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1.
BMC Genomics ; 23(1): 413, 2022 Jun 01.
Artigo em Inglês | MEDLINE | ID: mdl-35650521

RESUMO

BACKGROUND: Despite sexual development being ubiquitous to vertebrates, the molecular mechanisms underpinning this fundamental transition remain largely undocumented in many organisms. We designed a time course experiment that successfully sampled the period when Atlantic salmon commence their trajectory towards sexual maturation. RESULTS: Through deep RNA sequencing, we discovered key genes and pathways associated with maturation in the pituitary-ovarian axis. Analyzing DNA methylomes revealed a bias towards hypermethylation in ovary that implicated maturation-related genes. Co-analysis of DNA methylome and gene expression changes revealed chromatin remodeling genes and key transcription factors were both significantly hypermethylated and upregulated in the ovary during the onset of maturation. We also observed changes in chromatin state landscapes that were strongly correlated with fundamental remodeling of gene expression in liver. Finally, a multiomic integrated analysis revealed regulatory networks and identified hub genes including TRIM25 gene (encoding the estrogen-responsive finger protein) as a putative key regulator in the pituitary that underwent a 60-fold change in connectivity during the transition to maturation. CONCLUSION: The study successfully documented transcriptome and epigenome changes that involved key genes and pathways acting in the pituitary - ovarian axis. Using a Systems Biology approach, we identified hub genes and their associated networks deemed crucial for onset of maturation. The results provide a comprehensive view of the spatiotemporal changes involved in a complex trait and opens the door to future efforts aiming to manipulate puberty in an economically important aquaculture species.


Assuntos
Epigenoma , Transcriptoma , Animais , Feminino , Ovário/metabolismo , Análise de Sequência de RNA/métodos , Maturidade Sexual/genética
2.
Genet Sel Evol ; 54(1): 8, 2022 Jan 31.
Artigo em Inglês | MEDLINE | ID: mdl-35100964

RESUMO

BACKGROUND: Brown trout is one of the most widespread fresh-water fish species in Europe. The evolutionary history of and phylogenetic relationships between brown trout populations are complex, and this is especially true for Italian populations, which are heavily influenced in different ways by stocking practices. The characterization of the genetic structure of Italian brown trout populations may give information on the risk of losing endemic Italian populations due to lack of genetic diversity or to admixture with stocking populations. The identification of signatures of selection, and the information deriving from dense genotyping data will help genotype-informed breeding programs. We used a ddRAD-seq approach to obtain more than 100,000 single nucleotide polymorphisms (SNPs), and to characterize the population structure and signatures of selection in 90 brown trout samples. RESULTS: Italian brown trout populations are genetically differentiated, although the stocking practices have introduced strong admixture in endemic Italian trout, especially with the Atlantic lineage. Most of the analysed populations showed high levels of kinship and inbreeding. We detected putative signatures of selection using different approaches, and investigated if the regions were enriched for functional categories. Several regions putatively under selection and characterized by a reduction in heterozygosity across all the studied populations are enriched for genes involved in the response to viral infections. CONCLUSIONS: Our results, which show evidence of admixture with the Atlantic lineage (commonly used for stocking), confirm the need for controlling stocking practices, in order to avoid the erosion of the endemic gene pool; given the apparently high levels of kinship and inbreeding in local populations, our results also show the need to take action for increasing gene diversity. In addition, we used the genetically-distinct lineages to detect signatures of selection and we identified putative signatures of selection in several regions associated with resistance to infectious diseases. These constitute candidate regions for the study of resistance to infections in wild and farmed trout.


Assuntos
Truta , Animais , Genótipo , Endogamia , Filogenia , Truta/genética
3.
Mol Biol Evol ; 38(6): 2260-2272, 2021 05 19.
Artigo em Inglês | MEDLINE | ID: mdl-33528505

RESUMO

In the course of evolution, pecorans (i.e., higher ruminants) developed a remarkable diversity of osseous cranial appendages, collectively referred to as "headgear," which likely share the same origin and genetic basis. However, the nature and function of the genetic determinants underlying their number and position remain elusive. Jacob and other rare populations of sheep and goats are characterized by polyceraty, the presence of more than two horns. Here, we characterize distinct POLYCERATE alleles in each species, both associated with defective HOXD1 function. We show that haploinsufficiency at this locus results in the splitting of horn bud primordia, likely following the abnormal extension of an initial morphogenetic field. These results highlight the key role played by this gene in headgear patterning and illustrate the evolutionary co-option of a gene involved in the early development of bilateria to properly fix the position and number of these distinctive organs of Bovidae.


