Navegando por Autor "Guimarães, S. E. F."

Agora exibindo 1 - 20 de 23

Análise filogenética do gene da miogenina
(Arquivo Brasileiro de Medicina Veterinária e Zootecnia, 2008) Schierholt, A. S.; Fonseca, I.; Silva, P. V.; Paiva, S. R.; Chaves, L. C. S.; Lopes, P. S.; Faria, D. A.; Guimarães, S. E. F.
Estudou-se a filogenia do gene da miogenina, um membro da família MyoD, reguladora da miogênese, que ocorre durante o desenvolvimento embrionário, e sua história evolutiva em espécies domésticas que apresentem seqüências de DNA depositadas no Genbank, comparando-se o índice de substituição de nucleotídeos não-sinônimos pelo índice de substituição sinônima. Valores maiores do que um (1) indicaram que o gene sofreu mudanças que tornaram o organismo mais adaptado ao ambiente. As árvores filogenéticas foram obtidas por máxima verossimilhança, e os índices de substituição sinônima e não-sinônima foram analisadas pelo método de parcimônia. Os resultados indicaram que, provavelmente, o gene sofreu evolução adaptativa no grupo Ruminantia, Bos taurus e Ovis aries, depois que essas espécies divergiram do ancestral comum. Para as outras espécies analisadas, o gene parece ter evoluído de modo conservativo.
Analysis of the mouse high‐growth region in pigs
(Journal of Animal Breeding and Genetics, 2009-09-16) Pita, R. H.; Ramos, A. M.; Malek, M.; Lopes, P. S.; Guimarães, S. E. F.; Rothschild, M. F.
In the mouse, homozygous animals for the high growth mutation show a 30–50% increase in growth without becoming obese. This region is homologous to the distal part of pig chromosome 5 (SSC5). A previous genome scan detected several quantitative trait loci (QTL) in this region for body composition and meat quality using a three generation Berkshire × Yorkshire resource family. In this study, the effects on swine growth, fat and meat quality traits of three genes previously identified within the mouse high growth region were analysed. The genes studied were CASP2 and RIPKI domain containing adaptor with death domain (CRADD), suppressor of cytokine signalling 2 (SOCS2) and plexinC1 (PLXNC1). In addition, the influence of two other genes located very close to this region, namely the plasma membrane calcium‐transporting ATPase 1 (ATP2B1) and dual specificity phosphatase 6 (DUSP6) genes, was also investigated. Single nucleotide polymorphisms were identified and used to map these genes to the QTL region on SSC5. Results indicate significant associations between these genes and several phenotypic traits, including fat deposition and growth in pigs. The present study suggests associations of these genes with swine fat and growth related traits, but further studies are needed in order to clearly identify the genes involved in the regulation of the QTL located on SSC5.
Antibody response between pigs of Piau and a commercial breed naturally infected with Porcine circovirus 2
(Arquivo Brasileiro de Medicina Veterinária e Zootecnia, 2016-09) Bulos, L. H. S.; Gonzaga, N. F.; Souza, L. F. L.; Assao, V. S.; Leite, R. A. S.; Rebouças, M. S.; Scatamburlo, T. M.; Guimarães, J. D.; Guimarães, S. E. F.; Lopes, P. S.; Almeida, M. R. L.; Silva Júnior, A.
Brazilian pig population is made up of several naturalized breeds; among them the Piau breed is known for its rusticity and large fat stores. The naturalized breeds, in comparison with commercial ones, may have an increased resistance to diseases circulating in their territory. Thus, this study aimed to verify if there are differences between the serologic profile against Porcine circovirus 2 (PCV2) of Piau pigs and that of a commercial breed from a farm naturally infected by PCV2. The serum viral load was measured by qPCR, and levels of anti-PCV2 antibodies were measured by ELISA. The results showed that the serum viral load was similar across all animals. However, Piau piglets showed higher levels of antibodies compared to commercial piglets (P= 0.05), while sows of the commercial breed showed higher levels than the Piau breed (P< 0.01). There was not a statistical difference between pigs of different production stages in the seroprevalence of PCV2 or the blood viral load. This work demonstrates that, with regard to a natural PCV2 infection, the Piau breed has a different humoral immune response compared to the response developed by the commercial pigs. The results support the importance of conservation of native breeds.
