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1.
Anim Genet ; 49(6): 539-549, 2018 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-30192028

RESUMO

Progesterone signaling and uterine function are crucial in terms of pregnancy establishment. To investigate how the uterine tissue and its secretion changes in relation to puberty, we sampled tissue and uterine fluid from six pre- and six post-pubertal Brahman heifers. Post-pubertal heifers were sampled in the luteal phase. Gene expression of the uterine tissue was investigated with RNA-sequencing, whereas the uterine fluid was used for protein profiling with mass spectrometry. A total of 4034 genes were differentially expressed (DE) at a nominal P-value of 0.05, and 26 genes were significantly DE after Bonferroni correction (P < 3.1 × 10-6 ). We also identified 79 proteins (out of 230 proteins) that were DE (P < 1 × 10-5 ) in the uterine fluid. When we compared proteomics and transcriptome results, four DE proteins were identified as being encoded by DE genes: OVGP1, GRP, CAP1 and HBA. Except for CAP1, the other three had lower expression post-puberty. The function of these four genes hypothetically related to preparation of the uterus for a potential pregnancy is discussed in the context of puberty. All DE genes and proteins were also used in pathway and ontology enrichment analyses to investigate overall function. The DE genes were enriched for terms related to ribosomal activity. Transcription factors that were deemed key regulators of DE genes are also reported. Transcription factors ZNF567, ZNF775, RELA, PIAS2, LHX4, SOX2, MEF2C, ZNF354C, HMG20A, TCF7L2, ZNF420, HIC1, GTF3A and two novel genes had the highest regulatory impact factor scores. These data can help to understand how puberty influences uterine function.


Assuntos
Bovinos/genética , Proteoma , Maturidade Sexual/genética , Transcriptoma , Útero/fisiologia , Animais , Bovinos/fisiologia , Feminino , Fase Luteal , Análise de Sequência de RNA
2.
J Dairy Sci ; 100(2): 1246-1258, 2017 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-27889128

RESUMO

Female fertility in Holstein cattle can decline when intense genetic selection is placed on milk production. One approach to improving fertility is to identify the genomic regions and variants affecting fertility traits and then incorporate this knowledge into selection decisions. The objectives of this study were to identify or refine the positions of the genomic regions associated with lactation persistency, female fertility traits (age at first service, cow first service to conception, heifer and cow nonreturn rates), longevity traits (herd life, indirect herd life, and direct herd life), and lifetime profit index in the North American Holstein dairy cattle population. A genome-wide association study was performed for each trait, using a single SNP (single nucleotide polymorphism) regression mixed linear model and imputed high-density panel (777k) genotypes. No associations were identified for fertility traits. Several peak regions were detected for lifetime profit index, lactation persistency, and longevity. The results overlap with previous findings and identify some novel regions for lactation persistency. Previously proposed causative and candidate genes supported by this work include DGAT1, GRINA, and CPSF1, whereas new candidate genes are SLC2A4RG and THRB. Thus, the chromosomal regions identified in this study not only confirm several previous findings but also highlight new regions that may contribute to genetic variation in lactation persistency and longevity-associated traits in dairy cattle.


Assuntos
Estudo de Associação Genômica Ampla/veterinária , Longevidade , Animais , Bovinos , Feminino , Fertilidade/genética , Lactação/genética , Fenótipo
3.
Genet Mol Res ; 16(1)2017 Mar 22.
Artigo em Inglês | MEDLINE | ID: mdl-28340271

