Your browser doesn't support javascript.
loading
Mostrar: 20 | 50 | 100
Resultados 1 - 20 de 68
Filtrar
Mais filtros

Intervalo de ano de publicação
1.
Conserv Biol ; 38(1): e14154, 2024 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-37489292

RESUMO

Human water use combined with a recent megadrought have reduced river and stream flow through the southwest United States and led to periodic drying of formerly perennial river segments. Reductions in snowmelt runoff and increased extent of drying collectively threaten short-lived, obligate aquatic species, including the endangered Rio Grande silvery minnow (Hybognathus amarus). This species is subject to boom-and-bust population dynamics, under which large fluctuations in abundance are expected to lower estimates of effective population size and erode genetic diversity over time. Rates of diversity loss are also affected by additions of hatchery-origin fish used to supplement the wild population. We used demographic and genetic data from wild and hatchery individuals to examine the relationship of genetic diversity and effective population size to abundance over the last two decades. Genetic diversity was low during the early 2000s, but diversity and demographic metrics stabilized after the hatchery program was initiated and environmental conditions improved. Yet, from 2017 onward, allelic diversity declined (Cohen's d = 1.34) and remained low despite hatchery stocking and brief wild population recovery. Across the time series, single-sample estimates of effective population size based on linkage disequilibrium (LD Ne ) were positively associated (r = 0.53) with wild abundance and total abundance, but as the proportion of hatchery-origin spawners increased, LD Ne declined (r = -0.55). Megadrought limited wild spawner abundance and precluded refreshment of hatchery brood stocks with wild fish; hence, we predict a riverine population increasingly dominated by hatchery-origin individuals and accelerated loss of genetic diversity despite supplementation. We recommend an adaptive and accelerated management plan that integrates river flow management and hatchery operations to slow the pace of genetic diversity loss exacerbated by megadrought.


El uso humano del agua, combinado con una megasequía reciente, ha reducido el flujo de los ríos y arroyos en el suroeste de los Estados Unidos y ha provocado la seca periódica de segmentos de ríos que antes eran perennes. Las reducciones en la escorrentía del deshielo y el aumento de la sequía amenazan colectivamente a especies obligatoriamente acuáticas de vida corta, incluyendo la amenazada carpa chamizal (Hybognathus amarus). Esta especie está sujeta a una dinámica poblacional de explosión y colapso, bajo la cual se espera que grandes fluctuaciones en la abundancia reduzcan las estimaciones del tamaño efectivo de la población y erosionen la diversidad genética con el tiempo. Las tasas de pérdida de la diversidad también se ven afectadas por la adición de peces procedentes de criaderos usados para suplementar la población silvestre. Utilizamos datos demográficos y genéticos de individuos silvestres y de criaderos para examinar la relación entre la diversidad genética y el tamaño efectivo de la población con la abundancia durante las últimas dos décadas. La diversidad genética fue baja a principios de los 2000, pero las métricas de diversidad y demografía estabilizaron después de que se inició el programa de criadero y mejoraron las condiciones ambientales. Sin embargo, a partir de 2017, la diversidad alélica disminuyó (d de Cohen = 1,34) y se mantuvo baja a pesar de la suplementación con individuos de criaderos y la breve recuperación de la población silvestre. A lo largo del tiempo, las estimativas de muestras individuales del tamaño efectivo de la población basados en el desequilibrio de ligamiento (LD Ne) estaban asociadas positivamente (r = 0,53) con la abundancia silvestre y la abundancia total, pero a medida que la proporción de desovadores originados en criaderos aumentó, el LD Ne disminuyó (r = -0,55). La megasequía limitó la abundancia de desovadores silvestres e impidió el reabastecimiento de las poblaciones en cautiverio con peces silvestres; por lo tanto, predecimos una población ribereña cada vez más dominada por individuos procedentes de criaderos y una pérdida acelerada de diversidad genética a pesar de la suplementación. Recomendamos un plan de gestión adaptativo y acelerado que integre la gestión del caudal del río y las operaciones de criaderos para frenar el ritmo de pérdida de diversidad genética exacerbada por la megasequía.


Assuntos
Cyprinidae , Variação Genética , Humanos , Animais , Conservação dos Recursos Naturais , Cyprinidae/genética , Rios , Cruzamento
2.
Nucleic Acids Res ; 50(21): e124, 2022 11 28.
Artigo em Inglês | MEDLINE | ID: mdl-36156149

