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1.
Evol Appl ; 17(7): e13739, 2024 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-38948538

RESUMO

The Seychelles magpie-robin's (SMR) five island populations exhibit some of the lowest recorded levels of genetic diversity among endangered birds, and high levels of inbreeding. These populations collapsed during the 20th century, and the species was listed as Critically Endangered in the IUCN Red List in 1994. An assisted translocation-for-recovery program initiated in the 1990s increased the number of mature individuals, resulting in its downlisting to Endangered in 2005. Here, we explore the temporal genomic erosion of the SMR based on a dataset of 201 re-sequenced whole genomes that span the past ~150 years. Our sample set includes individuals that predate the bottleneck by up to 100 years, as well as individuals from contemporary populations established during the species recovery program. Despite the SMR's recent demographic recovery, our data reveal a marked increase in both the genetic load and realized load in the extant populations when compared to the historical samples. Conservation management may have reduced the intensity of selection by increasing juvenile survival and relaxing intraspecific competition between individuals, resulting in the accumulation of loss-of-function mutations (i.e. severely deleterious variants) in the rapidly recovering population. In addition, we found a 3-fold decrease in genetic diversity between temporal samples. While the low genetic diversity in modern populations may limit the species' adaptability to future environmental changes, future conservation efforts (including IUCN assessments) may also need to assess the threats posed by their high genetic load. Our computer simulations highlight the value of translocations for genetic rescue and show how this could halt genomic erosion in threatened species such as the SMR.

2.
Cell Rep Methods ; 4(7): 100820, 2024 Jul 15.
Artigo em Inglês | MEDLINE | ID: mdl-38986611

RESUMO

Holo-omics refers to the joint study of non-targeted molecular data layers from host-microbiota systems or holobionts, which is increasingly employed to disentangle the complex interactions between the elements that compose them. We navigate through the generation, analysis, and integration of omics data, focusing on the commonalities and main differences to generate and analyze the various types of omics, with a special focus on optimizing data generation and integration. We advocate for careful generation and distillation of data, followed by independent exploration and analyses of the single omic layers to obtain a better understanding of the study system, before the integration of multiple omic layers in a final model is attempted. We highlight critical decision points to achieve this aim and flag the main challenges to address complex biological questions regarding the integrative study of host-microbiota relationships.


Assuntos
Microbiota , Humanos , Metabolômica , Genômica , Proteômica/métodos , Biologia Computacional/métodos , Animais , Interações entre Hospedeiro e Microrganismos/genética
3.
Artigo em Inglês | MEDLINE | ID: mdl-38896155

RESUMO

AIMS: This systematic review aims to summarize the findings of empirical studies conducted in low- and middle-income countries (LMICs) examining the relationship between postpartum depression and anxiety, and child developmental outcomes measured at 24 months of child's age. METHODS: The study was performed as per PRISMA guidelines for a systematic review. EBESCO, ProQuest, PubMed, Science Direct, Google Scholar, and BMJ databases were examined, along with a forward and backward examination of the citations published. The New Ottawa scales (NOS) was used to assess the quality of the studies. The findings of the studies were integrated using a narrative synthesis approach. RESULTS: The systematic review revealed that there are 14 studies examining the impact of postpartum depression (n=14) and postpartum anxiety (n=2) across different domains of child development in LMICs. Studies varied regarding the severity and duration of maternal depression, the context and nature of evaluation, and motherinfant characteristics which are important to understand the association between postpartum depression and anxiety and infant development. Maternal depression is negatively associated with language development, socio-emotional and behavioural development while its association with motor and cognitive development is inconsistent. The impact of maternal anxiety on infant development was examined in two studies, and both have identified a negative association. However, the results of the current review need to be interpreted within the scope and limitations of the methodologies adopted by each study details of which are elaborated in the manuscript. CONCLUSION: Postpartum depression and anxiety can have a wide range of effects on child development. Therefore, periodic infant developmental assessments should become part of routine psychiatric evaluation. There is a need for uniform guidelines for conducting studies and reporting data related to postpartum mental health and child development.

