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1.
BMC Genomics ; 23(1): 36, 2022 Jan 07.
Artigo em Inglês | MEDLINE | ID: mdl-34996352

RESUMO

BACKGROUND: Bioassessment and biomonitoring of meat products are aimed at identifying and quantifying adulterants and contaminants, such as meat from unexpected sources and microbes. Several methods for determining the biological composition of mixed samples have been used, including metabarcoding, metagenomics and mitochondrial metagenomics. In this study, we aimed to develop a method based on next-generation DNA sequencing to estimate samples that might contain meat from 15 mammalian and avian species that are commonly related to meat bioassessment and biomonitoring. RESULTS: In this project, we found the meat composition from 15 species could not be identified with the metabarcoding approach because of the lack of universal primers or insufficient discrimination power. Consequently, we developed and evaluated a meat mitochondrial metagenomics (3MG) method. The 3MG method has four steps: (1) extraction of sequencing reads from mitochondrial genomes (mitogenomes); (2) assembly of mitogenomes; (3) mapping of mitochondrial reads to the assembled mitogenomes; and (4) biomass estimation based on the number of uniquely mapped reads. The method was implemented in a python script called 3MG. The analysis of simulated datasets showed that the method can determine contaminant composition at a proportion of 2% and the relative error was < 5%. To evaluate the performance of 3MG, we constructed and analysed mixed samples derived from 15 animal species in equal mass. Then, we constructed and analysed mixed samples derived from two animal species (pork and chicken) in different ratios. DNAs were extracted and used in constructing 21 libraries for next-generation sequencing. The analysis of the 15 species mix with the method showed the successful identification of 12 of the 15 (80%) animal species tested. The analysis of the mixed samples of the two species revealed correlation coefficients of 0.98 for pork and 0.98 for chicken between the number of uniquely mapped reads and the mass proportion. CONCLUSION: To the best of our knowledge, this study is the first to demonstrate the potential of the non-targeted 3MG method as a tool for accurately estimating biomass in meat mix samples. The method has potential broad applications in meat product safety.


Assuntos
Genoma Mitocondrial , Metagenômica , Animais , Mamíferos , Carne , Análise de Sequência de DNA
2.
Environ Monit Assess ; 194(2): 72, 2022 Jan 08.
Artigo em Inglês | MEDLINE | ID: mdl-34997305

RESUMO

Knowing the composition of animals present in aquatic ecosystems can tell us about the anthropic pressures on these environments. One of these pressures is the occurrence of fecal contamination. However, this contamination can originate from more than one animal species in areas where urban and agricultural activities overlap. Mitochondrial DNA (mtDNA) has become the standard barcoding tool to identify the presence of animal species in environment. Amplicon-sequencing metagenomics is a powerful approach to derive the animal profile in an environment. However, PCR primers targeting mtDNA of a broad range of animals are highly degenerate or generate short DNA fragments that could cause ambiguous affiliation. Here we report the development of a new set of primers targeting the mitochondrial 16S ribosomal RNA genes of a broad range of terrestrial and aquatic animals, which include mammals, birds, and fishes. These primers successfully amplified mtDNA from environmental DNA (eDNA) extracted from surface waters. Sequencing the resulting amplicons revealed the presence of mammals and birds that may contribute in fecal contamination of surface water. In one of the river samples high in fecal indicator bacteria, human and bovine mtDNA accounted for 40.5% and 4.1% of the sequences, respectively, suggesting fecal contamination by these two animals. These findings indicate that our PCR primers coupled with amplicon-sequencing metagenomics contribute in profiling the animal diversity in the surface waters and its surrounding. This approach could be a valuable tool to identify simultaneously the potential contribution of various animals as sources of fecal contamination in surface waters.


