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1.
Anim Genet ; 54(4): 544-548, 2023 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-37313778

RESUMO

A structural variant (SV) in the agouti signaling protein gene (ASIP), namely ASIP-SV1, has been found to strongly correlate with the darkness of hair coat in specific regions of the body of bulls from the zebu (Bos indicus) Nellore breed. Here we visually analyzed the whole-genome sequence of zebu and taurine (Bos taurus) cattle to elucidate the extent of spread of ASIP-SV1 in different cattle populations. Of 216 sequences analyzed, 63 zebu (45.9%) and five taurine (6.3%) animals had at least one copy of ASIP-SV1. Four of the taurine animals presenting the SV were Romagnola cattle, a breed with history of zebu introgression. The remaining taurine animal was a Simmental, a breed frequently used in crossbreeding. These data provide evidence that ASIP-SV1 is commonly found in zebu populations, in addition to taurine animals with zebu admixture.


Assuntos
Cabelo , Hibridização Genética , Bovinos/genética , Masculino , Animais , Escuridão , Alelos
2.
Front Genet ; 12: 633132, 2021.
Artigo em Inglês | MEDLINE | ID: mdl-34122501

RESUMO

Heat stress has a detrimental impact on cattle health, welfare and productivity by affecting gene expression, metabolism and immune response, but little is known on the epigenetic mechanisms mediating the effect of temperature at the cellular and organism level. In this study, we investigated genome-wide DNA methylation in blood samples collected from 5 bulls of the heat stress resilient Nellore breed and 5 bulls of the Angus that are more heat stress susceptible, exposed to the sun and high temperature-high humidity during the summer season of the Brazilian South-East region. The methylomes were analyzed during and after the exposure by Reduced Representation Bisulfite Sequencing, which provided genome-wide single-base resolution methylation profiles. Significant methylation changes between stressful and recovery periods were observed in 819 genes. Among these, 351 were only seen in Angus, 366 were specific to Nellore, and 102 showed significant changes in methylation patterns in both breeds. KEGG and Gene Ontology (GO) enrichment analyses showed that responses were breed-specific. Interestingly, in Nellore significant genes and pathways were mainly involved in stress responses and cellular defense and were under methylated during heat stress, whereas in Angus the response was less focused. These preliminary results suggest that heat challenge induces changes in methylation patterns in specific loci, which should be further scrutinized to assess their role in heat tolerance.

4.
Rev Bras Parasitol Vet ; 30(1): e022020, 2021.
Artigo em Inglês | MEDLINE | ID: mdl-33729316

RESUMO

Leishmaniasis is a zoonotic disease caused by over 20 species of protozoan parasites of the genus Leishmania. Infection is commonly spread by sandflies and produces a wide spectrum of clinical signs and symptoms. Therefore, from an epidemiological and therapeutic standpoint, it is important to detect and differentiate Leishmania spp. The objective of this study was to combinate in silico and in vitro strategies to evaluate the analytical specificity of primers previously described in the literature. According to electronic PCR (e-PCR) analysis, 23 out of 141 pairs of primers selected through literature search matched their previously reported analytical specificity. In vitro evaluation of nine of these primer pairs by quantitative PCR (qPCR) confirmed the analytical specificity of five of them at the level of Leishmania spp., L. mexicana complex or Leishmania and Viannia subgenera. Based on these findings, the combination of e-PCR and qPCR is suggested to be a valuable approach to maximize the specificity of new primer pairs for the laboratory diagnosis of infections with Leishmania spp.


