Papers by Mauro Mandrioli
The yeast Wickerhamomyces anomalus (Pichia anomala) inhabits the midgut and reproductive system of the Asian malaria vector Anopheles stephensi
Environmental Microbiology, 2011
While symbiosis between bacteria and insects has been thoroughly investigated in the last two dec... more While symbiosis between bacteria and insects has been thoroughly investigated in the last two decades, investments on the study of yeasts associated with insects have been limited. Insect-associated yeasts are placed on different branches of the phylogenetic tree of fungi, indicating that these associations evolved independently on several occasions. Isolation of yeasts is frequently reported from insect habitats, and in some cases yeasts have been detected in the insect gut and in other organs/tissues. Here we show that the yeast Wickerhamomyces anomalus, previously known as Pichia anomala, is stably associated with the mosquito Anopheles stephensi, a main vector of malaria in Asia. Wickerhamomyces anomalus colonized pre-adult stages (larvae L(1)-L(4) and pupae) and adults of different sex and age and could be isolated in pure culture. By a combination of transmission electron microscopy and fluorescent in situ hybridization techniques, W. anomalus was shown to localize in the midgut and in both the male and female reproductive systems, suggesting multiple transmission patterns.
Applied and Environmental Microbiology, 2011
Here we present the first full characterization of the bacterial community of this important dise... more Here we present the first full characterization of the bacterial community of this important disease vector collected from BN-contaminated areas in Piedmont, Italy. Length heterogeneity PCR and denaturing gradient gel electrophoresis analysis targeting the 16S rRNA gene revealed the presence of a number of bacteria stably associated with the insect vector. In particular, symbiotic bacteria detected by PCR with high infection rates in adult individuals fell within the "Candidatus Sulcia muelleri" cluster in the Bacteroidetes and in the "Candidatus Purcelliella pentastirinorum" group in the Gammaproteobacteria, both previously identified in different leafhoppers and planthoppers. A high infection rate (81%) was also shown for another symbiont belonging to the Betaproteobacteria, designated the HO1-V symbiont. Because of the low level of 16S rRNA gene identity (80%) with the closest relative, an uncharacterized symbiont of the tick Haemaphysalis longicornis, we propose the new name "Candidatus Vidania fulgoroideae." Other bacterial endosymbionts identified in H. obsoletus were related to the intracellular bacteria Wolbachia pipientis, Rickettsia sp., and "Candidatus Cardinium hertigii." Fluorescent in situ hybridization coupled with confocal laser scanning microscopy and transmission electron microscopy showed that these bacteria are localized in the gut, testicles, and oocytes. As "Ca. Sulcia" is usually reported in association with other symbiotic bacteria, we propose that in H. obsoletus, it may occur in a bipartite or even tripartite relationship between "Ca. Sulcia" and "Ca. Purcelliella," "Ca. Vidania," or both.
Environmental Microbiology, 2009
However, in many vector models the ecology of symbionts and their capability of cross-colonizing ... more However, in many vector models the ecology of symbionts and their capability of cross-colonizing different hosts, an important feature in the symbiotic control approach, is poorly known. Here we show that the acetic acid bacterium Asaia, previously found in the malaria mosquito vector Anopheles stephensi, is also present in, and capable of cross-colonizing other sugar-feeding insects of phylogenetically distant genera and orders. PCR, real-time PCR and in situ hybridization experiments showed Asaia in the body of the mosquito Aedes aegypti and the leafhopper Scaphoideus titanus, vectors of human viruses and a grapevine phytoplasma respectively. Crosscolonization patterns of the body of Ae. aegypti, An. stephensi and S. titanus have been documented with Asaia strains isolated from An. stephensi or Ae. aegypti, and labelled with plasmid-or chromosome-encoded fluorescent proteins (Gfp and DsRed respectively). Fluorescence and confocal microscopy showed that Asaia, administered with the sugar meal, efficiently colonized guts, male and female reproductive systems and the salivary glands. The ability in cross-colonizing insects of phylogenetically distant orders indicated that Asaia adopts body invasion mechanisms independent from host-specific biological characteristics. This versatility is an important property for the development of symbiont-based control of different vector-borne diseases.