RESUMO

Fertility traits, such as heifer pregnancy, are economically important in cattle production systems, and are therefore, used in genetic selection programs. The aim of this study was to identify single nucleotide polymorphisms (SNPs) using RNA-sequencing (RNA-Seq) data from ovary, uterus, endometrium, pituitary gland, hypothalamus, liver, longissimus dorsi muscle, and adipose tissue in 62 candidate genes associated with heifer puberty in cattle. RNA-Seq reads were assembled to the bovine reference genome (UMD 3.1.1) and analyzed in five cattle breeds; Brangus, Brahman, Nellore, Angus, and Holstein. Two approaches used the Brangus data for SNP discovery 1) pooling all samples, and 2) within each individual sample. These approaches revealed 1157 SNPs. These were compared with those identified in the pooled samples of the other breeds. Overall, 172 SNPs within 13 genes (CPNE5, FAM19A4, FOXN4, KLF1, LOC777593, MGC157266, NEBL, NRXN3, PEPT-1, PPP3CA, SCG5, TSG101, and TSHR) were concordant in the five breeds. Using Ensembl's Variant Effector Predictor, we determined that 12% of SNPs were in exons (71% synonymous, 29% nonsynonymous), 1% were in untranslated regions (UTRs), 86% were in introns, and 1% were in intergenic regions. Since these SNPs were discovered in RNA, the variants were predicted to be within exons or UTRs. Overall, 160 novel transcripts in 42 candidate genes and five novel genes overlapping five candidate genes were observed. In conclusion, 1157 SNPs were identified in 62 candidate genes associated with puberty in Brangus cattle, of which, 172 were concordant in the five cattle breeds. Novel transcripts and genes were also identified.


Assuntos
Puberdade/genética , Animais , Sequência de Bases , Bovinos , Feminino , Fertilidade/genética , Genoma , Masculino , Polimorfismo de Nucleotídeo Único , Gravidez , RNA/genética , Seleção Genética , Análise de Sequência de RNA/métodos , Maturidade Sexual
4.
Anim Genet ; 47(1): 3-11, 2016 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-26490440

RESUMO

Genomic selection is becoming a standard tool in livestock breeding programs, particularly for traits that are hard to measure. Accuracy of genomic selection can be improved by increasing the quantity and quality of data and potentially by improving analytical methods. Adding genotypes and phenotypes from additional breeds or crosses often improves the accuracy of genomic predictions but requires specific methodology. A model was developed to incorporate breed composition estimated from genotypes into genomic selection models. This method was applied to age at puberty data in female beef cattle (as estimated from age at first observation of a corpus luteum) from a mix of Brahman and Tropical Composite beef cattle. In this dataset, the new model incorporating breed composition did not increase the accuracy of genomic selection. However, the breeding values exhibited slightly less bias (as assessed by deviation of regression of phenotype on genomic breeding values from the expected value of 1). Adding additional Brahman animals to the Tropical Composite analysis increased the accuracy of genomic predictions and did not affect the accuracy of the Brahman predictions.


Assuntos
Cruzamento , Bovinos/genética , Seleção Genética , Maturidade Sexual/genética , Adaptação Fisiológica , Animais , Feminino , Frequência do Gene , Genômica/métodos , Genótipo , Modelos Genéticos , Linhagem , Fenótipo
5.
BMC Genomics ; 16: 872, 2015 Oct 28.
Artigo em Inglês | MEDLINE | ID: mdl-26510479

RESUMO

BACKGROUND: Asian buffaloes (Bubalus bubalis) have an important socio-economic role. The majority of the population is situated in developing countries. Due to the scarce resources in these countries, very few species-specific biotechnology tools exist and a lot of cattle-derived technologies are applied to buffaloes. However, the application of cattle genomic tools to buffaloes is not straightforward and, as results suggested, despite genome sequences similarity the genetic polymorphisms are different. RESULTS: The first SNP chip genotyping platform designed specifically for buffaloes has recently become available. Herein, a genome-wide association study (GWAS) and gene network analysis carried out in buffaloes is presented. Target phenotypes were six milk production and four reproductive traits. GWAS identified SNP with significant associations and suggested candidate genes that were specific to each trait and also genes with pleiotropic effect, associated to multiple traits. CONCLUSIONS: Network predictions of interactions between these candidate genes may guide further molecular analyses in search of disruptive mutations, help select genes for functional experiments and evidence metabolism differences in comparison to cattle. The cattle SNP chip does not offer an optimal coverage of buffalo genome, thereafter the development of new buffalo-specific genetic technologies is warranted. An annotated reference genome would greatly facilitate genetic research, with potential impact to buffalo-based dairy production.