Assuntos
Leishmania , Leishmaniose , Psychodidae , Animais , Simulação por Computador , DNA de Protozoário , Leishmania/genética , Leishmaniose/diagnóstico , Leishmaniose/veterinária , Reação em Cadeia da Polimerase em Tempo Real/veterinária
5.
Rev. bras. parasitol. vet ; 30(1): e022020, 2021. tab
Artigo em Inglês | LILACS | ID: biblio-1156230

RESUMO

Abstract Leishmaniasis is a zoonotic disease caused by over 20 species of protozoan parasites of the genus Leishmania. Infection is commonly spread by sandflies and produces a wide spectrum of clinical signs and symptoms. Therefore, from an epidemiological and therapeutic standpoint, it is important to detect and differentiate Leishmania spp. The objective of this study was to combinate in silico and in vitro strategies to evaluate the analytical specificity of primers previously described in the literature. According to electronic PCR (e-PCR) analysis, 23 out of 141 pairs of primers selected through literature search matched their previously reported analytical specificity. In vitro evaluation of nine of these primer pairs by quantitative PCR (qPCR) confirmed the analytical specificity of five of them at the level of Leishmania spp., L. mexicana complex or Leishmania and Viannia subgenera. Based on these findings, the combination of e-PCR and qPCR is suggested to be a valuable approach to maximize the specificity of new primer pairs for the laboratory diagnosis of infections with Leishmania spp.


Resumo As leishmanioses são zoonoses causadas por mais de 20 espécies de protozoários do gênero Leishmania. As infecções são comumente disseminadas por flebotomíneos e causam um amplo espectro de manifestações clínicas. Portanto, a detecção e diferenciação de espécies de Leishmania são importantes do ponto de vista epidemiológico e terapêutico. O objetivo deste estudo foi combinar estratégias in silico e in vitro para avaliar a especificidade analítica dos primers descritos anteriormente na literatura. De acordo com a PCR eletrônica (e-PCR), 23 dos 141 pares de primers selecionados por meio de pesquisa da literatura estavam de acordo com a especificidade analítica anteriormente relatada. A avaliação in vitro de nove desses pares de primers, por PCR quantitativa (qPCR), confirmou a especificidade analítica de cinco deles ao nível de espécie de Leishmania, do complexo L. mexicana ou dos subgêneros Leishmania e Viannia. Com base nos resultados, sugere-se que a combinação de e-PCR e qPCR é uma abordagem valiosa para a validação e maximização da especificidade de novos pares de primers para o diagnóstico laboratorial de infecções com Leishmania spp.


Assuntos
Animais , Psychodidae , Leishmaniose/veterinária , Leishmania/genética , Simulação por Computador , Leishmaniose/diagnóstico , DNA de Protozoário , Reação em Cadeia da Polimerase em Tempo Real/veterinária
6.
Front Med (Lausanne) ; 7: 247, 2020.
Artigo em Inglês | MEDLINE | ID: mdl-32574335

RESUMO

Background: Ending the COVID-19 pandemic is arguably one of the most prominent challenges in recent human history. Following closely the growth dynamics of the disease is one of the pillars toward achieving that goal. Objective: We aimed at developing a simple framework to facilitate the analysis of the growth rate (cases/day) and growth acceleration (cases/day2) of COVID-19 cases in real-time. Methods: The framework was built using the Moving Regression (MR) technique and a Hidden Markov Model (HMM). The dynamics of the pandemic was initially modeled via combinations of four different growth stages: lagging (beginning of the outbreak), exponential (rapid growth), deceleration (growth decay), and stationary (near zero growth). A fifth growth behavior, namely linear growth (constant growth above zero), was further introduced to add more flexibility to the framework. An R Shiny application was developed, which can be accessed at https://theguarani.com.br/ or downloaded from https://github.com/adamtaiti/SARS-CoV-2. The framework was applied to data from the European Center for Disease Prevention and Control (ECDC), which comprised 3,722,128 cases reported worldwide as of May 8th 2020. Results: We found that the impact of public health measures on the prevalence of COVID-19 could be perceived in seemingly real-time by monitoring growth acceleration curves. Restriction to human mobility produced detectable decline in growth acceleration within 1 week, deceleration within ~2 weeks and near-stationary growth within ~6 weeks. Countries exhibiting different permutations of the five growth stages indicated that the evolution of COVID-19 prevalence is more complex and dynamic than previously appreciated. Conclusions: These results corroborate that mass social isolation is a highly effective measure against the dissemination of SARS-CoV-2, as previously suggested. Apart from the analysis of prevalence partitioned by country, the proposed framework is easily applicable to city, state, region and arbitrary territory data, serving as an asset to monitor the local behavior of COVID-19 cases.

