathway was originally characterized for its role in the dorsoventral patterning of the embryo. We found that, like Toll, DmMyD88 messenger RNA is maternally supplied to the embryo. Here we report the identification of a new mutant allele of DmMyD88, which generates a protein lacking the carboxy-terminal extension, normally located downstream of the Toll/IL-1 receptor domain. Homozygous mutant female flies lay dorsalized embryos that are rescued by expression of a transgenic DmMyD88 complementary DNA. The DmMyD88 mutation blocks the ventralizing activity of a gain-of-function Toll mutation. These results show that DmMyD88 encodes an essential component of the Toll pathway in dorsoventral pattern formation.},
keywords = {Adaptor Proteins, Alleles, Animals, Antigens, Base Sequence, Cell Surface, Complementary, Developmental, Differentiation, DNA, DNA Transposable Elements, Egg Proteins, Embryo, Exons, Female, Gene Expression Regulation, Genetically Modified, Genotype, imler, Immunity, Immunologic, Innate, Insertional, M3i, Male, messenger, Morphogenesis, Mutagenesis, Myeloid Differentiation Factor 88, Nonmammalian, Oocytes, Protein Biosynthesis, Protein Structure, Receptors, Reverse Transcriptase Polymerase Chain Reaction, RNA, Signal Transducing, Tertiary, Toll-Like Receptors, Zygote},
pubstate = {published},
tppubtype = {article}
}
MyD88 is an adapter protein in the signal transduction pathway mediated by interleukin-1 (IL-1) and Toll-like receptors. A Drosophila homologue of MyD88 (DmMyD88) was recently shown to be required for the Toll-mediated immune response. In Drosophila, the Toll pathway was originally characterized for its role in the dorsoventral patterning of the embryo. We found that, like Toll, DmMyD88 messenger RNA is maternally supplied to the embryo. Here we report the identification of a new mutant allele of DmMyD88, which generates a protein lacking the carboxy-terminal extension, normally located downstream of the Toll/IL-1 receptor domain. Homozygous mutant female flies lay dorsalized embryos that are rescued by expression of a transgenic DmMyD88 complementary DNA. The DmMyD88 mutation blocks the ventralizing activity of a gain-of-function Toll mutation. These results show that DmMyD88 encodes an essential component of the Toll pathway in dorsoventral pattern formation.
1999
Lowenberger C A, Smartt C T, Bulet Philippe, Ferdig M T, Severson D W, Hoffmann Jules A, Christensen B M
Insect immunity: molecular cloning, expression, and characterization of cDNAs and genomic DNA encoding three isoforms of insect defensin in Aedes aegypti Journal Article
In: Insect Mol. Biol., vol. 8, no. 1, pp. 107–118, 1999, ISSN: 0962-1075.
Abstract | BibTeX | Tags: Aedes, Amino Acid, Animals, Base Sequence, Blotting, Chromosome Mapping, Cloning, Complementary, Defensins, DNA, Gene Expression, Hemolymph, hoffmann, M3i, Molecular, Northern, Protein Isoforms, Proteins, Sequence Homology
@article{lowenberger_insect_1999,
title = {Insect immunity: molecular cloning, expression, and characterization of cDNAs and genomic DNA encoding three isoforms of insect defensin in Aedes aegypti},
author = {C A Lowenberger and C T Smartt and Philippe Bulet and M T Ferdig and D W Severson and Jules A Hoffmann and B M Christensen},
issn = {0962-1075},
year = {1999},
date = {1999-02-01},
journal = {Insect Mol. Biol.},
volume = {8},
number = {1},
pages = {107--118},