Assuntos
Búfalos/genética , Animais , Indústria de Laticínios , Estudo de Associação Genômica Ampla , Genótipo , Polimorfismo de Nucleotídeo Único/genética
6.
Nat Genet ; 4(2): 206-10, 1993 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-8348158

RESUMO

The presence or absence of horns in Bos taurus is thought to be under the genetic control of the autosomal polled locus, characterized by two alleles: P dominant over p, and causing the polled or hornless phenotype. We have demonstrated genetic linkage between the polled locus and two microsatellite markers, GMPOLL-1 and GMPOLL-2, and have assigned the corresponding linkage group to bovine chromosome 1. This confirms the existence of the postulated polled locus and the hypothesized inheritance pattern. It will allow marker assisted selection for the polledness trait in breeding programs and is a first step towards positional cloning and molecular study of a gene that has been subjected to both natural and artificial selection.


Assuntos
Bovinos/genética , Mapeamento Cromossômico , DNA Satélite/genética , Genes , Cornos/crescimento & desenvolvimento , Alelos , Animais , Cruzamento , Bovinos/anatomia & histologia , Feminino , Marcadores Genéticos , Células Híbridas , Escore Lod , Masculino , Linhagem , Fenótipo , Roedores , Seleção Genética
7.
NPJ Sci Food ; 7(1): 50, 2023 Sep 16.
Artigo em Inglês | MEDLINE | ID: mdl-37717060

RESUMO

The decline in fresh milk in the Western world has in part been substituted by an increased consumption of plant-based beverages (PBB). These are often marketed as healthy and sustainable alternatives to milk and dairy foodstuff, although studies have suggested PBB to be of lower nutrient quality. The current study considered different brands of almond-, oat-, rice-, coconut- and soya-based beverages for a comparative analysis and found that they indeed presented lower contents of total protein, lipids, amino acids, and minerals than cow and goat milk. The only exception was given by soya-based beverages which approximated the protein content (3.47% vs. 3.42 and 3.25% in cow and goat milk, respectively) and amino acid composition of animal milk, and also demonstrated high mineral content. The natural presence of phyto-compounds in PBB characterised as antinutrients and their potential to exacerbate the issue of low nutrient quality by lowering bioavailability have been discussed.

8.
J Anim Breed Genet ; 129(2): 107-19, 2012 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-22394233

RESUMO

Fine mapping of quantitative trait loci (QTL) for 16 ultrasound measurements and carcass merit traits that were collected from 418 hybrid steers was conducted using 1207 SNP markers covering the entire genome. These SNP markers were evaluated using a Bayesian shrinkage estimation method and the empirical critical significant thresholds (α = 0.05 and α = 0.01) were determined by permutation based on 3500 permuted datasets for each trait to control the genome-wide type I error rates. The analyses identified a total of 105 QTLs (p < 0.05) for seven ultrasound measure traits including ultrasound backfat, ultrasound marbling and ultrasound ribeye area and 113 QTLs for seven carcass merit traits of carcass weight, grade fat, average backfat, ribeye area, lean meat yield, marbling and yield grade. Proportion of phenotypic variance accounted for by a single QTL ranged from 0.06% for mean ultrasound backfat to 4.83% for carcass marbling (CMAR) score, while proportion of the phenotypic variance accounted for by all significant (p < 0.05) QTL identified for a single trait ranged from 4.54% for carcass weight to 23.87% for CMAR.


Assuntos
Bovinos/genética , Estudo de Associação Genômica Ampla , Carne , Polimorfismo de Nucleotídeo Único , Locos de Características Quantitativas , Animais , Teorema de Bayes , Pesos e Medidas Corporais , Bovinos/fisiologia , Carne/análise
9.
Genet Mol Res ; 10(4): 3948-62, 2011 Oct 25.
Artigo em Inglês | MEDLINE | ID: mdl-22033911

RESUMO

Bovine spongiform encephalopathy (BSE) is a fatal disorder in cattle characterized by progressive neurodegeneration of the central nervous system. We investigated the molecular mechanisms involved in neurodegeneration during prion infection through the identification of genes that are differentially expressed (DE) between experimentally infected and non-challenged cattle. Gene expression of caudal medulla from control and orally infected animals was compared by microarray analysis using 24,000 bovine oligonucleotides representing 16,846 different genes to identify DE genes associated with BSE disease. In total, 182 DE genes were identified between normal and BSE-infected tissues (>2.0-fold change, P < 0.01); 81 DE genes had gene ontology functions, which included synapse function, calcium ion regulation, immune and inflammatory response, apoptosis, and cytoskeleton organization; 13 of these genes were found to be involved in 26 different Kyoto Encyclopedia of Genes and Genomes (KEGG) pathways. The expression of five DE genes associated with synapse function (tachykinin, synuclein, neuropeptide Y, cocaine, amphetamine-responsive transcript, and synaptosomal-associated protein 25 kDa) and three DE genes associated with calcium ion regulation (parvalbumin, visinin-like, and cadherin) was further validated in the medulla tissue of cattle at different infection times (6, 12, 42, and 45 months post-infection) by qRT-PCR. These data will contribute to a better understanding of the molecular mechanisms of neuropathology in bovine species.


