Papers by rodolfo semignine costa
<p>Heat maps representing a selection of deregulated transcripts, provided by the DAVID too... more <p>Heat maps representing a selection of deregulated transcripts, provided by the DAVID tool, in <i>tim-Gl4(U)/UAS-miR-210 versus</i> control samples (<i>tim-Gl4(U)/+</i>) involved in (A) phototransduction (12 transcripts). A color-coded scale for the normalized expression values is used: yellow and blue represent high and low expression levels in <i>miR-210</i> over-expressing flies, compared to controls. The expression level of each transcript was calculated as Log2 (<i>miR-210</i>/CTRL). A complete list of differentially expressed genes identified by SAM two class algorithm is provided in the Supplementary Information (<a href="http://www.plosgenetics.org/article/info:doi/10.1371/journal.pgen.1007500#pgen.1007500.s013" target="_blank">S3</a> and <a href="http://www.plosgenetics.org/article/info:doi/10.1371/journal.pgen.1007500#pgen.1007500.s019" target="_blank">S9</a> Tables). (B) Heat map representing deregulated transcripts, provided by the DAVID tool, in <i>tim-Gl4(U)/UAS-miR-210</i> versus control samples (<i>tim-Gl4(U)/+</i>) involved in circadian rhythms (22 transcripts), at ZT0 and ZT12. (C) Optomotor responses at ZT18 of <i>tim-Gl4</i>,<i>tub-Gl80</i><sup><i>ts</i></sup><i>/UAS-miR-210</i> flies kept at 23°C (23°C-23°C) or 29°C (29°C-23°C) during development. A total of 100 flies per genotype were analysed. <i>miR-210</i> over-expressing flies (grey) showed a significant decrease in the optomotor response compared to controls (black). (Mean ± SEM; t-test * p<0.05).</p
Frontiers in Neuroscience
The aims of the present study were to obtain sleep quality and sleep timing information in a grou... more The aims of the present study were to obtain sleep quality and sleep timing information in a group of university students and to evaluate the effects of a circadian hygiene education initiative. All students of the University of Padova (approximately 64,000) were contacted by e-mail (major campaigns in October 2019 and October 2020) and directed to an ad hoc website for collection of demographics and sleep quality/timing information. Participants (n = 5,740) received one of two sets of circadian hygiene advice (“A regular life” or “Bright days and dark nights”). Every month, they were then asked how easy it had been to comply and provided with the advice again. At any even month from joining, they completed the sleep quality/timing questionnaires again. Information on academic performance was obtained post hoc, together with representative samples of lecture (n = 5,972) and examination (n = 1,800) timings, plus lecture attendances (n = 25,302). Fifty-two percent of students had poor...
The aims of the present study were to obtain sleep quality and sleep timing information in a grou... more The aims of the present study were to obtain sleep quality and sleep timing information in a group of university students, and to evaluate the effects of a circadian hygiene education initiative. All students of the University of Padova (approximately 64,000) were contacted by e-mail (major campaigns in October 2019 and October 2020) and directed to an ad hoc website for collection of demographics and sleep quality/timing information. Participants (n=5740) received one of two sets of circadian hygiene advice (“A regular life” or “Bright days and dark nights”). Every month, they were then asked how easy it had been to comply, and provided with the advice again. At any even month from joining, they completed the sleep quality/timing questionnaires again. Information on academic performance was obtained post hoc, together with representative samples of lecture (n=5972) and exam (n=1800) timings, plus lecture attendances (n=25,302). 52% of students had poor sleep quality and 82% showed ...
Genetics, 2001
A genomic fragment from Drosophila virilis that contained all the no-on-transientA (nonA) coding ... more A genomic fragment from Drosophila virilis that contained all the no-on-transientA (nonA) coding information, plus several kilobases of upstream material, was identified. Comparisons of nonA sequences and the gene nonA-like in D. melanogaster, a processed duplication of nonA, suggest that it arose before the split between D. melanogaster and D. virilis. In both species, another gene that lies <350 bp upstream from the nonA transcription starts, and that probably corresponds to the lethal gene l(1)i19, was identified. This gene encodes a protein that shows similarities to GPI1, which is required for the biosynthesis of glycosylphosphatidylinositol (GPI), a component for anchoring eukaryotic proteins to membranes, and so we have named it dGpi1. The molecular evolution of nonA and dGpi1 sequences show remarkable differences, with the latter revealing a level of amino acid divergence that is as high as that of transformer and with extremely low levels of codon bias. Nevertheless, in ...
