RESUMO
To explore the spatio-temporal dynamics of endangered fin whales (Balaenoptera physalus) within the baleen whale (Mysticeti) lineages, we analyzed 148 published mitochondrial genome sequences of baleen whales. We used a Bayesian coalescent approach as well as Bayesian inferences and maximum likelihood methods. The results showed that the fin whales had a single maternal origin, and that there is a significant correlation between geographic location and evolution of global fin whales. The most recent common female ancestor of this species lived approximately 9.88 million years ago (Mya). Here, North Pacific fin whales first appeared about 7.48 Mya, followed by a subsequent divergence in Southern Hemisphere approximately 6.63 Mya and North Atlantic about 4.42 Mya. Relatively recently, approximately 1.76 and 1.42 Mya, there were two additional occurrences of North Pacific populations; one originated from the Southern Hemisphere and the other from an uncertain location. The evolutionary rate of this species was 1.002 × 10-3 substitutions/site/My. Our Bayesian skyline plot illustrates that the fin whale population has the rapid expansion event since ~ 2.5 Mya, during the Quaternary glaciation stage. Additionally, this study indicates that the fin whale has a sister group relationship with humpback whale (Meganoptera novaeangliae) within the baleen whale lineages. Of the 16 genomic regions, NADH5 showed the most powerful signal for baleen whale phylogenetics. Interestingly, fin whales have 16 species-specific amino acid residues in eight mitochondrial genes: NADH2, COX2, COX3, ATPase6, ATPase8, NADH4, NADH5, and Cytb.
Assuntos
Evolução Biológica , Baleia Comum , Animais , Teorema de Bayes , Espécies em Perigo de Extinção , Feminino , Baleia Comum/classificação , Baleia Comum/genética , Genoma Mitocondrial , Filogenia , FilogeografiaRESUMO
BACKGROUND: Africa is home to numerous cattle breeds whose diversity has been shaped by subtle combinations of human and natural selection. African Sanga cattle are an intermediate type of cattle resulting from interbreeding between Bos taurus and Bos indicus subspecies. Recently, research has asserted the potential of Sanga breeds for commercial beef production with better meat quality as compared to Bos indicus breeds. Here, we identified meat quality related gene regions that are positively selected in Ankole (Sanga) cattle breeds as compared to indicus (Boran, Ogaden, and Kenana) breeds using cross-population (XP-EHH and XP-CLR) statistical methods. RESULTS: We identified 238 (XP-EHH) and 213 (XP-CLR) positively selected genes, of which 97 were detected from both statistics. Among the genes obtained, we primarily reported those involved in different biological process and pathways associated with meat quality traits. Genes (CAPZB, COL9A2, PDGFRA, MAP3K5, ZNF410, and PKM2) involved in muscle structure and metabolism affect meat tenderness. Genes (PLA2G2A, PARK2, ZNF410, MAP2K3, PLCD3, PLCD1, and ROCK1) related to intramuscular fat (IMF) are involved in adipose metabolism and adipogenesis. MB and SLC48A1 affect meat color. In addition, we identified genes (TIMP2, PKM2, PRKG1, MAP3K5, and ATP8A1) related to feeding efficiency. Among the enriched Gene Ontology Biological Process (GO BP) terms, actin cytoskeleton organization, actin filament-based process, and protein ubiquitination are associated with meat tenderness whereas cellular component organization, negative regulation of actin filament depolymerization and negative regulation of protein complex disassembly are involved in adipocyte regulation. The MAPK pathway is responsible for cell proliferation and plays an important role in hyperplastic growth, which has a positive effect on meat tenderness. CONCLUSION: Results revealed several candidate genes positively selected in Ankole cattle in relation to meat quality characteristics. The genes identified are involved in muscle structure and metabolism, and adipose metabolism and adipogenesis. These genes help in the understanding of the biological mechanisms controlling beef quality characteristics in African Ankole cattle. These results provide a basis for further research on the genomic characteristics of Ankole and other Sanga cattle breeds for quality beef.