Assuntos
Encefalopatia Espongiforme Bovina/genética , Bulbo/metabolismo , Animais , Bovinos , Bases de Dados Genéticas , Encefalopatia Espongiforme Bovina/metabolismo , Encefalopatia Espongiforme Bovina/patologia , Expressão Gênica , Perfilação da Expressão Gênica/veterinária , Genoma , Bulbo/patologia , Análise em Microsséries/veterinária
10.
J Anim Breed Genet ; 128(4): 305-13, 2011 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-21749477

RESUMO

The objective of this study was to identify single-nucleotide polymorphisms using a bovine chromosome 14 high-density SNP panel after accounting for the effect of DGAT1. Linkage disequilibrium information and sire heterozygosity were used to select markers for linkage analysis on bovine chromosome 14 for milk production traits in 321 Holstein animals. Results show putative milk peaks at 42 and 61 cM, both at p<0.10, a fat yield peak at 42 and 63 cM, both at p<0.05; a protein yield peak at 42 (p<0.01) and 84 cM (p<0.05); fat per cent peaks at 3 (p<0.01) and 29 cM (p<0.05), and a protein per cent peak at 4 cM (p<0.05). Once quantitative trait loci positions were established, allele substitution effects for all markers were evaluated using the same statistical model. Overlaying information between quantitative trait loci (QTL) and allele effect analysis enabled the identification (p<0.01) of 20 SNPs under the milk yield QTL, 2 under both of the fat yield peaks, 8 and 9 under the protein yield peaks, 2 and 6 for the fat per cent peaks and 5 for the protein per cent peak. One SNP in particular, ss61514555:A>C, showed association with 3 of the 5 traits: milk (p=1.59E-04), fat (p=6.88E-05) and protein yields (p=5.76E-05). Overall, combining information from linkage disequilibrium, sire heterozygosity and genetic knowledge of traits enabled the characterization of additional markers with significant associations with milk production traits.


Assuntos
Indústria de Laticínios , Ligação Genética , Lactação/genética , Leite/metabolismo , Polimorfismo de Nucleotídeo Único/genética , Locos de Características Quantitativas/genética , Alelos , Animais , Bovinos , Cromossomos de Mamíferos/genética , Feminino , Marcadores Genéticos , Genótipo , Desequilíbrio de Ligação , Mapeamento Físico do Cromossomo
11.
Anim Genet ; 40(5): 766-9, 2009 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-19466932

RESUMO

A SNP in the promoter region of insulin like growth factor-1 (IGF1) (c.-512C>T) was analysed for associations with 10 fat deposition and carcass merit traits in hybrid (n = 455), Angus (n = 204) and Charolais (n = 186) beef cattle populations. Significant associations of the SNP were found for ultrasound backfat thickness (P = 0.030), carcass average backfat (P = 0.015) and carcass lean meat yield (LMY) (P = 0.023) in the Angus beef population, with the 'CC' genotype showing higher fat depth and lower LMY than the 'TT' genotype. Analyses of transcription factor binding sites based on transcription element search system prediction revealed that the 'C' allele introduces a binding site for nuclear factor I, which has an adipose tissue-specific regulatory role and thus may contribute to the SNP effect on fat deposition in the population of pure Angus cattle, a breed with greater fat depth than the hybrid and Charolais breeds.


