RESUMEN
Chagas disease affects around 8 million people globally, with Latin America bearing approximately 10,000 deaths each year. Combatting the disease relies heavily on vector control methods, necessitating the identification of new targets. Within insect genomes, genes harboring small open reading frames (smORFs - < 100 amino acids) present numerous potential candidates. In our investigation, we elucidate the pivotal role of the archetypal smORF-containing gene, mille-pattes/polished-rice/tarsalless (mlpt/pri/tal), in the post-embryonic development of the kissing bug Rhodnius prolixus. Injection of double-stranded RNA targeting mlpt (dsmlpt) during nymphal stages yields a spectrum of phenotypes hindering post-embryonic growth. Notably, fourth or fifth stage nymphs subjected to dsmlpt do not undergo molting. These dsmlpt nymphs display heightened mRNA levels of JHAMT-like and EPOX-like, enzymes putatively involved in the juvenile hormone (JH) pathway, alongside increased expression of the transcription factor Kr-h1, indicating changes in the hormonal control. Histological examination reveals structural alterations in the hindgut and external cuticle of dsmlpt nymphs compared to control (dsGFP) counterparts. Furthermore, significant changes in the vector's digestive physiology were observed, with elevated hemozoin and glucose levels in the posterior midgut of dsmlpt nymphs. Importantly, dsmlpt nymphs exhibit impaired metacyclogenesis of Trypanosoma cruzi, the causative agent of Chagas disease, underscoring the crucial role of proper gut organization in parasite differentiation. Thus, our findings constitute the first evidence of a smORF-containing gene's regulatory influence on vector physiology, parasitic cycle, and disease transmission.
Asunto(s)
Proteínas de Insectos , Muda , Ninfa , Rhodnius , Animales , Rhodnius/genética , Rhodnius/fisiología , Rhodnius/crecimiento & desarrollo , Ninfa/crecimiento & desarrollo , Ninfa/genética , Ninfa/fisiología , Muda/genética , Proteínas de Insectos/genética , Proteínas de Insectos/metabolismo , Hormonas Juveniles/metabolismo , Sistemas de Lectura Abierta , DigestiónRESUMEN
Introduction: A characteristic of the COVID-19 pandemic has been the sequential emergence and global dissemination of SARS-CoV-2 variants, noted for their enhanced transmission efficiency. These variants with mutations in the Spike glycoprotein (S-glycoprotein), which interacts with ACE2 receptors in human cells is critical for infection, affects the transmissibility of the virus, which is a matter of great concern for public health. Objective: This research analyses the effects these variants on a cohort of vaccinated and naturally infected individuals from the cities of Macaé-RJ, Rio das Ostras-RJ, and Campos dos Goytacazes-RJ, Brazil, from March 2021 to March 2023. Methods: This investigation encompasses the Alpha (B.1.1.7), Gamma (P.1), Delta (B.1.617.2, B.1.671.3), and Omicron (BQ.1, BQ.1.1 sublines, and BF.7) variants, focusing on their genomic surveillance and implications for the disease's epidemiology. The experimental analysis included a control group (vaccinated and uninfected subjects), and an infected group (post-vaccinated subjects). Samples from nasopharyngeal swabs underwent viral detection via RT-qPCR for diagnosis confirmation. RNase H-dependent RT-qPCR (rhAmp-PCR) and third-generation sequencing were used to detect SARS-CoV-2 variants. Anti-S-glycoprotein immunoglobulins were also evaluated for vaccinated infected and noninfected volunteers. Symptoms from infected individuals were compiled in order to reveal patterns of clinical signs associated with viral infection. Results: The study included 289 participants, with infections identified by Gamma (n = 44), Delta (n = 189), and Omicron (n = 56) variants. The prevalent symptoms among the naturally infected participants were cough, fever, sore throat, headache, and runny nose. For Omicron, cognitive symptoms such as memory loss and concentration issues were reported. Interestingly, the infected vaccinated group had higher anti-S-glycoprotein IgM production (n = 28, 0.2833 ± 0.09768 OD) compared to the uninfected vaccinated group (n = 14, 0.1035 ± 0.03625 OD). Conversely, anti-S-glycoprotein IgG production was higher in the control group (n = 12, 1.770 ± 0.1393 OD) than in the infected vaccinated group (n = 26, 1.391 ± 0.1563 OD). Conclusion: This comprehensive study enables monitoring of predominant variants and their correlation with clinical cases, providing valuable insights for public health. Our research group continues to survey circulating variants, contributing to the global understanding of the pandemic.
