162 research outputs found
Genetic structure of gilthead seabream, Sparus aurata, in the Central Mediterranean Sea
Abstract
The gilthead seabream, Sparus aurata, represents an important economic resource for Mediterranean aquaculture. In spite of its wide geographic distribution and economic importance, only recently studies have been carried out on the genetic composition of natural populations, which have revealed a picture of a heterogeneous degree of genetic differentiation among S. aurata populations. In this study an allozyme analysis of samples from six different collecting sites along the Italian and Croatian coasts was carried out, covering an area in the Central Mediterranean sea that has yet to be investigated through gene-enzyme systems. Data on 26 gene loci, 10 of which are polymorphic, indicate a slight but significant genetic structure (FST = 0.0167) of the species. A hierarchical analysis of population subdivision made it possible to identify three different assemblages found in the Adriatic Sea, Tyrrhenian Sea and Sardinian Channel, though an isolation by distance model can be rejected. The results are discussed in the light of previous literature and taking conservation into consideration
Deciphering a multi-event in a non-complex set of detrital zircon UâPb ages from Carboniferous graywackes of SW Iberia
The determination of UâPb ages from detrital zircons of sedimentary rocks using LA-ICP-MS has been widely
used for the purpose of provenance analysis. One problem that frequently arises is finding a population that
appears to be non-complex despite several perceptible age peaks in its spectrum. These peaks are qualitatively
defined by means of relative probability diagrams, or PDFs, but it is difficult to quantify their statistical significance
relative to a zircon forming multi-event. Thus, can a multi-event in a non-complex set of detrital zircon
UâPb ages be deciphered and characterized?
The aim of this study is to attempt to provide an answer to this question by means of statistical analysis. Its
objectives are: a) to determine the best minimum number of zircon age populations (peaks), BmPs, b) for the
characterization of each peak in terms of age and event duration; c) to compare the results obtained from two
datasets showing similar zircon ages; and d) to demonstrate the usefulness of deciphering these BmPs. First,
cluster analysis is carried out, aimed at grouping zircon ages into a set of consistent clusters. A Gaussian Kernel
function is then fitted to each cluster and summed to obtain a theoretical PDFm (modeled probability density
function). Finally, the selected modeled PDFm (that built on the BmPs) is that which reports the lowest number
of peaks for which the difference as compared with the original gPDF (global probability density function) is
equal to or below 5%. Deciphered BmP peaks can be characterized and used for characterizing and providing
an understanding of related event(s).
A geological interpretation, based on the results obtained, is attempted. This includes a robust measure for
maximum age of deposition for both Cabrela and MĂ©rtola graywackes
The provenance of Late Ediacaran and Early Ordovician siliciclastic rocks in the
UâPb geochronology of detrital zircon from Late Ediacaran (Beiras Group greywackes) and Early Ordovician
(Sarnelhas arkosic quartzites and Armorican quartzites of Penacova) sedimentary rocks of the
southwest Central Iberian Zone (SW CIZ) constrain the evolution of northern Gondwana active-passive
margin transition. The LA-ICP-MS UâPb data set (375 detrital zircons with 90â110% concordant ages) is
dominated by Neoproterozoic ages (75% for the greywakes and 60% for the quartzites), among which the
main age cluster (more significant for Beiras Group greywackes) is Cryogenian (c.840â750 Ma), while a
few Mesoproterozoic and Tonian ages are also present (percentages <8%). These two features, and the
predominance of Cryogenian ages over Ediacaran ages, distinguish the Beiras Group greywackes (SW
CIZ) from the time-equivalent Serie Negra (Ossa-Morena Zone â OMZ), with which they are in inferred
contact. The age spectra of the Beiras Group greywackes also reveal three major episodes of zircon crystallisation