Assuntos
Cruzamento , Bovinos/genética , Qualidade dos Alimentos , Genômica , Carne Vermelha , Animais , Filogenia , PigmentaçãoRESUMO
The Korean native horse (Jeju horse) is one of the most important animals in Korean historical, cultural, and economical viewpoints. In the early 1980s, the Jeju horse was close to extinction. The aim of this study is to explore the phylogenomics of Korean native horse focusing on spatio-temporal dynamics. We determined complete mitochondrial genome sequences for the first Korean native (n = 6) and additional Mongolian (n = 2) horses. Those sequences were analyzed together with 143 published ones using Bayesian coalescent approach as well as three different phylogenetic analysis methods, Bayesian inference, maximum likelihood, and neighbor-joining methods. The phylogenomic trees revealed that the Korean native horses had multiple origins and clustered together with some horses from four European and one Middle Eastern breeds. Our phylogenomic analyses also supported that there was no apparent association between breed or geographic location and the evolution of global horses. Time of the most recent common ancestor of the Korean native horse was approximately 13,200-63,200 years, which was much younger than 0.696 My of modern horses. Additionally, our results showed that all global horse lineages including Korean native horse existed prior to their domestication events occurred in about 6000-10,000 years ago. This is the first study on phylogenomics of the Korean native horse focusing on spatio-temporal dynamics. Our findings increase our understanding of the domestication history of the Korean native horses, and could provide useful information for horse conservation projects as well as for horse genomics, emergence, and the geographical distribution.
Assuntos
Cavalos/genética , Animais , Teorema de Bayes , Evolução Biológica , Cruzamento , DNA Mitocondrial/genética , Genoma Mitocondrial/genética , Coreia (Geográfico) , Mitocôndrias/genética , Filogenia , Filogeografia/métodos , Análise de Sequência de DNA/métodosRESUMO
BACKGROUND: Whales have captivated the human imagination for millennia. These incredible cetaceans are the only mammals that have adapted to life in the open oceans and have been a source of human food, fuel and tools around the globe. The transition from land to water has led to various aquatic specializations related to hairless skin and ability to regulate their body temperature in cold water. RESULTS: We present four common minke whale (Balaenoptera acutorostrata) genomes with depth of ×13 ~ ×17 coverage and perform resequencing technology without a reference sequence. Our results indicated the time to the most recent common ancestors of common minke whales to be about 2.3574 (95% HPD, 1.1521 - 3.9212) million years ago. Further, we found that genes associated with epilation and tooth-development showed signatures of positive selection, supporting the morphological uniqueness of whales. CONCLUSIONS: This whole-genome sequencing offers a chance to better understand the evolutionary journey of one of the largest mammals on earth.
Assuntos
Evolução Biológica , Genoma , Baleia Anã/classificação , Baleia Anã/genética , Animais , Teorema de Bayes , Golfinhos/classificação , Golfinhos/genética , Golfinhos/metabolismo , Sequenciamento de Nucleotídeos em Larga Escala , Baleia Anã/metabolismo , Filogenia , Análise de Sequência de DNARESUMO
BACKGROUND: Body mass index (BMI) has been used as an indirect predictor for the risk of metabolic syndrome. However, there are challenges in evaluating the risk of metabolic syndrome using BMI in certain parts of the world. Therefore, it is worth exploring additional factors that could supplement BMI to predict the risk of metabolic syndrome. In this study, we assessed the combined effect of BMI and perception for predicting metabolic syndrome. METHODS: We used the fifth Korea National Health and Nutrition Examination Surveys (KNHANES V, 2010-12, N = 16,537) in this study. Multivariable logistic regression analysis was performed to examine the association while controlling for potential confounding variables. We also performed an analysis for the combined effect of BMI and perception of body size, and subgroup analysis by age group or moderate physical activity. RESULTS: Data from 16,537 participants were analyzed in this study (males: 6,978, females: 9,559). Among them, metabolic syndrome was diagnosed in 1,252 (17.9%) males and 2,445 (25.6%) females, respectively. The combination of BMI and body size perception had a positive relation with the presence of metabolic syndrome. People who perceived themselves to be overweight for their body size had a higher risk for metabolic syndrome even if they have the same BMI. CONCLUSION: Our findings suggest that the combination of body size perception and BMI is useful in predicting the risk of metabolic syndrome. The use of complementary predictors could reduce the risk for inaccurate prediction of metabolic syndrome.