Assuntos
Tecido Adiposo/anatomia & histologia , Composição Corporal/genética , Fator de Crescimento Insulin-Like I/genética , Animais , Pesos e Medidas Corporais/veterinária , Cruzamento , Bovinos , Primers do DNA/genética , Estudos de Associação Genética/veterinária , Modelos Lineares , Polimorfismo de Nucleotídeo Único/genética , Especificidade da Espécie , Fatores de Transcrição/metabolismo
12.
J Anim Breed Genet ; 126(3): 216-27, 2009 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-19646150

RESUMO

The detection and mapping of genetic markers linked to quantitative trait loci (QTL) can be utilized to enhance genetic improvement of livestock populations. With the completion of the bovine genome sequence assembly, single nucleotide polymorphisms (SNP) assays spanning the whole bovine genome and research work on large scale identification, validation and analysis of genotypic variation in cattle has become possible. The objective of the present study was to perform a whole genome scan to identify and map QTL affecting milk production traits and somatic cell scores using linkage disequilibrium (LD) regression and 1536 SNP markers. Three and 18 SNP were found to be associated with only milk yield (MY) at a genome and chromosome wise significance (p < 0.05) level respectively. Among the 21 significant SNP, 16 were in a region reported to have QTL for MY in other dairy cattle populations and while the rest five were new QTL finding. Four SNP out of 21 are significant for the milk production traits (MY, fat yield, protein yield (PY), and milk contents) in the present study. Six and nine SNP were associated with PY at a genome and chromosome wise significant (p < 0.05) level respectively. Three and 17 SNP were found to be associated with FY at a genome and chromosome wise significant (p < 0.05) level. Five and seven SNP were mapped with somatic cell score at a genome and chromosome wise significant (p < 0.05) level respectively. The results of this study have revealed QTL for MY, PY, protein percentage, FY, fat percentage, somatic cell score and persistency of milk in the Canadian dairy cattle population. The chromosome regions identified in this study should be further investigated to potentially identify the causative mutations underlying the QTL.


Assuntos
Bovinos/genética , Bovinos/metabolismo , Estudo de Associação Genômica Ampla , Leite/metabolismo , Locos de Características Quantitativas/genética , Animais , Canadá , Feminino , Marcadores Genéticos/genética , Genótipo , Desequilíbrio de Ligação , Metabolismo dos Lipídeos/genética , Masculino , Leite/química , Proteínas do Leite/metabolismo , Polimorfismo de Nucleotídeo Único/genética
13.
Biochem Biophys Res Commun ; 368(3): 455-7, 2008 Apr 11.
Artigo em Inglês | MEDLINE | ID: mdl-18252194

RESUMO

Adipose tissue contains a large portion of stem cells. These cells appear morphologically like fibroblasts and are primarily derived from the stromal cell fraction. Mature (lipid-filled) adipocytes possess the ability to become proliferative cells and have been shown to produce progeny cells that possess the same morphological (fibroblast-like) appearance as the stem cells from the stromal fraction. A closer examination of mature adipocyte-derived progeny cells may prove to be an emerging area of growth/metabolic physiology that may modify present thinking about adipose tissue renewal capabilities. Knowledge of these cells may also prove beneficial in cell-based therapies for tissue repair, regeneration, or engineering.


Assuntos
Adipócitos/citologia , Células-Tronco Adultas/citologia , Técnicas de Cultura de Células/métodos , Engenharia Tecidual/métodos , Adipócitos/fisiologia , Células-Tronco Adultas/fisiologia , Animais , Diferenciação Celular , Células Cultivadas , Humanos
14.
Anim Genet ; 39(3): 225-31, 2008 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-18318789

RESUMO

Feed efficiency is an economically important trait in beef cattle. Net feed efficiency, measured as residual feed intake (RFI), is the difference between actual feed intake and the predicted feed intake required for maintenance and gain of the animal. SNPs that show associations with RFI may be useful quantitative trait nucleotides for marker-assisted selection. This study identified associations between SNPs underlying five RFI QTL on five bovine chromosomes (BTA2, 5, 10, 20 and 29) with measures of dry matter intake (DMI), RFI and feed conversion ratio (FCR) in beef cattle. Six SNPs were found to have effects on RFI (P < 0.05). The largest single SNP allele substitution effect for RFI was -0.25 kg/day located on BTA2. The combined effects of the SNPs found significant in this experiment explained 6.9% of the phenotypic variation of RFI. Not all the RFI SNPs showed associations with DMI and FCR even though these traits are highly correlated with RFI (r = 0.77 and r = 0.62 respectively). This shows that these SNPs may be affecting the underlying biological mechanisms of feed efficiency beyond feed intake control and weight gain efficiency. These SNPs can be used in marker-assisted selection but first it will be important to verify these effects in independent populations of cattle.