Associação do loco BoLA-DRB3.2 com produção de leite em bovinos da raça Gir
(Arquivo Brasileiro de Medicina Veterinária e Zootecnia, 2005-06) Guimarães, S. E. F.; Machado, M. A.; Nascimento, C. S.; Martinez, M. L.; Silva, M. V. G. B.; Campos, A. L.; Teodoro, R. L.; Verneque, R. S.
A associação entre os alelos do loco BoLA-DRB3.2, identificados pela técnica de PCR-RFLP, e a produção de leite na raça Gir foi estudada por meio da análise de dados moleculares e fenotípicos de 424 vacas Gir, utilizando um modelo misto, sob modelo animal. Os dados moleculares consistiam dos genótipos dos animais para os alelos do loco BoLA-DRB3.2 e os dados fenotípicos eram referentes à produção de leite em até 305 dias de lactação. O loco é altamente polimórfico nesta raça, sendo identificados sete alelos (BoLA-DRB3.2*4, *8, *11, *19, *28, *41 e *48) que não haviam sido encontrados em animais zebuínos. Dois alelos (*16 e *29) estavam significativamente associados com maiores produções de leite, sugerindo que o próprio loco BoLA-DRB3.2 ou um QTL a ele ligado influencia a produção de leite de vacas Gir.
Bayesian GWAS and network analysis revealed new candidate genes for number of teats in pigs
(Journal of Applied Genetics, 2014-08-08) Verardo, L. L.; Silva, F. F.; Varona, L.; Resende, M. D. V.; Bastiaansen, J. W. M.; Lopes, P. S.; Guimarães, S. E. F.
The genetic improvement of reproductive traits such as the number of teats is essential to the success of the pig industry. As opposite to most SNP association studies that consider continuous phenotypes under Gaussian assumptions, this trait is characterized as a discrete variable, which could potentially follow other distributions, such as the Poisson. Therefore, in order to access the complexity of a counting random regression considering all SNPs simultaneously as covariate under a GWAS modeling, the Bayesian inference tools become necessary. Currently, another point that deserves to be highlighted in GWAS is the genetic dissection of complex phenotypes through candidate genes network derived from significant SNPs. We present a full Bayesian treatment of SNP association analysis for number of teats assuming alternatively Gaussian and Poisson distributions for this trait. Under this framework, significant SNP effects were identified by hypothesis tests using 95 % highest posterior density intervals. These SNPs were used to construct associated candidate genes network aiming to explain the genetic mechanism behind this reproductive trait. The Bayesian model comparisons based on deviance posterior distribution indicated the superiority of Gaussian model. In general, our results suggest the presence of 19 significant SNPs, which mapped 13 genes. Besides, we predicted gene interactions through networks that are consistent with the mammals known breast biology (e.g., development of prolactin receptor signaling, and cell proliferation), captured known regulation binding sites, and provided candidate genes for that trait (e.g., TINAGL1 and ICK).
Disruption of bovine sperm functions in the presence of aplastic midpiece defect
(Andrology, 2019) Díaz-Miranda, E. A.; Maitan, P. P.; Machado, T. P.; Camilo, B. S.; Lima, D. A.; Okano, D. S.; Penitente-Filho, J. M.; Machado-Neves, M.; Oliveira, L. L.; Guimarães, S. E. F.; Costa, E. P. da; Guimarães, J. D.
Bulls are of great importance in the productive chain and for this reason they should have a good semen quality. There is no doubt that sperm morphology is very important to bull fertility, although little is known about how exactly the abnormal morphologies may affect sperm functions.To detail the morphological description of the aplastic midpiece defect (AMD), as well as to understand its consequences for male fertility based on membrane and acrosome status, mitochondrial membrane potential and DNA integrity parameters.The bulls were divided into two groups: control, consisting of satisfactory potential breeders (n = 3); and AMD, consisting of unsatisfactory potential breeders with a high percentage of AMD (n = 3). Bulls were evaluated by the breeding soundness evaluation; five ejaculates were collected from each animal and analyzed by flow cytometry. Spermatozoa from AMD group exhibited lower sperm motility and vigor (p < 0.05). In addition, it also exhibited lower mitochondrial membrane potential (p < 0.05), a higher percentage of spermatozoa with DNA fragmentation (p < 0.05), lower acrosome and plasma membrane integrity (p < 0.05), and higher lipid bilayer sperm membrane disorganization (p < 0.05) in comparison with control bulls. These findings may be due to oxidative stress and a reduction of the energy production capacity in addition to an alteration in the structural composition of the sperm cell. Moreover, semen with a high percentage of AMD may also be undergoing apoptosis.Bulls with a high percentage of AMD in their semen are not suitable for reproduction. Furthermore, it suggests there is a putative genetic basis for this sperm defect.