Assuntos
Imagem Corporal , Índice de Massa Corporal , Tamanho Corporal , Síndrome Metabólica , Adulto , Idoso , Estudos Transversais , Exercício Físico , Feminino , Humanos , Modelos Logísticos , Masculino , Síndrome Metabólica/diagnóstico , Síndrome Metabólica/epidemiologia , Pessoa de Meia-Idade , Sobrepeso , Percepção , República da Coreia/epidemiologia , Fatores de Risco , Adulto JovemRESUMO
Porcine reproductive and respiratory syndrome virus (PRRSV) has been investigated extensively at the molecular level. Nevertheless, genome wide study on the temporal and spatial dynamics of the virus is non-existed. To explore this topic, we determined complete coding genome sequences for four PRRSV isolates and analyzed them together with 122 global published ones using the Bayesian coalescent approach as well as Bayesian inferences and maximum likelihood methods. All EU-type viruses belonged to one of two groups or were unclassified (5 isolates), and all NA-type isolates were divided into one of three major groups or were unclassified (1 isolate). Here, there was no apparent association between temporal or geographic origin and heterogeneity of global PRRSVs. Of the eight ORFs, ORF1a showed the most powerful evolutionary signal. Our findings also indicated that the PRRS virus evolved at a rate of 1.98 × 10-3 substitutions/site/year, and the most recent common ancestor of the virus existed 786.4 years ago. Here, EU-type viruses segregated 115.7 years ago, while NA-type isolates diverged 179.8 years before the present. In addition, our reconstruction of the effective population size depicted five phases of epidemic growth: an initial constant, followed sequentially by slow decrease, slight increase, sharp decline, and then a rapid expansion approaching the present.
RESUMO
To trace the genetic history of porcine reproductive and respiratory syndrome virus (PRRSV), we determined the complete sequences of ORFs 5 to 7 of four PRRSV isolates. These sequences were analyzed together with published sequences from 146 isolates from various parts of the world using a Bayesian coalescent approach as well as Bayesian inference and maximum-likelihood methods. All of the European-type (EU-type) viruses were classified into one of two groups or unclassified (4 isolates), while all North American-type (NA-type) viruses belonged to one of three major groups or were unclassified (5 isolates). Within each genotype, no apparent periodic and/or geographic influence on the evolution of PRRSVs was observed. The evolutionary rate of PRRSV isolates was estimated to be 1.55 × 10(-3) substitutions/site/year, and the time of the most recent common ancestor (TMRCA) was 491.2 years ago. Here, the TMRCA for the EU- and NA-type viruses was 58.7 and 62.6 years ago, respectively. A Bayesian skyline plot revealed that the viruses evolved at an almost constant population size until the late 1970s, when they experienced a population expansion that continued until the late 1980s. The population size then remained constant again until the early 2000s, when a rapid, sharp decline in the effective number of infections occurred.