7.
Front Genet ; 11: 573344, 2020.
Artigo em Inglês | MEDLINE | ID: mdl-33584786

RESUMO

Milk production phenotypes are the main focus of genetic selection in dairy herds, and although there are many genes identified as related to the biology of these traits in pure breeds, little is known about crossbreed animals. This study aimed to identify potential genes associated with the 305-day milk yield in 337 crossbreed Gir × Holstein (Girolando) animals. Milk production records were genotyped for 45,613 single-nucleotide polymorphisms (SNPs). This dataset was used for a genome-wide association study (GWAS) using the 305-day milk yield adjusted for the fixed effects of herd and year and linear and quadratic effects of age at calving (in days) and calving factor averaged per animal. Genes within the significant SNPs were retrieved from the Bos taurus ARS-UCD1.2 assembly (bosTau9) for gene ontology analysis. In summary, the GWAS identified 52 SNPs associated [p ≤ 10-4, false discovery rate (FDR) = 8.77%] with milk production, including NUB1 and SLC24A2, which were previously described as related to milk production traits in cattle. The results suggest that SNPs associated mainly with NUB1 and SLC24A2 could be useful to understand milk production in Girolando and used as predictive markers for selecting genetic predisposition for milk yield in Girolando.

8.
Rev. Soc. Bras. Med. Trop ; 53: e20190320, 2020. tab, graf
Artigo em Inglês | LILACS | ID: biblio-1057289

RESUMO

Abstract INTRODUCTION: This study aimed to investigate human exposure to Leishmania spp. infection and sandflies in an area endemic for the disease. METHODS: The presence of antibodies specific for Leishmania spp. and saliva of Lutzomyia spp. and that of L. infantum DNA in blood were evaluated. RESULTS: Antibodies against Leishmania spp. and sandfly saliva were observed in 20.8% and 37.7% of individuals, respectively. DNA of Leishmania spp. was amplified from the blood of one patient. CONCLUSIONS: The results suggest that Leishmania spp. infection may be underdiagnosed in this area.


Assuntos
Humanos , Animais , Masculino , Feminino , Adolescente , Adulto , Idoso , Adulto Jovem , Psychodidae/parasitologia , Insetos Vetores/parasitologia , Leishmania/isolamento & purificação , Leishmaniose Visceral/transmissão , Brasil , Ensaio de Imunoadsorção Enzimática , Reação em Cadeia da Polimerase , Leishmania/genética , Leishmania/imunologia , Leishmaniose Visceral/epidemiologia , Pessoa de Meia-Idade
9.
Rev Soc Bras Med Trop ; 53: e20190320, 2019.
Artigo em Inglês | MEDLINE | ID: mdl-31859954

RESUMO

INTRODUCTION: This study aimed to investigate human exposure to Leishmania spp. infection and sandflies in an area endemic for the disease. METHODS: The presence of antibodies specific for Leishmania spp. and saliva of Lutzomyia spp. and that of L. infantum DNA in blood were evaluated. RESULTS: Antibodies against Leishmania spp. and sandfly saliva were observed in 20.8% and 37.7% of individuals, respectively. DNA of Leishmania spp. was amplified from the blood of one patient. CONCLUSIONS: The results suggest that Leishmania spp. infection may be underdiagnosed in this area.