4.
Cell ; 187(14): 3531-3540.e13, 2024 Jul 11.
Artigo em Inglês | MEDLINE | ID: mdl-38942016

RESUMO

A number of species have recently recovered from near-extinction. Although these species have avoided the immediate extinction threat, their long-term viability remains precarious due to the potential genetic consequences of population declines, which are poorly understood on a timescale beyond a few generations. Woolly mammoths (Mammuthus primigenius) became isolated on Wrangel Island around 10,000 years ago and persisted for over 200 generations before becoming extinct around 4,000 years ago. To study the evolutionary processes leading up to the mammoths' extinction, we analyzed 21 Siberian woolly mammoth genomes. Our results show that the population recovered quickly from a severe bottleneck and remained demographically stable during the ensuing six millennia. We find that mildly deleterious mutations gradually accumulated, whereas highly deleterious mutations were purged, suggesting ongoing inbreeding depression that lasted for hundreds of generations. The time-lag between demographic and genetic recovery has wide-ranging implications for conservation management of recently bottlenecked populations.


Assuntos
Extinção Biológica , Genoma , Mamutes , Mutação , Animais , Mamutes/genética , Genoma/genética , Sibéria , Filogenia , Evolução Molecular , Fatores de Tempo
5.
Food Res Int ; 187: 114358, 2024 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-38763642

RESUMO

One third of the food produced for human consumption is currently lost or wasted. Insects have a high potential for converting organic waste- and by-products into food and feed for a growing human population due to symbiosis with microorganisms. These symbioses provide an untapped reservoir of functional microbiomes that can be used to improve industrial insect production but are poorly studied in most insect species. Here we review the most current understanding and challenges of valorizing organic waste- and by-products through insects and their microbiomes for food and feed, and emerging novel food technologies that can be used to investigate and manipulate host(insects)-microbiome interactions. We further construct a holistic framework, by integration of novel food technologies including holo-omics, genome editing, breeding, phage therapy, and administration of prebiotics and probiotics to investigate and manipulate host(insects)-microbiome interactions, and solutions for achieving stakeholder acceptance of novel food technologies for a sustainable food production.


Assuntos
Insetos , Microbiota , Animais , Insetos/microbiologia , Ração Animal/microbiologia , Humanos , Tecnologia de Alimentos , Resíduos , Simbiose , Probióticos , Prebióticos
6.
Nature ; 629(8013): 851-860, 2024 May.
Artigo em Inglês | MEDLINE | ID: mdl-38560995

RESUMO

Despite tremendous efforts in the past decades, relationships among main avian lineages remain heavily debated without a clear resolution. Discrepancies have been attributed to diversity of species sampled, phylogenetic method and the choice of genomic regions1-3. Here we address these issues by analysing the genomes of 363 bird species4 (218 taxonomic families, 92% of total). Using intergenic regions and coalescent methods, we present a well-supported tree but also a marked degree of discordance. The tree confirms that Neoaves experienced rapid radiation at or near the Cretaceous-Palaeogene boundary. Sufficient loci rather than extensive taxon sampling were more effective in resolving difficult nodes. Remaining recalcitrant nodes involve species that are a challenge to model due to either extreme DNA composition, variable substitution rates, incomplete lineage sorting or complex evolutionary events such as ancient hybridization. Assessment of the effects of different genomic partitions showed high heterogeneity across the genome. We discovered sharp increases in effective population size, substitution rates and relative brain size following the Cretaceous-Palaeogene extinction event, supporting the hypothesis that emerging ecological opportunities catalysed the diversification of modern birds. The resulting phylogenetic estimate offers fresh insights into the rapid radiation of modern birds and provides a taxon-rich backbone tree for future comparative studies.