Effect of heat stress and feeding phosphorus levels on pig electron transport chain gene expression
(Animal, 2013-09-09) Weller, M. M. D. C. A.; Alebrante, L.; Campos, P. H. R. F.; Saraiva, A.; Silva, B. A. N.; Donzele, J. L.; Oliveira, R. F. M.; Silva, F. F.; Gasparino, E.; Lopes, P. S.; Guimarães, S. E. F.
The purpose of this study was to evaluate the effect of temperature and different levels of available phosphorus (aP) on the expression of nine genes encoding electron transport chain proteins in the Longissimus dorsi (LD) muscle of pigs. Two trials were carried out using 48 high-lean growth pigs from two different growth phases: from 15 to 30 kg (phase 1) and from 30 to 60 kg (phase 2). Pigs from growth phase 1 were fed with three different levels of dietary aP (0.107%, 0.321% or 0.535%) and submitted either to a thermoneutral (24°C and RH at 76%) or to a heat stress (34°C and RH at 70%) environment. Pigs from growth phase 2 were fed with three different levels of dietary aP (0.116%, 0.306% or 0.496%) and submitted either to a thermoneutral (22ºC and RH at 77%) or to a heat stress (32ºC and RH at 73%) environment. Heat stress decreased (P<0.001) average daily feed intake at both growth phases. At 24°C, pigs in phase 1 fed the 0.321% aP diet had greater average daily gain and feed conversion (P<0.05) than those fed the 0.107% or 0.535% while, at 34°C pigs fed the 0.535% aP had the best performance (P<0.05). Pigs from phase 2 fed the 0.306% aP had best performance in both thermal environments. Gene expression profile was analyzed by quantitative real-time polymerase chain reaction. Irrespective of growing phase, the expression of six genes was lower (P<0.05) at high temperature than at thermoneutrality. The lower expression of these genes under high temperatures evidences the effects of heat stress by decreasing oxidative metabolism, through adaptive physiological mechanisms in order to reduce heat production. In pigs from phase 1, six genes were differentially expressed across aP levels (P<0.05) in the thermoneutral and one gene in the heat stress. In pigs from phase 2, two genes were differentially expressed across aP levels (P<0.05) in both thermal environments. These data revealed strong evidence that phosphorus and thermal environments are key factors to regulate oxidative phosphorylation with direct implications on animal performance.
Effect of maternal nutrition and days of gestation on pituitary gland and gonadal gene expression in cattle
(Journal of Dairy Science, 2016-04) Weller, M. M. D. C. A.; Fortes, M. R. S.; Marcondes, M. I.; Rotta, P. P.; Gionbeli, T. R. S.; Valadares Filho, S. C.; Campos, M. M.; Silva, F. F.; Silva, W.; Moore, S.; Guimarães, S. E. F.
This study investigated effects of maternal overnutrition on gonadal development and pituitary-gonadal gene expression in cattle fetuses at mid- and late-gestation. Twenty-seven multiparous dry cows were fed either high (ad libitum, H) or moderate (M) intake of the same diet. Twelve cows from H (n = 6) and M (n = 6) intake carrying females fetuses were euthanized at 199 and 268 d of gestation (DG; n = 3 for H or M on each DG). Fifteen cows from H (n = 6) and M intake (n = 9) carrying male fetuses were euthanized at 139, 199, and 241 DG (n = 2 for H and n = 3 for M on each DG). Fetal gonads and pituitary gland were sampled for gene expression and histological analyses. Sex-specific responses to maternal intake were observed. Primordial and total follicle numbers were lower in fetal ovaries from H than in M intake cows. These results were the reverse for preantral and antral follicles. Volumetric proportion and diameter of seminiferous cord were lower in fetal testis of H than M intake cows. The expression level of FSHB was greater in pituitary gland of the female fetus from H compared with M intake cows, irrespective of DG, whereas LHB gene expression did not differ. In males, FSHB and LHB gene expression levels were similar between maternal intake groups. Fetal ovarian expression of P450 aromatase, StAR, BMPR2, TGFBR1, GDF9, FSHR, Bax, and CASP3 genes were higher in H than in M intake cows, irrespective of DG. Fetal testicular expression of StAR, HSD17B3, IGF1, IGF2, and IGF1R genes was higher in M than in H intake cows. The differences in gene expression for steroidogenesis, folliculogenesis, and apoptosis may explain the distinct pattern of follicular growth between offspring of M and H intake cows. By contrast, the lower volumetric proportion, diameter, and length of seminiferous cord may relate to decreased gene expression in fetal testis from H intake cows. In conclusion, maternal H intake seems to affect fetal ovarian follicular growth and number of follicles, which may affect the size of ovarian reserve in their offspring. In male fetus, maternal H intake seems to disturb testicular development and may have implications on sperm production. The underlying mechanism of differential gene expression and the effect on offspring reproductive potential should be the focus of further research, especially considering larger sample size, reducing the chance for type I errors.