Assuntos
Animais , Aves , Bovinos , DNA Mitocondrial , Ecossistema , Monitoramento Ambiental , Fezes , Peixes/genética , Humanos , Mamíferos/genética , Metagenômica , RNA Ribossômico 16S/genética
3.
Environ Monit Assess ; 194(2): 60, 2022 Jan 06.
Artigo em Inglês | MEDLINE | ID: mdl-34993649

RESUMO

The Accra Plain of Ghana is experiencing rapid urbanization, but there is scant information on its impact on local biodiversity. We assessed the changes in land use/land cover of the Accra Plain since 1991 and evaluated how the observed changes have influenced local small mammals in forest fragments. We applied supervised classification and intensity analysis time-series Landsat imagery data to assess land use/land cover changes between 1991 and 2017. Small mammals were surveyed in two forest fragments, the Pinkwae and Adumanya forests from June 2019 to January 2020, using capture-mark-recapture technique. We compared our data with baseline data gathered in 1991-1992, when large areas of the city remained mostly undeveloped. Our data revealed that the urban area has increased by 832%, while the forest area declined by 85% between 1991 and 2017. The Pinkwae and Adumanya forests, which covered 120 and 1.5 ha, respectively, in 1991 have each been reduced to < 1 ha. We found changes in the small mammal species composition in the forest fragments, but not species richness due to species turnover. Grammomys poensis and Dephomys defua are first records for the Accra Plain. Our data suggested that small forest fragments within the urbanizing landscape are important for maintaining the local small mammal species. For the conservation of local small mammals in urbanizing landscapes, it is important to maintain the greatest possible number of small forest fragments and establish policies that prevent forest remnants from being further depleted.


Assuntos
Conservação dos Recursos Naturais , Urbanização , Animais , Biodiversidade , Ecossistema , Monitoramento Ambiental , Florestas , Gana , Mamíferos
4.
Methods Mol Biol ; 2374: 139-147, 2022.
Artigo em Inglês | MEDLINE | ID: mdl-34562249

RESUMO

The Hedgehog (Hh) family of secreted proteins governs embryonic development and adult tissue homeostasis by regulating the abundance, localization, and activity of the GPCR family protein Smoothened (Smo). Smo trafficking and subcellular accumulation are controlled by multiple posttranslational modifications (PTMs) including phosphorylation, ubiquitination, and sumoylation, which appears to be conserved from Drosophila to mammals. Smo ubiquitination is dynamically regulated by E3 ubiquitin ligases and deubiquitinases (dubs) and is opposed by Hh signaling. By contrast, Smo sumoylation is stimulated by Hh, which counteracts Smo ubiquitination by recruiting the dub USP8. We describe cell-base assays for Smo ubiquitination and its regulation by Hh and the E3 ligases in Drosophila. We also describe assays for Smo sumoylation in both Drosophila and mammalian cultured cells.


Assuntos
Sumoilação , Ubiquitinação , Animais , Drosophila/metabolismo , Proteínas de Drosophila/genética , Proteínas de Drosophila/metabolismo , Proteínas Hedgehog/metabolismo , Mamíferos/metabolismo , Receptores Acoplados a Proteínas G/genética , Receptores Acoplados a Proteínas G/metabolismo , Receptor Smoothened/genética , Receptor Smoothened/metabolismo , Ubiquitina-Proteína Ligases/genética , Ubiquitina-Proteína Ligases/metabolismo
5.
Methods Mol Biol ; 2383: 529-545, 2022.
Artigo em Inglês | MEDLINE | ID: mdl-34766311

RESUMO

The efficacy of transfection reagents and nanoparticles is often assessed by measuring levels of expressed reporter protein. Fluorescence and luminescence based assays provide sensitive, quantifiable and repeatable approaches. The genes expressing reporter protein can be integrated into the cells to create stable reporter cell lines or can be expressed from a transfected plasmid. Green fluorescent protein, luciferase, and secreted alkaline phosphatase are well-established reporters with versatile applications. Monitoring changes in live cells during and after transfection offer opportunities to reveal related mechanisms, efficacy, and bottlenecks of transfection.In this chapter, we describe the experimental setup and considerations for in vitro screening of delivery vectors. This can further be extended to measurements in reporter cell lines.


