Leandro Teixeira Barbosa

Identification of Suitable Reference Genes for Real Time Quantitative Polymerase Chain Reaction Assays on Pectoralis major Muscle in Chicken ( Gallus gallus )

Thirteen reference genes were investigated to determine their stability to be used as a housekeeping in gene expression studies in skeletal muscle of chickens. Five different algorithms were used for ranking of reference genes and results suggested that individual rankings of the genes differed among them. The stability of the expression of reference genes were validated using samples obtained from the Pectoralis major muscle in chicken. Samples were obtained from chickens in different development periods post hatch and under different nutritional diets. For gene expression calculation the ΔΔCt approach was applied to compare relative expression of pairs of genes within each of 52 samples when normalized to mitochondrially encoded cytochrome c oxidase II (MT-CO2) target gene. Our findings showed that hydroxymethylbilane synthase (HMBS) and hypoxanthine phosphoribosyl transferase 1 (HPRT1) are the most stable reference genes while transferrin receptor (TFRC) and beta-2-microglobulin (B2M) ranked as the least stable genes in the Pectoralis major muscle of chickens. Moreover, our results revealed that HMBS and HPRT1 gene expression did not change due to dietary variations and thus it is recommended for accurate normalization of RT-qPCR data in chicken Pectoralis major muscle.

Estimation of variance components, genetic parameters and genetic trends for litter size of swines

Records of Large White breed animals were used to estimate variance components, genetic parameters and trends for the character total number of born piglets (TNBP) as measure of litter size. For obtaining variance components and genetic parameters, it was used the Restricted Maximum Likelihood Method using MTDFREML software. Two mixed models (additive and repeatability) were evaluated. The additive model contained fixed effect of the contemporary group and the following random effects: direct additive genetic and residual effect for the first parturition. Repeatability model had the same effects of the additive model plus parturition order fixed effect and non-correlated animal permanent environment random effect for the second, third and forth parturition. Direct additive heritability estimates for TNBP were 0.15 and 0.20 for the additive and repeatability models, respectively. The estimate of the ration among variance of the non-correlated effect of animal permanent environment effect and the phenotypic variance, expressed as total variance proportion (c2) was 0.09. The estimates of yearly genetic trends obtained in the additive and repeatability models have similar behaviors (0.02 piglets/sow/year).

Expression of genes related to antioxidant activity in Nile tilapia kept under salinity stress and fed diets containing different levels of vitamin C

ABSTRACT The aim of this study was to examine whether (1) severe changes in salinity produced increased stress, and (2) vitamin C supplementation might reduce the observed damage in Nile tilapia. The parameters measured included condition factor, survival rate, and gene expression of catalase (CAT), heat shock protein 70 (HSP70), glutathione reductase (GSR), glutathione synthase (GSS), and glutathione peroxidase (GPx). The investigation was conducted with 160 Nile tilapia divided into four treatment groups: freshwater; 7 or 21 parts per thousand (‰) salinity, all fed a basal diet; as well as a fourth treatment group consisting of fish kept at 21‰ salinity fed a diet supplemented with vitamin C (1500 mg/kg). For gene expression analysis, liver samples were collected after 24 h or after 14 d. After 24 h, fish raised in 21‰ salinity and fed with the diet supplemented with vitamin C showed similar GPx expression as the control freshwater group. GSS expression in 21‰ salinity was similar to fish exposed to 7‰ salinity. Nile tilapia exposed to 21‰ salinity without vitamin C supplementation exhibited the highest HSP70 gene expression levels after 24 h. After 14-dtreatment, the lowest survival rate was observed in the 21‰ salinity group. After 14 d, the highest expression of GPx and GSR levels was detected in fish in the 21‰ salinity group that received vitamin C. Data indicate that vitamin C supplementation enhanced the expression of genes related to antioxidant capacity in Nile tilapia exposed to higher salinity, thereby increasing protection against the oxidative effects induced by high water salinity.

Avaliação de características de desempenho e de carcaça de codornas de corte por meio da análise de componentes principais

Foram utilizados dados de 288 codornas de corte (Coturnix coturnix coturnix) para avaliar a possibilidade de resumir a informacao contida no complexo de variaveis originais, eliminando-se variaveis inexpressivas por meio da tecnica de componentes principais. Foram registrados o peso vivo (PVIVO) e pesos do peito (PPEITO), das coxas (PCOXA), da gordura abdominal (GA), das visceras comestiveis (figado, moela e coracao) (FIG, MOELA e CORA) e da carcaca eviscerada (PCEVIS). As carcacas foram secas e trituradas para a avaliacao do teor materia seca (MS), gordura (GORD) e proteina bruta (PB). Dos 11 componentes principais, sete (63,6%) apresentaram variância menor que 0,7 (autovalor inferior a 0,7), sendo sugeridas para descarte, respectivamente, em ordem de menor importância, para explicar a variacao total das seguintes variaveis: PCEVIS, PPEITO, PCOXA, CORA, FIG MOELA e GORD. Com base nos resultados, recomenda-se manter as seguintes variaveis em experimentos futuros: PVIVO, MS, PB e GA.