abstract = {Aedes aegypti were immune activated by injection with bacteria, and the expression of insect defensins was measured over time. Northern analyses indicated that defensin transcriptional activity continued for at least 21 days after bacterial injection, and up to 10 days after saline inoculation. Mature defensin levels in the haemolymph reached approximately 45 microM at 24 h post inoculation. cDNAs encoding the preprodefensins of three previously described mature Ae. aegypti defensins were amplified by PCR, cloned and sequenced. Genomic clones were amplified using primers designed against the cDNA sequence. Sequence comparison indicates that there is significant inter- and intra-isoform variability in the signal peptide and prodefensin sequences of defensin genes. Preprodefensin sequences of isoforms A and B are very similar, consisting of a signal peptide region of twenty amino acids, a prodefensin region of thirty-eight amino acids and a forty amino acid mature peptide domain. The sequence encoding isoform C is significantly different, comprising a signal peptide region of twenty-three amino acids, a prodefensin region of thirty-six amino acids, and the mature protein domain of forty amino acids. Analysis of the genomic clones of each isoform revealed one intron spatially conserved in the prodefensin region of all sequences. The intron in isoforms A and B is 64 nt long, and except for a 4 nt substitution in one clone, these intron sequences are identical. The intron in isoform C is 76 nt long and does not share significant identity with the intron sequences of isoforms A or B. The defensin gene mapped to chromosome 3, between two known loci, blt and LF168.},
keywords = {Aedes, Amino Acid, Animals, Base Sequence, Blotting, Chromosome Mapping, Cloning, Complementary, Defensins, DNA, Gene Expression, Hemolymph, hoffmann, M3i, Molecular, Northern, Protein Isoforms, Proteins, Sequence Homology},
pubstate = {published},
tppubtype = {article}
}
Aedes aegypti were immune activated by injection with bacteria, and the expression of insect defensins was measured over time. Northern analyses indicated that defensin transcriptional activity continued for at least 21 days after bacterial injection, and up to 10 days after saline inoculation. Mature defensin levels in the haemolymph reached approximately 45 microM at 24 h post inoculation. cDNAs encoding the preprodefensins of three previously described mature Ae. aegypti defensins were amplified by PCR, cloned and sequenced. Genomic clones were amplified using primers designed against the cDNA sequence. Sequence comparison indicates that there is significant inter- and intra-isoform variability in the signal peptide and prodefensin sequences of defensin genes. Preprodefensin sequences of isoforms A and B are very similar, consisting of a signal peptide region of twenty amino acids, a prodefensin region of thirty-eight amino acids and a forty amino acid mature peptide domain. The sequence encoding isoform C is significantly different, comprising a signal peptide region of twenty-three amino acids, a prodefensin region of thirty-six amino acids, and the mature protein domain of forty amino acids. Analysis of the genomic clones of each isoform revealed one intron spatially conserved in the prodefensin region of all sequences. The intron in isoforms A and B is 64 nt long, and except for a 4 nt substitution in one clone, these intron sequences are identical. The intron in isoform C is 76 nt long and does not share significant identity with the intron sequences of isoforms A or B. The defensin gene mapped to chromosome 3, between two known loci, blt and LF168.
1996
Barillas-Mury Carolina, Charlesworth A, Gross I, Richman A, Hoffmann Jules A, Kafatos Fotis C
Immune factor Gambif1, a new rel family member from the human malaria vector, Anopheles gambiae Journal Article
In: EMBO J., vol. 15, no. 17, pp. 4691–4701, 1996, ISSN: 0261-4189.
