90 research outputs found
Molecular phylogeny, taxonomy and biogeography of the "haenydra" lineage (coleoptera, hydraenidae, genus hydraena)
The water beetle family Hydraenidae includes more than 1500 species worldwide, currently divided into four subfamilies: Hydraeninae, Ochthebiinae, Prosthetopinae and Orchymontinae. The majority of species are adapted for marginal life in the microscopic, mainly freshwater, aquatic world, feedeing dyatoms algae, even if details about the ecology of these beetles are poorly known. Most Hydraenidae species usually live in a layer of nearly stationary waters, where they adhere to the submerged stones within the fastest regions of cold, clean and fastflowing perennial streams. Hydraena Kugelann represents the largest genus within the water beetle family Hydraenidae, and in particular within Hydraeninae, with about 850 species widely distributed all over the world and several hundreds not yet described. In a recent cladistic analysis, based on morphological characters, Hydraena s.l. was split in two subgenera: Hydraenopsis Janssens (Gondwanian) and Hydraena s.str. (Laurasian). Moreover, within Hydraena s.str, some derived and well-supported monophyletic clades were recognised, and defined as âlineagesâ. Among them, the "Haenydra" Rey lineage, previously considered by many authors as a valid genus/subgenus, includes about 90 species distributed esclusively in western Palaearctic, from Portugal to Iran, but absent in North Africa. According mainly to male genitalia features, "Haenydra" species could be divided into several species groups and complexes.
The first objective of the present project was to completely reâexaminate morphology (analyzing the diagnostic characters in a cladistic standpoint), taxonomy, ecology, biogeography and conservation of the whole lineage. Furthermore, the second aim of the present work was to investigate the molecular phylogeny of the "Haenydra" lineage using both mitochondrial (COI, 16S rDNA, NAD1, tRNALeu) and nuclear (18S rDNA, 28S rDNA) markers, in order to clarify the evolutionary relationships among the different species groups and complexes, and to confirm the phylogenetic position of the "Haenydra" lineage within the large genus Hydraena s.l. In fact, although the monophyly of "Haenydra" is generally accepted, hydraenid specialists have been often discordant about the phylogenetic position of the lineage within Hydraena, sometimes considering it a basal taxon, sometimes a derived lineage. Moreover, molecular clocks were used to investigate the natural history of Hydraena s.str., and particularly of "Haenydra".
Preliminarly results well supported the monophyly and the derived phylogenetic position of the âHaenydraâ lineage, that was split in two major monophyletic clades: the H. gracilis and the H. dentipes clades (that split ca. 7.5 MYA), each one including several sub-clades, often corresponding to previously morphologically defined species groups/complexe
Molecular phylogeny, taxonomy and biogeography of the "haenydra" lineage (coleoptera, hydraenidae, genus hydraena)
The water beetle family Hydraenidae includes more than 1500 species worldwide, currently divided into four subfamilies: Hydraeninae, Ochthebiinae, Prosthetopinae and Orchymontinae. The majority of species are adapted for marginal life in the microscopic, mainly freshwater, aquatic world, feedeing dyatoms algae, even if details about the ecology of these beetles are poorly known. Most Hydraenidae species usually live in a layer of nearly stationary waters, where they adhere to the submerged stones within the fastest regions of cold, clean and fastflowing perennial streams. Hydraena Kugelann represents the largest genus within the water beetle family Hydraenidae, and in particular within Hydraeninae, with about 850 species widely distributed all over the world and several hundreds not yet described. In a recent cladistic analysis, based on morphological characters, Hydraena s.l. was split in two subgenera: Hydraenopsis Janssens (Gondwanian) and Hydraena s.str. (Laurasian). Moreover, within Hydraena s.str, some derived and well-supported monophyletic clades were recognised, and defined as âlineagesâ. Among them, the "Haenydra" Rey lineage, previously considered by many authors as a valid genus/subgenus, includes about 90 species distributed esclusively in western Palaearctic, from Portugal to Iran, but absent in North Africa. According mainly to male genitalia features, "Haenydra" species could be divided into several species groups and complexes.