Assuntos
Insetos Vetores/parasitologia , Leishmania/isolamento & purificação , Leishmaniose Visceral/transmissão , Psychodidae/parasitologia , Adolescente , Adulto , Idoso , Animais , Brasil , Ensaio de Imunoadsorção Enzimática , Feminino , Humanos , Leishmania/genética , Leishmania/imunologia , Leishmaniose Visceral/epidemiologia , Masculino , Pessoa de Meia-Idade , Reação em Cadeia da Polimerase , Adulto Jovem
10.
Front Genet ; 10: 442, 2019.
Artigo em Inglês | MEDLINE | ID: mdl-31231417

RESUMO

Like most West African Bos taurus, the shorthorn Muturu is under threat of replacement or crossbreeding with zebu. Their populations are now reduced to a few hundred breeding individuals and they are considered endangered. So far, the genetic variation and genetic basis of the trypanotolerant Muturu environmental adaptation have not been assessed. Here, we present genome-wide candidate positive selection signatures in Muturu following within-population iHS and between population Rsb signatures of selection analysis. We compared the results in Muturu with the ones obtained in N'Dama, a West African longhorn trypanotolerant taurine, and in two European taurine (Holstein and Jersey). The results reveal candidate signatures of selection regions in Muturu including genes linked to the innate (e.g., TRIM10, TRIM15, TRIM40, and TRIM26) and the adaptive (e.g., JSP.1, BOLA-DQA2, BOLA-DQA5, BOLA-DRB3, and BLA-DQB) immune responses. The most significant regions are identified on BTA 23 at the bovine major histocompatibility complex (MHC) (iHS analysis) and on BTA 12 at genes including a heat tolerance gene (INTS6) (Rsb analysis). Other candidate selected regions include genes related to growth traits/stature (e.g., GHR and GHRHR), coat color (e.g., MITF and KIT), feed efficiency (e.g., ZRANB3 and MAP3K5) and reproduction (e.g., RFX2, SRY, LAP3, and GPX5). Genes under common signatures of selection regions with N'Dama, including for adaptive immunity and heat tolerance, suggest shared mechanisms of adaptation to environmental challenges for these two West African taurine cattle. Interestingly, out of the 242,910 SNPs identified within the candidate selected regions in Muturu, 917 are missense SNPs (0.4%), with an unequal distribution across 273 genes. Fifteen genes including RBBP8, NID1, TEX15, LAMA3, TRIM40, and OR12D3 comprise 220 missense variants, each between 11 and 32. Our results, while providing insights into the candidate genes under selection in Muturu, are paving the way to the identification of genes and their polymorphisms linked to the unique tropical adaptive traits of the West Africa taurine, including trypanotolerance.

12.
Front Genet ; 9: 627, 2018.
Artigo em Inglês | MEDLINE | ID: mdl-30581455

RESUMO

Navel injuries caused by friction against the pasture can promote infection, reproductive problems and costly treatments in beef cattle raised in extensive systems. A haplotype-based genome-wide association study (GWAS) was performed for visual scores of navel length at yearling in Nellore cattle (Bos indicus) using data from 2,016 animals and 503,088 single nucleotide polymorphism (SNP) markers. The strongest signal (p = 1.01 × 10-9) was found on chromosome 5 spanning positions 47.9-48.2 Mbp. This region contains introns 3 and 4 and exons 4 and 5 of the high mobility group AT-hook 2 gene (HMGA2). Further inspection of the region with whole genome sequence data of 21 Nellore bulls revealed correlations between counts of the significant haplotype and copy number gains of a ∼6.2 kbp segment of intron 3 of HMGA2. Analysis of genome sequences from five African B. indicus and four European Bos taurus breeds revealed that the copy number variant (CNV) is indicine-specific. This intronic CNV was then validated through quantitative polymerase chain reaction (qPCR) using Angus animals as copy neutral controls. Importantly, the CNV was not detectable by means of conventional SNP-based GWAS or SNP probe intensity analyses. Given that HMGA2 affects the expression of the insulin-like growth factor 2 gene (IGF2) together with the pleomorphic adenoma gene 1 (PLAG1), and that the latter has been repeatedly shown to be associated with quantitative traits of economic importance in cattle, these findings highlight the emerging role of variants impacting the insulin-like growth factor pathway to cattle breeding.