Assuntos
Evolução Biológica , Cabras/genética , Proteínas de Homeodomínio/genética , Cornos , Ovinos/genética , Animais , Biometria , Regulação da Expressão Gênica no Desenvolvimento , Cabras/embriologia , Cabras/metabolismo , Proteínas de Homeodomínio/metabolismo , Masculino , Camundongos Transgênicos , Mutação , Ovinos/embriologia , Ovinos/metabolismo
4.
Mol Biol Evol ; 38(3): 838-855, 2021 03 09.
Artigo em Inglês | MEDLINE | ID: mdl-32941615

RESUMO

How animals, particularly livestock, adapt to various climates and environments over short evolutionary time is of fundamental biological interest. Further, understanding the genetic mechanisms of adaptation in indigenous livestock populations is important for designing appropriate breeding programs to cope with the impacts of changing climate. Here, we conducted a comprehensive genomic analysis of diversity, interspecies introgression, and climate-mediated selective signatures in a global sample of sheep and their wild relatives. By examining 600K and 50K genome-wide single nucleotide polymorphism data from 3,447 samples representing 111 domestic sheep populations and 403 samples from all their seven wild relatives (argali, Asiatic mouflon, European mouflon, urial, snow sheep, bighorn, and thinhorn sheep), coupled with 88 whole-genome sequences, we detected clear signals of common introgression from wild relatives into sympatric domestic populations, thereby increasing their genomic diversities. The introgressions provided beneficial genetic variants in native populations, which were significantly associated with local climatic adaptation. We observed common introgression signals of alleles in olfactory-related genes (e.g., ADCY3 and TRPV1) and the PADI gene family including in particular PADI2, which is associated with antibacterial innate immunity. Further analyses of whole-genome sequences showed that the introgressed alleles in a specific region of PADI2 (chr2: 248,302,667-248,306,614) correlate with resistance to pneumonia. We conclude that wild introgression enhanced climatic adaptation and resistance to pneumonia in sheep. This has enabled them to adapt to varying climatic and environmental conditions after domestication.


Assuntos
Adaptação Biológica/genética , Resistência à Doença/genética , Introgressão Genética , Ovinos/genética , Animais , Evolução Biológica , Mudança Climática , Variação Genética , Filogeografia , Pneumonia/imunologia , Ovinos/imunologia
5.
Acta Neuropathol Commun ; 8(1): 142, 2020 08 20.
Artigo em Inglês | MEDLINE | ID: mdl-32819427

RESUMO

Ovine congenital progressive muscular dystrophy (OCPMD) was first described in Merino sheep flocks in Queensland and Western Australia in the 1960s and 1970s. The most prominent feature of the disease is a distinctive gait with stiffness of the hind limbs that can be seen as early as 3 weeks after birth. The disease is progressive. Histopathological examination had revealed dystrophic changes specifically in type I (slow) myofibres, while electron microscopy had demonstrated abundant nemaline bodies. Therefore, it was never certain whether the disease was a dystrophy or a congenital myopathy with dystrophic features. In this study, we performed whole genome sequencing of OCPMD sheep and identified a single base deletion at the splice donor site (+ 1) of intron 13 in the type I myofibre-specific TNNT1 gene (KT218690 c.614 + 1delG). All affected sheep were homozygous for this variant. Examination of TNNT1 splicing by RT-PCR showed intron retention and premature termination, which disrupts the highly conserved 14 amino acid C-terminus. The variant did not reduce TNNT1 protein levels or affect its localization but impaired its ability to modulate muscle contraction in response to Ca2+ levels. Identification of the causative variant in TNNT1 finally clarifies that the OCPMD sheep is in fact a large animal model of TNNT1 congenital myopathy. This model could now be used for testing molecular or gene therapies.