Effects of nutrient intake level on mammary parenchyma growth and gene expression in crossbred (Holstein × Gyr) prepubertal heifers
(Journal of Dairy Science, 2016-12) Weller, M. M. D. C. A.; Albino, Ronan L.; Marcondes, M. I.; Silva, W.; Daniels, K. M.; Campos, M. M.; Duarte, M. S.; Mescouto, M. L.; Silva, F. F.; Guimarães, S. E. F.
This study investigated the effects of increased nutrient intake levels on prepubertal mammary parenchyma development in crossbreed (Holstein × Gyr) dairy heifers. Eighteen heifers age 3 to 4 mo were fed 1 of 3 nutrient intake levels (n = 6 per treatment) designed to sustain an average daily gain of 0.0 kg/d (maintenance, MA), 0.5 kg/d (low gain, LG), or 1.0 kg/d (high gain, HG). Serum blood samples collected on d 42 and 84 after a 12-h fast were analyzed for triglycerides, leptin, insulin, and insulin-like growth factor 1 (IGF-1). Liver and mammary parenchyma were biopsied on d 42 and harvested on d 84 for gene expression analysis. Parenchyma samples were also used for biochemical and histological analysis. Mammary parenchyma weight was lower in HG than in MA or LG heifers, but mammary extraparenchymal fat was greater in HG heifers than in other groups. Heifers fed the HG diet had a greater fraction of ether extract in their parenchyma than the others and a smaller fraction of crude protein in their parenchyma than MA heifers. Moreover, the HG and LG heifers had greater body fat mass than MA heifers. Nutrient intake level had no effect on the number of intraparenchymal adipocytes. Heifers fed the HG diet had greater serum IGF-1 than the others, and serum insulin was lower in the MA than the HG or LG heifers. Liver GHR, IGF1, and IGFBP3 mRNA expression was higher, but IGFBP2 mRNA was lower in HG heifers than in others. The parenchyma mRNA expression of lipogenic markers, such as CD36, ACCA, FASN, and ADIPOR1, was upregulated by nutrient intake level. Significant nutrient intake × time interactions for lipogenic genes during the experimental period indicated variable gene expression depending on the time point of prepubertal mammary gland development. Overall, our data suggest that enhancing nutrient intake increased body fat accumulation and lipogenesis in the mammary gland to the detriment of parenchyma growth. Moreover, increased lipogenesis in the parenchyma of HG heifers may indicate that fat accumulation occurred because of adipocyte hypertrophy and not differences in adipogenesis. The implications of these results for milk yield needs to be elucidated.
Effects of pregnancy and feeding level on carcass and meat quality traits of Nellore cows
(Meat Science, 2013-05) Duarte, M. S.; Gionbelli, M. P.; Paulino, P. V. R.; Serão, N. V. L.; Silva, L. H. P.; Mezzomo, R.; Dodson, M. V.; Du, M.; Busboom, J. R.; Guimarães, S. E. F.; Valadares Filho, S. C.
Carcass and meat quality traits of 16 pregnant and 5 non-pregnant cows fed at 1.2 times maintenance and 16 pregnant and 6 non-pregnant fed ad libitum were evaluated. Pregnancy did not affect final body weight (FBW; P = 0.0923), cold carcass yield (CCY; P = 0.0513), longissimus muscle area (LMA; P = 0.8260), rib fat thickness (RFT; P = 0.1873) and shear force (WBSF; P = 0.9707). A lower FBW (P = 0.0028), LMA (P = 0.0048) and RFT (P = 0.0001) were observed in feed restricted cows. However, no differences were found for CCY (P = 0.7243) and WBSF (P = 0.0759) among feeding level groups. These data suggests that carcass and meat quality traits are not affected by pregnancy status in Nellore cows. Moreover, although cows experiencing feed restriction did have reduced deposition of subcutaneous fat and lean tissue, there were no major impacts on meat quality traits.