Abstract | BibTeX | Tags: Amino Acid, Animals, Anopheles, Base Sequence, Biological Transport, Cell Nucleus, Cells, Complementary, Cultured, DNA, DNA-Binding Proteins, hoffmann, Insect Proteins, Insect Vectors, M3i, NF-kappa B, Proto-Oncogene Proteins, Proto-Oncogene Proteins c-rel, Sequence Homology, Trans-Activators, Transcriptional Activation
@article{barillas-mury_immune_1996,
title = {Immune factor Gambif1, a new rel family member from the human malaria vector, Anopheles gambiae},
author = {Carolina Barillas-Mury and A Charlesworth and I Gross and A Richman and Jules A Hoffmann and Fotis C Kafatos},
issn = {0261-4189},
year = {1996},
date = {1996-09-01},
journal = {EMBO J.},
volume = {15},
number = {17},
pages = {4691--4701},
abstract = {A novel rel family member, Gambif1 (gambiae immune factor 1), has been cloned from the human malaria vector, Anopheles gambiae, and shown to be most similar to Drosophila Dorsal and Dif. Gambif1 protein is translocated to the nucleus in fat body cells in response to bacterial challenge, although the mRNA is present at low levels at all developmental stages and is not induced by infection. DNA binding activity to the kappaB-like sites in the A.gambiae Defensin and the Drosophila Diptericin and Cecropin promoters is also induced in larval nuclear extracts following infection. Gambif1 has the ability to bind to kappaB-like sites in vitro. Co-transfection assays in Drosophila mbn-2 cells show that Gambif1 can activate transcription by interacting with the Drosophila Diptericin regulatory elements, but is not functionally equivalent to Dorsal in this assay. Gambif1 protein translocation to the nucleus and the appearance of kappaB-like DNA binding activity can serve as molecular markers of activation of the immune system and open up the possibility of studying the role of defence reactions in determining mosquito susceptibility/refractoriness to malaria infection.},
keywords = {Amino Acid, Animals, Anopheles, Base Sequence, Biological Transport, Cell Nucleus, Cells, Complementary, Cultured, DNA, DNA-Binding Proteins, hoffmann, Insect Proteins, Insect Vectors, M3i, NF-kappa B, Proto-Oncogene Proteins, Proto-Oncogene Proteins c-rel, Sequence Homology, Trans-Activators, Transcriptional Activation},
pubstate = {published},
tppubtype = {article}
}
A novel rel family member, Gambif1 (gambiae immune factor 1), has been cloned from the human malaria vector, Anopheles gambiae, and shown to be most similar to Drosophila Dorsal and Dif. Gambif1 protein is translocated to the nucleus in fat body cells in response to bacterial challenge, although the mRNA is present at low levels at all developmental stages and is not induced by infection. DNA binding activity to the kappaB-like sites in the A.gambiae Defensin and the Drosophila Diptericin and Cecropin promoters is also induced in larval nuclear extracts following infection. Gambif1 has the ability to bind to kappaB-like sites in vitro. Co-transfection assays in Drosophila mbn-2 cells show that Gambif1 can activate transcription by interacting with the Drosophila Diptericin regulatory elements, but is not functionally equivalent to Dorsal in this assay. Gambif1 protein translocation to the nucleus and the appearance of kappaB-like DNA binding activity can serve as molecular markers of activation of the immune system and open up the possibility of studying the role of defence reactions in determining mosquito susceptibility/refractoriness to malaria infection.
Richman A M, Bulet Philippe, Hetru Charles, Barillas-Mury Carolina, Hoffmann Jules A, Kafalos Fotis C
Inducible immune factors of the vector mosquito Anopheles gambiae: biochemical purification of a defensin antibacterial peptide and molecular cloning of preprodefensin cDNA Journal Article
In: Insect Mol. Biol., vol. 5, no. 3, pp. 203–210, 1996, ISSN: 0962-1075.
Abstract | BibTeX | Tags: Amino Acid, Animals, Anopheles, Base Sequence, Blood Bactericidal Activity, Blood Proteins, Cloning, Complementary, Defensins, DNA, Escherichia coli, Female, Gene Expression, Genes, hoffmann, Insect, Insect Vectors, Larva, M3i, Micrococcus luteus, Molecular, Sequence Homology
@article{richman_inducible_1996,
title = {Inducible immune factors of the vector mosquito Anopheles gambiae: biochemical purification of a defensin antibacterial peptide and molecular cloning of preprodefensin cDNA},
author = {A M Richman and Philippe Bulet and Charles Hetru and Carolina Barillas-Mury and Jules A Hoffmann and Fotis C Kafalos},
issn = {0962-1075},
year = {1996},
date = {1996-08-01},
journal = {Insect Mol. Biol.},
volume = {5},
number = {3},
pages = {203--210},