Assuntos
Miotonia Congênita/patologia , Miotonia Congênita/veterinária , Doenças dos Ovinos/genética , Doenças dos Ovinos/patologia , Troponina T/genética , Animais , Modelos Animais de Doenças , Músculo Esquelético/patologia , Ovinos
6.
Nat Commun ; 11(1): 2815, 2020 06 04.
Artigo em Inglês | MEDLINE | ID: mdl-32499537

RESUMO

Understanding the genetic changes underlying phenotypic variation in sheep (Ovis aries) may facilitate our efforts towards further improvement. Here, we report the deep resequencing of 248 sheep including the wild ancestor (O. orientalis), landraces, and improved breeds. We explored the sheep variome and selection signatures. We detected genomic regions harboring genes associated with distinct morphological and agronomic traits, which may be past and potential future targets of domestication, breeding, and selection. Furthermore, we found non-synonymous mutations in a set of plausible candidate genes and significant differences in their allele frequency distributions across breeds. We identified PDGFD as a likely causal gene for fat deposition in the tails of sheep through transcriptome, RT-PCR, qPCR, and Western blot analyses. Our results provide insights into the demographic history of sheep and a valuable genomic resource for future genetic studies and improved genome-assisted breeding of sheep and other domestic animals.


Assuntos
Criação de Animais Domésticos/métodos , Animais Selvagens/genética , Fator de Crescimento Derivado de Plaquetas/metabolismo , Carneiro Doméstico/genética , Alelos , Animais , Cruzamento , Feminino , Frequência do Gene , Variação Genética , Genética , Genômica , Genótipo , Sequenciamento de Nucleotídeos em Larga Escala , Desequilíbrio de Ligação , Mutação , Fenótipo , Polimorfismo de Nucleotídeo Único , Seleção Genética , Análise de Sequência de DNA , Ovinos , Especificidade da Espécie , Sequenciamento Completo do Genoma
7.
Genet Sel Evol ; 52(1): 27, 2020 May 27.
Artigo em Inglês | MEDLINE | ID: mdl-32460767

RESUMO

BACKGROUND: Distinct domestication events, adaptation to different climatic zones, and divergent selection in productive traits have shaped the genomic differences between taurine and indicine cattle. In this study, we assessed the impact of artificial selection and environmental adaptation by comparing whole-genome sequences from European taurine and Asian indicine breeds and from African cattle. Next, we studied the impact of divergent selection by exploiting predicted and experimental functional annotation of the bovine genome. RESULTS: We identified selective sweeps in beef cattle taurine and indicine populations, including a 430-kb selective sweep on indicine cattle chromosome 5 that is located between 47,670,001 and 48,100,000 bp and spans five genes, i.e. HELB, IRAK3, ENSBTAG00000026993, GRIP1 and part of HMGA2. Regions under selection in indicine cattle display significant enrichment for promoters and coding genes. At the nucleotide level, sites that show a strong divergence in allele frequency between European taurine and Asian indicine are enriched for the same functional categories. We identified nine single nucleotide polymorphisms (SNPs) in coding regions that are fixed for different alleles between subspecies, eight of which were located within the DNA helicase B (HELB) gene. By mining information from the 1000 Bull Genomes Project, we found that HELB carries mutations that are specific to indicine cattle but also found in taurine cattle, which are known to have been subject to indicine introgression from breeds, such as N'Dama, Anatolian Red, Marchigiana, Chianina, and Piedmontese. Based on in-house genome sequences, we proved that mutations in HELB segregate independently of the copy number variation HMGA2-CNV, which is located in the same region. CONCLUSIONS: Major genomic sequence differences between Bos taurus and Bos indicus are enriched for promoter and coding regions. We identified a 430-kb selective sweep in Asian indicine cattle located on chromosome 5, which carries SNPs that are fixed in indicine populations and located in the coding sequences of the HELB gene. HELB is involved in the response to DNA damage including exposure to ultra-violet light and is associated with reproductive traits and yearling weight in tropical cattle. Thus, HELB likely contributed to the adaptation of tropical cattle to their harsh environment.


