RESUMO
In Parkinson's disease (PD), post-mortem studies in affected brain regions have demonstrated a decline in mitochondrial number and function. This combined with many studies in cell and animal models suggest that mitochondrial dysfunction is central to PD pathology. We and others have shown that the mitochondrial protein deacetylase, SIRT3, has neurorestorative effects in PD models. In this study, to determine whether there is a link between PD pathology and SIRT3, we analysed SIRT3 levels in human subjects with PD, and compared to age-matched controls. In the SNc of PD subjects, SIRT3 was reduced by 56.8 ± 15.5% compared to control, regardless of age (p < 0.05, R = 0.6539). Given that age is the primary risk factor for PD, this finding suggests that reduced SIRT3 may contribute to PD pathology. Next, we measured whether there was a correlation between α-synuclein and SIRT3. In a parallel study, we assessed the disease-modifying potential of SIRT3 over-expression in a seeding model of α-synuclein. In PFF rats, infusion of rAAV1.SIRT3-myc reduced abundance of α-synuclein inclusions by 30.1 ± 18.5%. This was not observed when deacetylation deficient SIRT3H248Y was transduced, demonstrating the importance of SIRT3 deacetylation in reducing α-synuclein aggregation. These studies confirm that there is a clear difference in SIRT3 levels in subjects with PD compared to age-matched controls, suggesting a link between SIRT3 and the progression of PD. We also demonstrate that over-expression of SIRT3 reduces α-synuclein aggregation, further validating AAV.SIRT3-myc as a potential disease-modifying solution for PD.
RESUMO
The incidence of begomovirus infections in crop plants sharply increased in Brazil during the 1990s following the introduction of the invasive B biotype of the whitefly vector, Bemisia tabaci. It is believed that this biotype transmitted begomoviruses from noncultivated plants to crop species with greater efficiency than indigenous B. tabaci biotypes. Either through rapid host adaptation or selection pressure in genetically diverse populations of noncultivated hosts, over the past 20 years various previously unknown begomovirus species have became progressively more prevalent in cultivated species such as tomato. Here we assess the genetic structure of begomovirus populations infecting tomatoes and noncultivated hosts in southeastern Brazil. Between 2005 and 2010, we sampled and sequenced 126 DNA-A and 58 DNA-B full-length begomovirus components. We detected nine begomovirus species in tomatoes and eight in the noncultivated host samples, with four species common to both tomatoes and noncultivated hosts. Like many begomoviruses, most species are obvious interspecies recombinants. Furthermore, species identified in tomato have probable parental viruses from noncultivated hosts. While the population structures of five well-sampled viral species all displayed geographical subdivision, a noncultivated host-infecting virus was more genetically variable than the four predominantly tomato-infecting viruses.
Assuntos
Begomovirus/classificação , Begomovirus/genética , Variação Genética , Filogeografia , Recombinação Genética , Solanum lycopersicum/virologia , Begomovirus/isolamento & purificação , Brasil , DNA Viral/química , DNA Viral/genética , Evolução Molecular , Dados de Sequência Molecular , Doenças das Plantas/virologia , Análise de Sequência de DNARESUMO
"Deep-sea" cephalopods are here defined as cephalopods that spend a significant part of their life cycles outside the euphotic zone. In this chapter, the state of knowledge in several aspects of deep-sea cephalopod research are summarized, including information sources for these animals, diversity and general biogeography and life cycles, including reproduction. Recommendations are made for addressing some of the remaining knowledge deficiencies using a variety of traditional and more recently developed methods. The types of oceanic gear that are suitable for collecting cephalopod specimens and images are reviewed. Many groups of deep-sea cephalopods require taxonomic reviews, ideally based on both morphological and molecular characters. Museum collections play a vital role in these revisions, and novel (molecular) techniques may facilitate new use of old museum specimens. Fundamental life-cycle parameters remain unknown for many species; techniques developed for neritic species that could potentially be applied to deep-sea cephalopods are discussed. Reproductive tactics and strategies in deep-sea cephalopods are very diverse and call for comparative evolutionary and experimental studies, but even in the twenty-first century, mature individuals are still unknown for many species. New insights into diet and trophic position have begun to reveal a more diverse range of feeding strategies than the typically voracious predatory lifestyle known for many cephalopods. Regular standardized deep-sea cephalopod surveys are necessary to provide insight into temporal changes in oceanic cephalopod populations and to forecast, verify and monitor the impacts of global marine changes and human impacts on these populations.