RESUMO

Animal cell lines often undergo extreme genome restructuring events, including polyploidy and segmental aneuploidy that can impede de novo whole-genome assembly (WGA). In some species like Drosophila, cell lines also exhibit massive proliferation of transposable elements (TEs). To better understand the role of transposition during animal cell culture, we sequenced the genome of the tetraploid Drosophila S2R+ cell line using long-read and linked-read technologies. WGAs for S2R+ were highly fragmented and generated variable estimates of TE content across sequencing and assembly technologies. We therefore developed a novel WGA-independent bioinformatics method called TELR that identifies, locally assembles, and estimates allele frequency of TEs from long-read sequence data (https://github.com/bergmanlab/telr). Application of TELR to a ∼130x PacBio dataset for S2R+ revealed many haplotype-specific TE insertions that arose by transposition after initial cell line establishment and subsequent tetraploidization. Local assemblies from TELR also allowed phylogenetic analysis of paralogous TEs, which revealed that proliferation of TE families in vitro can be driven by single or multiple source lineages. Our work provides a model for the analysis of TEs in complex heterozygous or polyploid genomes that are recalcitrant to WGA and yields new insights into the mechanisms of genome evolution in animal cell culture.


Assuntos
Elementos de DNA Transponíveis , Poliploidia , Animais , Elementos de DNA Transponíveis/genética , Filogenia , Drosophila/genética , Linhagem Celular
3.
Mol Ecol ; 32(2): 316-334, 2023 01.
Artigo em Inglês | MEDLINE | ID: mdl-36321869

RESUMO

Many long-term genetic monitoring programmes began before next-generation sequencing became widely available. Older programmes can now transition to new marker systems usually consisting of 1000s of SNP loci, but there are still important questions about comparability, precision, and accuracy of key metrics estimated using SNPs. Ideally, transitioned programmes should capitalize on new information without sacrificing continuity of inference across the time series. We combined existing microsatellite-based genetic monitoring information with SNP-based microhaplotypes obtained from archived samples of Rio Grande silvery minnow (Hybognathus amarus) across a 20-year time series to evaluate point estimates and trajectories of key genetic metrics. Demographic and genetic monitoring bracketed multiple collapses of the wild population and included cases where captive-born repatriates comprised the majority of spawners in the wild. Even with smaller sample sizes, microhaplotypes yielded comparable and in some cases more precise estimates of variance genetic effective population size, multilocus heterozygosity and inbreeding compared to microsatellites because many more microhaplotype loci were available. Microhaplotypes also recorded shifts in allele frequencies associated with population bottlenecks. Trends in microhaplotype-based inbreeding metrics were associated with the fraction of hatchery-reared repatriates to the wild and should be incorporated into future genomic monitoring. Although differences in accuracy and precision of some metrics were observed between marker types, biological inferences and management recommendations were consistent.


Assuntos
Genética Populacional , Polimorfismo de Nucleotídeo Único , Polimorfismo de Nucleotídeo Único/genética , Frequência do Gene , Endogamia , Repetições de Microssatélites
4.
Mol Ecol ; 32(15): 4362-4380, 2023 08.
Artigo em Inglês | MEDLINE | ID: mdl-37316984

RESUMO

In organisms reproducing sexually, speciation occurs when increasing divergence results in pre- or post-zygotic reproductive isolation between lineages. Studies focusing on reproductive isolation origin in early stages of speciation are common and many rely on genomic scans to infer introgression providing limited information on the genomic architecture of reproductive isolation long-term maintenance. This study analyses a natural hybrid zone between two species in a late stage of speciation. We used ddRADseq genotyping in the contact between Podarcis bocagei and P. carbonelli to examine admixture extent, analyse hybrid zone stability and assess genome-wide variation in selection against introgression. We confirmed strong but incomplete reproductive isolation in a bimodal hybrid zone. New findings revealed population genetic structure within P. carbonelli in the contact zone; geographical and genomic clines analysis suggested strong selection against gene flow, but a relatively small proportion of the loci can introgress, mostly within the narrow contact zone. However, geographical clines revealed that a few introgressed loci show signs of potential positive selection, particularly into P. bocagei. Geographical clines also detected a signal of hybrid zone movement towards P. bocagei distribution. Genomic cline analysis revealed heterogeneous patterns of introgression among loci within the syntopy zone, but the majority maintain a strong association with the genomic background of origin. However, incongruences between both cline approaches were found, potentially driven by confounding effects on genomic clines. Last, an important role of the Z chromosome in reproductive isolation is suggested. Importantly, overall patterns of restricted introgression seem to result from numerous strong intrinsic barriers across the genome.