Assuntos
Bovinos/genética , DNA Helicases/genética , Alelos , Animais , Sequência de Bases/genética , Cruzamento , Variações do Número de Cópias de DNA/genética , Dano ao DNA/genética , DNA Helicases/metabolismo , Domesticação , Feminino , Frequência do Gene/genética , Genótipo , Masculino , Mutação de Sentido Incorreto/genética , Fases de Leitura Aberta/genética , Fenótipo , Polimorfismo de Nucleotídeo Único/genética , Regiões Promotoras Genéticas/genética , Seleção Genética/genética , Sequenciamento Completo do Genoma
8.
Front Genet ; 11: 264, 2020.
Artigo em Inglês | MEDLINE | ID: mdl-32318091

RESUMO

The introduction of wild Atlantic salmon into captivity, and their subsequent artificial selection for production traits, has caused phenotypic differences between domesticated fish and their wild counterparts. Identification of regions of the genome underling these changes offers the promise of characterizing the early biological consequences of domestication. In the current study, we sequenced a population of farmed European Atlantic salmon and compared the observed patterns of SNP variation to those found in conspecific wild populations. This identified 139 genomic regions that contained significantly elevated SNP homozygosity in farmed fish when compared to their wild counterparts. The most extreme was adjacent to versican, a gene involved in control of neural crest cell migration. To control for false positive signals, a second and independent dataset of farmed and wild European Atlantic salmon was assessed using the same methodology. A total of 81 outlier regions detected in the first dataset showed significantly reduced homozygosity within the second one, strongly suggesting the genomic regions identified are enriched for true selection sweeps. Examination of the associated genes identified a number previously characterized as targets of selection in other domestic species and that have roles in development, behavior and olfactory system. These include arcvf, sema6, errb4, id2-like, and 6n1-like genes. Finally, we searched for evidence of parallel sweeps using a farmed population of North American origin. This failed to detect a convincing overlap to the putative sweeps present in European populations, suggesting the factors that drive patterns of variation under domestication and early artificial selection were largely independent. This is the first analysis on domestication of aquaculture species exploiting whole-genome sequence data and resulted in the identification of sweeps common to multiple independent populations of farmed European Atlantic salmon.

9.
Mol Ecol Resour ; 19(6): 1497-1515, 2019 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-31359622

RESUMO

Whole genome sequences (WGS) greatly increase our ability to precisely infer population genetic parameters, demographic processes, and selection signatures. However, WGS may still be not affordable for a representative number of individuals/populations. In this context, our goal was to assess the efficiency of several SNP genotyping strategies by testing their ability to accurately estimate parameters describing neutral diversity and to detect signatures of selection. We analysed 110 WGS at 12× coverage for four different species, i.e., sheep, goats and their wild counterparts. From these data we generated 946 data sets corresponding to random panels of 1K to 5M variants, commercial SNP chips and exome capture, for sample sizes of five to 48 individuals. We also extracted low-coverage genome resequencing of 1×, 2× and 5× by randomly subsampling reads from the 12× resequencing data. Globally, 5K to 10K random variants were enough for an accurate estimation of genome diversity. Conversely, commercial panels and exome capture displayed strong ascertainment biases. Besides the characterization of neutral diversity, the detection of the signature of selection and the accurate estimation of linkage disequilibrium (LD) required high-density panels of at least 1M variants. Finally, genotype likelihoods increased the quality of variant calling from low coverage resequencing but proportions of incorrect genotypes remained substantial, especially for heterozygote sites. Whole genome resequencing coverage of at least 5× appeared to be necessary for accurate assessment of genomic variations. These results have implications for studies seeking to deploy low-density SNP collections or genome scans across genetically diverse populations/species showing similar genetic characteristics and patterns of LD decay for a wide variety of purposes.