Follicular dynamics and gene expression in granulosa cells, corpora lutea and oocytes from gilts of breeds with low and high ovulation rates
(Reproduction, Fertility and Development, 2013-03-07) Silva, P. V.; Guimarães, S. E. F.; Guimarães, J. D.; Nascimento, C. S.; Lopes, P. S.; Siqueira, J. B.; Amorim, L. S.; Silva, F. Fonseca e; Foxcroft, G. R.
Follicular dynamics and the expression of candidate genes using real-time polymerase chain reaction (PCR) were compared during the oestrous cycle of pig breeds with high (commercial line; n = 24) and low (local Brazilian Piau; n = 21) ovulation rates and prolificacy. Gilts were killed on Days 0, 4, 10 and 18 of the oestrous cycle and visible ovarian follicles were classified by follicular diameter. Recovered cumulus–oocyte complexes were classified as normal or atretic and frozen in liquid nitrogen until RNA extraction. Low ovulation rates and/or prolificacy in Piau gilts was associated with a different pattern of follicle development, with lower numbers of small follicles on Day 18, fewer large follicles on Days 0 and 18 (P ≤ 0.05) and a higher proportion of atretic follicles on Days 0 and 18 (P ≤ 0.05). Compared with commercial line gilts, less-prolific Piau gilts exhibited higher expression of apoptotic genes during luteolysis (CASP3 and FASL; P ≤ 0.05), decreased expression of TGFBR2 and BAX mRNA in the corpus luteum (P ≤ 0.05), higher expression of apoptotic genes (FAS, BCL2 and CASP8; P ≤ 0.05) in granulosa cells and a greater abundance (P ≤ 0.05) of genes controlling oocyte-secreted factors (GDF9, BMP15 and BMP6), suggesting underlying mechanisms controlling differences in follicular development, ovulation rate and inherent prolificacy in this pig breed.
Gene expression profile in zebu dairy cows (Bos taurus indicus) with mastitis caused by Streptococcus agalactiae
(Livestock Science, 2015-10) Fonseca, I.; Cardoso, F. F.; Higa, R. H.; Giachetto, P. F.; Brandão, H. M.; Brito, M. A. V. P.; Ferreira, M. B. D.; Guimarães, S. E. F.; Martins, M. F.
Mastitis is an inflammatory response in the mammary gland caused by an influx of somatic cells, composed mainly of neutrophils, macrophages and lymphocytes. The speed and efficacy of the host’s immune response to the invasive pathogen affects the establishment, persistence and severity of the infection. To characterize the gene expression and response mechanism to infection by Streptococcus agalactiae (S. agalactiae) in zebu dairy cows of the Gyr breed, we carried out a transcriptome study of the cells present in the milk from 17 animals. Milk samples were collected before inoculation (hour 0) and 4, 9 and 24 h after inoculation of the bacteria into one of the quarters and at 0 and 24 h from one of the quarters not inoculated. The transcriptome analysis was done by the microarray and real-time PCR techniques. The microarray technique revealed the existence of 32 differentially expressed genes between inoculation and 4 h afterward. The validation of these results by real-time PCR was done for eight genes. Besides these eight genes, the expression of six others was evaluated by real-time PCR even though they did not present a significant difference by the microarray technique. Of the 14 genes analyzed by real-time PCR, all showed a significant difference in expression for at least one of the comparisons between times. This analysis indicated an increase in the expression of all the genes that presented a significant difference in relation to hour 0, with most of them presenting maximum expression 24 h after inoculation of the pathogen. Comparison of the gene expression between the inoculated and non-inoculated quarters showed greater expression in nine genes in the inoculated quarters. Analyses of gene networks revealed three modules with distinct characteristics 24 h after inoculation and showed that some mechanisms are altered in Gyr dairy cows after infection of the mammary gland by S. agalactiae. In this study it was possible to verify changes in the expression of at least 14 genes related to the immune response of zebuine animals against intramammary infection caused by S. agalactiae. These genes can play important roles in fighting intramammary infection and maintaining the tissue during infection.
Genetic correlations between feed efficiency traits, and growth performance and carcass traits in purebred and crossbred pigs
(Journal of Animal Science, 2017-11-23) Godinho, R. M.; Bergsma, R.; Silva, F. F.; Sevillano, C. A.; Knol, E. F.; Lopes, M. S.; Lope, P. S.; Bastiaansen, J. W. M.; Guimarães, S. E. F.