Assuntos
Aves , Evolução Molecular , Genoma , Filogenia , Animais , Aves/genética , Aves/classificação , Aves/anatomia & histologia , Encéfalo/anatomia & histologia , Extinção Biológica , Genoma/genética , Genômica , Densidade Demográfica , Masculino , Feminino
7.
8.
Curr Biol ; 34(5): 1142-1147.e6, 2024 03 11.
Artigo em Inglês | MEDLINE | ID: mdl-38350445

RESUMO

Directly observing the chronology and tempo of adaptation in response to ecological change is rarely possible in natural ecosystems. Sedimentary ancient DNA (sedaDNA) has been shown to be a tractable source of genome-scale data of long-dead organisms1,2,3 and to thereby potentially provide an understanding of the evolutionary histories of past populations.4,5 To date, time series of ecosystem biodiversity have been reconstructed from sedaDNA, typically using DNA metabarcoding or shotgun sequence data generated from less than 1 g of sediment.6,7 Here, we maximize sequence coverage by extracting DNA from ∼50× more sediment per sample than the majority of previous studies1,2,3 to achieve genotype resolution. From a time series of Late Pleistocene sediments spanning from a marine to freshwater ecosystem, we compare adaptive genotypes reconstructed from the environmental genomes of three-spined stickleback at key time points of this transition. We find a staggered temporal dynamic in which freshwater alleles at known loci of large effect in marine-freshwater divergence of three-spined stickleback (e.g., EDA)8 were already established during the brackish phase of the formation of the isolation basin. However, marine alleles were still detected across the majority of marine-freshwater divergence-associated loci, even after the complete isolation of the lake from marine ingression. Our retrospective approach to studying adaptation from environmental genomes of three-spined sticklebacks at the end of the last glacial period complements contemporary experimental approaches9,10,11 and highlights the untapped potential for retrospective "evolve and resequence" natural experiments using sedaDNA.


Assuntos
Ecossistema , Smegmamorpha , Animais , Adaptação Fisiológica/genética , Smegmamorpha/genética , Estudos Retrospectivos , Lagos
9.
mSystems ; 9(2): e0104323, 2024 Feb 20.
Artigo em Inglês | MEDLINE | ID: mdl-38294254

RESUMO

Animals and their associated microbiota share long evolutionary histories. However, it is not always clear how host genotype and microbiota interact to affect phenotype. We applied a hologenomic approach to explore how host-microbiota interactions shape lifetime growth and parasite infection in farmed Atlantic salmon (Salmo salar). Multi-omics data sets were generated from the guts of 460 salmon, 82% of which were naturally infected with an intestinal cestode. A single Mycoplasma bacterial strain, MAG01, dominated the gut metagenome of large, non-parasitized fish, consistent with previous studies showing high levels of Mycoplasma in the gut microbiota of healthy salmon. While small and/or parasitized salmon also had high abundance of MAG01, we observed increased alpha diversity in these individuals, driven by increased frequency of low-abundance Vibrionaceae and other Mycoplasma species that carried known virulence genes. Colonization by one of these cestode-associated Mycoplasma strains was associated with host individual genomic variation in long non-coding RNAs. Integrating the multi-omic data sets revealed coordinated changes in the salmon gut mRNA transcriptome and metabolome that correlated with shifts in the microbiota of smaller, parasitized fish. Our results suggest that the gut microbiota of small and/or parasitized fish is in a state of dysbiosis that partly depends on the host genotype, highlighting the value of using a hologenomic approach to incorporate the microbiota into the study of host-parasite dynamics.IMPORTANCEStudying host-microbiota interactions through the perspective of the hologenome is gaining interest across all life sciences. Intestinal parasite infections are a huge burden on human and animal health; however, there are few studies investigating the role of the hologenome during parasite infections. We address this gap in the largest multi-omics fish microbiota study to date using natural cestode infection of farmed Atlantic salmon. We find a clear association between cestode infection, salmon lifetime growth, and perturbation of the salmon gut microbiota. Furthermore, we provide the first evidence that the genetic background of the host may partly determine how the gut microbiota changes during parasite-associated dysbiosis. Our study therefore highlights the value of a hologenomic approach for gaining a more in-depth understanding of parasitism.