Assuntos
Evolução Molecular , Fases de Leitura Aberta , Filogeografia , Vírus da Síndrome Respiratória e Reprodutiva Suína/classificação , Vírus da Síndrome Respiratória e Reprodutiva Suína/genética , Animais , Análise por Conglomerados , Genótipo , Dados de Sequência Molecular , Taxa de Mutação , Síndrome Respiratória e Reprodutiva Suína/virologia , Vírus da Síndrome Respiratória e Reprodutiva Suína/isolamento & purificação , RNA Viral/genética , Análise de Sequência de DNA , SuínosRESUMO
We determined complete 1D gene sequences for one serotype A and seven additional serotype O Korean foot-and-mouth disease viruses (FMDV) and then analyzed them together with published sequences for 180 type A and 300 type O isolates from throughout the world using a Bayesian coalescent approach. Here, Korean serotype A virus was linked with those from Laos. Korean serotype O viruses were divided into three clades and were closely related to isolates from Japan, Thailand, the UK, France, Ireland, South Africa, and Singapore, as well as Laos. There was no apparent correlation between time, country, or host species and the evolution of global FMDVs. Additionally, our results showed that purifying selection acts on the overall 1D sequences and there was no evidence of recombination among the FMDV sequences. The evolutionary rates were 5.77 × 10(-3) substitutions/site/year for serotype A and 4.81 × 10(-3) substitutions/site/year for serotype O. Serotype A viruses diverged approximately 110 years ago, while serotype O isolates segregated approximately 127 years before the present. In both serotype isolates, the effective number of infections remained constant until the late 1990 s, after which the virus population size underwent a rapid, sharp decline until the present.
Assuntos
Doenças dos Bovinos/virologia , Vírus da Febre Aftosa/classificação , Vírus da Febre Aftosa/genética , Febre Aftosa/virologia , Doenças dos Suínos/virologia , Animais , Proteínas do Capsídeo/genética , Bovinos , Doenças dos Bovinos/epidemiologia , Análise por Conglomerados , Evolução Molecular , Febre Aftosa/epidemiologia , Vírus da Febre Aftosa/isolamento & purificação , Genótipo , Epidemiologia Molecular , Dados de Sequência Molecular , Filogeografia , República da Coreia/epidemiologia , Seleção Genética , Análise de Sequência de DNA , Suínos , Doenças dos Suínos/epidemiologia , Fatores de TempoRESUMO
The purpose of this study was to examine the urban-rural differences in the prevalence and associated factors with type 2 diabetes mellitus (T2DM) in Korean adults. A total of 1,060 adults >30 yr of age from urban (189 males and 331 females) and rural districts (219 males and 321 females) were recruited. Anthropometric measures, blood pressure, lipid profiles, and fasting and 2-hr after 75-g oral glucose load blood glucose were obtained. The crude- and age-standardized prevalence of T2DM was 15.4% and 14.5%, and 11.7% and 8.6% in urban and rural districts, respectively. Diabetic subjects were older and obese, and had a higher triglyceride level, and systolic blood pressure compared to non-diabetes in both population. Multivariate regression analysis revealed that older age, high triglyceride levels, central obesity, and hypertension were significantly associated with T2DM in both areas. Low monthly incomes were significantly associated with T2DM in urban population, while a family history of T2DM was significantly associated with T2DM in rural area. T2DM is more prevalent in urban than in rural population, and low economic status or genetic factor is differently associated with T2DM in both population, respectively.
Assuntos
Diabetes Mellitus Tipo 2/epidemiologia , Adulto , Fatores Etários , Idoso , Diabetes Mellitus Tipo 2/complicações , Feminino , Humanos , Hipertensão/complicações , Masculino , Pessoa de Meia-Idade , Obesidade/complicações , Prevalência , Análise de Regressão , República da Coreia/epidemiologia , Fatores de Risco , População Rural , Fatores Socioeconômicos , Triglicerídeos/sangue , População UrbanaRESUMO
A Bayesian approach was utilized to further investigate the molecular phylogeny of canine parvovirus 2 (CPV-2) with emphasis on Korean isolates, and the complete VP2 gene sequences for 23 Korean isolates in 2007 and two vaccine strains were determined. Of the 44 Korean CPVs, 40 were identified as CPV-2a, three as CPV-2b, and the remaining one as a CPV-2a variant having a Gly300Asp mutation. Compared with CPV-2a, our findings also showed the presence of six additional amino acid substitutions (Thr440Ala, Ile418Thr, Pro435Ser, Asp413Asn, Thr322Ser, and Tyr324Ile) within the VP2 gene of the Korean isolates. In the phylogenetic tree, the overall Korean CPVs did not emerge as an independent clade within the global CPVs, nor did they show a close relationship to the CPVs from any other country. Our VP2 sequence data also revealed no geographic influence on the spread of CPVs worldwide. dN/dS analysis showed that purifying selection is acting on the VP2 gene of Korean CPVs.