Assuntos
Especiação Genética , Isolamento Reprodutivo , Genoma , Hibridização Genética , Genômica , Fluxo Gênico
5.
Mol Ecol ; 32(14): 4003-4017, 2023 07.
Artigo em Inglês | MEDLINE | ID: mdl-37143304

RESUMO

Major histocompatibility complex (MHC) genes are crucial for the adaptive immune response of jawed vertebrates. Their variation, reaching extreme levels, is driven mainly by an arms race between hosts and pathogens. One hypothesised mechanism contributing to MHC polymorphism is adaptive introgression, the exchange of genetic variants between hybridising species favoured by selection, yet its effect on MHC variation is poorly understood. Detection of adaptive MHC introgression, though challenging, may be facilitated by the analysis of species complexes forming multiple hybrid zones. Here, we investigated MHC introgression in six hybrid zones formed by seven species of Podarcis lizards inhabiting the Iberian Peninsula. To differentiate adaptive introgression from neutral introgression, we compared the patterns of gene exchange in MHC and genome-wide markers. We found elevated sharing of MHC alleles in the proximity of contact beyond the areas of detectable genome-wide admixture in most hybrid zones and, in half of them, asymmetric MHC exchange. In general, the elevated MHC allele sharing between species pairs with abutting ranges compared to geographically isolated species pairs also supports the prevalence of introgression. Collectively, our results demonstrate widespread MHC introgression in the Iberian Podarcis complex and suggest its adaptiveness. Contrary to previous results from Triturus newts, we did not observe differences in the rate of introgression between MHC classes. Our work adds support to the emerging view of adaptive introgression as a key mechanism shaping MHC diversity. It also raises questions about the effect of elevated MHC variation and factors leading to the asymmetry of adaptive introgression.


Assuntos
Lagartos , Animais , Lagartos/genética , Polimorfismo Genético , Alelos , Salamandridae/genética , Seleção Genética
6.
J Hered ; 114(5): 470-487, 2023 08 23.
Artigo em Inglês | MEDLINE | ID: mdl-37347974

RESUMO

Sex determination systems and genetic sex differentiation across fishes are highly diverse but are unknown for most Cypriniformes, including Rio Grande silvery minnow (Hybognathus amarus). In this study, we aimed to detect and validate sex-linked markers to infer sex determination system and to demonstrate the utility of combining several methods for sex-linked marker detection in nonmodel organisms. To identify potential sex-linked markers, Nextera-tagmented reductively amplified DNA (nextRAD) libraries were generated from 66 females, 64 males, and 60 larvae of unknown sex. These data were combined with female and male de novo genomes from Nanopore long-read sequences. We identified five potential unique male nextRAD-tags and one potential unique male contig, suggesting an XY sex determination system. We also identified two single-nucleotide polymorphisms (SNPs) in the same contig with values of FST, allele frequencies, and heterozygosity conforming with expectations of an XY system. Through PCR we validated the marker containing the sex-linked SNPs and a single nextRAD-tag sex-associated marker but it was not male specific. Instead, more copies of this locus in the male genome were suggested by enhanced amplification in males. Results are consistent with an XY system with low differentiation between sex-determining regions. Further research is needed to confirm the level of differentiation between the sex chromosomes. Nonetheless, this study highlighted the power of combining reduced representation and whole-genome sequencing for identifying sex-linked markers, especially when reduced representation sequencing does not include extensive variation between sexes, either because such variation is not present or not captured.


Assuntos
Cipriniformes , Masculino , Animais , Feminino , Cipriniformes/genética , Cromossomo Y , Genoma , Cromossomos Sexuais/genética , Deriva Genética , Marcadores Genéticos , Processos de Determinação Sexual/genética
7.
Prog Mol Subcell Biol ; 60: 27-56, 2021.
Artigo em Inglês | MEDLINE | ID: mdl-34386871

RESUMO

The fact that satellite DNAs (satDNAs) in eukaryotes are abundant genomic components, can perform functional roles, but can also change rapidly across species while being homogenous within a species, makes them an intriguing and fascinating genomic component to study. It is also becoming clear that satDNAs represent an important piece in genome architecture and that changes in their structure, organization, and abundance can affect the evolution of genomes and species in many ways. Since the discovery of satDNAs more than 50 years ago, species from the Drosophila genus have continuously been used as models to study several aspects of satDNA biology. These studies have been largely concentrated in D. melanogaster and closely related species from the Sophophora subgenus, even though the vast majority of all Drosophila species belong to the Drosophila subgenus. This chapter highlights some studies on the satDNA structure, organization, and evolution in two species groups from the Drosophila subgenus: the repleta and virilis groups. We also discuss and review the classification of other abundant tandem repeats found in these species in the light of the current information available.


Assuntos
DNA Satélite , Drosophila , Animais , DNA Satélite/genética , Drosophila/genética , Drosophila melanogaster/genética , Evolução Molecular , Filogenia
8.
Mol Phylogenet Evol ; 164: 107270, 2021 11.
Artigo em Inglês | MEDLINE | ID: mdl-34352374