Assuntos
Técnicas de Cultura de Células , Mamíferos , Animais , Linhagem Celular , Genes Reporter , Plasmídeos/genética , Transfecção
6.
Gene ; 808: 145999, 2022 Jan 15.
Artigo em Inglês | MEDLINE | ID: mdl-34627942

RESUMO

Gut microbiome influence the health and evolution of mammals and multiple factors modulate the structure and function of gut microbiome. However, the specific changes of the diets and phylogeny on the gut microbiome were unclear. Here, we compared the gut microbiome of 16 rare wild mammals. All data (>200G 16S rRNA gene sequences) were generated using a high-throughput sequencing platform. Firmicutes and Bacteroidetes were the most predominant phyla in all mammals. However, Proteobacteria was an additionally dominant phylum specifically detected in the microbiome of carnivores and omnivores. Moreover, the dominant phyla in canids were Firmicutes, Bacteroidetes, Proteobacteria, and Fusobacteria. Phylogenetic reconstructions based on the gut microbiome and mitochondrial genome of these mammals were similar. The impact of the host on the microbiome community composition was most evident when considering conspecific and congeneric relationships. Similarity clustering showed that the gut microbiome of herbivores was clustered together, and the other clade comprised both omnivores and carnivores. Collectively, these results revealed that phylogenetic relationships and diet have an important impact on the gut microbiome, and thus the gut microbiome community composition may reflect both the phylogenetic relationships and diets. This study provides valuable basic data to facilitate future efforts related to animal conservation and health.


Assuntos
Dieta/tendências , Microbioma Gastrointestinal/genética , Mamíferos/microbiologia , Animais , Animais Selvagens/genética , Animais Selvagens/microbiologia , Bactérias/genética , Evolução Biológica , Carnivoridade/fisiologia , Dieta/veterinária , Evolução Molecular , Fezes/microbiologia , Comportamento Alimentar/fisiologia , Microbioma Gastrointestinal/efeitos dos fármacos , Herbivoria/genética , Sequenciamento de Nucleotídeos em Larga Escala/métodos , Mamíferos/genética , Microbiota/genética , Filogenia , RNA Ribossômico 16S/genética
7.
Sci Total Environ ; 806(Pt 4): 150944, 2022 Feb 01.
Artigo em Inglês | MEDLINE | ID: mdl-34655626

RESUMO

The charismatic giant panda (Ailuropoda melanoleuca) is an iconic species of wildlife conservation worldwide. As the most effective measure to protect giant pandas and their habitats, China has established 67 giant panda nature reserves (GPNR) during the last five decades, which also bring benefits to many sympatric medium- and large-bodied mammals (MLM). To better inform the planning of the GPNR network with the view of preserving regional MLM diversity, we investigated the zeta diversity (a novel index to measure species compositional turnover considering the contributions of both rare and common species) patterns (i.e. zeta decline and retention rate curve) of MLMs across 40 GPNRs. The effects of species' body mass and conservation status on the zeta diversity patterns were tested. Further, we applied the multi-site generalized dissimilarity modelling (MS-GDM) framework to explore the impacts of environmental and geographic distances on MLM turnover. The results indicated that there are a core set of 17 MLM species sympatric with the giant panda in the GPNRs. Species' body mass can affect the patterns of zeta decline and retention rate curves, and the number of large-bodied species shared by multiple GPNRs is higher than that of medium-bodied species across zeta orders. The MS-GDM revealed the important roles of difference in habitat heterogeneity and spatial distance between GPNRs in driving MLM turnover. Consequently, we advocate maintaining and increasing the diversity of (natural) habitats in GPNRs to protect giant panda's sympatric MLM diversity. The government should consider optimizing the GPNR network (e.g. incorporating multiple small GPNRs into one single large reserve) to capture the most turnover of MLMs, and the newly-established Giant Panda National Park is relevant to fulfilling this long-term goal.