Genetics, 2000
In Drosophila, the clock gene period (per), is an integral component of the circadian clock and a... more In Drosophila, the clock gene period (per), is an integral component of the circadian clock and acts via a negative autoregulatory feedback loop. Comparative analyses of per genes in insects and mammals have revealed that they may function in similar ways. However in the giant silkmoth, Antheraea pernyi, per expression and that of the partner gene, tim, is not consistent with the negative feedback role. As an initial step in developing an alternative dipteran model to Drosophila, we have identified the per orthologue in the housefly, Musca domestica. The Musca per sequence highlights a pattern of conservation and divergence similar to other insect per genes. The PAS dimerization domain shows an unexpected phylogenetic relationship in comparison with the corresponding region of other Drosophila species, and this appears to correlate with a functional assay of the Musca per transgene in Drosophila melanogaster per-mutant hosts. A simple hypothesis based on the coevolution of the PERIO...
Journal of Molecular Medicine, 2021
Mutations in BCS1L are the most frequent cause of human mitochondrial disease linked to complex I... more Mutations in BCS1L are the most frequent cause of human mitochondrial disease linked to complex III deficiency. Different forms of BCS1L-related diseases and more than 20 pathogenic alleles have been reported to date. Clinical symptoms are highly heterogenous, and multisystem involvement is often present, with liver and brain being the most frequently affected organs. BCS1L encodes a mitochondrial AAA + -family member with essential roles in the latest steps in the biogenesis of mitochondrial respiratory chain complex III. Since Bcs1 has been investigated mostly in yeast and mammals, its function in invertebrates remains largely unknown. Here, we describe the phenotypical, biochemical and metabolic consequences of Bcs1 genetic manipulation in Drosophila melanogaster. Our data demonstrate the fundamental role of Bcs1 in complex III biogenesis in invertebrates and provide novel, reliable models for BCS1L-related human mitochondrial diseases. These models recapitulate several features ...
Genetics, 2001
The nonA gene of Drosophila melanogaster is important for normal vision, courtship song, and viab... more The nonA gene of Drosophila melanogaster is important for normal vision, courtship song, and viability and lies ∼350 bp downstream of the dGpi1 gene. Full rescue of nonA mutant phenotypes can be achieved by transformation with a genomic clone that carries ∼2 kb of 5′ regulatory material and that encodes most of the coding sequence of dGpi1. We have analyzed this 5′ region by making a series of deleted fragments, fusing them to yeast GAL4 sequences, and driving UAS-nonA expression in a mutant nonA background. Regions that both silence and enhance developmental tissue-specific expression of nonA and that are necessary for generating optomotor visual responses are identified. Some of these overlap the dGpi1 sequences, revealing cis-regulation by neighboring gene sequences. The largest 5′ fragment was unable to rescue the normal electroretinogram (ERG) consistently, and no rescue at all was observed for the courtship song phenotype. We suggest that sequences within the nonA introns that...
Frontiers in Physiology, 2021
Genetics, 1994
The threonine-glycine (Thr-Gly) repeat region of the period (per) gene of eight natural populatio... more The threonine-glycine (Thr-Gly) repeat region of the period (per) gene of eight natural populations of Drosophila simulans from Europe and North Africa was analyzed by polymerase chain reaction, DNA sequencing and heteroduplex formation. Five different length alleles encoding 21, 23, 25 and two different kinds of 24 Thr-Gly pairs in the uninterrupted repeat were found. In the 3' region flanking the repeat 6 nucleotide substitutions (3 synonymous, 3 replacement) were observed in three different combinations that we called haplotypes I, II and III. The complete linkage disequilibrium observed between the haplotypes and these length variants allowed us to infer from the repeat length, the DNA sequence at the 3' polymorphic sites. The haplotypes were homogeneously distributed across Europe and North Africa. The data show statistically significant departures from neutral expectations according to the Tajima test. The results suggest that balancing selection might have played a ro...