Identification and molecular characterization of R1 transposable elements in the cabbage moth Mamestra brassicae
Caryologia, 2003
The structure of insect DNA methyltransferase 2 (DNMT2) DNA binding domain is responsible for the non-CpG methylation in insect genomes
Caryologia, 2004
... 1988; Yoder et al. 1997; Margot et al. 2000). ... 1_d-pse 180 EMP-----ESPS-2_d-mel 181 EMP---... more ... 1988; Yoder et al. 1997; Margot et al. 2000). ... 1_d-pse 180 EMP-----ESPS-2_d-mel 181 EMP-----GAIA-3_a-gam 186 -----EEIIT 4_x-lae 184 EFPSQHSIDPGRRRVIHCSE ...
Conservation of HP1 and methylated H3 histones as heterochromatic epigenetic markers in the holocentric chromosomes of the cabbage moth, Mamestra brassicae (Lepidoptera)
European Journal of Entomology, 2005
Entomologia, Jul 12, 2013
Despite their involvement in different processes, histone genes have been analysed in few insects... more Despite their involvement in different processes, histone genes have been analysed in few insects. In order to improve the knowledge about this important gene family, genes coding for histones have been analysed in the aphid Acyrthosiphon pisum showing that at the amino acid level, aphid histones are highly conserved. In particular, data from A. pisum confirm that H1 is the most variable of the five histones, whereas histones H3 and H4 are highly conserved with the H3 almost identical from insects to vertebrates. A. pisum histone genes are organized in a quintet with the H1 gene followed by H2A and H2B genes that are adjacent and transcribed in same directions, in the opposite strand in respect to the H1 gene. At the 3' end of the histone cluster, genes H3 and H4 constitute an oppositely transcribed pair. The span of the aphid histone genes (more than 7 kb) is greater than the average length of the histone cluster till now reported in insects (about 5 kb). Furthermore, spacers that separate the aphid histone genes vary in length. The histone genes have been mapped in A. pisum and successively in the aphids Myzus persicae and Rhopalosiphum padi showing that they are present in a single large cluster located in an interstitial position of autosomes 1, differently from what reported in the Russian wheat aphid Diuraphis noxia, where histone genes have been localized in a telomere of the two X chromosomes suggesting a dynamic organization of this multigene family in aphids. Acknowledgements: we are greatly indebted to Emanuele Mazzoni (Università Cattolica di Piacenza, Italy) and Manuel Plantagenest (INRA, France) for sending us the aphid strains. This work is supported by the grant Experimental approach to the study of evolution from the Department of Animal Biology of the University of Modena and Reggio Emilia (M.M.).
Chromosome Research an International Journal on the Molecular Supramolecular and Evolutionary Aspects of Chromosome Biology, Feb 1, 2007
Monomethylated-K9 H3 histones (Me9H3) and heterochromatin protein 1 (HP1) are reported as heteroc... more Monomethylated-K9 H3 histones (Me9H3) and heterochromatin protein 1 (HP1) are reported as heterochromatin markers in several eukaryotes possessing monocentric chromosomes. In order to confirm that these epigenetic markers are evolutionarily conserved, we sequenced the HP1 cDNA and verified the distribution of Me9H3 histones and HP1 in the holocentric chromosomes of the aphid Acyrthosiphon pisum. Sequencing indicates that A. pisum HP1 cDNA (called ApHP1) is 1623 bp long, including a 170 bp long 5 ¶UTR and a 688 bp long 3 ¶UTR. The ApHP1 protein consists of 254 amino acidic residues, has a predicted molecular mass of 28 kDa and a net negative charge. At the structural level, it shows an N terminal chromo domain and a chromo shadow domain at the C terminus linked by a short hinge region. At the cytogenetic level, ApHP1 is located exclusively in the heterochromatic regions of the chromosomes. The same heterochromatic regions were labelled after immunostaining with antibodies against Me9H3 histones, confirming that Hp1 and Me9H3 co-localize at heterochromatic chromosomal areas. Surprisingly, aphid heterochromatin lacks DNA methylation and methylated cytosine residues were mainly spread at euchromatic regions. Finally, the absence of DNA methylation is observed also in aphid rDNA genes that have been repeatedly described as mosaic of methylated and unmethylated units in vertebrates.