Assuntos
Ursidae , Animais , China , Conservação dos Recursos Naturais , Ecossistema , Mamíferos
8.
Chemosphere ; 287(Pt 2): 132089, 2022 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-34509765

RESUMO

Plant essential oil-based insecticides, with special reference to those that may be obtained from largely available biomasses, represent a valuable tool for Integrated Pest Management. However, the sublethal effects and the potential effects on aggressive insect traits of these green insecticides are understudied. Herein, the lethal and sub-lethal effects of the carlina oxide, constituting more than 97% of the whole Carlina acaulis (Asteraceae) root essential oil (EO), were determined against an invasive polyphagous tephritid pest, Ceratitis capitata (medfly). The carlina oxide was formulated in a mucilaginous solution containing carboxymethylcellulose sodium salt, sucrose, and hydrolysed proteins, showing high ingestion toxicity on medfly adults. The behavioural effects of carlina oxide at LC10 and LC30 were evaluated on the medfly aggressive traits, which are crucial for securing reproductive success in both sexes. Insecticide exposure affected the directionality of aggressive actions, but not the aggression escalation intensity and duration. The EO safety to mammals was investigated by studying its acute toxicity on the stomach, liver, and kidney of rats after oral administration. Only the highest dose (1000 mg/kg) of the EO caused modest neurological signs and moderate effects on the stomach, liver, and kidney. The other doses, which are closer to the practical use of the EO when formulated in protein baits, did not cause side effects. Overall, C. acaulis-based products are effective and safe to non-target mammals, deserving further consideration for eco-friendly pesticide formulations.


Assuntos
Asteraceae , Ceratitis capitata , Inseticidas , Óleos Voláteis , Animais , Inseticidas/toxicidade , Mamíferos , Óleos Voláteis/toxicidade , Ratos
9.
Ecol Lett ; 25(1): 218-239, 2022 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-34761516

RESUMO

Understanding climate change impacts on top predators is fundamental to marine biodiversity conservation, due to their increasingly threatened populations and their importance in marine ecosystems. We conducted a systematic review of the effects of climate change (prolonged, directional change) and climate variability on seabirds and marine mammals. We extracted data from 484 studies (4808 published studies were reviewed), comprising 2215 observations on demography, phenology, distribution, diet, behaviour, body condition and physiology. The likelihood of concluding that climate change had an impact increased with study duration. However, the temporal thresholds for the effects of climate change to be discernibly varied from 10 to 29 years depending on the species, the biological response and the oceanic study region. Species with narrow thermal ranges and relatively long generation times were more often reported to be affected by climate change. This provides an important framework for future assessments, with guidance on response- and region-specific temporal dimensions that need to be considered when reporting effects of climate change. Finally, we found that tropical regions and non-breeding life stages were poorly covered in the literature, a concern that should be addressed to enable a better understanding of the vulnerability of marine predators to climate change.


Assuntos
Mudança Climática , Ecossistema , Animais , Aves , Mamíferos , Oceanos e Mares
10.
Artigo em Inglês | MEDLINE | ID: mdl-34343670

RESUMO

The present review provides a comparative insight into structure, function and control of leptin system in fishes, herptiles, birds and mammals. In general, leptin acts as an anorexigenic hormone since its administration results in decrease of food intake in vertebrates. Nonetheless, functional paradox arises in fishes from contradictory observations on level of leptin during fasting and re-feeding. In addition, leptin is shown to modulate metabolic functions in fishes, reptiles, birds and mammals. Leptin also regulates reproductive and immune functions though more studies are warranted in non-mammalian vertebrates. The expression of leptin and its receptor is influenced by numerous factors including sex steroids, stress and stress-induced catecholamines and glucocorticoids though their effect in non-mammalian vertebrates is hard to be generalized due to limited studies.