Assuntos
Evolução Biológica , Cefalópodes/fisiologia , Ecossistema , Oceanos e Mares , Animais , Cefalópodes/genética , DemografiaRESUMO
Biodiversity assessment is a mandatory task for sustainable and adaptive management for the next decade, and long-term ecological monitoring programs are a cornerstone for understanding changes in ecosystems. The Brazilian Long-Term Ecological Research Program (PELD) is an integrated effort model supported by public funds that finance ecological studies at 34 locations. By interviewing and compiling data from project coordinators, we assessed monitoring efforts, targeting biological groups and scientific production from nine PELD projects encompassing coastal lagoons to mesophotic reefs and oceanic islands. Reef environments and fish groups were the most often studied within the long-term projects. PELD projects covered priority areas for conservation but missed sensitive areas close to large cities, as well as underrepresenting ecosystems on the North and Northeast Brazilian coast. Long-term monitoring projects in marine and coastal environments in Brazil are recent (<5 years), not yet integrated as a network, but scientifically productive with considerable relevance for academic and human resources training. Scientific production increased exponentially with project age, despite interruption and shortage of funding during their history. From our diagnosis, we recommend some actions to fill in observed gaps, such as: enhancing projects' collaboration and integration; focusing on priority regions for new projects; broadening the scope of monitored variables; and, maintenance of funding for existing projects.
Assuntos
Biodiversidade , Ecossistema , Animais , Humanos , Brasil , Oceanos e Mares , PeixesRESUMO
Traumatic mating, that is, copulation that involves wounding the partner's body, is a widespread phenomenon that is particularly prevalent in hermaphroditic animals. Traumatic mating is generally a collateral side effect of diverse strategies (from physical anchorage to injection of substances to manipulate the partner), but the trauma could also be adaptive by itself if it delays remating by the injured partner. In the Tricladida (the clade of planarian flatworms), reciprocal sperm transfer is often assumed to occur by means of a 'regular' nontraumatic copulation, that is, insertion of the penis through the partner's gonopore and deposition of the ejaculate into its genital atrium, with subsequent sperm migration to the oviducts. However, while studying the anatomy of Brazilian land planarians for taxonomic purposes, we found foreign bodies, reminiscent of spermatophores, implanted within the parenchyma of Choeradoplana albonigra (Riester, 1938). Herein, we describe and illustrate several lines of morphological evidence indicating that these foreign bodies likely represent a novel case of intragenital copulatory wounding (e.g., structural and histochemical similarity to land planarians spermatophores; implantation at the level of the gonopore; vestiges of rupture of the genital atrium's wall), corroborating that traumatic mating is pervasive and underreported in Metazoa. We also propose two different hypotheses to explain such copulatory wounding, viz., that it concerns (1) a regular mating strategy or (2) an accidental effect of the copulation. In any event, this land planarian may prove useful as a novel, noninsect terrestrial model organism to investigate the evolution of traumatic mating.