in the source area during the Neoproterozoic that are probably associated with a long-lived
system of magmatism that developed either along or in the vicinity of the northern Gondwana margin
at: (1) c. 850â700 Ma â Pan-African suture (not well represented in OMZ); (2) c. 700â635 Ma â early
Cadomian arc; and (3) c. 635â545 Ma â late Cadomian arc. Comparison of Neoproterozoic ages and those
of the Paleoproterozoic (c. 2â1.8 Ga) and Archean (mainly Neoarchean â 2.8â2.6 Ga, but also older) in the
Beiras Group greywackes with UâPb ages of Cadomian correlatives shows that: (1) SW CIZ, OMZ, Saxo-
Thuringian Zone, North Armorican Cadomian Belt and Anti-Atlas) evolved together during the formation
of back-arc basins on the northern Gondwana active margin and (2) all recorded synorogenic basins that
were filled during the Ediacaran by detritus resulting from erosion of the West African craton, the Pan-
African suture and a long-lived Cadomian magmatic arc. Differences in detrital zircon age populations in
the greywackes of the Beiras Group (SW CIZ Cadomian basement) and the Serie Negra (OMZ Cadomian
basement) are also observed in their respective overlying Early Ordovician quartzites. Since both these
SW Iberia Cadomian basements evolved together along the active margin of Gondwana (but sufficiently
separated to account for the differences in their detrital zircon content), this continuation of differing
zircon populations into the Early Ordovician suggests that the inferred contact presently juxtaposing
the Beiras Group and the Serie Negra is not pre-Early Ordovician and so is unlikely to demonstrate a
Cadomian suture
. U-Pb detrital zircon ages from the Beiras Group: Implications for the Neoproterozoic evolution of the SW Iberia
U-Pb detrital zircon ages from the Beiras Group greywackes (SW Central Iberian Zone - CIZ) indicate a maximum
depositional age of late Ediacaran (c. 560-578 Ma). Two salient features distinguish the Beiras Group from the SĂ©rie
Negra greywackes (age equivalent from the Ossa-Morena Zone - OMZ): i) The presence of Tonian and
Mesoproterozoic (<8%) age clusters in the Beiras Group greywackes, that are almost absent in the OMZ, imply either a
distinct or an additional source of detrital zircons from the West African Craton; and 2) The higher content of Cryogenian
zircon ages of the Beiras Group greywackes (mainly at c. 840-750 Ma and c. 685-660 Ma), that contrast with the
dominant Ediacaran zircon ages of the SĂ©rie Negra greywackes (OMZ). The Cryogenian zircon forming events that are
dominant in the SW CIZ basins are probably related to a different source with early Cadomian juvenile crust (c. 700-635
Ma) and with a possible contribution of the Pan-African suture (c. 850-700 Ma). The Nd isotopic signatures support the
addition of a juvenile source to pre-existent older crust for the Beiras Group metasediments. Although the Beiras Group
(SW CIZ) and Serie Negra (OMZ) late Ediacaran basins have evolved together in the active margin of Gondwana, they
were sufficiently separated to account for the differences in their detrital zircon content and isotopic signatures
Intra-crustal recycling and crustal-mantle interactions in
In situ O-isotope compositions of detrital, inherited and melt-precipitated zircons with
Neoproterozoic to Ordovician ages are presented to assess the crustal evolution of the North
Gondwana margin. Different groups of pre-Mesozoic rocks from SW Iberia were targeted:
i) Ediacaran paragneisses and meta-greywakes of the Ossa-Morena Zone â the Serie Negra
Group deposited at ~ 560 Ma in a Cadomian magmatic arc setting (Pereira et al., 2008); ii)
Early to Middle Cambrian orthogneisses and volcaniclastic rocks of the Ossa-Morena Zone â
Evora Massif igneous complexes related to ensialic rifting at ~ 530â500 Ma (Pereira et al., 2008,
Chichorro et al., 2008); iii) Late Cambrian to Early Ordovician volcaniclastic rocks and granites
of the Ossa-MorenaâCentral Iberian transition zone â the Urra Formation and Portalegre
granite formed at ~ 495â 488 Ma in a extensional setting (SolĂĄ et al., 2008); iv) Carboniferous
granitoids (Nisa and Arraiolos granites) containing inherited zircons with Cambrian to
Ordovician ages (SolĂĄ, this volume).