Assuntos
Leptina , Receptores para Leptina , Animais , Peixes , Mamíferos , Receptores para Leptina/genética , Vertebrados
11.
Biochim Biophys Acta Gen Subj ; 1866(1): 130012, 2022 01.
Artigo em Inglês | MEDLINE | ID: mdl-34536507

RESUMO

BACKGROUND: The carbohydrate fraction of mammalian milk is constituted of lactose and oligosaccharides, most of which contain a lactose unit at their reducing ends. Although lactose is the predominant saccharide in the milk of most eutherians, oligosaccharides significantly predominate over lactose in the milk of monotremes and marsupials. SCOPE OF REVIEW: This review describes the most likely process by which lactose and milk oligosaccharides were acquired during the evolution of mammals and the mechanisms by which these saccharides are digested and absorbed by the suckling neonates. MAJOR CONCLUSIONS: During the evolution of mammals, c-type lysozyme evolved to α-lactalbumin. This permitted the biosynthesis of lactose by modulating the substrate specificity of ß4galactosyltransferase 1, thus enabling the concomitant biosynthesis of milk oligosaccharides through the activities of several glycosyltransferases using lactose as an acceptor. In most eutherian mammals the digestion of lactose to glucose and galactose is achieved through the action of intestinal lactase (ß-galactosidase), which is located within the small intestinal brush border. This enzyme, however, is absent in neonatal monotremes and macropod marsupials. It has therefore been proposed that in these species the absorption of milk oligosaccharides is achieved by pinocytosis or endocytosis, after which digestion occurs through the actions of several lysosomal acid glycosidases. This process would enable the milk oligosaccharides of monotremes and marsupials to be utilized as a significant energy source for the suckling neonates. GENERAL SIGNIFICANCE: The evolution and significance of milk oligosaccharides is discussed in relation to the evolution of mammals.


Assuntos
Lactose/metabolismo , Leite/metabolismo , Oligossacarídeos/metabolismo , Animais , Animais Lactentes/metabolismo , Evolução Biológica , Evolução Molecular , Galactose/metabolismo , Galactosiltransferases/metabolismo , Glucose/metabolismo , Lactalbumina/metabolismo , Lactose/genética , Mamíferos/metabolismo , Leite/química , Oligossacarídeos/genética
12.
J Cell Biol ; 221(2)2022 02 07.
Artigo em Inglês | MEDLINE | ID: mdl-34878519

RESUMO

The neuronal axon is packed with cytoskeletal filaments, membranes, and organelles, many of which move between the cell body and axon tip. Here, we used cryo-electron tomography to survey the internal components of mammalian sensory axons. We determined the polarity of the axonal microtubules (MTs) by combining subtomogram classification and visual inspection, finding MT plus and minus ends are structurally similar. Subtomogram averaging of globular densities in the MT lumen suggests they have a defined structure, which is surprising given they likely contain the disordered protein MAP6. We found the endoplasmic reticulum in axons is tethered to MTs through multiple short linkers. We surveyed membrane-bound cargos and describe unexpected internal features such as granules and broken membranes. In addition, we detected proteinaceous compartments, including numerous virus-like capsid particles. Our observations outline novel features of axonal cargos and MTs, providing a platform for identification of their constituents.


Assuntos
Axônios/ultraestrutura , Compartimento Celular , Microscopia Crioeletrônica , Espaço Intracelular/metabolismo , Mamíferos/metabolismo , Microtúbulos/ultraestrutura , Tomografia , Animais , Axônios/metabolismo , Capsídeo/metabolismo , Capsídeo/ultraestrutura , Citoesqueleto/metabolismo , Citoesqueleto/ultraestrutura , Drosophila melanogaster/metabolismo , Drosophila melanogaster/ultraestrutura , Retículo Endoplasmático/metabolismo , Retículo Endoplasmático/ultraestrutura , Gânglios Espinais/metabolismo , Microtúbulos/metabolismo , Análise Multivariada , Proteínas do Tecido Nervoso/metabolismo
13.
Physiol Rev ; 102(1): 7-60, 2022 01 01.
Artigo em Inglês | MEDLINE | ID: mdl-33880962