Assuntos
Genoma/genética , Polimorfismo de Nucleotídeo Único/genética , Animais , Exoma/genética , Frequência do Gene/genética , Genética Populacional/métodos , Genômica/métodos , Genótipo , Técnicas de Genotipagem/métodos , Cabras/genética , Heterozigoto , Sequenciamento de Nucleotídeos em Larga Escala/métodos , Desequilíbrio de Ligação/genética , Análise de Sequência de DNA/métodos , Ovinos/genética , Sequenciamento Completo do Genoma/métodos
10.
BMC Genomics ; 20(1): 139, 2019 Feb 15.
Artigo em Inglês | MEDLINE | ID: mdl-30770720

RESUMO

BACKGROUND: A key developmental transformation in the life of all vertebrates is the transition to sexual maturity, whereby individuals are capable of reproducing for the first time. In the farming of Atlantic salmon, early maturation prior to harvest size has serious negative production impacts. RESULTS: We report genome wide association studies (GWAS) using fish measured for sexual maturation in freshwater or the marine environment. Genotypic data from a custom 50 K single nucleotide polymorphism (SNP) array was used to identify 13 significantly associated SNP for freshwater maturation with the most strongly associated on chromosomes 10 and 11. A higher number of associations (48) were detected for marine maturation, and the two peak loci were found to be the same for both traits. The number and broad distribution of GWAS hits confirmed a highly polygenetic nature, and GWAS performed separately within males and females revealed sex specific genetic behaviour for loci co-located with positional candidate genes phosphatidylinositol-binding clathrin assembly protein-like (picalm) and membrane-associated guanylate kinase, WW and PDZ domain-containing protein 2 (magi2). CONCLUSIONS: The results extend earlier work and have implications for future applied breeding strategies to delay maturation in this important aquaculture species.


Assuntos
Pesqueiros , Herança Multifatorial , Salmo salar/genética , Maturidade Sexual/genética , Maturidade Sexual/fisiologia , Animais , Sequência de Bases , Cruzamento , Bases de Dados Genéticas , Feminino , Água Doce , Expressão Gênica , Frequência do Gene , Variação Genética , Estudo de Associação Genômica Ampla , Genótipo , Guanilato Quinases/genética , Masculino , Proteínas Monoméricas de Montagem de Clatrina/genética , Polimorfismo de Nucleotídeo Único , Água do Mar , Fatores Sexuais , Tasmânia , Sequenciamento Completo do Genoma
11.
Front Genet ; 9: 369, 2018.
Artigo em Inglês | MEDLINE | ID: mdl-30271423

RESUMO

The availability of a reference genome assembly for Atlantic salmon, Salmo salar, SNP genotyping platforms and low cost sequencing are enhancing the understanding of both life history and production-related traits in this important commercial species. We collected and analyzed transcriptomes from selected tissues of Atlantic salmon to inform future functional and comparative genomics studies. Messenger RNA (mRNA) was isolated from pituitary gland, brain, ovary, and liver before Illumina sequencing produced a total of 640 million 150-bp paired-end reads. Following read mapping, feature counting, and normalization, cluster analysis identified genes highly expressed in a tissue-specific manner. We identified a cluster of 508 tissue specific genes for pituitary gland, 3395 for brain, 2939 for ovary, and 539 for liver. Functional profiling identified gene clusters describing the unique functions of each tissue. Moreover, highly-expressed transcription factors (TFs) present in each tissue-specific gene cluster were identified. TFs belonging to homeobox and bhlh families were identified for pituitary gland, pou and zf-c2h2 families for brain, arid, and zf-c2h2 for ovary and rxr-like family for liver. The data and analysis presented are relevant to the emerging Functional Annotation of All Salmonid Genomes (FAASG) initiative that is seeking to develop a detailed understanding of both salmonid evolution and the genomic elements that drive gene expression and regulation.

12.
Gigascience ; 7(3): 1-17, 2018 03 01.
Artigo em Inglês | MEDLINE | ID: mdl-29618048

RESUMO

Genome sequences for hundreds of mammalian species are available, but an understanding of their genomic regulatory regions, which control gene expression, is only beginning. A comprehensive prediction of potential active regulatory regions is necessary to functionally study the roles of the majority of genomic variants in evolution, domestication, and animal production. We developed a computational method to predict regulatory DNA sequences (promoters, enhancers, and transcription factor binding sites) in production animals (cows and pigs) and extended its broad applicability to other mammals. The method utilizes human regulatory features identified from thousands of tissues, cell lines, and experimental assays to find homologous regions that are conserved in sequences and genome organization and are enriched for regulatory elements in the genome sequences of other mammalian species. Importantly, we developed a filtering strategy, including a machine learning classification method, to utilize a very small number of species-specific experimental datasets available to select for the likely active regulatory regions. The method finds the optimal combination of sensitivity and accuracy to unbiasedly predict regulatory regions in mammalian species. Furthermore, we demonstrated the utility of the predicted regulatory datasets in cattle for prioritizing variants associated with multiple production and climate change adaptation traits and identifying potential genome editing targets.