abstract = {Larvae of the mosquito vector of human malaria, Anopheles gambiae, were inoculated with bacteria and extracts were biochemically fractionated by reverse-phase HPLC. Multiple induced polypeptides and antibacterial activities were observed following bacterial infection, including a member of the insect defensin family of antibacterial proteins. A cDNA encoding An. gambiae preprodefensin was isolated using PCR primers based on phylogenetically conserved sequences. The mature peptide is highly conserved, but the signal and propeptide segments are not, relative to corresponding defensin sequences of other insects. Defensin expression is induced in response to bacterial infection, in both adult and larval stages. In contrast, pupae express defensin mRNA constitutively. Defensin expression may prove a valuable molecular marker to monitor the An. gambiae host response to infection by parasitic protozoa of medical importance.},
keywords = {Amino Acid, Animals, Anopheles, Base Sequence, Blood Bactericidal Activity, Blood Proteins, Cloning, Complementary, Defensins, DNA, Escherichia coli, Female, Gene Expression, Genes, hoffmann, Insect, Insect Vectors, Larva, M3i, Micrococcus luteus, Molecular, Sequence Homology},
pubstate = {published},
tppubtype = {article}
}
Larvae of the mosquito vector of human malaria, Anopheles gambiae, were inoculated with bacteria and extracts were biochemically fractionated by reverse-phase HPLC. Multiple induced polypeptides and antibacterial activities were observed following bacterial infection, including a member of the insect defensin family of antibacterial proteins. A cDNA encoding An. gambiae preprodefensin was isolated using PCR primers based on phylogenetically conserved sequences. The mature peptide is highly conserved, but the signal and propeptide segments are not, relative to corresponding defensin sequences of other insects. Defensin expression is induced in response to bacterial infection, in both adult and larval stages. In contrast, pupae express defensin mRNA constitutively. Defensin expression may prove a valuable molecular marker to monitor the An. gambiae host response to infection by parasitic protozoa of medical importance.
1994
Fehlbaum P, Bulet Philippe, Michaut L, Lagueux Marie, Broekaert W F, Hetru Charles, Hoffmann Jules A
Insect immunity. Septic injury of Drosophila induces the synthesis of a potent antifungal peptide with sequence homology to plant antifungal peptides Journal Article
In: J. Biol. Chem., vol. 269, no. 52, pp. 33159–33163, 1994, ISSN: 0021-9258.
Abstract | BibTeX | Tags: Amino Acid, Animals, Antifungal Agents, Base Sequence, Cloning, Complementary, DNA, hoffmann, Insect Proteins, M3i, Male, messenger, Microbial Sensitivity Tests, Molecular, Peptide Biosynthesis, Peptides, Plants, Protein Biosynthesis, Protein Precursors, Proteins, RNA, Sequence Homology
@article{fehlbaum_insect_1994,
title = {Insect immunity. Septic injury of Drosophila induces the synthesis of a potent antifungal peptide with sequence homology to plant antifungal peptides},
author = {P Fehlbaum and Philippe Bulet and L Michaut and Marie Lagueux and W F Broekaert and Charles Hetru and Jules A Hoffmann},
issn = {0021-9258},
year = {1994},
date = {1994-12-01},
journal = {J. Biol. Chem.},
volume = {269},
number = {52},
pages = {33159--33163},
abstract = {In response to a septic injury (pricking with a bacteria-soaked needle) larvae and adults of Drosophila produce considerable amounts of a 44-residue peptide containing 8 cysteines engaged in intramolecular disulfide bridges. The peptide is synthesized in the fat body, a functional homologue of the mammalian liver, and secreted into the blood of the insect. It exhibits potent antifungal activity but is inactive against bacteria. This novel inducible peptide, which we propose to name drosomycin, shows a significant homology with a family of 5-kDa cysteine-rich plant antifungal peptides recently isolated from seeds of Brassicaceae. This finding underlines that plants and insects can rely on similar molecules in their innate host defense.},
keywords = {Amino Acid, Animals, Antifungal Agents, Base Sequence, Cloning, Complementary, DNA, hoffmann, Insect Proteins, M3i, Male, messenger, Microbial Sensitivity Tests, Molecular, Peptide Biosynthesis, Peptides, Plants, Protein Biosynthesis, Protein Precursors, Proteins, RNA, Sequence Homology},
pubstate = {published},
tppubtype = {article}
}
In response to a septic injury (pricking with a bacteria-soaked needle) larvae and adults of Drosophila produce considerable amounts of a 44-residue peptide containing 8 cysteines engaged in intramolecular disulfide bridges. The peptide is synthesized in the fat body, a functional homologue of the mammalian liver, and secreted into the blood of the insect. It exhibits potent antifungal activity but is inactive against bacteria. This novel inducible peptide, which we propose to name drosomycin, shows a significant homology with a family of 5-kDa cysteine-rich plant antifungal peptides recently isolated from seeds of Brassicaceae. This finding underlines that plants and insects can rely on similar molecules in their innate host defense.