A compilation the results for the period ~ 3.4 Ga to ~ 450 Ma reveals that: a) Archean zircons
show little variation in d18O, with most values lying between 4.7 and 7.5â°, (average 6.2â°)
comparable with usual d18O of zircons from Archean elsewhere (e.g., Valley et al., 2005); b)
the range of d18O in Paleoproterozoic grains increases between 2.1 and 1.8 Ga with d18O
>7.5â°, indicating increasing supracrustal recycling, but at ~ 1.8 Ga the d18O has mantle-like
values (<5.1â°), documenting a crustal growth episode at this time; c) rare Mesoproterozoic
grains have mildly evolved d18O values in the range 5.6â7.1â°); d) Tonian grains have low d18O
values (4.2â5.6â°) typical of mantle-derived juvenile magmas but also higher values of 9.9â°
suggesting intra-crustal recycling; e) CryogenianâOrdovician zircons show more variable and
higher d18O values (~4 to >10â°), indicating great diversity and mixing of sources through
intra-crustal recycling and crustâmantle interactions; f) some d18O values near to or below
mantle composition (5.3 ± 0.3â°) were recorded at ~ 590 Ma (Ediacaran) suggesting input of
mantle material into the crust; g) a decrease in variance of d18O occurs from 575 Ma to the
Ediacaran/Cambrian boundary, suggesting a relative decrease in the magmatic contribution of
surface-derived material; h) in Cambrian times, the average d18O is higher in the 536â520Ma
interval (7.0â°) than in the 520â488 interval (6.2â°), which can be taken as a signal of gradual
opening of the system to mantle-derived, mafic, rift-related igneous complexes; i) higher values
of d18O (>7.5 â°) recorded at ~ 623â574 Ma and 490â470Ma mark periods of pronounced
increase in crustal recycling
New insights from UâPb zircon dating of Early Ordovician magmatism on
The Central IberianâOssa-Morena transition zone (SW Iberian Massif) represents a segment of the northern Gondwana margin with a long
geodynamic evolution, characterized by the superposition of Cadomian and Variscan events. The Early Ordovician is mainly represented by
porphyritic felsic volcaniclastic rocks (the Urra Formation) that pass up into a siliciclastic sediments typical of the Central Iberian Zone (Lower
Ordovician Armorican Quartzite Formation). The Urra Formation unconformably overlies the previously deformed and metamorphosed Ediacaran
sediments of the SĂ©rie Negra (with Ossa-Morena Zone paleogeographic affinity). New SHRIMP zircon data obtained from the Urra Formation
volcaniclastic rocks indicate an Early Ordovician age (206Pb/238U ages ranging from 494.6±6.8 Ma to 488.3±5.2 Ma) for this magmatic event.