Assuntos
Infecções por Cestoides , Microbioma Gastrointestinal , Doenças Parasitárias , Salmo salar , Humanos , Animais , Microbioma Gastrointestinal/genética , Aquicultura , Disbiose/veterinária
10.
Am J Epidemiol ; 193(1): 214-226, 2024 Jan 08.
Artigo em Inglês | MEDLINE | ID: mdl-37667811

RESUMO

Postnatal mental health is often assessed using self-assessment questionnaires in epidemiologic research. Differences in response style, influenced by language, culture, and experience, may mean that the same response may not have the same meaning in different settings. These differences need to be identified and accounted for in cross-cultural comparisons. Here we describe the development and application of anchoring vignettes to investigate the cross-cultural functioning of the Edinburgh Postnatal Depression Scale (EPDS) in urban community samples in India (n = 549) and the United Kingdom (n = 828), alongside a UK calibration sample (n = 226). Participants completed the EPDS and anchoring vignettes when their children were 12-24 months old. In an unadjusted item-response theory model, UK mothers reported higher depressive symptoms than Indian mothers (d = 0.48, 95% confidence interval: 0.358, 0.599). Following adjustment for differences in response style, these positions were reversed (d = -0.25, 95% confidence interval: -0.391, -0.103). Response styles vary between India and the United Kingdom, indicating a need to take these differences into account when making cross-cultural comparisons. Anchoring vignettes offer a valid and feasible method for global data harmonization.


Assuntos
Depressão Pós-Parto , Feminino , Criança , Humanos , Lactente , Pré-Escolar , Depressão Pós-Parto/diagnóstico , Depressão Pós-Parto/psicologia , Mães/psicologia , Reino Unido , Inquéritos e Questionários , Saúde Mental , Escalas de Graduação Psiquiátrica
11.
Clin Child Psychol Psychiatry ; 29(2): 424-438, 2024 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-37233024

RESUMO

BACKGROUND: Literature has emphasized the role of biopsychosocial factors in internalizing disorders; however, the role of developmental competencies of a child have not been explored much in this context. The current study aimed to understand the differences in developmental competencies, temperament, parenting practices and psychosocial adversities between children with and without internalizing disorders. METHOD: The sample consisted of 200 children and adolescents aged seven to 18 years, with equal number of those with and without an internalizing disorder; and one of their parents. Psychopathology, temperament, interpersonal competence, emotion regulation, executive function, self-concept, adaptive behaviour, parenting practices, life events, family environment and abnormal psychosocial situations were measured using standardized tools. FINDINGS: Discriminant analysis revealed that temperamental domains of sociability and rhythmicity, developmental competencies of adaptive behaviour and self-concept, parenting practices involving father's involvement and overall positive parenting differentiated the clinical and control groups better. Among psychosocial adversities, family environment domains of cohesion and organization, and subjective stress from life events and abnormal psychosocial situations were the most important discriminators. CONCLUSION: The current study reveals that specific individual factors involving temperament and developmental competencies and environmental factors involving parenting practices and psychosocial adversities are significantly associated with internalizing disorders. This has implications for the mental health care of children and adolescents with internalizing disorders.


Assuntos
Regulação Emocional , Poder Familiar , Criança , Humanos , Adolescente , Adaptação Psicológica , Função Executiva , Pais
12.
Clin Child Psychol Psychiatry ; 29(2): 526-539, 2024 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-37807910

RESUMO

OBJECTIVE: Impairments in episodic future thinking and anticipatory pleasure were noted to explain the depressive symptoms in adults however similar studies are not there in adolescents. This study examined whether there are impairments in episodic future thinking and anticipatory pleasure in clinically-depressed adolescents as compared to non-depressed adolescents, and their association with depression when controlled for executive functions and anxiety symptoms among the depressed adolescents. METHODS: The study included 29 adolescents with major depression and 29 adolescents from local schools through convenient sampling technique. All the participants were assessed with standardized measures of depression and anxiety, episodic future thinking, anticipatory pleasure and executive functioning. RESULTS: Depressed adolescents significantly differed from the non-depressed adolescents in autobiographical memory specificity, anticipatory pleasure, and specific dimensions of executive functions. The ANCOVAs indicated executive function slightly attenuated group differences on future specificity which were still non-significant (all p's > .05). For memory specificity and for anticipatory pleasure, group differences were still significant at p < .05 level. CONCLUSION: Adolescents with major depressive episode may display similar, but less pronounced, impairments in future thinking than what is previously reported in adults. Though, autobiographical specificity is prominent. The deficits are attributable to depression than executive functioning deficits.