Dimarcq Jean-Luc, Hoffmann Danièle, Meister Marie, Bulet Philippe, Lanot R, Reichhart Jean-Marc, Hoffmann Jules A
Characterization and transcriptional profiles of a Drosophila gene encoding an insect defensin. A study in insect immunity Journal Article
In: Eur. J. Biochem., vol. 221, no. 1, pp. 201–209, 1994, ISSN: 0014-2956.
Abstract | BibTeX | Tags: Animals, Base Sequence, Blood Proteins, Chromosome Mapping, Cloning, Complementary, Defensins, DNA, Gene Expression, Genetic, Gram-Positive Bacteria, hoffmann, Larva, M3i, Molecular, Molecular Structure, Nucleic Acid, Protein Precursors, Regulatory Sequences, reichhart, Transcription
@article{dimarcq_characterization_1994,
title = {Characterization and transcriptional profiles of a Drosophila gene encoding an insect defensin. A study in insect immunity},
author = {Jean-Luc Dimarcq and Danièle Hoffmann and Marie Meister and Philippe Bulet and R Lanot and Jean-Marc Reichhart and Jules A Hoffmann},
issn = {0014-2956},
year = {1994},
date = {1994-04-01},
journal = {Eur. J. Biochem.},
volume = {221},
number = {1},
pages = {201--209},
abstract = {Insect defensins are a family of 4-kDa, cationic, inducible antibacterial peptides which bear six cysteine residues engaged in three intramolecular disulfide bridges. They owe their name to certain sequence similarities with defensins from mammalian neutrophiles and macrophages. We report the characterization of a novel defensin isoform from Drosophila and the cloning of the gene encoding a preprodefensin. The gene, which is intronless and present in a single copy/haploid genome, maps at position 46CD on the right arm of the second chromosome. The analysis of the upstream region of the gene reveals the presence of multiple putative cis-regulatory sequences similar to mammalian regulatory motifs of acute-phase-response genes. Transcriptional profiles indicate that the Drosophila defensin gene is induced by bacterial challenge with acute-phase kinetics. It is also expressed in the absence of immune challenge during metamorphosis. These and other data on the Drosophila defensin gene lead us to suggest that insect and mammalian defensins have evolved independently.},
keywords = {Animals, Base Sequence, Blood Proteins, Chromosome Mapping, Cloning, Complementary, Defensins, DNA, Gene Expression, Genetic, Gram-Positive Bacteria, hoffmann, Larva, M3i, Molecular, Molecular Structure, Nucleic Acid, Protein Precursors, Regulatory Sequences, reichhart, Transcription},
pubstate = {published},
tppubtype = {article}
}
Insect defensins are a family of 4-kDa, cationic, inducible antibacterial peptides which bear six cysteine residues engaged in three intramolecular disulfide bridges. They owe their name to certain sequence similarities with defensins from mammalian neutrophiles and macrophages. We report the characterization of a novel defensin isoform from Drosophila and the cloning of the gene encoding a preprodefensin. The gene, which is intronless and present in a single copy/haploid genome, maps at position 46CD on the right arm of the second chromosome. The analysis of the upstream region of the gene reveals the presence of multiple putative cis-regulatory sequences similar to mammalian regulatory motifs of acute-phase-response genes. Transcriptional profiles indicate that the Drosophila defensin gene is induced by bacterial challenge with acute-phase kinetics. It is also expressed in the absence of immune challenge during metamorphosis. These and other data on the Drosophila defensin gene lead us to suggest that insect and mammalian defensins have evolved independently.