RESUMO

The spermatozoon is a highly differentiated and polarized cell, with two main structures: the head, containing a haploid nucleus and the acrosomal exocytotic granule, and the flagellum, which generates energy and propels the cell; both structures are connected by the neck. The sperm's main aim is to participate in fertilization, thus activating development. Despite this common bauplan and function, there is an enormous diversity in structure and performance of sperm cells. For example, mammalian spermatozoa may exhibit several head patterns and overall sperm lengths ranging from ∼30 to 350 µm. Mechanisms of transport in the female tract, preparation for fertilization, and recognition of and interaction with the oocyte also show considerable variation. There has been much interest in understanding the origin of this diversity, both in evolutionary terms and in relation to mechanisms underlying sperm differentiation in the testis. Here, relationships between sperm bauplan and function are examined at two levels: first, by analyzing the selective forces that drive changes in sperm structure and physiology to understand the adaptive values of this variation and impact on male reproductive success and second, by examining cellular and molecular mechanisms of sperm formation in the testis that may explain how differentiation can give rise to such a wide array of sperm forms and functions.


Assuntos
Exocitose/fisiologia , Interações Espermatozoide-Óvulo/fisiologia , Espermatozoides/fisiologia , Testículo/citologia , Animais , Evolução Biológica , Humanos , Masculino , Mamíferos/fisiologia , Espermatozoides/citologia
14.
Acta Trop ; 225: 106206, 2022 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-34687642

RESUMO

The protozoan Trypanosoma cruzi, the causative agent of Chagas disease, is transmitted by infected feces or consumption of blood-sucking triatomine insects to several mammalian orders including Chiroptera. In Chile, the distribution of several insectivorous and one hematophagous bat species overlaps with those of triatomine vectors, but the T. cruzi infection status of local chiropterans is unknown. In 2018, we live-captured bats from two protected areas in Chile to collect plagiopatagium tissue, feces and perianal swab samples, in search for T. cruzi-DNA by real time PCR assays using species-specific primers. In Pan de Azúcar island (∼26°S), we examined a roost of Desmodus rotundus (common vampire bat) and sampled tissue from 17 individuals, detecting T. cruzi-DNA in five of them. In Las Chinchillas National Reserve (∼31°S), we examined two roosts of Histiotus montanus (small big-eared brown bat), collecting feces or perianal swab samples from eight individuals, detecting T. cruzi-DNA in four of them. This is the first report of T. cruzi-DNA evidence in bat species from Chile. Both vector-borne and oral transmission are potential infection routes that can explain our results. Further investigation is needed for a better understanding of the role of bats in the T. cruzi transmission cycle.


Assuntos
Doença de Chagas , Quirópteros , Trypanosoma cruzi , Animais , Doença de Chagas/veterinária , Chile , Humanos , Mamíferos , Trypanosoma cruzi/genética
15.
Adv Exp Med Biol ; 1354: 77-107, 2022.
Artigo em Inglês | MEDLINE | ID: mdl-34807438

RESUMO

Normal calcium and bone homeostasis in the adult is virtually fully explained by the interactions of several key regulatory hormones, including parathyroid hormone, 1,25 dihydroxy vitamin D3, fibroblast growth factor-23, calcitonin, and sex steroids (estradiol and testosterone). In utero, bone and mineral metabolism is regulated differently from the adult. During development, it is the placenta and not the fetal kidneys, intestines, or skeleton that is the primary source of minerals for the fetus. The placenta is able to meet the almost inexhaustible needs of the fetus for minerals by actively driving the transport of calcium and phosphorus from the maternal circulation to the growing fetus. These fundamentally important minerals are maintained in the fetal circulation at higher concentrations than those in maternal blood. Maintenance of these inordinately higher fetal levels is necessary for the developing skeleton to accrue sufficient minerals by term. Importantly, in livestock species, prenatal mineralization of the skeleton is crucial for the high levels of offspring activity soon after birth. Calcium is required for mineralization, as well as a plethora of other physiological functions. Placental calcium and phosphate transport are regulated by several mechanisms that are discussed in this review. It is clear that phosphate and calcium metabolism is intimately interrelated and, therefore, placental transport of these minerals cannot be considered in isolation.