Assuntos
Bovinos/genética , Ingestão de Alimentos/genética , Desequilíbrio de Ligação , Polimorfismo de Nucleotídeo Único , Ração Animal , Animais , Genótipo , Masculino , Locos de Características Quantitativas , Aumento de Peso
15.
Anim Genet ; 39(6): 597-605, 2008 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-18717667

RESUMO

The objective of this study was to quantify the extent of linkage disequilibrium (LD) on bovine chromosomes 19 and 29 and to study the pattern of selection signatures in beef and dairy breeds (Angus and Holstein) of Bos taurus. The extent of LD was estimated for 370 and 186 single nucleotide polymorphism markers on BTA19 and 29 respectively using the square of the correlation coefficient (r(2)) among alleles at pairs of loci. A comparison of the extent of LD found that the decline of LD followed a similar pattern in both breeds. We observed long-range LD and found that LD dissipates to background levels at a locus separation of about 20 Mb on both chromosomes. Along each chromosome, patterns of LD were variable in both breeds. We find that a minimum of 30 000 informative and evenly spaced markers would be required for whole-genome association studies in cattle. In addition, we have identified chromosomal regions that show some evidence of selection for economically important traits in Angus and Holstein cattle. The results of this study are of importance for the design and application of association studies.


Assuntos
Bovinos/genética , Mapeamento Cromossômico/veterinária , Indústria de Laticínios , Desequilíbrio de Ligação , Produtos da Carne , Animais , Genótipo , Haplótipos , Polimorfismo de Nucleotídeo Único , Seleção Genética
16.
Anim Genet ; 39(1): 40-5, 2008 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-18162103

RESUMO

Meat tenderness has been difficult to improve using standard genetic selection. Marker assisted selection holds great promise if markers for meat tenderness can be identified. Here, we report quantitative trait loci (QTL) for beef tenderness identified in 598 animals of three Charolais-Brahman x Belmont Red pedigrees after screening the whole genome using 183 DNA markers. In addition to the usual Warner-Bratzler peak force measurements, tenderness was also measured using compression, adhesion and pressure-heat-treated peak force. Three QTL for meat tenderness in the M. longissimus lumborum muscle were found, two of which have not been reported before. One is located in the HEL9-CSSM47 interval on bovine chromosome 8 with a LOD of 3.1 and an effect of 1.02 phenotypic standard deviations for tensile strength of cooked muscle as measured by adhesion. A second QTL is located near CSRM60 on bovine chromosome 10 with a LOD of 2.4 and an effect of 0.48 phenotypic standard deviations for compression. The third QTL is in a region of bovine chromosome 7 that has previously been reported to have a QTL affecting peak force. This region also shows effects on compression and a combined tenderness index. These QTL are all for the myofibrillar component of meat tenderness. No QTL were found for pressure-treated peak force, which is an estimate of the connective tissue component muscle of meat tenderness.


Assuntos
Bovinos/genética , Carne , Locos de Características Quantitativas , Animais , Bovinos/classificação , Bovinos/fisiologia , Mapeamento Cromossômico , Força Compressiva , Feminino , Escore Lod , Masculino , Músculo Esquelético/fisiologia , Linhagem , Fenótipo , Especificidade da Espécie , Resistência à Tração
17.
J Dairy Sci ; 91(7): 2844-56, 2008 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-18565942

RESUMO

Genetic improvement of livestock populations can be achieved through detection and mapping of genetic markers linked to quantitative trait loci (QTL). With the completion of the bovine genome sequence assembly, single nucleotide polymorphism (SNP) assays spanning the whole bovine genome and research work on large-scale identification, validation, and analysis of genotypic variation in cattle has become possible. A total of 462 Canadian Holstein Bulls were used to test the association between SNP and QTL. Single locus linkage disequilibrium regression model was implemented to perform a whole genome scan to identify and map QTL affecting conformation and functional traits. One thousand five hundred thirty-six SNP markers from introns and exons of potential QTL regions for economically important traits across the bovine genome were selected for association analysis. A total of 45 and 151 SNP were found to be associated with 17 conformation and functional traits at a genome- and chromosome-wise significance level, respectively. Among the 196 significant SNP, 169 of them are newly detected in this study, whereas 27 of them have been reported in previous literature and 161 of these were located in genes and are worth further investigating to potentially identify the causative mutations underlying the QTL. The single locus linkage disequilibrium regression method using SNP marker genotypes has proven to be a successful methodology for detecting and mapping QTL in dairy cattle populations.