13.
PLoS One ; 13(8): e0201876, 2018.
Artigo em Inglês | MEDLINE | ID: mdl-30089161

RESUMO

Zebu cattle (Bos taurus indicus) are highly adapted to tropical regions. However, females reach puberty after taurine heifers, which affects the economic efficiency of beef cattle breeding in the tropical regions. The aims of this study were to establish associations between the haplotype alleles of the bovine genome and age at first calving (AFC) in the Nelore cattle, and to identify the genes and quantitative trait loci (QTL) related to this phenotype. A total of 2,273 Nelore cattle (995 males and 1,278 females) genotyped using the Illumina BovineHD BeadChip were used in the current study. The association analysis included females with valid first calving records as well as open heifers. Linkage disequilibrium (LD) analysis among the markers was performed using blocks of 5, 10, and 15 markers, which were determined by sliding windows shifting one marker at a time. Then, the haplotype block size to be used in the association study was chosen based on the highest r2 average among the SNPs in the block. The five HapAlleles most strongly associated with the trait (top five) were considered as significant associations. The results of the analysis revealed four genomic regions related to AFC, which overlapped with 20 QTL of the reproductive traits reported previously. Furthermore, there were 19 genes related to reproduction in those regions. In conclusion, the use of haplotypes allowed the detection of chromosomal regions associated with AFC in Nelore cattle, and provided the basis for elucidating the mechanisms underlying this trait.


Assuntos
Alelos , Cruzamento , Bovinos/genética , Haplótipos , Reprodução/genética , Criação de Animais Domésticos , Animais , Feminino , Estudo de Associação Genômica Ampla , Desequilíbrio de Ligação , Masculino , Fenótipo , Polimorfismo de Nucleotídeo Único , Locos de Características Quantitativas
14.
Sci Rep ; 7(1): 17140, 2017 12 07.
Artigo em Inglês | MEDLINE | ID: mdl-29215042

RESUMO

The recent evolution of cattle is marked by fluctuations in body size. Height in the Bos taurus lineage was reduced by a factor of ~1.5 from the Neolithic to the Middle Ages, and increased again only during the Early Modern Ages. Using haplotype analysis, we found evidence that the bovine PLAG1 mutation (Q) with major effects on body size, weight and reproduction is a >1,000 years old derived allele that increased rapidly in frequency in Northwestern European B. taurus between the 16th and 18th centuries. Towards the 19th and 20th centuries, Q was introgressed into non-European B. taurus and Bos indicus breeds. These data implicate a major role of Q in recent changes in body size in modern cattle, and represent one of the first examples of a genomic sweep in livestock that was driven by selection on a complex trait.


Assuntos
Osso e Ossos , Proteínas de Ligação a DNA/genética , Pleiotropia Genética , Genética Populacional , Haplótipos , Mutação , Postura , Animais , Bovinos , Desequilíbrio de Ligação
15.
Vet Parasitol ; 234: 13-18, 2017 Jan 30.
Artigo em Inglês | MEDLINE | ID: mdl-28115177

RESUMO

Quantification of Leishmania infantum load via real-time quantitative polymerase chain reaction (qPCR) in lymph node aspirates is an accurate tool for diagnostics, surveillance and therapeutics follow-up in dogs with leishmaniasis. However, qPCR requires infrastructure and technical training that is not always available commercially or in public services. Here, we used a machine learning technique, namely Radial Basis Artificial Neural Network, to assess whether parasite load could be learned from clinical data (serological test, biochemical markers and physical signs). By comparing 18 different combinations of input clinical data, we found that parasite load can be accurately predicted using a relatively small reference set of 35 naturally infected dogs and 20 controls. In the best case scenario (use of all clinical data), predictions presented no bias or inflation and an accuracy (i.e., correlation between true and predicted values) of 0.869, corresponding to an average error of ±38.2 parasites per unit of volume. We conclude that reasonable estimates of L. infantum load from lymph node aspirates can be obtained from clinical records when qPCR services are not available.