The inherited zircon cores indicate the presence of multicycle protoliths with different Precambrian ages: Neoproterozoic (698â577 Ma),
Paleoproterozoic (2.33 Ga) and Paleoarchean (3.2â3.3 Ga). There is a noticeable lack of Meso- to Neoarchean and Mesoproterozoic ages. The
data support the hypothesis that the volcaniclastic rocks were derived by partial melting of Cadomian basement (linked to a West African Craton
provenance). The Urra Formation volcaniclastic rocks have rhyolitic to dacitic compositions, are peraluminous and similar to calc-alkaline high-K
series suites elsewhere. Isotopic signatures present a wide range of values (87Sr/86Sr)t=0.7085â0.7190, more restricted ΔNdt (â2.65 to â0.35) and
ÎŽ18O=9.63â10.34â°, compatible with magmas derived from crustal rocks, including portions of the lower crust. Some samples show disturbance
of the RbâSr system as shown by unrealistic values for (87Sr/86Sr)tb0.703, probably due to Variscan deformation and metamorphism. The
volcaniclastic rocks with a significant sedimentary contribution (upper unit) are distinguished from the others by the lowest values of ΔNdt (â5.53
to â4.85). The geochemical data are compatible with an orogenic geodynamic environment. However, the âorogenicâ signature can be considered
to represent, in part, an inherited feature caused by melting of the Cadomian basement which also has calc-alkaline affinities. The Early
Ordovician crustal growth and associated magmatism, represented by the Urra felsic volcaniclastic rocks and associated calc-alkaline granitoids,
diorites and gabbros, can be interpreted in terms of the underplating and temporal storage of mantle-derived magmas as the potential source for the
âorogenic meltsâ that were intruded during Early Paleozoic extension. This record of Early Ordovician magmatism has striking similarities with
other correlatives from the Iberian, Bohemian and Armorican massifs that are discussed in this paper. This comparison reinforces the probable
existence of a large-scale crustal melting process linked to a significant episode of extension on the northern Gondwana margin that probably
resulted in the birth of the Rheic Ocean
Dengue virus targets RBM10 deregulating host cell splicing and innate immune response
RNA-seq experiments previously performed by our laboratories showed enrichment in intronic sequences and alterations in alternative splicing in dengue-infected human cells. The transcript of the SAT1 gene, of well-known antiviral action, displayed higher inclusion of exon 4 in infected cells, leading to an mRNA isoform that is degraded by non-sense mediated decay. SAT1 is a spermidine/spermine acetyl-transferase enzyme that decreases the reservoir of cellular polyamines, limiting viral replication. Delving into the molecular mechanism underlying SAT1 pre-mRNA splicing changes upon viral infection, we observed lower protein levels of RBM10, a splicing factor responsible for SAT1 exon 4 skipping. We found that the dengue polymerase NS5 interacts with RBM10 and its sole expression triggers RBM10 proteasome-mediated degradation. RBM10 over-expression in infected cells prevents SAT1 splicing changes and limits viral replication, while its knock-down enhances the splicing switch and also benefits viral replication, revealing an anti-viral role for RBM10. Consistently, RBM10 depletion attenuates expression of interferon and pro-inflammatory cytokines. In particular, we found that RBM10 interacts with viral RNA and RIG-I, and even promotes the ubiquitination of the latter, a crucial step for its activation. We propose RBM10 fulfills diverse pro-inflammatory, anti-viral tasks, besides its well-documented role in splicing regulation of apoptotic genes.Fil: Pozzi, MarĂa Berta. Consejo Nacional de Investigaciones CientĂficas y TĂ©cnicas. Oficina de CoordinaciĂłn Administrativa Ciudad Universitaria. Instituto de