Assuntos
Transtorno Depressivo Maior , Memória Episódica , Adulto , Humanos , Adolescente , Função Executiva , Depressão , Prazer
13.
Food Microbiol ; 117: 104372, 2024 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-37919016

RESUMO

Interest in fermented foods, especially plant-based ones, has increased considerably in the last decade. Miso-a Japanese paste traditionally fermented with soybeans, salt, and koji (Aspergillus oryzae grown on grains or beans)-has gained attention among chefs for its rich flavour and versatility. Some chefs have even been experimenting with making novel misos with untraditional substrates to create new flavours. Such novel fermented foods also offer new scientific opportunities. To explore the microbial diversity of these new traditional foods, we sampled six misos made by the team at a leading restaurant called Noma in Copenhagen (Denmark), using yellow peas (including a nixtamalised treatment), lupin seeds, Swedish Vreta peas, grey peas, and Gotland lentils as substrates. All misos were made with the same recipe and fermented for 3 months at 28 °C. Samples were collected at the end of fermentation for subsequent shotgun metagenomic sequencing and a genome-resolved metagenomic analysis. The taxonomic profile of the samples revealed the presence of koji mould (A. oryzae) and Bacillus amyloliquefaciens in all misos. Various species of the genera Latilactobacillus, Lactiplantibacillus, Pediococcus and Staphylococcus were also detected. The Metagenome-Assembled Genomes (MAGs) revealed genomic sequences belonging to 12 different species and functional analyses of these MAGs were performed. Notably, we detected the presence of Exiguobacterium-the first reported instance of the genus in miso-and Average Nucleotide Identity (ANI) analyses suggest a potentially new species. We hope these results will improve the scientific literature on misos and contribute to developing novel fermented plant-based foods.


Assuntos
Fabaceae , Alimentos Fermentados , Alimentos de Soja , Glycine max , Metagenômica , Aromatizantes/análise , Fermentação
14.
BMC Psychiatry ; 23(1): 829, 2023 11 13.
Artigo em Inglês | MEDLINE | ID: mdl-37957589

RESUMO

BACKGROUND: Mental health conditions are common during pregnancy and the first year after childbirth. Early detection allows timely support and treatment to be offered, but identifying perinatal mental health conditions may be challenging due to stigma and under-recognition of symptoms. Asking about symptoms of mental health conditions during routine antenatal and postnatal appointments can help to identify women at risk. This study explores women's awareness of perinatal mental health conditions, their views on the acceptability of being asked about mental health and any preference for specific assessment tools in two regions in India. METHODS: Focus group discussions (FGDs) were conducted with pregnant, post-partum and non-perinatal women in Kangra, Himachal Pradesh (northern India) and Bengaluru, Karnataka (southern India). Settings included a hospital antenatal clinic and obstetric ward, Anganwadi Centres and Primary Health Centres. FGDs were facilitated, audio-recorded and transcribed. Narratives were coded for emerging themes and analysed using thematic analysis. RESULTS: Seven FGDs including 36 participants were conducted. Emerging themes were: manifestations of and contributors to mental health conditions; challenges in talking about mental health; and the acceptability of being asked about mental health. Difficult familial relationships, prioritising the needs of others and pressure to have a male infant were cited as key stressors. Being asked about mental health was generally reported to be acceptable, though some women felt uncomfortable with questions about suicidality. No preference for any specific assessment tool was reported. CONCLUSIONS: Women face many stressors during the perinatal period including difficult familial relationships and societal pressure to bear a male infant. Being asked about mental health was generally considered to be acceptable, but questions relating to suicidality may be challenging in a community setting, requiring sensitivity by the interviewer. Future studies should assess the acceptability of mental health assessments in 'real world' antenatal and postnatal clinics and explore ways of overcoming the associated challenges in resource-constrained settings.