Assuntos
Genoma/genética , Genômica , Transcriptoma/genética , Animais , Bovinos , Mapeamento Cromossômico , Biologia Computacional , Humanos , Mamíferos , Regiões Promotoras Genéticas , Especificidade da Espécie , Suínos/genética
13.
Sci Rep ; 8(1): 5664, 2018 04 04.
Artigo em Inglês | MEDLINE | ID: mdl-29618750

RESUMO

Teleost fish exhibit a remarkable diversity in the control of sex determination, offering the opportunity to identify novel differentiation mechanisms and their ecological consequences. Here, we perform GWAS using 4715 fish and 46,501 SNP to map sex determination to three separate genomic locations in Atlantic salmon (Salmo salar). To characterize each, whole genome sequencing was performed to 30-fold depth of coverage using 20 fish representing each of three identified sex lineages. SNP polymorphism reveals male fish carry a single copy of the male specific region, consistent with an XX/XY or male heterogametric sex system. Haplotype analysis revealed deep divergence between the putatively ancestral locus on chromosome 2, compared with loci on chromosomes 3 and 6. Haplotypes in fish carrying either the chromosome 3 or 6 loci were nearly indistinguishable, indicating a founding event that occurred following the speciation event that defined Salmo salar from other salmonids. These findings highlight the evolutionarily fluid state of sex determination systems in salmonids, and resolve to the sequence level differences in animals with divergent sex lineages.


Assuntos
Cromossomos , Evolução Molecular , Loci Gênicos , Polimorfismo de Nucleotídeo Único , Salmo salar/genética , Processos de Determinação Sexual/genética , Animais , Feminino , Genoma , Genômica , Masculino , Sequenciamento Completo do Genoma
14.
Nat Commun ; 9(1): 859, 2018 02 28.
Artigo em Inglês | MEDLINE | ID: mdl-29491421

RESUMO

Domestication fundamentally reshaped animal morphology, physiology and behaviour, offering the opportunity to investigate the molecular processes driving evolutionary change. Here we assess sheep domestication and artificial selection by comparing genome sequence from 43 modern breeds (Ovis aries) and their Asian mouflon ancestor (O. orientalis) to identify selection sweeps. Next, we provide a comparative functional annotation of the sheep genome, validated using experimental ChIP-Seq of sheep tissue. Using these annotations, we evaluate the impact of selection and domestication on regulatory sequences and find that sweeps are significantly enriched for protein coding genes, proximal regulatory elements of genes and genome features associated with active transcription. Finally, we find individual sites displaying strong allele frequency divergence are enriched for the same regulatory features. Our data demonstrate that remodelling of gene expression is likely to have been one of the evolutionary forces that drove phenotypic diversification of this common livestock species.


Assuntos
Evolução Molecular , Genoma , Elementos Reguladores de Transcrição , Ovinos/genética , Animais , Cruzamento , Feminino , Frequência do Gene , Masculino , Anotação de Sequência Molecular , Filogenia , Ovinos/classificação
15.
Nat Commun ; 9(1): 813, 2018 03 06.
Artigo em Inglês | MEDLINE | ID: mdl-29511174

RESUMO

The evolutionary basis of domestication has been a longstanding question and its genetic architecture is becoming more tractable as more domestic species become genome-enabled. Before becoming established worldwide, sheep and goats were domesticated in the fertile crescent 10,500 years before present (YBP) where their wild relatives remain. Here we sequence the genomes of wild Asiatic mouflon and Bezoar ibex in the sheep and goat domestication center and compare their genomes with that of domestics from local, traditional, and improved breeds. Among the genomic regions carrying selective sweeps differentiating domestic breeds from wild populations, which are associated among others to genes involved in nervous system, immunity and productivity traits, 20 are common to Capra and Ovis. The patterns of selection vary between species, suggesting that while common targets of selection related to domestication and improvement exist, different solutions have arisen to achieve similar phenotypic end-points within these closely related livestock species.