Assuntos
Cálcio , Fosfatos , Animais , Feminino , Feto , Mamíferos , Hormônio Paratireóideo , Placenta , Placentação , Gravidez , Vitamina D
16.
Endocrinology ; 163(1)2022 01 01.
Artigo em Inglês | MEDLINE | ID: mdl-34534278

RESUMO

Cross-talk between peripheral tissues is essential to ensure the coordination of nutrient intake with disposition during the feeding period, thereby preventing metabolic disease. This mini-review considers the interactions between the key peripheral tissues that constitute the metabolic clock, each of which is considered in a separate mini-review in this collation of articles published in Endocrinology in 2020 and 2021, by Martchenko et al (Circadian rhythms and the gastrointestinal tract: relationship to metabolism and gut hormones); Alvarez et al (The microbiome as a circadian coordinator of metabolism); Seshadri and Doucette (Circadian regulation of the pancreatic beta cell); McCommis et al (The importance of keeping time in the liver); Oosterman et al (The circadian clock, shift work, and tissue-specific insulin resistance); and Heyde et al (Contributions of white and brown adipose tissues to the circadian regulation of energy metabolism). The use of positive- and negative-feedback signals, both hormonal and metabolic, between these tissues ensures that peripheral metabolic pathways are synchronized with the timing of food intake, thus optimizing nutrient disposition and preventing metabolic disease. Collectively, these articles highlight the critical role played by the circadian clock in maintaining metabolic homeostasis.


Assuntos
Relógios Circadianos/fisiologia , Ritmo Circadiano , Comportamento Alimentar , Homeostase , Fígado/fisiologia , Adipócitos/citologia , Animais , Endocrinologia/métodos , Ingestão de Energia , Metabolismo Energético/fisiologia , Retroalimentação Fisiológica , Hepatócitos/citologia , Hepatócitos/metabolismo , Humanos , Intestinos/fisiologia , Ilhotas Pancreáticas/citologia , Mamíferos/fisiologia , Doenças Metabólicas/metabolismo , Microbiota , Modelos Biológicos , Células Musculares/citologia , Músculo Esquelético/fisiologia
17.
J Cell Biol ; 221(1)2022 01 03.
Artigo em Inglês | MEDLINE | ID: mdl-34787651

RESUMO

The function of cellular structures at the mesoscale is dependent on their geometry and proportionality to cell size. The mitotic spindle is a good example why length and shape of intracellular organelles matter. Spindle length determines the distance over which chromosomes will segregate, and spindle shape ensures bipolarity. While we still lack a systematic and quantitative understanding of subcellular morphology, new imaging techniques and volumetric data analysis promise novel insights into scaling relations across different species. Here, we introduce Spindle3D, an open-source plug-in that allows for the quantitative, consistent, and automated analysis of 3D fluorescent data of spindles and chromatin. We systematically analyze different mammalian cell types, including somatic cells, stem cells, and one- and two-cell embryos, to derive volumetric relations of spindle, chromatin, and the cell. Taken together, our data indicate that mitotic spindle width is a robust indicator of spindle volume, which correlates linearly with chromatin and cell volume both within single cell types and across mammalian species.


Assuntos
Mamíferos/metabolismo , Fuso Acromático/metabolismo , Animais , Tamanho Celular , Cromatina/metabolismo , Fluorescência , Células HEK293 , Células HeLa , Humanos , Camundongos
18.
Mol Cell ; 81(24): 5099-5111.e8, 2021 12 16.
Artigo em Inglês | MEDLINE | ID: mdl-34919820