RESUMO

Unravelling when divergent lineages constitute distinct species can be challenging, particularly in complex scenarios combining cryptic diversity and phylogenetic discordances between different types of molecular markers. Combining a phylogenetic approach with the study of contact zones can help to overcome such difficulties. The Podarcis hispanicus species complex has proven to be prosperous in independent evolutionary units, sometimes associated with cryptic diversity. Previous studies have revealed that one of the species of this complex, P. guadarramae, comprises two deeply divergent yet morphologically indistinguishable evolutionary units, currently regarded as subspecies (P. g. guadarramae and P. g. lusitanicus). In this study we used molecular data to address the systematics of the two lineages of Podarcis guadarramae and the closely related P. bocagei. Firstly, we reconstructed the species tree of these three and two additional taxa based on 30 nuclear loci using the multispecies coalescent with and without gene flow. Secondly, we used SNPs obtained from RADseq data to analyze the population structure across the distribution limits P. g. lusitanicus and P. g. guadarramae, and for comparison, a contact zone between P. bocagei and P. g. lusitanicus. Nuclear phylogenetic relationships between these three taxa are clearly difficult to determine due to the influence of gene flow, but our results give little support to the monophyly of P. guadarramae, potentially due to a nearly simultaneous divergence between them. Genetic structure and geographic cline analysis revealed that the two lineages of P. guadarramae replace each other abruptly across the sampled region and that gene flow is geographically restricted, implying the existence of strong reproductive isolation. Podarcis bocagei and P. g. lusitanicus show a similar degree of genetic differentiation and reproductive isolation, with very low levels of admixture in syntopy. These results support that all three forms are equally differentiated and reproductively isolated. In consequence, we conclude that the two former subspecies of Podarcis guadarramae constitute valid, yet cryptic species, that should be referred to as P. lusitanicus and P. guadarramae.


Assuntos
Núcleo Celular/genética , Lagartos , Filogenia , Animais , Genômica , Lagartos/classificação , Lagartos/genética , Polimorfismo de Nucleotídeo Único , Análise de Sequência de DNA
9.
Heredity (Edinb) ; 126(3): 463-476, 2021 03.
Artigo em Inglês | MEDLINE | ID: mdl-33199832

RESUMO

Recent empirical studies have demonstrated that speciation with gene flow is more common than previously thought. From a conservation perspective, the potential negative effects of hybridization raise concerns on the genetic integrity of endangered species. However, introgressive hybridization has also been growingly recognized as a source of diversity and new advantageous alleles. Carbonell's wall lizard (Podarcis carbonelli) is an endangered species whose distribution overlaps with four other congeneric species. Our goal here was to determine whether P. carbonelli is completely reproductively isolated from its congeners and to evaluate the relevance of hybridization and interspecific gene flow for developing a conservation plan. We used restriction site associated DNA (RAD) sequencing to discover SNPs in samples from four contact zones between P. carbonelli and four other species. Principal component analysis, multilocus genotype assignment and interspecific heterozygosity suggest incomplete reproductive isolation and ongoing gene flow between species. However, hybridization dynamics vary across all pairs, suggesting complex interactions between multiple intrinsic and extrinsic barriers. Despite seemingly ubiquitous interspecific gene flow, we found evidence of strong reproductive isolation across most contact zones. Instead, indirect effects of hybridization like waste of reproductive effort in small isolated populations may be more problematic. Our results highlight the need to further evaluate the consequences of introgression for P. carbonelli, both on a geographic and genomic level and included in a comprehensive and urgently needed conservation plan. Besides, those findings will add important insights on the potential effects of hybridization and introgression for endangered species.


Assuntos
Lagartos , Isolamento Reprodutivo , Animais , Fluxo Gênico , Genótipo , Hibridização Genética , Lagartos/genética
10.
BMC Evol Biol ; 20(1): 141, 2020 11 02.
Artigo em Inglês | MEDLINE | ID: mdl-33138771

RESUMO

BACKGROUND: The Drosophilidae family is traditionally divided into two subfamilies: Drosophilinae and Steganinae. This division is based on morphological characters, and the two subfamilies have been treated as monophyletic in most of the literature, but some molecular phylogenies have suggested Steganinae to be paraphyletic. To test the paraphyletic-Steganinae hypothesis, here, we used genomic sequences of eight Drosophilidae (three Steganinae and five Drosophilinae) and two Ephydridae (outgroup) species and inferred the phylogeny for the group based on a dataset of 1,028 orthologous genes present in all species (> 1,000,000 bp). This dataset includes three genera that broke the monophyly of the subfamilies in previous works. To investigate possible biases introduced by small sample sizes and automatic gene annotation, we used the same methods to infer species trees from a set of 10 manually annotated genes that are commonly used in phylogenetics. RESULTS: Most of the 1,028 gene trees depicted Steganinae as paraphyletic with distinct topologies, but the most common topology depicted it as monophyletic (43.7% of the gene trees). Despite the high levels of gene tree heterogeneity observed, species tree inference in ASTRAL, in PhyloNet, and with the concatenation approach strongly supported the monophyly of both subfamilies for the 1,028-gene dataset. However, when using the concatenation approach to infer a species tree from the smaller set of 10 genes, we recovered Steganinae as a paraphyletic group. The pattern of gene tree heterogeneity was asymmetrical and thus could not be explained solely by incomplete lineage sorting (ILS). CONCLUSIONS: Steganinae was clearly a monophyletic group in the dataset that we analyzed. In addition to ILS, gene tree discordance was possibly the result of introgression, suggesting complex branching processes during the early evolution of Drosophilidae with short speciation intervals and gene flow. Our study highlights the importance of genomic data in elucidating contentious phylogenetic relationships and suggests that phylogenetic inference for drosophilids based on small molecular datasets should be performed cautiously. Finally, we suggest an approach for the correction and cleaning of BUSCO-derived genomic datasets that will be useful to other researchers planning to use this tool for phylogenomic studies.