FisiologĂa, BiologĂa Molecular y Neurociencias. Universidad de Buenos Aires. Facultad de Ciencias Exactas y Naturales. Instituto de FisiologĂa, BiologĂa Molecular y Neurociencias; Argentina. Universidad de Buenos Aires. Facultad de Ciencias Exactas y Naturales. Departamento de FisiologĂa, BiologĂa Molecular y Celular; ArgentinaFil: Bragado, Laureano Fabian Tomas. Consejo Nacional de Investigaciones CientĂficas y TĂ©cnicas. Oficina de CoordinaciĂłn Administrativa Ciudad Universitaria. Instituto de FisiologĂa, BiologĂa Molecular y Neurociencias. Universidad de Buenos Aires. Facultad de Ciencias Exactas y Naturales. Instituto de FisiologĂa, BiologĂa Molecular y Neurociencias; Argentina. Universidad de Buenos Aires. Facultad de Ciencias Exactas y Naturales. Departamento de FisiologĂa, BiologĂa Molecular y Celular; ArgentinaFil: Mammi, Pablo AndrĂ©s. Consejo Nacional de Investigaciones CientĂficas y TĂ©cnicas. Oficina de CoordinaciĂłn Administrativa Ciudad Universitaria. Instituto de FisiologĂa, BiologĂa Molecular y Neurociencias. Universidad de Buenos Aires. Facultad de Ciencias Exactas y Naturales. Instituto de FisiologĂa, BiologĂa Molecular y Neurociencias; Argentina. Universidad de Buenos Aires. Facultad de Ciencias Exactas y Naturales. Departamento de FisiologĂa, BiologĂa Molecular y Celular; ArgentinaFil: Torti, Maria Florencia. Consejo Nacional de Investigaciones CientĂficas y TĂ©cnicas. Oficina de CoordinaciĂłn Administrativa Ciudad Universitaria. Instituto de QuĂmica BiolĂłgica de la Facultad de Ciencias Exactas y Naturales. Universidad de Buenos Aires. Facultad de Ciencias Exactas y Naturales. Instituto de QuĂmica BiolĂłgica de la Facultad de Ciencias Exactas y Naturales; Argentina. Universidad de Buenos Aires. Facultad de Ciencias Exactas y Naturales. Departamento de QuĂmica BiolĂłgica; ArgentinaFil: Gaioli, Nicolas Ezequiel. Consejo Nacional de Investigaciones CientĂficas y TĂ©cnicas. Oficina de CoordinaciĂłn Administrativa Ciudad Universitaria. Instituto de FisiologĂa, BiologĂa Molecular y Neurociencias. Universidad de Buenos Aires. Facultad de Ciencias Exactas y Naturales. Instituto de FisiologĂa, BiologĂa Molecular y Neurociencias; Argentina. Universidad de Buenos Aires. Facultad de Ciencias Exactas y Naturales. Departamento de FisiologĂa, BiologĂa Molecular y Celular; ArgentinaFil: Gebhard, Leopoldo German. Consejo Nacional de Investigaciones CientĂficas y TĂ©cnicas; Argentina. Universidad Nacional de Quilmes. Departamento de Ciencia y TecnologĂa; ArgentinaFil: Garcia Sola, Martin Emilio. Consejo Nacional de Investigaciones CientĂficas y TĂ©cnicas. Oficina de CoordinaciĂłn Administrativa Ciudad Universitaria. Instituto de FisiologĂa, BiologĂa Molecular y Neurociencias. Universidad de Buenos Aires. Facultad de Ciencias Exactas y Naturales. Instituto de FisiologĂa, BiologĂa Molecular y Neurociencias; Argentina. Universidad de Buenos Aires. Facultad de Ciencias Exactas y Naturales. Departamento de FisiologĂa, BiologĂa Molecular y Celular; ArgentinaFil: Drago, Rita Vaz. Universidade Nova de Lisboa. Faculdade de Ciencias Medicas; PortugalFil: Iglesias, Nestor Gabriel. Universidad Nacional de Quilmes. Departamento de Ciencia y TecnologĂa; Argentina. Consejo Nacional de Investigaciones CientĂficas y TĂ©cnicas; ArgentinaFil: Garcia, Cybele. Consejo Nacional de Investigaciones CientĂficas y TĂ©cnicas. Oficina de CoordinaciĂłn Administrativa Ciudad Universitaria. Instituto de QuĂmica BiolĂłgica de la Facultad de Ciencias Exactas y Naturales. Universidad de Buenos Aires. Facultad de Ciencias Exactas y Naturales. Instituto de QuĂmica BiolĂłgica de la Facultad de Ciencias Exactas y Naturales; Argentina. Universidad de Buenos Aires. Facultad de Ciencias Exactas y Naturales. Departamento de QuĂmica BiolĂłgica; ArgentinaFil: Gamarnik, Andrea Vanesa. Consejo Nacional de Investigaciones CientĂficas y TĂ©cnicas. Oficina de CoordinaciĂłn