Drosophila Chromosomal Polymorphism: From Population Aspects to Origin Mechanisms of Inversions

High rates of chromosomal rearrangements are remarkably abundant in Drosophila Fallén, 1832 (Insecta, Diptera) genus, highlighting the paracentric inversions. Since different species of this genus are paradigms for genetics, evolutionary, and population studies, polymorphism analyses for chromosomal inversions have provided basic knowledge for beautiful biological questions. Chromosomal inversions suppress meiotic recombination and thus, natural selection can act to preserve favorable gene complexes. Analyses of natural and laboratory populations show that these polymorphisms provide adaptive advantages to their carriers in relation to diverse factors, such as niche exploration and climatic factors. In addition, due to their monophyletic origin, they also serve as genetic markers for the construction of unrooted phylogenies. With the increasing domain of molecular techniques and genome sequencing, factors such as the reuse of breakpoints by different inversions and the mechanisms that give rise to these polymorphisms have been exploited with scientific refinement. These analyses show the presence of regions that are hot spots for breakpoints, fitting the fragile breakage chromosomal evolution model, as well as the involvement of transposition elements at the origin of chromosomal inversions

Summer precipitation variability over South America on long and short intraseasonal timescales

A dipole pattern in convection between the South Atlantic convergence zone and the subtropical plains of southeastern South America characterizes summer intraseasonal variability over the region. The dipole pattern presents two main bands of temporal variability, with periods between 10 and 30Â days, and 30 and 90Â days; each influenced by different large-scale dynamical forcings. The dipole activity on the 30--90-day band is related to an eastward traveling wavenumber-1 structure in both OLR and circulation anomalies in the tropics, similar to that associated with the Madden--Julian oscillation. The dipole is also related to a teleconnection pattern extended along the South Pacific between Australia and South America. Conversely, the dipole activity on the 10--30-day band does not seem to be associated with tropical convection anomalies. The corresponding circulation anomalies exhibit, in the extratropics, the structure of Rossby-like wave trains, although their sources are not completely clear

Plausible Drying and Wetting Scenarios for Summer in Southeastern South America

Summer rainfall trends in southeastern South America (SE-SA) have received attention in recent decades because of their importance for climate impacts. More than one driving mechanism has been identified for the trends, some of which have opposing effects. It is still not clear how much each mechanism has contributed to the observed trends or how their combined influence will affect future changes. Here, we address the second question and study how the CMIP6 summer SE-SA rainfall response to greenhouse warming can be explained by mechanisms related to large-scale extratropical circulation responses in the Southern Hemisphere to remote drivers (RDs) of regional climate change. We find that the regional uncertainty is well represented by combining the influence of four RDs: tropical upper-tropospheric amplification of surface warming, the delay in the stratospheric polar vortex breakdown date, and two RDs characterizing recognized tropical Pacific SST warming patterns. Applying a storyline framework, we identify the combination of RD responses that lead to the most extreme drying and wetting scenarios. Although most scenarios involve wetting, SE-SA drying can result if high upper-tropospheric tropical warming and early stratospheric polar vortex breakdown conditions are combined with low central and eastern Pacific warming. We also show how the definition of the SE-SA regional box can impact the results since the spatial patterns characterizing the dynamical influences are complex and the rainfall changes can be averaged out if these are not considered when aggregating. This article’s perspective and the associated methodology are applicable to other regions of the globe. Significance Statement: Summer rainfall in southeastern South America (SE-SA) affects an area where around 200 million people live. The observed trends suggest long-term wetting, and most climate models predict a wetting response to greenhouse warming. However, in this work, we find that there is a physically plausible combination of large-scale circulation changes that can promote drying, which means SE-SA drying is a possibility that cannot be ignored. We also show that the definition of the SE-SA regional box can impact regional rainfall analysis since the spatial patterns characterizing the dynamical influences are complex and the changes can be averaged out if these are not considered when aggregating. This perspective and the associated methodology are applicable to other regions of the globe

Seasonal cycle of precipitation variability in South America on intraseasonal timescales

The seasonal cycle of the intraseasonal (IS) variability of precipitation in South America is described through the analysis of bandpass filtered outgoing longwave radiation (OLR) anomalies. The analysis is discriminated between short (10--30 days) and long (30--90 days) intraseasonal timescales. The seasonal cycle of the 30--90-day IS variability can be well described by the activity of first leading pattern (EOF1) computed separately for the wet season (October--April) and the dry season (May--September). In agreement with previous works, the EOF1 spatial distribution during the wet season is that of a dipole with centers of actions in the South Atlantic Convergence Zone (SACZ) and southeastern South America (SESA), while during the dry season, only the last center is discernible. In both seasons, the pattern is highly influenced by the activity of the Madden--Julian Oscillation (MJO). Moreover, EOF1 is related with a tropical zonal-wavenumber-1 structure superposed with coherent wave trains extended along the South Pacific during the wet season, while during the dry season the wavenumber-1 structure is not observed. The 10--30-day IS variability of OLR in South America can be well represented by the activity of the EOF1 computed through considering all seasons together, a dipole but with the stronger center located over SESA. While the convection activity at the tropical band does not seem to influence its activity, there are evidences that the atmospheric variability at subtropical-extratropical regions might have a role. Subpolar wavetrains are observed in the Pacific throughout the year and less intense during DJF, while a path of wave energy dispersion along a subtropical wavetrain also characterizes the other seasons. Further work is needed to identify the sources of the 10--30-day-IS variability in South America