Assuntos
Drosophilidae/genética , Especiação Genética , Filogenia , Animais , Genômica
11.
J Mol Evol ; 86(6): 353-364, 2018 07.
Artigo em Inglês | MEDLINE | ID: mdl-29934734

RESUMO

Despite their essential role in the process of chromosome segregation in eukaryotes, kinetochore proteins are highly diverse across species, being lost, duplicated, created, or diversified during evolution. Based on comparative genomics, the duplication of the inner kinetochore proteins CenH3 and Cenp-C, which are interdependent in their roles of establishing centromere identity and function, can be said to be rare in animals. Surprisingly, the Drosophila CenH3 homolog Cid underwent four independent duplication events during evolution. Particularly interesting are the highly diverged Cid1 and Cid5 paralogs of the Drosophila subgenus, which are probably present in over one thousand species. Given that CenH3 and Cenp-C likely co-evolve as a functional unit, we investigated the molecular evolution of Cenp-C in species of Drosophila. We report yet another Cid duplication (leading to Cid6) within the Drosophila subgenus and show that not only Cid, but also Cenp-C is duplicated in the entire subgenus. The Cenp-C paralogs, which we named Cenp-C1 and Cenp-C2, are highly divergent. Both Cenp-C1 and Cenp-C2 retain key motifs involved in centromere localization and function, while some functional motifs are conserved in an alternate manner between the paralogs. Interestingly, both Cid5 and Cenp-C2 are male germline-biased and evolved adaptively. However, it is currently unclear if the paralogs subfunctionalized or if the new copies acquired a new function. Our findings point towards a specific inner kinetochore composition in a specific context (i.e., spermatogenesis), which could prove valuable for the understanding of how the extensive kinetochore diversity is related to essential cellular functions.


Assuntos
Proteína Centromérica A/genética , Proteínas Cromossômicas não Histona/genética , Proteínas de Drosophila/genética , Drosophila melanogaster/genética , Evolução Molecular , Duplicação Gênica , Genes de Insetos , Células Germinativas/metabolismo , Animais , Viés , Proteína Centromérica A/metabolismo , Proteínas Cromossômicas não Histona/metabolismo , Cromossomos/genética , Proteínas de Drosophila/metabolismo , Funções Verossimilhança , Masculino , Filogenia
12.
Biol Lett ; 14(1)2018 01.
Artigo em Inglês | MEDLINE | ID: mdl-29386361

RESUMO

Satellite DNAs (satDNAs) are major components of eukaryote genomes. However, because of their quick divergence, the evolutionary origin of a given satDNA family can rarely be determined. Herein we took advantage of available primate sequenced genomes to determine the origin of the CapA satDNA (approx. 1500 bp long monomers), first described in the tufted capuchin monkey Sapajus apella We show that CapA is an abundant satDNA in Platyrrhini, whereas in the genomes of most eutherian mammals, including humans, this sequence is present only as a single copy located within a large intron of the NOS1AP (nitric oxide synthase 1 adaptor protein) gene. Our data suggest that this intronic CapA-like sequence gave rise to the CapA satDNA and we discuss possible mechanisms implicated in this event. This is the first report to our knowledge of a single copy intronic sequence giving origin to a satDNA that reaches up to 100 000 copies in some genomes.


Assuntos
DNA Satélite/genética , Evolução Molecular , Íntrons/genética , Platirrinos/genética , Animais , Eutérios/genética , Humanos , Análise de Sequência de DNA
13.
Chromosome Res ; 23(3): 597-613, 2015 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-26408292