Selection for feed efficiency (FE) is a strategy to reduce the production costs per unit of animal product, which is one of the major objectives of current animal breeding programs. In pig breeding, selection for FE and other traits traditionally takes place based on purebred pig (PB) performance at the nucleus level, while pork production typically makes use of crossbred animals (CB). The success of this selection, therefore, depends on the genetic correlation between the performance of PB and CB (rpc) and on the genetic correlation (rg) between FE and the other traits that are currently under selection. Different traits are being used to account for FE, but the rpc has been reported only for feed conversion rate. Therefore, this study aimed 1) to estimate the rpc for growth performance, carcass, and FE traits; 2) to estimate rg between traits within PB and CB populations; and 3) to compare three different traits representing FE: feed conversion rate, residual energy intake (REI), and residual feed intake (RFI). Phenotypes of 194,445 PB animals from 23 nucleus farms, and 46,328 CB animals from three farms where research is conducted under near commercial production conditions were available for this study. From these, 22,984 PB and 8,657 CB presented records for feed intake. The PB population consisted of five sire and four dam lines, and the CB population consisted of terminal cross-progeny generated by crossing sires from one of the five PB sire lines with commercially available two-way maternal sow crosses. Estimates of rpc ranged from 0.61 to 0.71 for growth performance traits, from 0.75 to 0.82 for carcass traits, and from 0.62 to 0.67 for FE traits. Estimates of rg between growth performance, carcass, and FE traits differed within PB and CB. REI and RFI showed substantial positive rg estimates in PB (0.84) and CB (0.90) populations. The magnitudes of rpc estimates indicate that genetic progress is being realized in CB at the production level from selection on PB performance at nucleus level. However, including CB phenotypes recorded on production farms, when predicting breeding values, has the potential to increase genetic progress for these traits in CB. Given the genetic correlations with growth performance traits and the genetic correlation between the performance of PB and CB, REI is an attractive FE parameter for a breeding program.
Heritability estimate and genetic correlations of reproductive features in Nellore Bulls, offspring of super precocious, precocious and normal cows under extensive farming conditions
(Reproduction in Domestic Animals, 2011-07-26) Pinho, Rogério Oliveira; Siqueira, J. B.; Oba, E.; Quintino, H. P.; Eler, J. P.; Miranda Neto, T.; Guimarães, S. E. F.; Guimarães, J. D.
The present work aimed to estimate heritability and genetic correlations of reproductive features of Nellore bulls, offspring of mothers classified as superprecocious (M1), precocious (M2) and normal (M3). Twenty one thousand hundred and eighty‐six animals with average age of 21.29 months were used, evaluated through the breeding soundness evaluation from 1999 to 2008. The breeding soundness features included physical semen evaluation (progressive sperm motility and sperm vigour), semen morphology (major, minor and total sperm defects), scrotal circumference (SC), testicular volume (TV) and SC at 18 months of age (SC18). The components of variance, heritability and genetic correlations for and between the features were estimated simultaneously by restricted maximum likelihood, with the use of the vce software system vs 6. The heritability estimates were high for SC18, SC and TV (0.43, 0.63 and 0.54; 0.45, 0.45 and 0.44; 0.42, 0.45 and 0.41, respectively for the categories of mothers M1, M2 and M3) and low for physical and morphological semen aspects. The genetic correlations between SC18 and SC were high, as well as between these variables with TV. High and positive genetic correlations were recorded among SC18, SC and TV with the physical aspects of the semen, although no favourable association was verified with the morphological aspects, for the three categories of mothers. It can be concluded that the mother’s sexual precocity did not affect the heritability of their offspring reproduction features
Iberian origin of Brazilian local pig breeds based on Cytochrome b (MT‐CYB) sequence
(Animal Genetics, 2009-10) Souza, C. A.; Paiva, S. R.; Pereira, R. W.; Guimarães, S. E. F.; Dutra Jr, W. M.; Murata, L. S.; Mariante, A. S.
The aim of this work was to investigate the possible origin of local Brazilian pig breeds through Cytochrome b (MT-CYB) mitochondrial analyses. The results indicated that the main local pig breeds descended from two different European maternal lineages, both Iberian varieties. The haplotype relationship analysis showed that Monteiro, Nilo, Piau and Tatu breeds share haplotypes only with Iberian varieties, while the Moura breed presented a different maternal lineage. The Moura appears to share a high frequency of haplotypes with the Black Hairy Iberian variety and Hungarian Mangalica breed.