PLOS Genetics, 2018
Single microRNAs are usually associated with hundreds of putative target genes that can influence... more Single microRNAs are usually associated with hundreds of putative target genes that can influence multiple phenotypic traits in Drosophila, ranging from development to behaviour. We investigated the function of Drosophila miR-210 in circadian behaviour by misexpressing it within circadian clock cells. Manipulation of miR-210 expression levels in the PDF (pigment dispersing factor) positive neurons affected the phase of locomotor activity, under both light-dark conditions and constant darkness. PER cyclical expression was not affected in clock neurons, however, when miR-210 was up-regulated, a dramatic alteration in the morphology of PDF ventral lateral neuron (LNv) arborisations was observed. The effect of miR-210 in shaping neuronal projections was confirmed in vitro, using a Drosophila neuronal cell line. A transcriptomic analysis revealed that miR-210 overexpression affects the expression of several genes belonging to pathways related to circadian processes, neuronal development, GTPases signal transduction and photoreception. Collectively, these data reveal the role of miR-210 in modulating circadian outputs in flies and guiding/remodelling PDF positive LNv arborisations and indicate that miR-210 may have pleiotropic effects on the clock, light perception and neuronal development.
Journal of biological rhythms, 2018
The fruit fly Drosophila melanogaster survives thermally stressful conditions in a state of repro... more The fruit fly Drosophila melanogaster survives thermally stressful conditions in a state of reproductive dormancy (diapause), manifested by reduced metabolic activity and arrested ovarian development in females. Unlike insects that rely primarily on photoperiodic stimuli to initiate the diapause program, in this species dormancy is regulated by low temperature and enhanced by shorter photoperiods. Overwintering phenotypes are usually studied under simple laboratory conditions, where animals are exposed to rectangular light-dark (LD) cycles at a constant temperature. We sought to adopt more realistic diapause protocols by generating LD profiles that better mimic outdoor conditions. Experimental flies were subjected to semi-natural late autumn and summer days, while control females received the same amounts of light but in rectangular LD cycles (LD 8:16 and LD 15:9, respectively). We observed that semi-natural autumnal days induced a higher proportion of females to enter dormancy, whi...
Frontiers in molecular neuroscience, 2018
Light is the main environmental stimulus that synchronizes the endogenous timekeeping systems in ... more Light is the main environmental stimulus that synchronizes the endogenous timekeeping systems in most terrestrial organisms. cryptochrome (dCRY) is a light-responsive flavoprotein that detects changes in light intensity and wavelength around dawn and dusk. We have previously shown that dCRY acts through Inactivation No Afterpotential D (INAD) in a light-dependent manner on the Signalplex, a multiprotein complex that includes visual-signaling molecules, suggesting a role for dCRY in fly vision. Here, we predict and demonstrate a novel Ca-dependent interaction between dCRY and calmodulin (CaM). Through yeast two hybrid, coimmunoprecipitation (Co-IP), nuclear magnetic resonance (NMR) and calorimetric analyses we were able to identify and characterize a CaM binding motif in the dCRY C-terminus. Similarly, we also detailed the CaM binding site of the scaffold protein INAD and demonstrated that CaM bridges dCRY and INAD to form a ternary complex . Our results suggest a process whereby a r...
Scientific reports, Jan 18, 2017
Antarctic krill (Euphausia superba) is a key species in Southern Ocean ecosystem where it plays a... more Antarctic krill (Euphausia superba) is a key species in Southern Ocean ecosystem where it plays a central role in the Antarctic food web. Available information supports the existence of an endogenous timing system in krill enabling it to synchronize metabolism and behavior with an environment characterized by extreme seasonal changes in terms of day length, food availability, and surface ice extent. A screening of our transcriptome database "KrillDB" allowed us to identify the putative orthologues of 20 circadian clock components. Mapping of conserved domains and phylogenetic analyses strongly supported annotations of the identified sequences. Luciferase assays and co-immunoprecipitation experiments allowed us to define the role of the main clock components. Our findings provide an overall picture of the molecular mechanisms underlying the functioning of the endogenous circadian clock in the Antarctic krill and shed light on their evolution throughout crustaceans speciatio...