The first objective of the present project was to completely reâexaminate morphology (analyzing the diagnostic characters in a cladistic standpoint), taxonomy, ecology, biogeography and conservation of the whole lineage. Furthermore, the second aim of the present work was to investigate the molecular phylogeny of the "Haenydra" lineage using both mitochondrial (COI, 16S rDNA, NAD1, tRNALeu) and nuclear (18S rDNA, 28S rDNA) markers, in order to clarify the evolutionary relationships among the different species groups and complexes, and to confirm the phylogenetic position of the "Haenydra" lineage within the large genus Hydraena s.l. In fact, although the monophyly of "Haenydra" is generally accepted, hydraenid specialists have been often discordant about the phylogenetic position of the lineage within Hydraena, sometimes considering it a basal taxon, sometimes a derived lineage. Moreover, molecular clocks were used to investigate the natural history of Hydraena s.str., and particularly of "Haenydra".
Preliminarly results well supported the monophyly and the derived phylogenetic position of the âHaenydraâ lineage, that was split in two major monophyletic clades: the H. gracilis and the H. dentipes clades (that split ca. 7.5 MYA), each one including several sub-clades, often corresponding to previously morphologically defined species groups/complexe
The Evolutionary Conserved SWI/SNF Subunits ARID1A and ARID1B Are Key Modulators of Pluripotency and Cell-Fate Determination
Organismal development is a process that requires a fine-tuned control of cell fate and identity, through timely regulation of lineage-specific genes. These processes are mediated by the concerted action of transcription factors and protein complexes that orchestrate the interaction between cis-regulatory elements (enhancers, promoters) and RNA Polymerase II to elicit transcription. A proper understanding of these dynamics is essential to elucidate the mechanisms underlying developmental diseases. Many developmental disorders, such as Coffin-Siris Syndrome, characterized by growth impairment and intellectual disability are associated with mutations in subunits of the SWI/SNF chromatin remodeler complex, which is an essential regulator of transcription. ARID1B and its paralog ARID1A encode for the two largest, mutually exclusive, subunits of the complex. Mutations in ARID1A and, especially, ARID1B are recurrently associated with a very wide array of developmental disorders, suggesting that these two SWI/SNF subunits play an important role in cell fate decision. In this mini-review we therefore discuss the available scientific literature linking ARID1A and ARID1B to cell fate determination, pluripotency maintenance, and organismal development
Molecular and morphological analyses confirm two new species of the Hydraena emarginataâsaga clade (Coleoptera, Hydraenidae) from Spain and France
El documento auto-archivado en Digital.CSIC es el PRE-PRINT del autor. La versiĂłn definitiva se publicĂł posteriormente en Zootaxa 2760 : 29-38 (2011)Using morphological and molecular analyses, the existence of two undescribed species, H. diazi from northâeastern Spain
and French Pyrenees, and H. fosterorum from northâcentral Spain is confirmed. These species are members of a European
endemic complex of hydraenid beetles, the Hydraena emarginataâsaga clade, belonging to the âHaenydraâ lineage. The
two new species are described and the geographic range of the widespread H. saga is revised.A visit of the first author to the NMW was supported by Synthesys (Application ATâTAFâ53); the work of IR was funded by projects CGL2007â61665 and CGL2010â15755.Peer reviewe
Cerebral stroke in a teenage girl with paroxysmal nocturnal hemoglobinuria