Assuntos
Doenças do Cão/virologia , Infecções por Parvoviridae/veterinária , Parvovirus Canino/classificação , Substituição de Aminoácidos , Animais , Teorema de Bayes , Cães , Coreia (Geográfico) , Dados de Sequência Molecular , Infecções por Parvoviridae/virologia , Parvovirus Canino/genética , Filogenia , Proteínas Estruturais Virais/genéticaRESUMO
Twenty-four genomic segments of Cotesia plutellae bracovirus (CpBV) were completely sequenced, and their genomic structures were analyzed. The aggregated genome size is 351,299 bp long and exhibits an average GC content of approximately 34.6%. Average coding density is about 32.3%, and 125 putative open reading frames (ORFs) are predicted. More than half (52.5%) of predicted genes are annotated as hypothetical, but they share sequence similarities with those of other bracoviral genomes. The annotated ORFs can be classified into the known bracoviral families, in which a family of protein tyrosine phosphatase is the largest, including 36 ORFs, suggesting a significant role during parasitization. In addition, 8 and 7 ORFs encode ankyrin-like and EP1-like genes, respectively. Some predicted genes are known only in Cotesia-associated bracoviral genomes. Phylogenetic analyses based on PTP, ankyrin and EP1-like gene groups revealed no correlation between bracoviruses.
Assuntos
Ordem dos Genes , Genoma Viral , Himenópteros/virologia , Polydnaviridae/genética , Animais , Anquirinas/genética , Sequência de Bases , Genes Virais , Glicoproteínas/genética , Dados de Sequência Molecular , Fases de Leitura Aberta/genética , Proteínas Tirosina Fosfatases/genética , Proteínas Virais/genéticaRESUMO
Serum samples from 3315 pigs from 363 farms located throughout all nine Korean provinces were tested for the presence of encephalomyocarditis virus (EMCV) antibodies using the virus neutralization test. The seroprevalence of EMCV in the total pig population was 9.1%, whereas in the herd the prevalence was 43.5%. The first two EMCVs isolated were K3 and K11; these strains were isolated in 1990 from a mummy and a stillborn fetus, respectively, suspected of having EMCV. Phylogenetic analyses of the capsid coding region and the VP3/VP1 genes using the Bayesian approach, and a neighbor-joining analysis, revealed that the EMCV strains fell into two clusters: groups 1 and 2, with two sub-clusters within group 1, group 1a and 1b. The Korean isolates belonged to the group 1a cluster, along with strains BJC3 (China), B424/90 (Greece) and BEL-2887A/91 (Belgium), whereas five strains isolated from Sus scrofa in Belgium (B279/95, B440/95), Italy (I001/96, I136/86), and Cyprus (C108/95) belonged to the group 2 cluster.
Assuntos
Infecções por Cardiovirus/veterinária , Vírus da Encefalomiocardite/isolamento & purificação , Filogenia , Doenças dos Suínos/epidemiologia , Animais , Anticorpos Antivirais/sangue , Infecções por Cardiovirus/epidemiologia , Infecções por Cardiovirus/virologia , Vírus da Encefalomiocardite/genética , Variação Genética , Genoma Viral , Coreia (Geográfico)/epidemiologia , Estudos Soroepidemiológicos , SuínosRESUMO
PURPOSE: This study aimed to develop a scale measuring the Patient-Centered Nursing Culture (PCNC) and provide a basic tool to improve PCNC in Korea. METHODS: A conceptual framework and construct factors were extracted through extensive literature review and in-depth interviews with nursing professionals. In total, 59 items were derived based on the pilot survey. Data were collected from 357 nurses working at general hospitals and analyzed for verifying the reliability and validity of the scale. RESULTS: Nine factors containing 54 items were extracted from the exploratory factor analysis to verify the construct validity. The nine factors were top management leadership, policy and procedure, education and training, middle management leadership, supportive teamwork, nursing workplace environment, professional competence, patient-centered nursing activity, and nurses' values. These items were verified by convergent, discriminant, and concurrent validity testing. The internal consistency reliability was acceptable (Cronbach's α=.96). CONCLUSION: The developed PCNC scale is expected to be used as the tool for the development of theory and improvement of PCNC, the empirical testing for cause and effect of PCNC, the development of interventions, education and training programs for improving PCNC, and indicators for evaluation or accreditation of hospital service quality.