Journal of insect physiology, Jan 12, 2018
Unlike many insects where photoperiod per se induces diapause, reproductive arrest in Drosophila ... more Unlike many insects where photoperiod per se induces diapause, reproductive arrest in Drosophila melanogaster adult females is observed at colder temperatures and can be enhanced by shorter photoperiods. Traditional experimental protocols raise flies at 25 °C from the larval stage and then the adults are placed at 12 °C for between 12 and 28 days. After 12 days diapause levels are usually higher than at 28 days, suggesting that the flies are in a cold induced quiescence, rather than a true diapause. By raising flies at more realistic lower temperatures, we observe quite dramatic and counter-intuitive effects on diapause, whose levels nevertheless correlate with various indices of cryoprotectant metabolites as well as resistance to chill shock. We also observe that photoperiodic effects are minimised when very small temperature oscillations associated with the light-dark incubator cycles are neutralised. Our results suggest that the reported photoperiodic component of fly diapause, a...
Scientific reports, 2018
In response to adverse environmental conditions many organisms from nematodes to mammals deploy a... more In response to adverse environmental conditions many organisms from nematodes to mammals deploy a dormancy strategy, causing states of developmental or reproductive arrest that enhance somatic maintenance and survival ability at the expense of growth or reproduction. Dormancy regulation has been studied in C. elegans and in several insects, but how neurosensory mechanisms act to relay environmental cues to the endocrine system in order to induce dormancy remains unclear. Here we examine this fundamental question by genetically manipulating aminergic neurotransmitter signaling in Drosophila melanogaster. We find that both serotonin and dopamine enhance adult ovarian dormancy, while the downregulation of their respective signaling pathways in endocrine cells or tissues (insulin producing cells, fat body, corpus allatum) reduces dormancy. In contrast, octopamine signaling antagonizes dormancy. Our findings enhance our understanding of the ability of organisms to cope with unfavorable e...
Journal of biological rhythms, 2017
The spread of adaptive genetic variants in populations is a cornerstone of evolutionary theory bu... more The spread of adaptive genetic variants in populations is a cornerstone of evolutionary theory but with relatively few biologically well-understood examples. Previous work on the ls-tim variant of timeless, which encodes the light-sensitive circadian regulator in Drosophila melanogaster, suggests that it may have originated in southeastern Italy. Flies characterized by the new allele show photoperiod-related phenotypes likely to be adaptive in seasonal environments. ls-tim may be spreading from its point of origin in Italy by directional selection, but there are alternative explanations for its observed clinal geographical distribution, including balancing selection and demography. From population analyses of ls-tim frequencies collected on the eastern side of the Iberian Peninsula, we show that ls-tim frequencies are inverted compared with those in Italy. This pattern is consistent with a scenario of directional selection rather than latitude-associated balancing selection. Neutral...
Frontiers in Molecular Neuroscience, 2017
Drosophila CRYPTOCHROME (CRY) is a blue light sensitive protein with a key role in circadian phot... more Drosophila CRYPTOCHROME (CRY) is a blue light sensitive protein with a key role in circadian photoreception. A main feature of CRY is that light promotes an interaction with the circadian protein TIMELESS (TIM) resulting in their ubiquitination and degradation, a mechanism that contributes to the synchronization of the circadian clock to the environment. Moreover, CRY participates in non-circadian functions such as magnetoreception, modulation of neuronal firing, phototransduction and regulation of synaptic plasticity. In the present study we used co-immunoprecipitation, yeast 2 hybrid (Y2H) and in situ proximity ligation assay (PLA) to show that CRY can physically associate with the presynaptic protein BRUCHPILOT (BRP) and that CRY-BRP complexes are located mainly in the visual system. Additionally, we present evidence that light-activated CRY may decrease BRP levels in photoreceptor termini in the distal lamina, probably targeting BRP for degradation.