Assuntos
Doenças do Cão/parasitologia , Leishmaniose/veterinária , Linfonodos/parasitologia , Redes Neurais de Computação , Carga Parasitária/veterinária , Animais , Doenças do Cão/diagnóstico , Doenças do Cão/patologia , Cães , Leishmaniose/diagnóstico , Leishmaniose/parasitologia , Leishmaniose/patologia
16.
Cad Saude Publica ; 32(8): e00026115, 2016 Sep 05.
Artigo em Inglês | MEDLINE | ID: mdl-27598014

RESUMO

The age structure of the dog population is essential for planning and evaluating control programs for zoonotic diseases. We analyzed data of an owned-dog census in order to characterize, for the first time, the structure of a dog population under compulsory culling in a visceral leishmaniasis endemic area (Panorama, São Paulo State, Brazil) that recorded a dog-culling rate of 28% in the year of the study. Data on 1,329 households and 1,671 owned dogs revealed an owned dog:human ratio of 1:7. The mean age of dogs was estimated at 1.73 years; the age pyramid indicated high birth and mortality rates at the first year of age with an estimated cumulative mortality of 78% at the third year of age and expected life span of 2.75 years. In spite of the high mortality, a growth projection simulation suggested that the population has potential to grow in a logarithmic scale over the years. The estimated parameters can be further applied in models to maximize the impact and minimize financial inputs of visceral leishmaniasis control measures.


Assuntos
Distribuição por Idade , Abate de Animais , Censos , Doenças do Cão/epidemiologia , Leishmaniose Visceral/veterinária , Abate de Animais/estatística & dados numéricos , Animais , Brasil/epidemiologia , Doenças do Cão/mortalidade , Cães , Leishmaniose Visceral/epidemiologia , Leishmaniose Visceral/mortalidade , Propriedade/estatística & dados numéricos , Previsões Demográficas/métodos , Taxa de Sobrevida
17.
Cad. Saúde Pública (Online) ; 32(8): e00026115, 2016. tab, graf
Artigo em Inglês | LILACS | ID: biblio-952297

RESUMO

Abstract: The age structure of the dog population is essential for planning and evaluating control programs for zoonotic diseases. We analyzed data of an owned-dog census in order to characterize, for the first time, the structure of a dog population under compulsory culling in a visceral leishmaniasis endemic area (Panorama, São Paulo State, Brazil) that recorded a dog-culling rate of 28% in the year of the study. Data on 1,329 households and 1,671 owned dogs revealed an owned dog:human ratio of 1:7. The mean age of dogs was estimated at 1.73 years; the age pyramid indicated high birth and mortality rates at the first year of age with an estimated cumulative mortality of 78% at the third year of age and expected life span of 2.75 years. In spite of the high mortality, a growth projection simulation suggested that the population has potential to grow in a logarithmic scale over the years. The estimated parameters can be further applied in models to maximize the impact and minimize financial inputs of visceral leishmaniasis control measures.