Assuntos
Transtornos Mentais , Saúde Mental , Feminino , Gravidez , Masculino , Humanos , Índia , Transtornos Mentais/psicologia , Pesquisa Qualitativa , Parto
15.
Mol Biol Evol ; 40(11)2023 Nov 03.
Artigo em Inglês | MEDLINE | ID: mdl-37950889

RESUMO

The domestic pigeon's exceptional phenotypic diversity was key in developing Darwin's Theory of Evolution and establishing the concept of artificial selection. However, unlike its domestic counterpart, its wild progenitor, the rock dove Columba livia has received considerably less attention. Therefore, questions regarding its domestication, evolution, taxonomy, and conservation status remain unresolved. We generated whole-genome sequencing data from 65 historical rock doves that represent all currently recognized subspecies and span the species' original geographic distribution. Our dataset includes 3 specimens from Darwin's collection, and the type specimens of 5 different taxa. We characterized their population structure, genomic diversity, and gene-flow patterns. Our results show the West African subspecies C. l. gymnocyclus is basal to rock doves and domestic pigeons, and suggests gene-flow between the rock dove's sister species C. rupestris, and the ancestor of rock doves after its split from West African populations. These genomes allowed us to propose a model for the evolution of the rock dove in light of the refugia theory. We propose that rock dove genetic diversity and introgression patterns derive from a history of allopatric cycles and dispersion waves during the Quaternary glacial and interglacial periods. To explore the rock dove domestication history, we combined our new dataset with available genomes from domestic pigeons. Our results point to at least 1 domestication event in the Levant that gave rise to all domestic breeds analysed in this study. Finally, we propose a species-level taxonomic arrangement to reflect the evolutionary history of the West African rock dove populations.


Assuntos
Columbidae , Genoma , Animais , Columbidae/genética
16.
Sci Rep ; 13(1): 18973, 2023 11 03.
Artigo em Inglês | MEDLINE | ID: mdl-37923927

RESUMO

It is important for allocation of resources to predict those COVID patients at high risk of dying or organ failure. Early signals to initiate cellular events of host immunity can be derived from essential fatty acid metabolites preceding the cascade of proinflammatory signals. Much research has focused on understanding later proinflammatory responses. We assessed if remodelling of plasma phospholipid content of essential fatty acids by the COVID-19 virus provides early markers for potential death and disease severity. Here we show that, at hospital admission, COVID-19 infected subjects who survive exhibit higher proportions of C20:4n-6 in plasma phospholipids concurrent with marked proinflammatory cytokine elevation in plasma compared to healthy subjects. In contrast, more than half of subjects who die of this virus exhibit very low C18:2n-6 and C20:4n-6 content in plasma phospholipids on hospital admission compared with healthy control subjects. Moreover, in these subjects who die, the low level of primary inflammatory signals indicates limited or aberrant stimulation of host immunity. We conclude that COVID-19 infection results in early fundamental remodelling of essential fatty acid metabolism. In subjects with high mortality, it appears that plasma n-6 fatty acid content is too low to stimulate cellular events of host immunity.


Assuntos
COVID-19 , Ácidos Graxos Insaturados , Humanos , Ácidos Graxos Insaturados/metabolismo , Ácidos Graxos , Fosfolipídeos , Ácidos Graxos Essenciais , Gravidade do Paciente , Hospitais
17.
BMC Biol ; 21(1): 267, 2023 11 22.
Artigo em Inglês | MEDLINE | ID: mdl-37993882

RESUMO

BACKGROUND: The red junglefowl, the wild outgroup of domestic chickens, has historically served as a reference for genomic studies of domestic chickens. These studies have provided insight into the etiology of traits of commercial importance. However, the use of a single reference genome does not capture diversity present among modern breeds, many of which have accumulated molecular changes due to drift and selection. While reference-based resequencing is well-suited to cataloging simple variants such as single-nucleotide changes and short insertions and deletions, it is mostly inadequate to discover more complex structural variation in the genome. METHODS: We present a pangenome for the domestic chicken consisting of thirty assemblies of chickens from different breeds and research lines. RESULTS: We demonstrate how this pangenome can be used to catalog structural variants present in modern breeds and untangle complex nested variation. We show that alignment of short reads from 100 diverse wild and domestic chickens to this pangenome reduces reference bias by 38%, which affects downstream genotyping results. This approach also allows for the accurate genotyping of a large and complex pair of structural variants at the K feathering locus using short reads, which would not be possible using a linear reference. CONCLUSIONS: We expect that this new paradigm of genomic reference will allow better pinpointing of exact mutations responsible for specific phenotypes, which will in turn be necessary for breeding chickens that meet new sustainability criteria and are resilient to quickly evolving pathogen threats.