RESUMO

The SARS-CoV-2 spike protein is a critical component of vaccines and a target for neutralizing monoclonal antibodies (nAbs). Spike is also undergoing immunogenic selection with variants that increase infectivity and partially escape convalescent plasma. Here, we describe Spike Display, a high-throughput platform to rapidly characterize glycosylated spike ectodomains across multiple coronavirus-family proteins. We assayed ∼200 variant SARS-CoV-2 spikes for their expression, ACE2 binding, and recognition by 13 nAbs. An alanine scan of all five N-terminal domain (NTD) loops highlights a public epitope in the N1, N3, and N5 loops recognized by most NTD-binding nAbs. NTD mutations in variants of concern B.1.1.7 (alpha), B.1.351 (beta), B.1.1.28 (gamma), B.1.427/B.1.429 (epsilon), and B.1.617.2 (delta) impact spike expression and escape most NTD-targeting nAbs. Finally, B.1.351 and B.1.1.28 completely escape a potent ACE2 mimic. We anticipate that Spike Display will accelerate antigen design, deep scanning mutagenesis, and antibody epitope mapping for SARS-CoV-2 and other emerging viral threats.


Assuntos
Mamíferos/virologia , SARS-CoV-2/genética , Glicoproteína da Espícula de Coronavírus/genética , Animais , Anticorpos Monoclonais/imunologia , Anticorpos Neutralizantes/imunologia , COVID-19/imunologia , COVID-19/virologia , Linhagem Celular , Epitopos/genética , Epitopos/imunologia , Células HEK293 , Humanos , Mamíferos/imunologia , Ligação Proteica/genética , Ligação Proteica/imunologia , SARS-CoV-2/imunologia , Glicoproteína da Espícula de Coronavírus/imunologia
19.
Sheng Li Xue Bao ; 73(6): 980-990, 2021 Dec 25.
Artigo em Chinês | MEDLINE | ID: mdl-34961873

RESUMO

The normal development of follicles involves a series of complex life processes such as ordered transcriptional activation and inhibition, which is crucial for female reproductive ability. Histone methylation can change the chromatin state in cells and affect the transcription activity of genes. Current studies indicate that epigenetic modifications such as histone methylation play an important regulatory role in follicular development in female mammals. This paper summarized the relationship between H3K4, H3K9 methylation and germ cell development, their regulatory effects, including their dynamical changes during follicular development, and the progress of H3K4me3 and other histone methylation binding to promoter regions of different genes to regulate gene expression and thus affect germ cell epigenetic reprogramming, oocyte transcription, meiosis and other processes. This review will provide a reference for the study of mechanisms related to histone methylation modification and the development and maturation of gonadal parenchymal cells.


Assuntos
Metilação de DNA , Histonas , Folículo Ovariano/crescimento & desenvolvimento , Animais , Epigênese Genética , Feminino , Mamíferos , Processamento de Proteína Pós-Traducional
20.
Proc Biol Sci ; 288(1963): 20211651, 2021 11 24.
Artigo em Inglês | MEDLINE | ID: mdl-34784766

RESUMO

Back and forth transmission of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) between humans and animals will establish wild reservoirs of virus that endanger long-term efforts to control COVID-19 in people and to protect vulnerable animal populations. Better targeting surveillance and laboratory experiments to validate zoonotic potential requires predicting high-risk host species. A major bottleneck to this effort is the few species with available sequences for angiotensin-converting enzyme 2 receptor, a key receptor required for viral cell entry. We overcome this bottleneck by combining species' ecological and biological traits with three-dimensional modelling of host-virus protein-protein interactions using machine learning. This approach enables predictions about the zoonotic capacity of SARS-CoV-2 for greater than 5000 mammals-an order of magnitude more species than previously possible. Our predictions are strongly corroborated by in vivo studies. The predicted zoonotic capacity and proximity to humans suggest enhanced transmission risk from several common mammals, and priority areas of geographic overlap between these species and global COVID-19 hotspots. With molecular data available for only a small fraction of potential animal hosts, linking data across biological scales offers a conceptual advance that may expand our predictive modelling capacity for zoonotic viruses with similarly unknown host ranges.


Assuntos
COVID-19 , SARS-CoV-2 , Animais , Especificidade de Hospedeiro , Humanos , Mamíferos , Glicoproteína da Espícula de Coronavírus
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