We report a case of paroxysmal nocturnal hemoglobinuria (PNH) in a 14 year-old girl presenting a cerebral arterial thrombosis. The initial diagnosis was carential anemia due to menarche following identification of slight macrocytic anemia, leucopenia and mild thrombocytopenia at routine blood analysis. The child was eventually referred to a childrenâs hospital after the onset of progressive fatigue, anorexia and paleness. Severe anemia (hemoglobin 6 g/dL) with negative Coombs test, mild leucopenia (white blood cells 4.9Ă109/L) and thrombocytopenia (platelets 97Ă109/L) and high values of lactate dehydrogenase (2855 U/L) were identified; a packed red cells transfusion was administered. Her condition worsened and she subsequently presented complete right hemiplegia, aphasia and coma; magnetic resonance imaging revealed a massive ischemic lesion. A diagnosis of PNH was eventually made following high sensitivity flow cytometry, which identified a PNH clone (CD66b negative equal to 93.7% of granulocytes). Fast recovery from neurologic and hematological problems occurred in response to anticoagulant therapy and intravenous therapy with eculizumab. We are convinced that PNH should be included in the differential diagnosis of children presenting with cytopenia
Young Transposable Elements Rewired Gene Regulatory Networks in Human and Chimpanzee Hippocampal Intermediate Progenitors
The hippocampus is associated with essential brain functions, such as learning and memory. Human hippocampal volume is significantly greater than expected compared with that of non-human apes, suggesting a recent expansion. Intermediate progenitors, which are able to undergo multiple rounds of proliferative division before a final neurogenic division, may have played a role in evolutionary hippocampal expansion. To investigate the evolution of gene regulatory networks underpinning hippocampal neurogenesis in apes, we leveraged the differentiation of human and chimpanzee induced pluripotent stem cells into TBR2 (or EOMES)-positive hippocampal intermediate progenitor cells (hpIPCs). We found that the gene networks active in hpIPCs are significantly different between humans and chimpanzees, with âŒ2500 genes being differentially expressed. We demonstrate that species-specific transposon-derived enhancers contribute to these transcriptomic differences. Young transposons, predominantly endogenous retroviruses and SINE-Vntr-Alus (SVAs), were co-opted as enhancers in a species-specific manner. Human-specific SVAs provided substrates for thousands of novel TBR2-binding sites, and CRISPR-mediated repression of these SVAs attenuated the expression of âŒ25% of the genes that are upregulated in human intermediate progenitors relative to the same cell population in the chimpanzee
Jun Upregulation Drives Aberrant Transposable Element Mobilization, Associated Innate Immune Response, and Impaired Neurogenesis in Alzheimerâs Disease
Adult neurogenic decline, inflammation, and neurodegeneration are phenotypic hallmarks of Alzheimer\u27s disease (AD). Mobilization of transposable elements (TEs) in heterochromatic regions was recently reported in AD, but the underlying mechanisms are still underappreciated. Combining functional genomics with the differentiation of familial and sporadic AD patient derived-iPSCs into hippocampal progenitors, CA3 neurons, and cerebral organoids, we found that the upregulation of the AP-1 subunit, c-Jun, triggers decondensation of genomic regions containing TEs. This leads to the cytoplasmic accumulation of HERVK-derived RNA-DNA hybrids, the activation of the cGAS-STING cascade, and increased levels of cleaved caspase-3, suggesting the initiation of programmed cell death in AD progenitors and neurons. Notably, inhibiting c-Jun effectively blocks all these downstream molecular processes and rescues neuronal death and the impaired neurogenesis phenotype in AD progenitors. Our findings open new avenues for identifying therapeutic strategies and biomarkers to counteract disease progression and diagnose AD in the early, pre-symptomatic stages
A Difficult Case of Ventriculitis in a 40-Year-Old Woman with Acute Myeloid Leukemia
Ventriculitis and nosocomial meningitis caused by carbapenem-resistant Gram-negative and vancomycin-resistant Gram-positive bacteria represent a growing treatment challenge. A case of ventriculitis and bacteremia caused by carbapenem-resistant, KPC-producing Klebsiella pneumoniae and vancomycin-resistant Enterococcus faecium in a young woman with acute leukemia who was successfully treated with meropenem/vaborbactam (MVB), rifampicin, and linezolid is described in this paper. This case report emphasizes the importance of a multidisciplinary strategy, including infectious focus control, for the treatment of device-associated central nervous system (CNS) infections from multidrug-resistant bacteria. Considering the novel resistance patterns, more research on drug penetration into the central nervous system, as well as on the necessity of association therapies, is needed