Os Caminhos da Luta pela Terra: Reconstrução Histórica do Assentamento "PDS Comunidade Agrária 21 de Dezembro"

This study tries to demonstrate the route of a group of people and their efforts towards a better quality of life, on the earliest beginnings of the fight for a plot of land. This paper aims to report the foundation process of PDS Comunidade Agrária 21 de Dezembro settlement in the Descalvado town, State of São Paulo, since the constitution of the first group and its journeys until the achievement of lands, and the consolidation of those families in the countryside. Thus, we look forward to better understanding this settlement foundation throughout the depiction and analysis of the fight for the land importance experienced by such families, and how that process whether influenced or not the collective allotment of this community. There was an attempt to emphasize the importance on the recovering of those families' memory, identifying the difficulties they faced since the first occupation until the appropriation of a plot of land, the several contacts established with politicians, religious, and syndical organisms up till now and in which areas those families had been or not benefited. The work is based on researches that deal with the memories of the fight for the land and workers' migration, mainly in this region of the interior of São Paulo. The methodological approach were obtained from daily fieldworkdata, photographs, periodicals and interviews with settled people who hadparticipated in the key moments of this essay.Keywords: Rural Settlements; History / Memory; Fight for the Land.Este trabalho procura mostrar a trajetória de um grupo de pessoas esua busca por melhores condições de vida, a partir do início da luta por um pedaçode terra. Pretende-se aqui relatar o processo de formação do assentamento PDSComunidade Agrária 21 de Dezembro em Descalvado/SP, desde a constituiçãodo primeiro grupo e suas viagens até a obtenção das terras e a consolidaçãodestas famílias no campo. Assim, espera-se melhor compreender a formação deste assentamento através da descrição e análise do valor da luta pela terra vivenciado pelas famílias e como este processo influenciou ou não a fragmentação do coletivo desta Comunidade. Procurou-se dar ênfase à importância do resgate da memória destas famílias, quais as dificuldades encontradas por elas desde a primeira ocupação até a apropriação de um lote de terras, os diversos contatos com órgãos políticos, religiosos, sindicais até os dias de hoje e no que isso beneficiou ou não as famílias. O trabalho é fundamentado em pesquisas que tratam das memórias da luta pela terra e migração dos trabalhadores, principalmente nesta região do interior paulista. A metodologia utilizada são registros feitos em diários de campo, fotografias, jornais e entrevistas com os assentados que participaram dos principais momentos desta jornada

Peptidylprolyl isomerase C (Ppic) regulates invariant Natural Killer T cell (iNKT) differentiation in mice

© 2021 The Authors. European Journal of Immunology published by Wiley-VCH GmbH. This is an open access article under the terms of the Creative Commons Attribution-NonCommercial-NoDerivs License, which permits use and distribution in any medium, provided the original work is properly cited, the use is non-commercial and no modifications or adaptations are made.Peptidyl-prolyl cis-trans isomerase C (Ppic) is expressed in several bone marrow (BM) hematopoietic progenitors and in T-cell precursors. Since the expression profile of Ppic in the hematoimmune system was suggestive that it could play a role in hematopoiesis and/or T lymphocyte differentiation, we sought to test that hypothesis in vivo. Specifically, we generated a Ppic-deficient mouse model by targeting the endogenous locus by CRISPR/Cas9 and tested the requirement of Ppic in hematopoiesis. Several immune cell lineages covering BM progenitors, lymphocyte precursors, as well as mature cells at the periphery were analyzed. While most lineages were unaffected, invariant NKT (iNKT) cells were reduced in percentage and absolute cell numbers in the Ppic-deficient thymus. This affected the most mature stages in the thymus, S2 and S3, and the phenotype was maintained at the periphery. Additionally, immature transitional T1 and T2 B lymphocytes were increased in the Ppic-deficient spleen, but the phenotype was lost in mature B lymphocytes. In sum, our data show that Ppic is dispensable for myeloid cells, platelets, erythrocytes, αβ, and γδ T lymphocytes in vivo in the steady state, while being involved in B- and iNKT cell differentiation.This work was supported by the Instituto Gulbenkian de Ciência (IGC) of the Calouste Gulbenkian Foundation, and the Portuguese National Research Council (Fundação para a Ciência e Tecnologia [FCT]) Grant PTDC/BIA-BID/30925/2017 to VCM, that also supports the salary of RSP. VCM is supported by an individual contract awarded by FCT (CEECIND/03106/2018). CVR is a PhD student of the IGC Integrative Biology and Biomedicine (IBB) PhD Program and supported by an individual FCT PhD Fellowship ref. PD/BD/139190/2018. This work had the support of the research infrastructures Congento LISBOA-01-0145-FEDER-022170 and PPBI-POCI-01-0145-FEDER-022122, both cofinanced by FCT and Lisboa2020, under PORTUGAL2020 agreement (European Regional Development Fund).info:eu-repo/semantics/publishedVersio