RESUMO

Drosophila INterspersed Elements (DINEs) constitute an abundant but poorly understood group of Helitrons present in several Drosophila species. The general structure of DINEs includes two conserved blocks that may or not contain a region with tandem repeats in between. These central tandem repeats (CTRs) are similar within species but highly divergent between species. It has been assumed that CTRs have independent origins. Herein, we identify a subset of DINEs, termed DINE-TR1, which contain homologous CTRs of approximately 150 bp. We found DINE-TR1 in the sequenced genomes of several Drosophila species and in Bactrocera tryoni (Acalyptratae, Diptera). However, interspecific high sequence identity (∼ 88 %) is limited to the first ∼ 30 bp of each tandem repeat, implying that evolutionary constraints operate differently over the monomer length. DINE-TR1 is unevenly distributed across the Drosophila phylogeny. Nevertheless, sequence analysis suggests vertical transmission. We found that CTRs within DINE-TR1 have independently expanded into satellite DNA-like arrays at least twice within Drosophila. By analyzing the genome of Drosophila virilis and Drosophila americana, we show that DINE-TR1 is highly abundant in pericentromeric heterochromatin boundaries, some telomeric regions and in the Y chromosome. It is also present in the centromeric region of one autosome from D. virilis and dispersed throughout several euchromatic sites in both species. We further found that DINE-TR1 is abundant at piRNA clusters, and small DINE-TR1-derived RNA transcripts (∼25 nt) are predominantly expressed in the testes and the ovaries, suggesting active targeting by the piRNA machinery. These features suggest potential piRNA-mediated regulatory roles for DINEs at local and genome-wide scales in Drosophila.


Assuntos
Drosophila/genética , Estruturas Genéticas , Genoma de Inseto , Genômica , Sequências Repetitivas Dispersas , Animais , Mapeamento Cromossômico , Biologia Computacional/métodos , DNA Satélite , Regulação da Expressão Gênica , Genômica/métodos , Gônadas/metabolismo , Heterocromatina/genética , Sequenciamento de Nucleotídeos em Larga Escala , Hibridização in Situ Fluorescente , Especificidade de Órgãos/genética , Filogenia , Cromossomos Politênicos/genética , RNA Interferente Pequeno/genética
14.
Genome Biol Evol ; 16(2)2024 02 01.
Artigo em Inglês | MEDLINE | ID: mdl-38368625

RESUMO

The clouded apollo (Parnassius mnemosyne) is a palearctic butterfly distributed over a large part of western Eurasia, but population declines and fragmentation have been observed in many parts of the range. The development of genomic tools can help to shed light on the genetic consequences of the decline and to make informed decisions about direct conservation actions. Here, we present a high-contiguity, chromosome-level genome assembly of a female clouded apollo butterfly and provide detailed annotations of genes and transposable elements. We find that the large genome (1.5 Gb) of the clouded apollo is extraordinarily repeat rich (73%). Despite that, the combination of sequencing techniques allowed us to assemble all chromosomes (nc = 29) to a high degree of completeness. The annotation resulted in a relatively high number of protein-coding genes (22,854) compared with other Lepidoptera, of which a large proportion (21,635) could be assigned functions based on homology with other species. A comparative analysis indicates that overall genome structure has been largely conserved, both within the genus and compared with the ancestral lepidopteran karyotype. The high-quality genome assembly and detailed annotation presented here will constitute an important tool for forthcoming efforts aimed at understanding the genetic consequences of fragmentation and decline, as well as for assessments of genetic diversity, population structure, inbreeding, and genetic load in the clouded apollo butterfly.


Assuntos
Borboletas , Animais , Feminino , Borboletas/genética , Conservação dos Recursos Naturais , Genômica , Elementos de DNA Transponíveis , Cromossomos , Anotação de Sequência Molecular
15.
Artigo em Inglês | MEDLINE | ID: mdl-38597520

RESUMO

The worldwide monkeypox (mpox) outbreak in 2022 showed a high frequency of sexually transmitted infections (STI). A cross-sectional study was carried out using secondary data from the Brazilian official mpox surveillance systems. A total of 10,169 mpox cases were identified, with a median age of 32 years. Among them, 92.3% were male at birth and 57.5% were men who have sex with other men (MSM). Approximately 11% were diagnosed with STI, including 5.8% with syphilis and 2.5% with genital herpes. Individuals aged from 25 to 34 years, MSM, individuals with HIV-positive status, and those manifesting skin eruptions or penile edema were associated with STI. Laboratory investigation for mpox must be implemented as a priority in STI clinics (especially for MSM) to mitigate neglected cases, ensure appropriate treatments, and prevent misdiagnoses.


Assuntos
Gonorreia , Infecções por HIV , Mpox , Minorias Sexuais e de Gênero , Infecções Sexualmente Transmissíveis , Adulto , Humanos , Masculino , Brasil/epidemiologia , Estudos Transversais , Demografia , Surtos de Doenças , Gonorreia/diagnóstico , Infecções por HIV/diagnóstico , Infecções por HIV/epidemiologia , Infecções por HIV/complicações , Homossexualidade Masculina , Infecções Sexualmente Transmissíveis/diagnóstico , Infecções Sexualmente Transmissíveis/epidemiologia
16.
Int J Gynaecol Obstet ; 166(1): 71-79, 2024 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-38425195