RESUMEN
The northern coast of the state of Rio de Janeiro harbors the largest coastal sandy plains (restingas) of southeastern Brazil, severely threatened due to recent human occupation. In this context, mammal inventories becomes urgent to support biodiversity conservation and management policies. This paper aims to update the knowledge on the mammalian species richness of Restinga de Jurubatiba National Park by analyzing pellets of the Barn owl Tyto furcata. The analyses of 4745 mammalian bone fragments (1739 individuals) revealed the occurrence of 17 species belonging to the orders Rodentia (9 spp.), Didelphimorphia (2 spp.) and Chiroptera (6 spp.). The rodents Mus musculus and Cerradomys goytaca accounted for 77.2% of the total individuals preyed, suggesting that the Barn owl hunts in both disturbed and natural open shrub formations. A compilation of previous records, together with those provided in the present study, indicates the occurrence of 44 species of mammals in the Restinga de Jurubatiba National Park, of which six (13.6%) were exclusively detected in pellets. These new records include species adapted to open formations of the interior of Brazil that were not previously reported in restingas on the basis of voucher-specimens, such as the rodents Necromys lasiurus and Calomys tener, the latter being recorded for the first time in the littoral of Rio de Janeiro state. This study underscores the importance of owl pellet analysis as a complementary and indispensable method for inventorying mammals. The results highlight the Restinga de Jurubatiba National Park as one of the restingas in Southeastern Brazil with the highest number of mammal species.
O litoral norte do estado do Rio de Janeiro possui a maior planície deltaica recoberta por restingas do sudeste brasileiro, porém sob intensa ameaça devido è ocupação humana recente. Neste contexto, a realização de inventários torna-se urgente para fortalecer políticas de manejo e conservação ambiental. Esse trabalho teve como objetivo complementar inventários mastofaunísticos do Parque Nacional da Restinga de Jurubatiba através da utilização de pelotas da coruja suindara Tyto furcata. A análise de 4745 fragmentos ósseos de mamíferos (1739 indivíduos) revelou a ocorrência de 17 espécies pertencentes ès ordens Rodentia (9 spp.), Didelphimorphia (2 spp.) e Chiroptera (6 spp.). Os roedores Mus musculus e Cerradomys goytaca foram responsáveis por 77,2% do total de indivíduos predados, sugerindo que a suindara caça tanto em ambientes peridomiciliares perturbados como em formações naturais arbustivas da restinga. A compilação de registros anteriores com os fornecidos pelo presente estudo indica a ocorrência de 44 espécies de mamíferos no Parque Nacional da Restinga de Jurubatiba, dentre as quais seis (13.6%) foram exclusivamente detectadas em pelotas. Dentre estes novos registros, destaca-se a presença de espécies adaptadas a formações abertas do interior do Brasil que não tinham sua ocorrência documentada em restingas a partir de espécimes-testemunho, como os roedores Necromys lasiurus e Calomys tener, esta última registrada pela primeira vez no litoral do estado do Rio de Janeiro. Esse estudo corrobora a importância das análises de pelotas de coruja como método complementar e imprescindível em inventários de mamíferos, além de destacar o Parque Nacional da Restinga de Jurubatiba como uma das restingas mais ricas em espécies de mamíferos do sudeste brasileiro.