Assuntos
Corpos Estranhos , Planárias , Animais , Copulação , Masculino , Reprodução , Comportamento Sexual AnimalRESUMO
BACKGROUND: The necessity of a competent vector for transmission is a primary ecological factor driving the host range expansion of plant arthropod-borne viruses, with vectors playing an essential role in disease emergence. Cassava begomoviruses severely constrain cassava production in Africa. Curiously, begomoviruses have never been reported in cassava in South America, the center of origin for this crop. It has been hypothesized that the absence of a competent vector in cassava is the reason why begomoviruses have not emerged in South America. METHODS: We performed a country-wide whitefly diversity study in cassava in Brazil. Adults and/or nymphs of whiteflies were collected from sixty-six cassava fields in the main agroecological zones of the country. A total of 1,385 individuals were genotyped based on mitochondrial cytochrome oxidase I sequences. RESULTS: A high species richness was observed, with five previously described species and two putative new ones. The prevalent species were Tetraleurodes acaciae and Bemisia tuberculata, representing over 75% of the analyzed individuals. Although we detected, for the first time, the presence of Bemisia tabaci Middle East-Asia Minor 1 (BtMEAM1) colonizing cassava in Brazil, it was not prevalent. The species composition varied across regions, with fields in the Northeast region showing a higher diversity. These results expand our knowledge of whitefly diversity in cassava and support the hypothesis that begomovirus epidemics have not occurred in cassava in Brazil due to the absence of competent vector populations. However, they indicate an ongoing adaptation process of BtMEAM1 to cassava, increasing the likelihood of begomovirus emergence in this crop.
RESUMO
Tentacles are remarkable anatomical structures in invertebrates for their diversity of form and function. In bivalves, tentacular organs are commonly associated with protective, secretory, and sensory roles. However, anatomical details are available for only a few species, rendering the diversity and evolution of bivalve tentacles still obscure. In Pteriomorphia, a clade including oysters, scallops, pearl oysters, and relatives, tentacles are abundant and diverse. We investigated tentacle anatomy in the group to understand variation, infer functions, and investigate patterns in tentacle diversity. Six species from four pteriomorphian families (Ostreidae, Pinnidae, Pteriidae, and Spondylidae) were collected and thoroughly investigated with integrative microscopy techniques, including histology, scanning electron microscopy, and confocal microscopy. Tentacles can be classified as middle fold tentacles (MFT) and inner fold tentacles (IFT) according to their position with respect to the folds of the mantle margin. While MFT morphology indicates intense secretion of mucosubstances, no evidence for secretory activity was found for IFT. However, both tentacle types have appropriate ciliary distribution and length to promote mucus transportation for cleaning and lubrication. Protective and sensory functions are discussed based on different lines of evidence, including secretion, cilia distribution, musculature, and innervation. Our results support the homology of MFT and IFT only for Pterioidea and Ostreoidea, considering their morphology, the presence of ciliated receptors at the tips, and branched innervation pattern. This is in accordance with recent phylogenetic hypotheses that support the close relationship between these superfamilies. In contrast, major structural differences indicate that MFT and IFT are probably not homologous across all pteriomorphians. By applying integrative microscopy, we were able to reveal anatomical elements that are essential for the understanding of homology and function when dealing with such superficially similar structures.
Assuntos
Estruturas Animais/anatomia & histologia , Bivalves/anatomia & histologia , Bivalves/fisiologia , Estruturas Animais/ultraestrutura , Animais , Bivalves/ultraestrutura , FilogeniaRESUMO
SUMMARY OBJECTIVES: To review the literature and present a contemporary image of androgen deprivation for prostate cancer. METHODS: We conducted a PubMed search on intermittent androgen deprivation. Articles obtained on intermittent androgen deprivation (IAD) and the experiences at Institut Montsouris were used for the review. RESULTS: IAD is an approach to hormonal deprivation that holds effective cancer control while preventing the morbidity associated with continuous androgen blockade. IAD nuances have been assessed by urological community teams in order to verify its possible potential benefits. Evidence based approach supports the idea of IAD as a standard of therapy for advanced prostate cancer requiring hormone deprivation. Variation among medical teams' criteria for the treatment and surveillance await standardization. CONCLUSIONS: Reassessing the gold standard of hormonal blockade in advanced prostate cancer is mandatory.The undeniable evolution of IAD needs to be embraced by the urological community.