RESUMO

BACKGROUND: Sexually transmitted infections (STIs) are a public health problem. The aim of the present study was to assess the prevalence and risk factors associated with at least one STI (Chlamydia trachomatis [CT], Neisseria gonorrhoeae [NG], Trichomonas vaginalis [TV], and Mycoplasma genitalium [MG]) in Brazil. METHODS: A cross-sectional study was conducted using secondary data from the pilot implementation of the National Service for molecular diagnosis of CT, NG, TV, and MG in pregnancy. We obtained Ministry of Health surveillance data from the implementation project. Data encompassing pregnant women aged 15-49 years from public antenatal clinics in Brazil in 2022 were included. RESULTS: A total of 2728 data of pregnant women were analyzed. The prevalence of at least one infection was 21.0% (573), with the highest prevalence in the Southeast region (23.3%) and the lowest in the Center-West region (15.4%). The prevalence of CT was 9.9% (270), NG 0.6% (16), TV 6.7% (184), and MG 7.8% (212). Factors associated with any infection were from 15 to 24 years (AOR = 1.93; 95% CI: 1.58-2.35); reported family income up to US$400 (AOR = 1.79; 95% CI: 1.03-3.34); declared not living maritally with their partners (AOR = 1.90, 95% CI: 1.52-2.37) and had more than one sexual partner in their lifetime (AOR = 2.09, 95% CI: 1.55-2.86). CONCLUSION: This study showed a high prevalence of at least one STI among pregnant women in Brazil, particularly among younger women. It also provides up-to-date national data on CT, NG, TV, and MG infections in this population. These findings underscore the importance of enhancing access to STI screening for young pregnant women within the Brazilian public health system.


Assuntos
Infecções por Chlamydia , Chlamydia trachomatis , Gonorreia , Infecções por Mycoplasma , Mycoplasma genitalium , Neisseria gonorrhoeae , Complicações Infecciosas na Gravidez , Vaginite por Trichomonas , Trichomonas vaginalis , Humanos , Feminino , Brasil/epidemiologia , Gravidez , Adulto , Estudos Transversais , Adolescente , Prevalência , Adulto Jovem , Mycoplasma genitalium/isolamento & purificação , Fatores de Risco , Infecções por Mycoplasma/epidemiologia , Infecções por Mycoplasma/diagnóstico , Gonorreia/epidemiologia , Gonorreia/diagnóstico , Neisseria gonorrhoeae/isolamento & purificação , Trichomonas vaginalis/isolamento & purificação , Complicações Infecciosas na Gravidez/epidemiologia , Complicações Infecciosas na Gravidez/diagnóstico , Chlamydia trachomatis/isolamento & purificação , Infecções por Chlamydia/epidemiologia , Infecções por Chlamydia/diagnóstico , Vaginite por Trichomonas/epidemiologia , Vaginite por Trichomonas/diagnóstico , Pessoa de Meia-Idade , Infecções Sexualmente Transmissíveis/epidemiologia , Infecções Sexualmente Transmissíveis/diagnóstico
17.
G3 (Bethesda) ; 14(3)2024 03 06.
Artigo em Inglês | MEDLINE | ID: mdl-38156703

RESUMO

Odysseus (OdsH) was the first speciation gene described in Drosophila related to hybrid sterility in offspring of mating between Drosophila mauritiana and Drosophila simulans. Its origin is attributed to the duplication of the gene unc-4 in the subgenus Sophophora. By using a much larger sample of Drosophilidae species, we showed that contrary to what has been previously proposed, OdsH origin occurred 62 MYA. Evolutionary rates, expression, and transcription factor-binding sites of OdsH evidence that it may have rapidly experienced neofunctionalization in male sexual functions. Furthermore, the analysis of the OdsH peptide allowed the identification of mutations of D. mauritiana that could result in incompatibility in hybrids. In order to find if OdsH could be related to hybrid sterility, beyond Sophophora, we explored the expression of OdsH in Drosophila arizonae and Drosophila mojavensis, a pair of sister species with incomplete reproductive isolation. Our data indicated that OdsH expression is not atypical in their male-sterile hybrids. In conclusion, we have proposed that the origin of OdsH occurred earlier than previously proposed, followed by neofunctionalization. Our results also suggested that its role as a speciation gene might be restricted to D. mauritiana and D. simulans.