UPDATING THE TAXONOMY AND DISTRIBUTION OF THE EUROPEAN OSMODERMA, AND STRATEGIES FOR THEIR CONSERVATION (Coleoptera, Scarabaeidae, Cetoniinae)
Results of a molecular analysis on the European hermit beetles (the Osmoderma eremita species-complex), recently published in a companion paper, are shortly dis- cussed and commented. These results indicate a clear-cut distinction between two clades. The first one includes the W-European O. eremita Scopoli, 1763, and the two Italian endemic taxa O. italicum Sparacio, 2000 and O. cristinae Sparacio, 1994, from southern peninsular Italy and Sicily, respectively. The second one includes the widespread E-European O. barnabita Motschulsky, 1845 (nom. resurr.), and the southern Balcanic O. lassallei Baraud & Tauzin, 1991 from Greece and European Turkey. Within the two clades, molecular data well support a specific rank for O. lassallei and O. barnÂabita on one side, and of O. eremita and O. cristinae on the other side, while the taxonomic position of O. italicum, more closely related with O. eremita, is still uncertain, waiting for analysis of additional specimens of this very rare taxon. Current geographical distribution, interspecific genetic diversification, and relatively low levels of intraspecific genetic divergence in O. eremita sensu stricto, are hypothesized to be the result of multiple speciation events (mainly occurred in refugial forest areas of the Italian and Balkan peninsulas and Sicily before and during the Pleistocene glacial peaks), followed by fast post-glacial northward and westward expansion of some species. The need of further genetic data on the rare and threatened hermit beetle species and the importance of more detailed information on their distribution ranges are emphasized and discussed, in order to plan conservation strategies in the near future. An updated worldwide checklist of the species of the genus Osmoderma is finally presented
UPDATING THE TAXONOMY AND DISTRIBUTION OF THE EUROPEAN OSMODERMA, AND STRATEGIES FOR THEIR CONSERVATION (COLEOPTERA, SCARABAEIDAE, CETONIINAE)
Results of a molecular analysis on the European hermit beetles (the Osmoderma eremita species-complex), recently published in a companion paper, are shortly dis- cussed and commented. These results indicate a clear-cut distinction between two clades. The first one includes the W-European O. eremita Scopoli, 1763, and the two Italian endemic taxa O. italicum Sparacio, 2000 and O. cristinae Sparacio, 1994, from southern peninsular Italy and Sicily, respectively. The second one includes the widespread E-European O. barnabita Motschulsky, 1845 (nom. resurr.), and the southern Balcanic O. lassallei Baraud & Tauzin, 1991 from Greece and European Turkey. Within the two clades, molecular data well support a specific rank for O. lassallei and O. barnÂabita on one side, and of O. eremita and O. cristinae on the other side, while the taxonomic position of O. italicum, more closely related with O. eremita, is still uncertain, waiting for analysis of additional specimens of this very rare taxon. Current geographical distribution, interspecific genetic diversification, and relatively low levels of intraspecific genetic divergence in O. eremita sensu stricto, are hypothesized to be the result of multiple speciation events (mainly occurred in refugial forest areas of the Italian and Balkan peninsulas and Sicily before and during the Pleistocene glacial peaks), followed by fast post-glacial northward and westward expansion of some species. The need of further genetic data on the rare and threatened hermit beetle species and the importance of more detailed information on their distribution ranges are emphasized and discussed, in order to plan conservation strategies in the near future. An updated worldwide checklist of the species of the genus Osmoderma is finally presented
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