Assuntos
Antagonistas de Androgênios/administração & dosagem , Antineoplásicos Hormonais/administração & dosagem , Neoplasias da Próstata/tratamento farmacológico , Progressão da Doença , Humanos , MasculinoRESUMO
The expression of alternative reproductive tactics (ARTs) by different-sized males of loliginid squids has been extensively investigated. In loliginids, alternative phenotypes are characterized by discontinuous differences in behavior, body size, sperm deposition site, and morphology and functioning of ejaculates. Large consort males guard females, display agonistic behaviors toward rival consort males, and mate with females in the male-parallel (MP) position. Small sneaker males avoid fighting contests and instead adopt furtive behaviors to access females guarded by consort males, mating with females in the head-to-head (HH) posture. Recently, the reappraisal of preserved material from the loliginid squid Doryteuthis pleii showed that intermediate-sized males (so-called "intermediate" males) had both sneaker- and consort-like ejaculates, leading to the hypothesis of them being a transitional stage between both phenotypes. Here, we describe observations made in captivity showing that intermediate males can display agonistic behaviors toward consort males and mate with females in both mating positions, depending on the male's current reproductive context, i.e., generally in HH, but switching to MP when the female is laying eggs. Such unusual findings of intermediate males simultaneously displaying behaviors of both sneaker and consort males comprise additional evidence corroborating the ontogenetic hypothesis for phenotypic expression of ARTs in this species. Taken together, our results indicate that (1) instead of competing with large consort males for female access and monopolization, small/young males adopt sneaker tactics to obtain mating opportunities, and (2) as they continue to grow, they gradually modify the morphology of their ejaculates and their mating behavior, going through an "intermediate" stage, before becoming large consort males.
RESUMO
Loliginid squids provide a unique model system to explore male alternative reproductive tactics (ARTs) and their linkage to size, behavioral decision making, and possibly age. Large individuals fight one another and the winners form temporary consortships with females, while smaller individuals do not engage in male-male agonistic bouts but use various sneaker tactics to obtain matings, each with varying mating and fertilization success. There is substantial behavioral flexibility in most species, as smaller males can facultatively switch to the alternative consort behaviors as the behavioral context changes. These forms of ARTs can involve different: mating posture; site of spermatophore deposition; fertilization success; and sperm traits. Most of the traits of male dimorphism (both anatomical and behavioral) are consistent with traditional sexual selection theory, while others have unique features that may have evolved in response to the fertilization environment faced by each temporary or permanent male morph.
RESUMO
Males from numerous animal taxa have evolved strategies for obstructing the female genitalia with copulatory plugs, reducing the risk of sperm competition and thus resulting in an advantage in sexual selection. Several lines of evidence suggest that sperm competition is a common feature in the complex squid mating systems, which include the evolution of alternative mating tactics (consort vs. sneaker). However, mating plugs have hitherto not been reported for the group. Investigating the female sperm-storage organ (i.e., seminal receptacle, SR) of the squid Doryteuthis plei, we found cases in which everted spermatophores (i.e., spermatangia) were implanted into the SR and blocking its opening. Here, we describe this finding of "plugged spermatangia" based on microscopy analyses (histology and microCT) of SRs of females from three experimental groups (before and after recent mating and after egg release). We show that sneaker male spermatophores may block the opening of the SR, possibly functioning as temporary copulatory plugs that physically obstruct the SR. Together with previous experimental data on spermatophore functioning, our results suggest that plug efficiency is high until at least 5 h after mating, when spermatangia are turgid and full of sperm, clogging the organ's opening. After that time, plugs gradually decrease their efficiency as they lose turgidity by releasing part of their sperm content. However, one experimental female still had a plugged spermatangium blocking a major portion of the opening even after 48 h without mating. Within the context of squid mating systems and sexual selection, we hypothesize that plugged spermatangia are a sneaker strategy associated with minimizing sperm competition between sneaker males.