Genetica, Sep 17, 2010
In order to study the structure of holocentric chromosomes in aphids, the localization and the co... more In order to study the structure of holocentric chromosomes in aphids, the localization and the composition of Rhopalosiphum padi heterochromatin and rDNA genes have been evaluated at cytogenetic and molecular level. In particular, heterochromatin resulted located on all the chromosomes both in intercalary and telomeric positions. Moreover, enzymatic digestion of R. padi genome put in evidence a DraI satellite DNA which has been isolated, cloned and sequenced. FISH experiments showed that this satellite DNA clusters in an intercalary C-positive band on the two X chromosomes.
Biochimica Et Biophysica Acta General Subjects, Jun 1, 2007
In invertebrates and vertebrates, innate immunity is considered the first line of defense mechani... more In invertebrates and vertebrates, innate immunity is considered the first line of defense mechanism against non-self material. In vertebrates, cytokines play a critical role in innate immune signalling. To date, however, the existence of genes encoding for invertebrate helical cytokines has been anticipated, but never demonstrated. Here, we report the first structural and functional evidence of a gene encoding for a putative helical cytokine in Drosophila melanogaster. Functional experiments demonstrate that its expression, as well as that of the antimicrobial factors defensin and cecropin A1, is significantly increased after immune stimulation. These observations suggest the involvement of helical cytokines in the innate immune response of invertebrates.
Biology of the Cell, 2003
The induction of anti-microbial peptides against Gram positive and negative bacteria in the IZD-M... more The induction of anti-microbial peptides against Gram positive and negative bacteria in the IZD-MB-0503 cell line from the lepidopteran Mamestra brassicae is demonstrated, while no anti-fungal activity is detected. The identification of a defensin-like molecule active against Gram positive bacteria is described for the first time in Lepidoptera. This molecule shows between 43% and 59% homology with group A defensins from other dipteran and hymenopteran species.
Circulating phagocytes: the ancient and conserved interface between immune and neuroendocrine function
Biological reviews of the Cambridge Philosophical Society, Jan 9, 2015
Immune and neuroendocrine functions display significant overlap in highly divergent and evolution... more Immune and neuroendocrine functions display significant overlap in highly divergent and evolutionarily distant models such as molluscs, crustaceans, insects and mammals. Fundamental players in this crosstalk are professional phagocytes: macrophages in vertebrates and immunocytes in invertebrates. Although they have different developmental origins, macrophages and immunocytes possess comparable functions and differentiate under the control of evolutionarily conserved transcription factors. Macrophages and immunocytes share their pools of receptors, signalling molecules and pathways with neural cells and the neuro-endocrine system. In crustaceans, adult transdifferentiation of circulating haemocytes into neural cells has been documented recently. In light of developmental, molecular and functional evidence, we propose that the immune-neuroendocrine role of circulating phagocytes pre-dates the split of protostomian and deuterostomian superphyla and has been conserved during the evoluti...
Plant-mediated interspecific horizontal transmission of an intracellular symbiont in insects
Scientific reports, 2015
Intracellular reproductive manipulators, such as Candidatus Cardinium and Wolbachia are verticall... more Intracellular reproductive manipulators, such as Candidatus Cardinium and Wolbachia are vertically transmitted to progeny but rarely show co-speciation with the host. In sap-feeding insects, plant tissues have been proposed as alternative horizontal routes of interspecific transmission, but experimental evidence is limited. Here we report results from experiments that show that Cardinium is horizontally transmitted between different phloem sap-feeding insect species through plants. Quantitative PCR and in situ hybridization experiments indicated that the leafhopper Scaphoideus titanus releases Cardinium from its salivary glands during feeding on both artificial media and grapevine leaves. Successional time-course feeding experiments with S. titanus initially fed sugar solutions or small areas of grapevine leaves followed by feeding by the phytoplasma vector Macrosteles quadripunctulatus or the grapevine feeder Empoasca vitis revealed that the symbionts were transmitted to both speci...