Assuntos
Bovinos/genética , Mapeamento Cromossômico/veterinária , Desequilíbrio de Ligação , Polimorfismo de Nucleotídeo Único , Locos de Características Quantitativas/genética , Animais , Marcadores Genéticos , Genoma , Genótipo , Masculino
18.
J Anim Sci ; 96(6): 2392-2398, 2018 Jun 04.
Artigo em Inglês | MEDLINE | ID: mdl-29788311

RESUMO

The adipose tissue has been recognized as an active endocrine organ which can modulate numerous physiological processes such as metabolism, appetite, immunity, and reproduction. The aim of this study was to look for differentially abundant proteins and their biological functions in the abdominal adipose tissue between pre- and postpubertal Brahman heifers. Twelve Brahman heifers were divided into 2 groups and paired on slaughter day. Prepubertal heifers had never ovulated and postpubertal heifers were slaughtered on the luteal phase of their second estrous cycle. After ensuring the occurrence of puberty in postpubertal heifers, abdominal adipose tissue samples were collected. Mass spectrometry proteomic analysis identified 646 proteins and revealed that 171 proteins showed differential abundance in adipose tissue between the pre- and postpuberty groups (adjusted P-value < 0.05). Data are available via ProteomeXchange with identifier PXD009452. Using a list of 51 highly differentially abundant proteins as the target (adjusted P-value < 10-5), we found 14 enriched pathways. The results indicated that gluconeogenesis was enhanced when puberty approached. The metabolism of glucose, lipids, and AA in the adipose tissue mainly participated in oxidation and energy supply for heifers when puberty occurred. Our study also revealed the differentially abundant proteins were enriched for estrogen signaling and PI3K-Akt signaling pathways, which are known integrators of metabolism and reproduction. These results suggest new candidate proteins that may contribute to a better understanding of the signaling mechanisms that relate adipose tissue function to puberty. Protein-protein interaction network analysis identified 4 hub proteins that had the highest degrees of connection: PGK1, ALDH5A1, EEF2, and LDHB. Highly connected proteins are likely to influence the functions of all differentially abundant proteins identified, directly or indirectly.


Assuntos
Tecido Adiposo/fisiologia , Bovinos/fisiologia , Proteômica , Maturidade Sexual/fisiologia , Animais , Estrogênios/metabolismo , Feminino , Regulação da Expressão Gênica no Desenvolvimento/fisiologia , Gluconeogênese/fisiologia , Fosfatidilinositol 3-Quinases/genética , Fosfatidilinositol 3-Quinases/metabolismo , Proteínas Proto-Oncogênicas c-akt/genética , Proteínas Proto-Oncogênicas c-akt/metabolismo , Reprodução , Transcriptoma
19.
J Anim Sci ; 96(2): 375-397, 2018 Mar 06.
Artigo em Inglês | MEDLINE | ID: mdl-29390120