Assuntos
Assistência Centrada no Paciente , Desenvolvimento de Programas , Adulto , Feminino , Administração Hospitalar , Humanos , Liderança , Masculino , Papel do Profissional de Enfermagem , Recursos Humanos de Enfermagem Hospitalar/psicologia , Competência Profissional , Inquéritos e Questionários , Local de TrabalhoRESUMO
BACKGROUND: Although self-directed learning (SDL) has become an essential instrument for educating nursing professionals, little is known about SDL among nurses in a developing country. METHOD: Data were collected using a structured self-reporting survey, which included Fisher's Self-Directed Learning Readiness (SDLR) scale, and a multiple linear regression analysis was conducted. RESULTS: The mean score per item on the SDLR was 4.31 of 5. The learning-related factors that influenced SDLR were motivation for learning and self-efficacy in English proficiency, and the working-related factor was job satisfaction. These variables accounted for 17.6% of the variance in SDLR scores. CONCLUSION: The SDLR of nurse learners in Sri Lanka was influenced not only by learning-related factors but also by working-related factors. Therefore, it is necessary to develop multidimensional strategies to strengthen nurses' SDLR. [J Contin Educ Nurs. 2019;50(1):41-48.].
Assuntos
Países em Desenvolvimento/estatística & dados numéricos , Bacharelado em Enfermagem/métodos , Autoaprendizagem como Assunto , Estudantes de Enfermagem/psicologia , Estudantes de Enfermagem/estatística & dados numéricos , Adulto , Estudos Transversais , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Sri LankaRESUMO
We sequenced the hemagglutinin (H) genes from four canine distemper virus (CDV) isolates obtained from three dogs and a marten in Korea. These sequences were included in subsequent H gene-focused phylogenetic tree analysis of 89 CDV strains. This analysis revealed eight clades designated as EU1, EU2, EU3, NA1, NA2, Asia 1, Asia 2 and Vaccine. Three of the Korean isolates (97Jindo, 98Marten and 07D111) occurred in the Asia 2 group that also contains many Japanese CDV strains isolated in 1998. The remaining Korean strain (07Q72) fell into the Asia 1 group. The 21 H protein sequences of 25 Asia 1 strains are generally predicted to bear nine potential N-linked glycosylation sites. In contrast, the 9 H protein sequences of 12 Asia 2 strains had eight potential N-linked glycosylation sites. The remaining strains had six (98Marten and 07D111) and seven (97Jindo) potential N-linked glycosylation sites.