Identification and expression levels of pig miRNAs in skeletal muscle
(Livestock Science, 2013-06) Verardo, L. L.; Nascimento, C. S.; Silva, F. F.; Gasparino, E.; Toriyama, E.; Barbosa, A. R.; Costa, K. A.; Lopes, P. S.; Guimarães, S. E. F.; Périssé, I. V.
MicroRNAs are a class of naturally occurring non-coding RNAs. Typically they are $22 nucleotides long and suppress translation of their targets genes. Several laboratories have attempted to identify miRNAs from pig muscle and the bioinformatics strategies using ESTs have proved to be successful for this aim. In this study we report an in silico identification of ncRNA in pig EST libraries focusing on novel pig miRNAs and further investigated the differential expression of pigs miRNAs (known and novel) by quantitative real-time PCR during preand postnatal stage from Commercial and local breed Piau pigs skeletal muscle tissue. We identified two miRNAs not yet described in pigs: hsa-miR-1207-5p and hsa-miR-665. Besides, we found 288 target genes for hsa-miR-1207-5p and 214 for hsa-miR-665; from them, four are muscle specific genes. Through expression analyses, differences were found between pre- and postnatal stages and genetics groups. The findings of miRNAs and their muscle-specific targets in pigs will be helpful for understanding the function and processing of this RNA class in the future. Besides, the miRNAs differentially expressed between Commercial and Piau breeds suggest that they can be used to uncover phenotypic differences across different genetic groups.
Linkage disequilibrium and haplotype block structure in six commercial pig lines
(Journal of Animal Science, 2013-08-01) Veroneze, R.; Lopes, P. S.; Guimarães, S. E. F.; Silva, F. F.; Lopes, M. S.; Harlizius, B.; Knol, E. F.
Linkage disequilibrium (LD) across the genome is critical information for association studies and genomic selection because it determines the number of SNP that should be used for a successful association analysis and genomic selection. Linkage disequilibrium also influences the accuracy of genomic breeding values. Some studies have demonstrated that SNP in strong LD are organized into discrete blocks of haplotypes, which are separated by possibly hot spots of recombination. To reduce the number of markers needed to be genotyped for association mapping, a set of SNP can be selected that labels all haplotype blocks. We estimated the LD, calculated the average haplotype block size for 6 pig lines, and compared the block size between lines. Six commercial pig lines were genotyped using the Illumina PorcineSNP60 (number of markers M = 62,163) Genotyping BeadChip (Illumina Inc.); on average, a panel of 37,623 SNP with an average minor allelic frequency (MAF) of 0.283 was included in the analysis. The LD declined as a function of distance. All pig lines had an average r2 above 0.3 for markers 100 to 150 apart. The estimated average block size was 394.885 kb, and blocks between 100 and 400 kb were most prominent (49.96%) in all lines. These results showed that the extent of LD in pigs is much larger than in the cattle population, in accordance with the genetic map length of pigs, which is much shorter than cattle. The evaluated lines have 2,640 to 3,037 blocks, covering 45% of the pig genome, on average. Differences in haplotype block size between lines were observed for some chromosomes (i.e., SSC 3, 5, 7, 13, 14, and 18), which provide a direction for future studies of haplotype block conservation or divergence across lines.
Performance strategies affect mammary gland development in prepubertal heifers
(Journal of Dairy Science, 2017-10) Albino, R. L.; Sguizzato, A. L.; Daniels, K. M.; Duarte, M. S.; Lopes, M. M.; Guimarães, S. E. F.; Weller, M. M. D. C. A.; Marcondes, M. I.