Assuntos
Proteínas de Drosophila , Infertilidade , Animais , Masculino , Evolução Biológica , Drosophila/genética , Proteínas de Drosophila/genética , Hibridização Genética
18.
Plants (Basel) ; 13(5)2024 Feb 26.
Artigo em Inglês | MEDLINE | ID: mdl-38475480

RESUMO

Plant endogenous mechanisms are not always sufficient enough to mitigate drought stress, therefore, the exogenous application of elicitors, such as salicylic acid, is necessary. In this study, we assessed the mitigating action of salicylic acid (SA) in cowpea genotypes under drought conditions. An experiment was conducted with two cowpea genotypes and six treatments of drought stress and salicylic acid (T1 = Control, T2 = drought stress (stress), T3 = stress + 0.1 mM of SA, T4 = stress + 0.5 mM of SA, T5 = stress + 1.0 mM of SA, and T6 = stress + 2.0 mM of SA). Plants were evaluated in areas of leaf area, stomatal conductance, photosynthesis, proline content, the activity of antioxidant enzymes, and dry grain production. Drought stress reduces the leaf area, stomatal conductance, photosynthesis, and, consequently, the production of both cowpea genotypes. The growth and production of the BRS Paraguaçu genotype outcompetes the Pingo de Ouro-1-2 genotype, regardless of the stress conditions. The exogenous application of 0.5 mM salicylic acid to cowpea leaves increases SOD activity, decreases CAT activity, and improves the production of both genotypes. The application of 0.5 mM of salicylic acid mitigates drought stress in the cowpea genotype, and the BRS Paraguaçu genotype is more tolerant to drought stress.

19.
Acta Ortop Bras ; 31(6): e267476, 2023.
Artigo em Inglês | MEDLINE | ID: mdl-38115877

RESUMO

We observe delayed referrals to appropriate Microsurgery Unit and definitive treatment of traumatic limb amputations. Cases with wrist proximal amputations have a deadline for surgical replantation as these configure life-threatening injuries. Objective: To analyze patients with traumatic proximal wrist upper limb amputations with prolonged ischemic time who underwent temporary artery catheterization to assess stump viability and results. Methods: A case-series study including all patients with a proximal wrist upper limb amputation and a cold ischemic time equal to or above six hours from 2017 to 2021. Results: In total, two surgeons operated eight patients who had experienced forearm amputation injuries. Median ischemia time totaled eight hours. All patients required additional surgeries, most commonly split-thickness skin graft or fixation revision (three patients). This study obtained five successful macroreimplantations. The mean cold ischemia time was longer in the group with successful macroreimplantations (7.4 hours) than of the unsuccessful group (9 hours). Conclusion: Macroreplantations require immediate referral to microsurgery and, although temporary artery catheterization helps surgical decision making, the technique seems to fail to influence outcomes. Level of Evidence IV, Retrospective Case Series.


Observa-se um atraso no referenciamento dos casos para o tratamento definitivo das amputações traumáticas de membros no Brasil. Casos com amputações proximais ao punho apresentam um prazo limite para reimplante, sendo lesões que promovem risco de vida ao paciente. Objetivo: Analisar os macrorreimplantes com tempo de isquemia prolongado submetidos à cateterização temporária da artéria, para determinar a viabilidade do coto de amputação, e seus resultados. Métodos: Série de casos de todos os pacientes com amputações traumáticas proximais ao punho, cujo tempo de isquemia fria foi igual ou superior a seis horas, entre 2017 e 2021. Resultados: A amostra foi composta por oito pacientes com amputações traumáticas de antebraço operados por dois cirurgiões. O tempo médio de isquemia foi de oito horas. Todos os pacientes necessitaram de cirurgias adicionais, sendo as mais comuns o enxerto de pele ou a revisão da fixação óssea. Sucesso do macrorreimplante foi observado em cinco pacientes. O tempo médio de isquemia fria foi maior no grupo com sucesso no macrorreimplante (7,4 horas) quando comparado com o grupo sem sucesso (9 horas). Conclusão: Os macrorreimplantes necessitam de transferência imediata para serviços especializados, e, apesar de a cateterização temporária arterial auxiliar no manejo cirúrgico, a técnica parece não interferir nos resultados. Nível de Evidência IV, Série de Casos.

20.
Insects ; 14(3)2023 Mar 04.
Artigo em Inglês | MEDLINE | ID: mdl-36975940

RESUMO

The red palm weevil (RPW), Rhynchophorus ferrugineus (Coleoptera: Curculionidae), is the most devastating pest of palm trees worldwide. Mitigation of the economic and biodiversity impact it causes is an international priority that could be greatly aided by a better understanding of its biology and genetics. Despite its relevance, the biology of the RPW remains poorly understood, and research on management strategies often focuses on outdated empirical methods that produce sub-optimal results. With the development of omics approaches in genetic research, new avenues for pest control are becoming increasingly feasible. For example, genetic engineering approaches become available once a species's target genes are well characterized in terms of their sequence, but also population variability, epistatic interactions, and more. In the last few years alone, there have been major advances in omics studies of the RPW. Multiple draft genomes are currently available, along with short and long-read transcriptomes, and metagenomes, which have facilitated the identification of genes of interest to the RPW scientific community. This review describes omics approaches previously applied to RPW research, highlights findings that could be impactful for pest management, and emphasizes future opportunities and challenges in this area of research.

SELEÇÃO DE REFERÊNCIAS
Detalhe da pesquisa