Assuntos
Vírus da Cinomose Canina/genética , Cinomose/virologia , Mustelidae/virologia , Animais , Cinomose/epidemiologia , Cães , Feminino , Variação Genética , Coreia (Geográfico)/epidemiologia , Masculino , FilogeniaRESUMO
PURPOSE: This study aimed to develop a Group REBT program with group counseling for nurses and test the effect of group counseling on their job stress, burnout, job satisfaction, organizational commitment, and turnover intention. METHODS: A quasi-experimental study with nonequivalent control group design was employed to identify the effect of the Group REBT program on nurses' job stress, burnout, job satisfaction, organizational commitment, and turnover intention. Data were collected from 47 participants from two hospitals. The data from the experimental (n=23) and control (n=24) groups were analyzed from January 5 to April 3, 2015. The Group REBT program was conducted eight tmes in all, once a week, with each session lasting 180 minutes. The effect of experimental intervention was measured for each group using a series of structured questionnaires at each of the phases: Pre-intervention, post-intervention (immediately after intervention), and post-intervention (four weeks after intervention). Following this, the significance of the changes in the scores was tested. RESULTS: The scores of the experimental group, which received the Group REBT program, were compared with those of the control group; the hypotheses were supported in terms of job stress (F=8.85, p<.001), burnout (F=5.62, p=.022), job satisfaction (F=2.70, p=.042), organizational commitment (F=2.97, p=.048), and turnover intention (F=4.60, p=.012). CONCLUSION: The Group REBT program was shown to be an effective intervention that could reduce nurses' job stress and burnout and increase job satisfaction and organizational commitment. Therefore, the Group REBT program can be adopted by nursing organizations to strategically decrease nurses' turnover intention.
Assuntos
Terapia Comportamental/métodos , Recursos Humanos de Enfermagem Hospitalar/psicologia , Desenvolvimento de Programas , Avaliação de Programas e Projetos de Saúde , Adulto , Esgotamento Profissional , Feminino , Humanos , Satisfação no Emprego , Masculino , Estresse Ocupacional , Cultura Organizacional , Reorganização de Recursos Humanos , Adulto JovemRESUMO
Recent comparative genomics studies have suggested that horizontal gene transfer (HGT) is one of the major processes in bacterial evolution. In this study, HGT events of 64 Chlamydia strains were investigated based on the pipeline employed in HGTree database constructed in our recent study. Tree reconciliation method was applied in order to calculate feasible HGT events. Following initial detection and an evaluation procedure, evidence of the HGT was identified in 548 gene families including 42 gene families transferred from outside of Chlamydiae phylum with high reliability. The donor species of inter-phylum HGT consists of 12 different bacterial and archaeal phyla, suggesting that Chlamydia might have even more various host range than in previous reports. In addition, each species of Chlamydia showed varying preference towards HGT, and genes engaged in HGT within Chlamydia and between other species showed different functional distribution. Also, examination of individual gene flows of niche-specific genes suggested that many of such genes are transferred mainly within Chlamydia genus. Our results uncovered novel features of HGT acting on Chlamydia genome evolution, and it would be also strong evidence that HGT is an ongoing process for intracellular pathogens. We expect that the results provide more insight into lineage- and niche-specific adaptations regarding their infectivity and pathogenicity.
Assuntos
Chlamydia/fisiologia , Transferência Genética Horizontal , Chlamydia/classificação , Biologia Computacional/métodos , Genoma Bacteriano , Virulência/genética , Sequenciamento Completo do GenomaRESUMO
Porcine epidemic diarrhea virus (PEDV), the causative agent of porcine epidemic diarrhea (PED), has led to tremendous economic losses in the global swine industry. Although the phylogeny of PEDV has been investigated extensively at the molecular level, there was no time-calibrated phylogenomic study on the virus. To improve insight into this topic, we analyzed 138 published genome sequences using the Bayesian coalescent analyses as well as Bayesian inferences and maximum likelihood methods. All of the global PEDV isolates were divided into six groups, except for one unclassified isolate. Of the six groups, Groups 1-5 comprised pandemic viruses while the remaining Group 6 contained classical isolates. Interestingly, the two clades, both pandemic and classical, consisted of clade-specific amino acid sequences in five genes: ORF1a, ORF1b, S, ORF3, and N. Within the pandemic clade, Group 1 and Group 2 originated from North America, whereas Group 3-Group 5 were derived from Asia. In Group 2, there was a common origin of S INDEL isolates. Within each group, there was no apparent association between temporal or geographic origin and heterogeneity of PEDVs. Our findings also showed that the PEDV virus evolved at a rate of 3.38 × 10-4 substitutions/site/year, and the most recent common ancestor of the virus emerged 75.9 years ago. Our Bayesian skyline plot analysis indicated that the PEDV had maintained constant effective population size excluding only a short period, around 2012, when a valley shaped decline in the effective number of infections occurred.