In Brazil, the majority of dairy cattle are Holstein × Gyr (H×G). It is unknown whether excessive energy intake negatively affects their mammary development to the same extent as in purebred Holsteins. We hypothesized that mammary development of H×G heifers can be affected by dietary energy supply. We evaluated the effect of different average daily gains (ADG) achieved by feeding different amounts of a standard diet during the growing period on biometric measurements, development of mammary parenchyma (PAR) and mammary fat pad (MFP), and blood hormones. At the outset of this 84-d experiment, H×G heifers (n = 18) weighed 102.2 ± 3.4 kg and were 3 to 4 mo of age. Heifers were randomly assigned to 1 of 3 ADG programs using a completely randomized design. Treatments were high gain (HG; n = 6), where heifers were fed to gain 1 kg/d; low gain (LG; n = 6), where heifers were fed to gain 0.5 kg/d; and maintenance (MA; n = 6), where heifers were fed to gain a minimal amount of weight per day. Heifers were fed varying amounts of a single TMR to support desired BW gains. Over the 84 d, periodic biometric and blood hormone measurements were obtained. On d 84, all heifers were slaughtered and carcass and mammary samples were collected. At the end, HG heifers weighed the most (181 ± 7.5 kg), followed by LG (146 ± 7.5 kg) and MA (107 ± 7.5 kg) heifers. The ADG were near expected values and averaged 0.907, 0.500, and 0.105 ± 0.03 kg/d for HG, LG, and MA, respectively. In addition, body lengths, heart girths, and withers heights were affected by dietary treatment, with MA heifers generally being the smallest and HG heifers generally being the largest. Body condition scores differed by treatment and were highest in HG and lowest in MA heifers; in vivo subcutaneous fat thickness measurement and direct analysis of carcass composition supported this. The HG heifers had the heaviest MFP, followed by LG and then MA heifers. Amount of PAR was highest in LG heifers and was the same for HG and MA heifers. The percentage of udder mass occupied by PAR was lowest in HG heifers, differing from LG and MA heifers. Composition of MFP was not evaluated. Regarding PAR composition, no differences in ash or DM were found. On the other hand, CP concentration of PAR for HG heifers was lower than that for LG heifers, which was lower than that for MA heifers. Regarding the fat content, HG treatment was higher than LG and MA treatment, which did not differ from each other. In PAR, differences in relative abundance of genes related to both stimulation and inhibition of mammary growth were observed to depend on dietary treatment, sampling day, or both. The same can be said for most of the blood hormones that were measured in this experiment. In this experiment, high ADG achieved by feeding different amounts of a standard diet during the growing period negatively affected mammary development.
Quantitative trait loci affecting milk production traits on bovine chromosome 6 in zebuine Gyr breed
(Journal of Dairy Science, 2011-02) Silva, A. A.; Azevedo, A. L. S.; Verneque, R. S.; Gasparini, K.; Peixoto, M. G. C. D.; Silva, M. V. G. B. da; Lopes, P. S.; Guimarães, S. E. F.; Machado, M. A.
Fourteen Brazilian dairy Gyr sire families with 657 daughters were analyzed for quantitative trait loci (QTL) on chromosome 6 by using a daughter design for 5 economic traits: milk, fat, and protein production, fat and protein percentage. The cows and sires were genotyped for 27 microsatellites with average spacing between markers of 4.9 cM. In the analyses across 14 families, for the largest significant families, and within family, a QTL was located for milk yield and fat yield close to marker BMS2508 at the 5% chromosome-wide significance level across families and 1% chromosome-wide within families. For fat percentage, a QTL near DIK4482 was identified at the 5% chromosome-wide significance level when all families were analyzed together and at the 1% chromosome-wide significance level within the largest significant families. The different analyses yielded results that were generally consistent for milk yield, fat yield, and fat percentage. The order of the markers in the derived map was consistent with that in the consensus map. Some QTL and candidate genes in dairy cattle for milk production traits are probably preserved in Bos taurus and Bos indicus.
Quantitative trait loci mapping for meat quality traits in swine chromosome 6
(Arquivo Brasileiro de Medicina Veterinária e Zootecnia, 2005-10) Pires, A. V.; Lopes, P. S.; Guimarães, S. E. F.; Guimarães, C. T.; Gomide, L. A. M.; Benevenuto Júnior, A. A.; Carmo, F. M. S.
The current study was carried out to perform QTL mapping on swine chromosome 6 (SSC6) associated to meat quality traits. The F2 population was produced by outbreed crossing using two native Brazilian breed Piau boars and 18 commercial sows. A total of 557 F2 animals were genotyped for 13 microsatellite markers. The traits evaluated on the F2 population were: pH measured 45 minutes and 24 hours post mortem (pH 45, pH24, respectively), drip loss (DL), cooking loss (CL), total loss (TL), intramuscular fat content (IMF), objective tenderness (OT), lightness (L), redness (A), yellowness (B), hue angle (h) and chrome (c). Data were analyzed by multiple regression developed for analysis of outbreed line crosses, using the QTL Express Software. Significant QTL were detected for pH45 and DL traits, and suggestive QTL for DL. QTL were not found for other traits. The pH45 and DL traits may be under the influence of one gene or a gene group located at about 76, 88 and 97cM. More markers should be included in the regions where F-value peaks and suggestive QTL for the DL trait were detected to ascertain whether they are real QTL.