Assuntos
Decapodiformes/fisiologia , Comportamento Sexual Animal/fisiologia , Animais , Feminino , Masculino , Reprodução , Espermatogônias/fisiologiaRESUMO
Sperm competition is a powerful postcopulatory selective force influencing male adaptations associated with increasing fertilization success, and it is usually related to the evolution of different strategies of ejaculate expenditure between individuals. Ejaculates may also be influenced by additional selective pressures associated with sperm competition, such as timing between insemination and fertilization, female reproductive tract morphology, and fertilization environment. Also, males that adopt alternative mating tactics may face distinct sperm competition pressures, which may lead to the evolution of intraspecific diversity in ejaculates. In loliginid squids, males with alternative reproductive tactics (sneakers and consorts) differ not only in mating behavior, but also transfer spermatophores into two distinct sites within the female. Here, we compared structure and functioning of spermatophores between sneakers and consorts in the squid Doryteuthis plei applying microscopy techniques and in vitro experiments. Sneakers and consorts exhibit differences in spermatophore structure that lead to distinct spermatophoric reactions and spermatangium morphologies. Moreover, in sneakers, sperm release lasts longer and their sperm show an aggregative behavior not detected in consorts. Slow sperm release may be a strategy to guarantee longer sperm provision, given the wide interval between sneaker mating and egg release. For consorts, in turn, intense and quick sperm discharge may be advantageous, as timing between mating and egg-laying is relatively short. Within the complex squid mating system, factors such as (i) different fertilization sites and (ii) interval between mating and egg release may also influence sperm competition, and ultimately shape the evolution of divergent ejaculates between dimorphic males.
Assuntos
Decapodiformes/fisiologia , Ejaculação/fisiologia , Caracteres Sexuais , Comportamento Sexual Animal/fisiologia , Espermatozoides/fisiologia , Animais , Feminino , Masculino , Espermatogônias/citologiaRESUMO
The epi-benthic dinoflagellate Ostreopsis cf. ovata Fukuyo has an increasingly global distribution. In Brazil there are reports of O. cf. ovata along the coast from 8°S to 27°S latitude and blooms have been registered on the Rio de Janeiro coastline. In the current study, an O. cf. ovata bloom is reported at Saint Paul's Rocks (0°55'10â³N; 29°20'33â³W), between the southern and northern hemispheres. The Archipelago is not inhabited and not subjected to eutrophication, due to isolation, and sustains a number of endemic species. Therefore, blooms of O. cf. ovata may potentially cause demise to trophic chains by affecting marine invertebrates and vertebrates.
Assuntos
Dinoflagellida/crescimento & desenvolvimento , Eutrofização , Poluição da Água/análise , Oceano Atlântico , Monitoramento AmbientalRESUMO
OBJETIVO: Revisar la bibliografía y presenter una visión contemporánea del bloqueo androgénico en el cáncer de próstata.MÉTODOS: Llevamos a cabo una búsqueda bibliográfica en PubMed sobre bloqueo androgénico intermitente (BAI). Para la elaboración del presente artículo utilizamos los artículos obtenidos y la experiencia del Instituto Mutualista Montsouris.RESULTADOS: El BAI es un abordaje del tratamiento de deprivación androgénica que mantiene un control oncológico eficaz y a la vez evita la morbilidad asociada con el bloqueo androgénico continuo. Los matices del BAI han sido evaluados por la comunidad urológica para verificar sus posibles beneficios. Un abordaje basado en la evidencia apoya la idea del BAI como un tratamiento estándar en cáncer de próstata avanzado que necesite bloqueo androgénico. Las variaciones entre los equipos médicos en los criterios de tratamiento y vigilancia están a la espera de estandarización.CONCLUSIONES: Es necesario revisar el Gold Standard del bloqueo androgénico en cáncer de próstata avanzado. La evolución innegable del BAI necesita que la comunidad urológica lo abrace(AU)
OBJECTIVES: To review the literature and present a contemporary image of androgen deprivation for prostate cancer.METHODS: We conducted a PubMed search on intermittent androgen deprivation. Articles obtained on intermittent androgen deprivation (IAD) and the experiences at Institut Montsouris were used for the review.RESULTS: IAD is an approach to hormonal deprivation that holds effective cancer control while preventing the morbidity associated with continuous androgen blockade. IAD nuances have been assessed by urological community teams in order to verify its possible potential benefits. Evidence based approach supports the idea of IAD as a standard of therapy for advanced prostate cancer requiring hormone deprivation. Variation among medical teams criteria for the treatment and surveillance await standardization. demosCONCLUSIONS:Reassessing the gold standard of hormonal blockade in advanced prostate cancer is mandatory. The undeniable evolution of IAD needs to be embraced by the urological community(AU)