Assuntos
Diarreia/genética , Evolução Molecular , Vírus da Diarreia Epidêmica Suína/genética , Doenças dos Suínos/genética , Animais , Diarreia/veterinária , Diarreia/virologia , Genoma Viral/genética , Filogenia , Vírus da Diarreia Epidêmica Suína/patogenicidade , Suínos/virologia , Doenças dos Suínos/virologiaRESUMO
The Thoroughbred horse breed was developed primarily for racing, and has a significant contribution to the qualitative improvement of many other horse breeds. Despite the importance of Thoroughbred racehorses in historical, cultural, and economical viewpoints, there was no temporal and spatial dynamics of them using the mitogenome sequences. To explore this topic, the complete mitochondrial genome sequences of 14 Thoroughbreds and two Przewalski's horses were determined. These sequences were analyzed together along with 151 previously published horse mitochondrial genomes from a range of breeds across the globe using a Bayesian coalescent approach as well as Bayesian inference and maximum likelihood methods. The racing horses were revealed to have multiple maternal origins and to be closely related to horses from one Asian, two Middle Eastern, and five European breeds. Thoroughbred horse breed was not directly related to the Przewalski's horse which has been regarded as the closest taxon to the all domestic horses and the only true wild horse species left in the world. Our phylogenomic analyses also supported that there was no apparent correlation between geographic origin or breed and the evolution of global horses. The most recent common ancestor of the Thoroughbreds lived approximately 8,100-111,500 years ago, which was significantly younger than the most recent common ancestor of modern horses (0.7286 My). Bayesian skyline plot revealed that the population expansion of modern horses, including Thoroughbreds, occurred approximately 5,500-11,000 years ago, which coincide with the start of domestication. This is the first phylogenomic study on the Thoroughbred racehorse in association with its spatio-temporal dynamics. The database and genetic history information of Thoroughbred mitogenomes obtained from the present study provide useful information for future horse improvement projects, as well as for the study of horse genomics, conservation, and in association with its geographical distribution.
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Cavalos/genética , Animais , Animais Selvagens/classificação , Animais Selvagens/genética , Teorema de Bayes , Cruzamento , Domesticação , Equidae/classificação , Equidae/genética , Evolução Molecular , Feminino , Genoma Mitocondrial , Cavalos/classificação , Masculino , Modelos Genéticos , Filogenia , Filogeografia , Análise Espaço-TemporalRESUMO
Haliotis discus hannai, a species of Pacific abalone, is a highly valuable food source throughout Northeast Asia. As H. discus hannai primarily feed on brown algae and largely extract their energy from algal polysaccharides, understanding the mechanisms by which they digest algal polysaccharides is essential for elucidating their energy metabolism. Gut microbes, as well as the host animal, are involved in the process of polysaccharide degradation. To identify algal polysaccharide-digestion mechanisms and their origin, we analyzed the metagenome and metatranscriptome of abalone visceral extracts. Microbial communities were characterized using the 16S rRNA gene sequences in the metagenome and our results differed significantly from those of previous studies using traditional microbiological methods such as bacterial cultivation and cloning. A greater diversity of bacterial taxa was identified here than was previously identified using cultivation methods. Furthermore, the most abundant bacterial taxa also differed from previous studies, which is not common when comparing the results of bacterial culturing with those of molecular methodologies. Based on the metatranscriptome, overall functions were identified and additional analyses were performed on the coding sequences of algal polysaccharide-digestive enzymes, including alginate lyase. Results of the transcriptomic analyses suggest that alginate lyase in the visceral extracts of H. discus hannai was produced by the host itself, not by visceral bacteria. This is the first next-generation sequencing study performed on abalone to characterize the visceral microbiota and the source of the ability to digest algal polysaccharides by analyzing the metagenome and metatranscriptome together.