Assuntos
Animais Domésticos/genética , Domesticação , Genoma , Cabras/genética , Carneiro Doméstico/genética , Animais , Evolução Biológica , Variação Genética/genética , Genômica , Haplótipos , Fenótipo , Filogenia , Seleção Genética , Sequenciamento Completo do Genoma
16.
Genomics ; 110(3): 143-148, 2018 05.
Artigo em Inglês | MEDLINE | ID: mdl-28917637

RESUMO

Copy number variation (CNV) represents a major source of genomic variation. We investigated the diversity of CNV distribution using SNP array data collected from a comprehensive collection of geographically dispersed sheep breeds. We identified 24,558 putative CNVs, which can be merged into 619 CNV regions, spanning 197Mb of total length and corresponding to ~6.9% of the sheep genome. Our results reveal a population differentiation in CNV between different geographical areas, including Africa, America, Asia, Southwestern Asia, Central Europe, Northern Europe and Southwestern Europe. We observed clear distinctions in CNV prevalence between diverse groups, possibly reflecting the population history of different sheep breeds. We sought to determine the gene content of CNV, and found several important CNV-overlapping genes (BTG3, PTGS1 and PSPH) which were involved in fetal muscle development, prostaglandin (PG) synthesis, and bone color. Our study generates a comprehensive CNV map, which may contribute to genome annotation in sheep.


Assuntos
Variações do Número de Cópias de DNA , Carneiro Doméstico/genética , Animais , Cruzamento , Cromossomos de Mamíferos , Genômica , Análise de Sequência com Séries de Oligonucleotídeos , Polimorfismo de Nucleotídeo Único
17.
Front Genet ; 9: 687, 2018.
Artigo em Inglês | MEDLINE | ID: mdl-30662453

RESUMO

Abalone breeding in southern Australia often involves the production of interspecies hybrids through crossing blacklip (Haliotos rubra) and greenlip (H. laevigata) parental populations. To assist applied breeding and investigate genetic divergence, this study applied genome sequencing and variant detection to develop and validate a SNP genotyping tool. Skim short read Illumina sequencing was performed using 24 individuals from each of the two parental species and a hybrid population. Raw reads were assembled into three population specific pools (each 12-15 fold coverage), before mapping was performed against a draft greenlip abalone reference genome. Variant detection identified 22.4 M raw variants across the three populations (SNP and indels), suggesting they are highly heterozygous. First stage filtering defined a high quality SNP collection of 2.2 M variants independently called in each of the three populations. Second stage filtering identified a much smaller set of variants for assay design and genotyping using a validation set of 191 abalone of known population and pedigree. Comparison of allele frequency data revealed a high proportion of SNP (43%) had divergent allele frequency (< 0.2) between the two parental populations, suggesting they should have utility for parentage assignment. A maximum likelihood approach was used to successfully assign 105 of 105 progeny to their known true parent amongst a set of 86 candidate parents, confirming the genotyping tool has utility for applied breeding. Analysis of pairwise allele sharing successfully discriminated animals into populations, and PCA of genetic distance grouped the hybrid animals with intermediate values between the two parental populations. The findings present a library of DNA polymorphism of utility to breeding and ecological application, and begins to characterize the divergence separating two economically important aquaculture species.

18.
Sci Rep ; 7(1): 7623, 2017 08 08.
Artigo em Inglês | MEDLINE | ID: mdl-28790322

RESUMO

Mouflon (Ovis aries musimon) became extinct from mainland Europe after the Neolithic, but remnant populations from the Mediterranean islands of Corsica and Sardinia have been used for reintroductions across Europe since the 19th-century. Mouflon x sheep hybrids are larger-bodied than mouflon, potentially showing increased male reproductive success, but little is known about genomic levels of admixture, or about the adaptive significance of introgression between resident mouflon and local sheep breeds. Here we analysed Ovine medium-density SNP array genotypes of 92 mouflon from six geographic regions, along with data from 330 individuals of 16 domestic sheep breeds. We found lower levels of genetic diversity in mouflon than in domestic sheep, consistent with past bottlenecks in mouflon. Introgression signals were bidirectional and affected most mouflon and sheep populations, being strongest in one Sardinian mouflon population. Developing and using a novel approach to identify chromosomal regions with consistent introgression signals, we infer adaptive introgression from mouflon to domestic sheep related to immunity mechanisms, but not in the opposite direction. Further, we infer that Soay and Sarda sheep carry introgressed mouflon alleles involved in bitter taste perception and/or innate immunity. Our results illustrate the potential for adaptive introgression even among recently diverged populations.