Resumo: É importante conhecer a estrutura etária da população canina para melhor planejar e avaliar os programas de controle de zoonoses. Os autores analisaram os dados de um censo de cães com donos para caracterizar, pela primeira vez, a estrutura etária de uma população canina sujeita à eliminação compulsória numa área endêmica de leishmaniose visceral (Panorama, Estado de São Paulo, Brasil) que registrou uma taxa de eliminação canina de 28% no ano do estudo. Os dados para 1.329 domicílios e 1.671 cães com donos mostraram uma razão de cães para humanos de 1:7. A média de idade dos cães foi estimada em 1,73 anos; a pirâmide etária indicou altas taxas de natalidade e de mortalidade no primeiro ano de vida, com uma estimativa de mortalidade cumulativa de 78% aos três anos de idade, e uma expectativa de vida de 2,75 anos. Apesar da alta mortalidade, uma simulação de projeção de crescimento sugeriu que a população tem o potencial de crescer numa escala logarítmica ao longo dos anos. Os parâmetros estimados podem ser aplicados também a modelos para maximizar o impacto e minimizar os insumos financeiros de medidas de controle da leishmaniose visceral.


Resumen: El conocimiento de la estructura etaria de una población de perros es esencial para la planificación de programas de control de zoonosis. Se analizaron datos de un censo de población canina domiciliada, con el objetivo de caracterizar, por primera vez, la estructura de una población de perros domiciliados en un área donde la eutanasia de perros positivos en leishmaniasis visceral es obligatoria (Panorama, São Paulo, Brasil), y que registró un 28% de casos de eutanasia en el año en que el censo fue realizado. Los datos de 1.329 domicilios y 1.671 perros resultaron en una razón perro:hombre de 1:7. La edad media de los perros fue estimada en 1,73 años; la pirámide de edad indica altas tasas de nacimiento y mortalidad hasta 1 año de vida, con tasa de mortalidad acumulada de un 78% en el tercer año de vida, y expectativa de vida de 2,75 años. A pesar de la alta tasa de mortalidad, la simulación de crecimiento poblacional sugiere que esta población tiene potencial de crecimiento en escala logarítmica a lo largo de los años. Los parámetros estimados pueden ser utilizados en modelos para maximizar el impacto y minimizar los costes de las medidas de control de la enfermedad.


Assuntos
Animais , Cães , Distribuição por Idade , Censos , Doenças do Cão/epidemiologia , Abate de Animais/estatística & dados numéricos , Leishmaniose Visceral/veterinária , Propriedade/estatística & dados numéricos , Brasil/epidemiologia , Taxa de Sobrevida , Previsões Demográficas/métodos , Doenças do Cão/mortalidade , Leishmaniose Visceral/mortalidade , Leishmaniose Visceral/epidemiologia
18.
BMC Genet ; 16: 75, 2015 Jul 04.
Artigo em Inglês | MEDLINE | ID: mdl-26141727

RESUMO

BACKGROUND: Peranakan Ongole (PO) is a major Indonesian Bos indicus breed that derives from animals imported from India in the late 19(th) century. Early imports were followed by hybridization with the Bos javanicus subspecies of cattle. Here, we used genomic data to partition the ancestry components of PO cattle and map loci implicated in birth weight. RESULTS: We found that B. javanicus contributes about 6-7% to the average breed composition of PO cattle. Only two nearly fixed B. javanicus haplotypes were identified, suggesting that most of the B. javanicus variants are segregating under drift or by the action of balancing selection. The zebu component of the PO genome was estimated to derive from at least two distinct ancestral pools. Additionally, well-known loci underlying body size in other beef cattle breeds, such as the PLAG1 region on chromosome 14, were found to also affect birth weight in PO cattle. CONCLUSIONS: This study is the first attempt to characterize PO at the genome level, and contributes evidence of successful, stabilized B. indicus x B. javanicus hybridization. Additionally, previously described loci implicated in body size in worldwide beef cattle breeds also affect birth weight in PO cattle.