Macroalgae from S. Miguel Island as a potential source of antiproliferative and antioxidant products

Ulva compressa, Gelidium microdon, Osmundea pinnatifida, Fucus spiralis and Cystoseira abies-marina from the coast of S. Miguel Island were screened for their in vitro cytotoxicity against HeLa tumour cell line, antioxidant potential and total phenolic content. From each alga, the hexane fraction (HF) of the methanol extract, the methanol residue (MF) and the dichloromethane extract (DE), were obtained and evaluated. The highest antiproliferative activity against HeLa cell line was found in C. abies-marina and F. spiralis DE (IC50 8.8 μg/mL and 10.7 μg/mL, respectively), and presented selective cytotoxicity, when tested against Vero cell line. Fluorescence microscopy studies of the two most active extracts suggest an apoptosis-inducing activity. Concerning the antioxidant activity, high values were found on F. spiralis MF and HF (EC50 0.62 μg/mL and 2.01 μg/mL, respectively), even higher than those obtained for trolox and quercetin. This high antioxidant activity in F. spiralis MF can be explained by its content in phenolic compounds, but not for HF, where the antioxidant compounds must be less polar. These results suggest that some macroalgae from the Azorean sea have great potential which could be considered for future applications in medicine, food production or cosmetics industry

Reassignment of Drosophila willistoni Genome Scaffolds to Chromosome II Arms

Drosophila willistoni is a geographically widespread Neotropical species. The genome of strain Gd-H4-1 from Guadeloupe Island (Caribbean) was sequenced in 2007 as part of the 12 Drosophila Genomes Project. The assembled scaffolds were joined based on conserved linkage and assigned to polytene chromosomes based on a handful of genetic and physical markers. This paucity of markers was particularly striking in the metacentric chromosome II, comprised two similarly sized arms, IIL and IIR, traditionally considered homologous to Muller elements C and B, respectively. In this paper we present the cytological mapping of 22 new gene markers to increase the number of markers mapped by in situ hybridization and to test the assignment of scaffolds to the polytene chromosome II arms. For this purpose, we generated, by polymerase chain reaction amplification, one or two gene probes from each scaffold assigned to the chromosome II arms and mapped these probes to the Gd-H4-1 strain's polytene chromosomes by nonfluorescent in situ hybridization. Our findings show that chromosome arms IIL and IIR correspond to Muller elements B and C, respectively, directly contrasting the current homology assignments in D. willistoni and constituting a major reassignment of the scaffolds to chromosome II arms

Mercury in juvenile solea senegalensis: Linking bioaccumulation, seafood safety, and neuro-oxidative responses under climate change-related stressors

.Mercury (Hg) is globally recognized as a persistent chemical contaminant that accumulates in marine biota, thus constituting an ecological hazard, as well as a health risk to seafood consumers. Climate change-related stressors may influence the bioaccumulation, detoxification, and toxicity of chemical contaminants, such as Hg. Yet, the potential interactions between environmental stressors and contaminants, as well as their impacts on marine organisms and seafood safety, are still unclear. Hence, the aim of this work was to assess the bioaccumulation of Hg and neuro-oxidative responses on the commercial flat fish species Solea senegalensis (muscle, liver, and brain) co-exposed to dietary Hg in its most toxic form (i.e., MeHg), seawater warming (ΔT°C = +4 °C), and acidification (pCO2 = +1000 μatm, equivalent to ΔpH =-0.4 units). In general, fish liver exhibited the highest Hg concentration, followed by brain and muscle. Warming enhanced Hg bioaccumulation, whereas acidification decreased this element's levels. Neuro-oxidative responses to stressors were affected by both climate change-related stressors and Hg dietary exposure. Hazard quotient (HQ) estimations evidenced that human exposure to Hg through the consumption of fish species may be aggravated in tomorrow's ocean, thus raising concerns from the seafood safety perspective.publishersversionpublishe