Administrativa Parque Centenario. Instituto de Investigaciones BioquĂmicas de Buenos Aires. FundaciĂłn Instituto Leloir. Instituto de Investigaciones BioquĂmicas de Buenos Aires; ArgentinaFil: Srebrow, Anabella. Consejo Nacional de Investigaciones CientĂficas y TĂ©cnicas. Oficina de CoordinaciĂłn Administrativa Ciudad Universitaria. Instituto de FisiologĂa, BiologĂa Molecular y Neurociencias. Universidad de Buenos Aires. Facultad de Ciencias Exactas y Naturales. Instituto de FisiologĂa, BiologĂa Molecular y Neurociencias; Argentina. Universidad de Buenos Aires. Facultad de Ciencias Exactas y Naturales. Departamento de FisiologĂa, BiologĂa Molecular y Celular; Argentin
Regulation of hippocampal postnatal and adult neurogenesis by adenosine A 2A receptor: Interaction with brain-derived neurotrophic factor
21 pĂĄginas, 7 figuras.Adenosine A2A receptor (A2A R) activation modulates several brain processes, ranging from neuronal maturation to synaptic plasticity. Most of these actions occur through the modulation of the actions of the neurotrophin brain-derived neurotrophic factor (BDNF). In this work, we studied the role of A2A Rs in regulating postnatal and adult neurogenesis in the rat hippocampal dentate gyrus (DG). Here, we show that A2A R activation with CGS 21680 promoted neural stem cell self-renewal, protected committed neuronal cells from cell death and contributed to a higher density of immature and mature neuronal cells, particularly glutamatergic neurons. Moreover, A2A R endogenous activation was found to be essential for BDNF-mediated increase in cell proliferation and neuronal differentiation. Our findings contribute to further understand the role of adenosinergic signaling in the brain and may have an impact in the development of strategies for brain repair under pathological conditions.Fundaç~ao para a CiĂȘncia e a Tecnologia, Grant/Award Numbers: IF/01227/2015, SFRH/BD/74662/2010, IMM/CT/35-2018, SFRH/BD/128280/2017, SFRH/BD/129710/2017; H2020-WIDESPREAD-05-2020-Twinning
(EpiEpinet) under grant agreement No, Grant/Award Number: 9524; Ministerio de Ciencia e Innovaci on, Grant/Award Number: PID2019-111225RB-I00; Spanish MICIU, Grant/Award Number: SAF2015-70433-R;
Generalitat Valenciana, Grant/Award Number: PROMETEO/2018/055; COST Action, Grant/Award Number: BM1402Peer reviewe
Karyotype and genome size of Iberochondrostoma almacai (Teleostei, Cyprinidae) and comparison with the sister-species I.lusitanicum
This study aimed to define the karyotype of the recently described Iberian endemic Iberochondrostoma almacai, to revisit the previously documented chromosome polymorphisms of its sister species I.lusitanicum using C-, Ag-/CMA3 and RE-banding, and to compare the two species genome sizes. A 2n = 50 karyotype (with the exception of a triploid I.lusitanicum specimen) and a corresponding haploid chromosome formula of 7M:15SM:3A (FN = 94) were found. Multiple NORs were observed in both species (in two submetacentric chromosome pairs, one of them clearly homologous) and a higher intra and interpopulational variability was evidenced in I.lusitanicum. Flow cytometry measurements of nuclear DNA content showed some significant differences in genome size both between and within species: the genome of I. almacai was smaller than that of I.lusitanicum (mean values 2.61 and 2.93 pg, respectively), which presented a clear interpopulational variability (mean values ranging from 2.72 to 3.00 pg). These data allowed the distinction of both taxa and confirmed the existence of two well differentiated groups within I. lusitanicum: one that includes the populations from the right bank of the Tejo and Samarra drainages, and another that reunites the southern populations. The peculiar differences between the two species, presently listed as âCritically Endangeredâ, reinforced the importance of this study for future conservation plans
- âŠ