RESUMO

The objective of this study was to develop and validate a customized cost-effective single nucleotide polymorphism (SNP) panel for genetic improvement of feed efficiency in beef cattle. The SNPs identified in previous association studies and through extensive analysis of candidate genomic regions and genes, were screened for their functional impact and allele frequency in Angus and Hereford breeds used as validation candidates for the panel. Association analyses were performed on genotypes of 159 SNPs from new samples of Angus (n = 160), Hereford (n = 329), and Angus-Hereford crossbred (n = 382) cattle using allele substitution and genotypic models in ASReml. Genomic heritabilities were estimated for feed efficiency traits using the full set of SNPs, SNPs associated with at least one of the traits (at P ≤ 0.05 and P < 0.10), as well as the Illumina bovine 50K representing a widely used commercial genotyping panel. A total of 63 SNPs within 43 genes showed association (P ≤ 0.05) with at least one trait. The minor alleles of SNPs located in the GHR and CAST genes were associated with decreasing effects on residual feed intake (RFI) and/or RFI adjusted for backfat (RFIf), whereas minor alleles of SNPs within MKI67 gene were associated with increasing effects on RFI and RFIf. Additionally, the minor allele of rs137400016 SNP within CNTFR was associated with increasing average daily gain (ADG). The SNPs genotypes within UMPS, SMARCAL, CCSER1, and LMCD1 genes showed significant over-dominance effects whereas other SNPs located in SMARCAL1, ANXA2, CACNA1G, and PHYHIPL genes showed additive effects on RFI and RFIf. Gene enrichment analysis indicated that gland development, as well as ion and cation transport are important physiological mechanisms contributing to variation in feed efficiency traits. The study revealed the effect of the Jak-STAT signaling pathway on feed efficiency through the CNTFR, OSMR, and GHR genes. Genomic heritability using the 63 significant (P ≤ 0.05) SNPs was 0.09, 0.09, 0.13, 0.05, 0.05, and 0.07 for ADG, dry matter intake, midpoint metabolic weight, RFI, RFIf, and backfat, respectively. These SNPs contributed to genetic variation in the studied traits and thus can potentially be used or tested to generate cost-effective molecular breeding values for feed efficiency in beef cattle.


Assuntos
Bovinos/genética , Metabolismo Energético/genética , Polimorfismo de Nucleotídeo Único/genética , Ração Animal , Animais , Peso Corporal/genética , Bovinos/fisiologia , Ingestão de Alimentos/genética , Metabolismo Energético/fisiologia , Genoma , Genômica , Genótipo , Fenótipo
20.
J Anim Sci ; 95(2): 599-615, 2017 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-28380590

RESUMO

To understand genes, pathways, and networks related to puberty, we characterized the transcriptome of two tissues: the pituitary gland and ovaries. Samples were harvested from pre- and postpubertal Brahman heifers (same age group). Brahman heifers () are older at puberty compared with , a productivity issue. With RNA sequencing, we identified differentially expressed (DEx) genes and important transcription factors (TF) and predicted coexpression networks. The number of DEx genes detected in the pituitary gland was 284 ( < 0.05), and was the most DEx gene (fold change = 4.12, = 0.01). The gene promotes bone mineralization through transforming growth factor-ß (TGFß) signaling. Further studies of the link between bone mineralization and puberty could target . In ovaries, 3,871 genes were DEx ( < 0.05). Four highly DEx genes were noteworthy for their function: (a γ-aminobutyric acid [GABA] transporter), (), and () and its receptor . These genes had higher ovarian expression in postpubertal heifers. The GABA and its receptors and transporters were expressed in the ovaries of many mammals, suggesting a role for this pathway beyond the brain. The pathway has been known to influence the timing of puberty in rats, via modulation of GnRH. The effects of at the hypothalamus, pituitary gland, and ovaries have been documented. and its receptors are known factors in the release of GnRH, similar to and GABA, although their roles in ovarian tissue are less clear. Pathways previously related to puberty such as TGFß signaling ( = 6.71 × 10), Wnt signaling ( = 4.1 × 10), and peroxisome proliferator-activated receptor (PPAR) signaling ( = 4.84 × 10) were enriched in our data set. Seven genes were identified as key TF in both tissues: , , , , , , and a novel gene. An ovarian subnetwork created with TF and significant ovarian DEx genes revealed five zinc fingers as regulators: , , , , and . Recent work of hypothalamic gene expression also pointed to zinc fingers as TF for bovine puberty. Although some zinc fingers may be ubiquitously expressed, the identification of DEx genes in common across tissues points to key regulators of puberty. The hypothalamus and pituitary gland had eight DEx genes in common. The hypothalamus and ovaries had 89 DEx genes in common. The pituitary gland and ovaries had 48 DEx genes in common. Our study confirmed the complexity of puberty and suggested further investigation on genes that code zinc fingers.


Assuntos
Bovinos/genética , Ovário/fisiologia , Hipófise/fisiologia , Maturidade Sexual/genética , Transcriptoma , Animais , Bovinos/crescimento & desenvolvimento , Bovinos/fisiologia , Feminino , Expressão Gênica , Hipotálamo/fisiologia , Receptores de GABA/genética , Maturidade Sexual/fisiologia , Fatores de Transcrição/genética , Ácido gama-Aminobutírico/genética
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