Assuntos
Peso ao Nascer/genética , Hibridização Genética , Locos de Características Quantitativas , Característica Quantitativa Herdável , Animais , Cruzamento , Bovinos , Mapeamento Cromossômico , Análise por Conglomerados , Estudos de Associação Genética , Genoma , Genótipo , Haplótipos , Fenótipo , Polimorfismo de Nucleotídeo Único
19.
BMC Genet ; 15: 47, 2014 Apr 17.
Artigo em Inglês | MEDLINE | ID: mdl-24739206

RESUMO

BACKGROUND: Descendants from the extinct aurochs (Bos primigenius), taurine (Bos taurus) and zebu cattle (Bos indicus) were domesticated 10,000 years ago in Southwestern and Southern Asia, respectively, and colonized the world undergoing complex events of admixture and selection. Molecular data, in particular genome-wide single nucleotide polymorphism (SNP) markers, can complement historic and archaeological records to elucidate these past events. However, SNP ascertainment in cattle has been optimized for taurine breeds, imposing limitations to the study of diversity in zebu cattle. As amplified fragment length polymorphism (AFLP) markers are discovered and genotyped as the samples are assayed, this type of marker is free of ascertainment bias. In order to obtain unbiased assessments of genetic differentiation and structure in taurine and zebu cattle, we analyzed a dataset of 135 AFLP markers in 1,593 samples from 13 zebu and 58 taurine breeds, representing nine continental areas. RESULTS: We found a geographical pattern of expected heterozygosity in European taurine breeds decreasing with the distance from the domestication centre, arguing against a large-scale introgression from European or African aurochs. Zebu cattle were found to be at least as diverse as taurine cattle. Western African zebu cattle were found to have diverged more from Indian zebu than South American zebu. Model-based clustering and ancestry informative markers analyses suggested that this is due to taurine introgression. Although a large part of South American zebu cattle also descend from taurine cows, we did not detect significant levels of taurine ancestry in these breeds, probably because of systematic backcrossing with zebu bulls. Furthermore, limited zebu introgression was found in Podolian taurine breeds in Italy. CONCLUSIONS: The assessment of cattle diversity reported here contributes an unbiased global view to genetic differentiation and structure of taurine and zebu cattle populations, which is essential for an effective conservation of the bovine genetic resources.


Assuntos
Análise do Polimorfismo de Comprimento de Fragmentos Amplificados , Bovinos/genética , Variação Genética , Genética Populacional , Animais , Cruzamento , Análise por Conglomerados , Conservação dos Recursos Naturais , Marcadores Genéticos , Genótipo , Modelos Genéticos
20.
PLoS One ; 8(5): e64280, 2013.
Artigo em Inglês | MEDLINE | ID: mdl-23696874

RESUMO

As the methodologies available for the detection of positive selection from genomic data vary in terms of assumptions and execution, weak correlations are expected among them. However, if there is any given signal that is consistently supported across different methodologies, it is strong evidence that the locus has been under past selection. In this paper, a straightforward frequentist approach based on the Stouffer Method to combine P-values across different tests for evidence of recent positive selection in common variations, as well as strategies for extracting biological information from the detected signals, were described and applied to high density single nucleotide polymorphism (SNP) data generated from dairy and beef cattle (taurine and indicine). The ancestral Bovinae allele state of over 440,000 SNP is also reported. Using this combination of methods, highly significant (P<3.17×10(-7)) population-specific sweeps pointing out to candidate genes and pathways that may be involved in beef and dairy production were identified. The most significant signal was found in the Cornichon homolog 3 gene (CNIH3) in Brown Swiss (P = 3.82×10(-12)), and may be involved in the regulation of pre-ovulatory luteinizing hormone surge. Other putative pathways under selection are the glucolysis/gluconeogenesis, transcription machinery and chemokine/cytokine activity in Angus; calpain-calpastatin system and ribosome biogenesis in Brown Swiss; and gangliosides deposition in milk fat globules in Gyr. The composite method, combined with the strategies applied to retrieve functional information, may be a useful tool for surveying genome-wide selective sweeps and providing insights in to the source of selection.


Assuntos
Modelos Teóricos , Seleção Genética/genética , Animais , Bovinos , Estudo de Associação Genômica Ampla , Polimorfismo de Nucleotídeo Único/genética , Locos de Características Quantitativas/genética
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