Southern blotting experiments performed on Mamestra brassicae genomic DNA after digestion with me... more Southern blotting experiments performed on Mamestra brassicae genomic DNA after digestion with methylation-sensitive restriction enzymes indicated that defensin gene is methylated at CpG targets in the promoter region. However, defensin gene is actively transcribed despite the presence of methylation. Experiments performed by genome demethylation indicated that demethylated defensin gene resulted in an altered expression after bacterial induction. In particular, no
Identification and chromosomal localization of mariner-like elements in the cabbage moth Mamestra brassicae (Lepidoptera)
Chromosome Research
Caryologia -Firenze-
A portion of the mitochondrial DNA from the 3' terminal of gene 12S rRNA to the 5' extremity of 1... more A portion of the mitochondrial DNA from the 3' terminal of gene 12S rRNA to the 5' extremity of 16S rRNA gene has been amplified by PCR from Salamandra atra aurorae genomic DNA in order to define the taxonomic position of S. atra aurorae within the Salamandra species. Analysis of the molecular data indicated that S. a. aurorae is quite different from S. salamandra, whereas S. a. aurorae and S. a. atra are more similar, although their mitochondrial DNA present several mutations. Our analysis suggested therefore that S. a. aurorae could really represent a new subspecies of alpine salamander. Finally, on the basis of the rate of sequence divergence, we could suggest that S. a. atra and S. a. aurorae diverged about three million years ago.
Southern blotting experiments performed on Mamestra brassicae genomic DNA after digestion with me... more Southern blotting experiments performed on Mamestra brassicae genomic DNA after digestion with methylation-sensitive restriction enzymes indicated that defensin gene is methylated at CpG targets in the promoter region. However, defensin gene is actively transcribed despite the presence of methylation. Experiments performed by genome demethylation indicated that demethylated defensin gene resulted in an altered expression after bacterial induction. In particular, no increase in gene expression was observed after induction with Gram positive bacteria if defensin gene was demethylated. The present results are intriguing since they indicate that in M. brassicae DNA methylation is not involved in gene silencing, but also that DNA methylation could be essential to assure the expression of specific genes. On the whole, data here presented argue against an unifying and evolutionary conserved role of cytosine methylation from invertebrates to vertebrates.
rDNA (18S-28S and 5S) colocalization and linkage between ribosomal genes and (TTAGGG)n telomeric sequence in the earthworm, Octodrilus complanatus (Annelida: Oligochaeta: Lumbricidae), revealed by single- and double-color FISH
Journal of Heredity
Spermatogonial and metaphase I chromosomes of the lumbricid earthworm Octodrilus complanatus (Ann... more Spermatogonial and metaphase I chromosomes of the lumbricid earthworm Octodrilus complanatus (Annelida: Oligochaeta) were examined using fluorescent in situ hybridization (FISH) with three repetitive DNA probes-5S rDNA, 18S-26S rDNA, and (TTAGGG)(n). Single-color FISH consistently mapped one chromosome pair per spread using either 5S rDNA or 18S-26S rDNA as probes. Simultaneous (18S-26S)-5S and (18S-26S)-(TTAGGG)(n) FISH demonstrated that repeated units of the two ribosomal families were overlapped and closely associated with telomeric sequences.
Hereditas
Mandrioli, M. and Manicardi, G. C. 2003. Analysis of insect holocentric chromosomes by atomic for... more Mandrioli, M. and Manicardi, G. C. 2003. Analysis of insect holocentric chromosomes by atomic force microscopy. -Hereditas 138: 129-132. Lund, Sweden.
Fast chromosomal evolution and karyotype instability: recurrent chromosomal rearrangements in the peach potato aphid Myzus persicae (Hemiptera: Aphididae)
Biological Journal of the Linnean Society, 2015
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Papers by Mauro Mandrioli