Mutation Research/Environmental Mutagenesis and Related Subjects, 1991
Scientific Reports, 2017
PER3 gene polymorphisms have been associated with differences in human sleep-wake phenotypes, and... more PER3 gene polymorphisms have been associated with differences in human sleep-wake phenotypes, and sensitivity to light. The aims of this study were to assess: i) the frequency of allelic variants at two PER3 polymorphic sites (rs57875989 length polymorphism: PER3 4 , PER3 5 ; rs228697 SNP: PER3 C , PER3 G) in relation to sleep-wake timing; ii) the effect of morning light on behavioural/circadian variables in PER3 4 /PER3 4 and PER3 5 /PER3 5 homozygotes. 786 Caucasian subjects living in Northern Italy donated buccal DNA and completed diurnal preference, sleep quality/timing and sleepiness/ mood questionnaires. 19 PER3 4 /PER3 4 and 11 PER3 5 /PER3 5 homozygotes underwent morning light administration, whilst monitoring sleep-wake patterns and the urinary 6-sulphatoxymelatonin (aMT6s) rhythm. No significant relationship was observed between the length polymorphism and diurnal preference. By contrast, a significant association was observed between the PER3 G variant and morningness (OR = 2.10), and between the PER3 G-PER3 4 haplotype and morningness (OR = 2.19), for which a mechanistic hypothesis is suggested. No significant differences were observed in sleep timing/ aMT6s rhythms between PER3 5 /PER3 5 and PER3 4 /PER3 4 subjects at baseline. After light administration, PER3 4 /PER3 4 subjects advanced their aMT6s acrophase (p < 0.05), and showed a trend of advanced sleep-wake timing. In conclusion, significant associations were observed between PER3 polymorphic variants/their combinations and both diurnal preference and the response to light. Clock genes and their products are associated with the current molecular model for the genesis of circadian rhythms 1. Allelic variants of clock genes affect the period and the phase of circadian rhythms 2. An important component of the biological clock is the Period (PER) gene family. The heterodimers formed by PER3 protein with PER1/2 and cryptochrome 1/2 (CRY1/2) enter the nucleus, inhibit CLOCK/BMAL1-mediated transcription 3 , thus contributing to the output pathway of circadian oscillations 4. The human PER3 gene shows higher levels of polymorphism compared to the other PER paralogs 5 , suggesting that PER3 may account for individual differences in human circadian and sleep phenotypes. The coding region of the PER3 gene contains a variable-number tandem-repeat (VNTR) polymorphism, i.e. a motif encoding 18 amino acids is repeated either four (PER3 4) or five (PER3 5) times in exon 18 6 (rs57875989, NM_001289861.1:c.3002-13_3042del54). The repeated unit contains a cluster of putative phosphorylation sites, and the polymorphism may influence PER3 function. There is some evidence that, in humans, PER3 may be related to diurnal preference, or the personal inclination to be more/less active at different times of the waking day. The PER3 4 allelic variant has been associated with physiological and pathological eveningness 6, 7 while the PER3 5 allele has been associated with morningness 7. In addition, the PER3 5 allele has been associated with enhanced suppression of nocturnal melatonin by administration of light at night 8. However, the effect of light in
Frontiers in Physiology, 2017
Patients with liver cirrhosis can develop hyperammonemia and hepatic encephalopathy (HE), accompa... more Patients with liver cirrhosis can develop hyperammonemia and hepatic encephalopathy (HE), accompanied by pronounced daytime sleepiness. Previous studies with healthy volunteers show that experimental increase in blood ammonium levels increases sleepiness and slows the waking electroencephalogram. As ammonium increases adenosine levels in vitro, and adenosine is a known regulator of sleep/wake homeostasis, we hypothesized that the sleepiness-inducing effect of ammonium is mediated by adenosine. Eight adult male Wistar rats were fed with an ammonium-enriched diet for 4 weeks; eight rats on standard diet served as controls. Each animal was implanted with electroencephalography/electromyography (EEG/EMG) electrodes and a microdialysis probe. Sleep EEG recording and cerebral microdialysis were carried out at baseline and after 6 h of sleep deprivation. Adenosine and metabolite levels were measured by high-performance liquid chromatography (HPLC) and targeted LC/MS metabolomics, respectively. Baseline adenosine and metabolite levels (12 of 16 amino acids, taurine, t4-hydroxy-proline, and acetylcarnitine) were lower in hyperammonemic animals, while putrescine was higher. After sleep deprivation, hyperammonemic animals exhibited a larger increase in adenosine levels, and a number of metabolites showed a different time-course in the two groups. In both groups the recovery period was characterized by a significant decrease in wakefulness/increase in NREM and REM sleep. However, while control animals exhibited a gradual compensatory effect, hyperammonemic animals showed a significantly shorter recovery phase. In conclusion, the adenosine/metabolite/EEG response to sleep deprivation was modulated by hyperammonemia, suggesting that ammonia affects homeostatic sleep regulation and its metabolic correlates.
Uploads
Papers by rodolfo semignine costa