Assuntos
Galinhas , Genoma , Animais , Galinhas/genética , Genótipo , Análise de Sequência de DNA , Genômica
18.
Mol Biol Evol ; 40(12)2023 Dec 01.
Artigo em Inglês | MEDLINE | ID: mdl-37995319

RESUMO

High genetic diversity is a good predictor of long-term population viability, yet some species persevere despite having low genetic diversity. Here we study the genomic erosion of the Seychelles paradise flycatcher (Terpsiphone corvina), a species that narrowly avoided extinction after having declined to 28 individuals in the 1960s. The species recovered unassisted to over 250 individuals in the 1990s and was downlisted from Critically Endangered to Vulnerable in the International Union for the Conservation of Nature Red List in 2020. By comparing historical, prebottleneck (130+ years old) and modern genomes, we uncovered a 10-fold loss of genetic diversity. Highly deleterious mutations were partly purged during the bottleneck, but mildly deleterious mutations accumulated. The genome shows signs of historical inbreeding during the bottleneck in the 1960s, but low levels of recent inbreeding after demographic recovery. Computer simulations suggest that the species long-term small Ne reduced the masked genetic load and made the species more resilient to inbreeding and extinction. However, the reduction in genetic diversity due to the chronically small Ne and the severe bottleneck is likely to have reduced the species adaptive potential to face environmental change, which together with a higher load, compromises its long-term population viability. Thus, small ancestral Ne offers short-term bottleneck resilience but hampers long-term adaptability to environmental shifts. In light of rapid global rates of population decline, our work shows that species can continue to suffer the effect of their decline even after recovery, highlighting the importance of considering genomic erosion and computer modeling in conservation assessments.


Assuntos
Espécies em Perigo de Extinção , Variação Genética , Humanos , Animais , Carga Genética , Endogamia , Aves/genética
20.
Biochemistry ; 62(19): 2841-2853, 2023 10 03.
Artigo em Inglês | MEDLINE | ID: mdl-37695675

RESUMO

In addition to amide hydrogen bonds and the hydrophobic effect, interactions involving π-bonded sp2 atoms of amides, aromatics, and other groups occur in protein self-assembly processes including folding, oligomerization, and condensate formation. These interactions also occur in aqueous solutions of amide and aromatic compounds, where they can be quantified. Previous analysis of thermodynamic coefficients quantifying net-favorable interactions of amide compounds with other amides and aromatics revealed that interactions of amide sp2O with amide sp2N unified atoms (presumably C═O···H-N hydrogen bonds) and amide/aromatic sp2C (lone pair π, n-π*) are particularly favorable. Sp3C-sp3C (hydrophobic), sp3C-sp2C (hydrophobic, CH-π), sp2C-sp2C (hydrophobic, π-π), and sp3C-sp2N interactions are favorable, sp2C-sp2N interactions are neutral, while sp2O-sp2O and sp2N-sp2N self-interactions and sp2O-sp3C interactions are unfavorable. Here, from determinations of favorable effects of 14 amides on naphthalene solubility at 10, 25, and 45 °C, we dissect amide-aromatic interaction free energies into enthalpic and entropic contributions and find these vary systematically with amide composition. Analysis of these results yields enthalpic and entropic contributions to intrinsic strengths of interactions of amide sp2O, sp2N, sp2C, and sp3C unified atoms with aromatic sp2C atoms. For each interaction, enthalpic and entropic contributions have the same sign and are much larger in magnitude than the interaction free energy itself. The amide sp2O-aromatic sp2C interaction is enthalpy-driven and entropically unfavorable, consistent with direct chemical interaction (e.g., lone pair-π), while amide sp3C- and sp2C-aromatic sp2C interactions are entropy-driven and enthalpically unfavorable, consistent with hydrophobic effects. These findings are relevant for interactions involving π-bonded sp2 atoms in protein processes.


Assuntos
Amidas , Água , Amidas/química , Entropia , Água/química , Termodinâmica , Proteínas/química , Naftalenos/química
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