Assuntos
Cruzamento/métodos , Haplótipos , Filogenia , Carneiro Doméstico/genética , Ovinos/genética , Animais , Cruzamentos Genéticos , Europa (Continente) , Feminino , França , Variação Genética , Espécies Introduzidas , Itália , Masculino , Filogeografia , Polimorfismo de Nucleotídeo Único , Ovinos/classificação , Carneiro Doméstico/classificação
19.
BMC Genomics ; 18(1): 484, 2017 06 27.
Artigo em Inglês | MEDLINE | ID: mdl-28655320

RESUMO

We describe an emerging initiative - the 'Functional Annotation of All Salmonid Genomes' (FAASG), which will leverage the extensive trait diversity that has evolved since a whole genome duplication event in the salmonid ancestor, to develop an integrative understanding of the functional genomic basis of phenotypic variation. The outcomes of FAASG will have diverse applications, ranging from improved understanding of genome evolution, to improving the efficiency and sustainability of aquaculture production, supporting the future of fundamental and applied research in an iconic fish lineage of major societal importance.


Assuntos
Aquicultura , Conservação dos Recursos Naturais , Genômica , Internacionalidade , Anotação de Sequência Molecular , Salmonidae/genética , Animais , Evolução Molecular , Genômica/economia , Genômica/normas , Fenótipo , Filogenia
20.
BMC Genomics ; 18(1): 229, 2017 03 14.
Artigo em Inglês | MEDLINE | ID: mdl-28288562

RESUMO

BACKGROUND: The detection of signatures of selection has the potential to elucidate the identities of genes and mutations associated with phenotypic traits important for livestock species. It is also very relevant to investigate the levels of genetic diversity of a population, as genetic diversity represents the raw material essential for breeding and has practical implications for implementation of genomic selection. A total of 1151 animals from nine goat populations selected for different breeding goals and genotyped with the Illumina Goat 50K single nucleotide polymorphisms (SNP) Beadchip were included in this investigation. RESULTS: The proportion of polymorphic SNPs ranged from 0.902 (Nubian) to 0.995 (Rangeland). The overall mean HO and HE was 0.374 ± 0.021 and 0.369 ± 0.023, respectively. The average pairwise genetic distance (D) ranged from 0.263 (Toggenburg) to 0.323 (Rangeland). The overall average for the inbreeding measures FEH, FVR, FLEUT, FROH and FPED was 0.129, -0.012, -0.010, 0.038 and 0.030, respectively. Several regions located on 19 chromosomes were potentially under selection in at least one of the goat breeds. The genomic population tree constructed using all SNPs differentiated breeds based on selection purpose, while genomic population tree built using only SNPs in the most significant region showed a great differentiation between LaMancha and the other breeds. We hypothesized that this region is related to ear morphogenesis. Furthermore, we identified genes potentially related to reproduction traits, adult body mass, efficiency of food conversion, abdominal fat deposition, conformation traits, liver fat metabolism, milk fatty acids, somatic cells score, milk protein, thermo-tolerance and ear morphogenesis. CONCLUSIONS: In general, moderate to high levels of genetic variability were observed for all the breeds and a characterization of runs of homozygosity gave insights into the breeds' development history. The information reported here will be useful for the implementation of genomic selection and other genomic studies in goats. We also identified various genome regions under positive selection using smoothed FST and hapFLK statistics and suggested genes, which are potentially under selection. These results can now provide a foundation to formulate biological hypotheses related to selection processes in goats.


Assuntos
Variação Genética , Genoma , Cabras/genética , Animais , Orelha/anatomia & histologia , Orelha/fisiologia , Frequência do Gene , Estudo de Associação Genômica Ampla , Genótipo , Heterozigoto , Homozigoto , Fenótipo , Polimorfismo de Nucleotídeo Único , Seleção Genética
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