Valor nutritivo da silagem de maniçoba ("Manihot pseudoglaziovii") com e sem fubá de milho como aditivo

O estudo foi conduzido com o objetivo de estudar o valor nutritivo da Manicoba sob a forma de silagem, com ou sem fuba de milho como aditivo. Os tratamentos utilizados foram: silagem de manicoba (SM) com quatro niveis (0; 10; 20 e 30%) de adicao de fuba de milho como aditivo, sendo cinco repeticoes por tratamento. O pH das silagens se manteve entre 4,1 e 4,3 tanto para silagens com e sem aditivo, indicando que ocorreu uma boa fermentacao lactica independente da adicao de fuba de milho. Para DIVMS ocorreram valores crescentes e significativos (P<0,05) a medida que houve aumento da adicao de fuba de milho, sendo que a inclusao de 20 % de fuba foi responsavel pelo maior valor deste parâmetro (65,1 %). As concentracoes de acido acetico e butirico foram reduzidas na medida em que foram adicionados niveis crescentes de aditivo. As concentracoes de acido lactico foram consideradas satisfatorias em todos os tratamentos. Ocorreu decrescimo significativo (p< 0,05) nos teores de FDN e FDA com a inclusao do fuba de milho, sendo encontrado o menor valor para o tratamento com 20 % de aditivo. Conclui-se que a silagem de manicoba e uma alternativa alimentar de bom valor nutricional, principalmente quando adicionado de fuba de milho como aditivo. O melhor nivel de inclusao de fuba de milho na silagem da manicoba e de 20%.

The role of cinnamon as a modulator of the expression of genes related to antioxidant activity and lipid metabolism of laying quails

Since cinnamon has vitamins and minerals in addition to antioxidants compounds in its chemical composition studies have shown the potential of cinnamon supplementation on some important characteristics in the performance of birds. Thus, this study was conducted under the hypothesis that the inclusion of cinnamon in the laying quail diet could influence the performance of the birds through the expression of genes related to antioxidant activity and lipid metabolism. To test this hypothesis, 144 Japanese quail (Coturnix japonica) with an initial age of 18 weeks and average weight of 133g were distributed in a completely randomized design with two treatments: no cinnamon supplementation (NCS—control group) and with supplementation of 9g/kg of cinnamon powder (CPS). The experiment lasted for 84 days. At the end of the experimental period, six animals from each treatment were euthanized by cervical dislocation, blood was collected and organs weighed. Liver tissue was collected for gene expression and biochemical analyses. We observed a significant effect of cinnamon inclusion on the weight of the pancreas (P = 0.0418), intestine (P = 0.0209) and ovary (P = 0.0389). Lower weights of the pancreas and intestine, and a higher ovary weight was observed in birds receiving the CPS diet. Quails fed with cinnamon supplementation also had better feed conversion per egg mass (2.426 g /g, P = 0.0126), and higher triglyceride (1516.60 mg/dL, P = 0.0207), uric acid (7.40 mg/dL, P = 0.0003) and VLDL (300.40 mg/dL, P = 0.0252) contents. A decreased content of thiobarbituric acid reactive substances (TBARS) and lower catalase activity was observed in the liver of quails from the CPS diet (0.086 nmoles/mg PTN, and 2.304 H2O2/min/mg PTN, respectively). Quails from the CPS group presented significantly greater expression of FAS (fatty acid synthase, 36,03 AU), ACC (Acetyl-CoA Carboxylase, 31.33 AU), APOAI (apolipoprotein A-I, 803,9 AU), ESR2 (estrogen receptor 2, 0.73 AU) SOD (superoxide dismutase, 4,933.9 AU) and GPx7 (glutathione peroxidase 7, 9.756 AU) than quails from the control group. These results allow us to suggest that cinnamon powder supplementation in the diet of laying quails can promote balance in the metabolism and better performance through the modulation of antioxidant activity and the expression of genes related to lipid metabolism.

Estimação de parâmetros genéticos de ovinos da raça Santa Inês utilizando modelos uni e bicaracterística

Objetivou-se nesse trabalho, estimar os parâmetros geneticos para caracteristicas de crescimento em ovinos da raca Santa Ines atraves do Metodo da Maxima Verossimilhanca Restrita (REML). Os componentes de (co)variâncias e os parâmetros geneticos foram estimados pelo Software MTDFREML (Multiple Trait Derivative-Free Restricted Maximum Likelihood). As caracteristicas avaliadas em modelos uni e bicaracteristica foram: peso ao nascimento (PN) e peso ao desmame (P90). Alem dos efeitos fixos de sexo, grupo contemporâneo e tipo de parto, foram utilizados os seguintes efeitos aleatorios: efeito genetico aditivo direto, efeito genetico aditivo materno e efeito residual. As estimativas de herdabilidade aditiva direta para PN foram 0,20 e 0,21, para os modelos uni e bicaracteristica, respectivamente. As estimativas de herdabilidade aditiva direta para P90 foram 0,04 e 0,07, para os modelos uni e bicaracteristica, respectivamente. A correlacao genetica entre PN e P90 foi de 0,11, indicando que ambas as caracteristicas devem ser trabalhadas simultaneamente.

Características Estruturais de Gramíneas Tropicais na Região dos Tabuleiros Costeiros Sergipanos

Neste trabalho, foram avaliadas, as caracteristicas morfogenicas de quatro especies de gramineas forrageiras na regiao litorânea de Sergipe. As especies Brachiaria humidicola, Urochloa mosambicensis, Digitaria eriantha pentzii Stent (capim-Pangolao) e Digitaria decumbes foram avaliadas quanto a: taxa de alongamento foliar, taxa de aparecimento foliar, duracao de vida da folha (DVF), taxa de alongamento do pseudocolmo (TxAlPs) e taxa de senescencia (TxSn). Com a analise dos resultados pelo teste de medias (Tukey) a 5% de probabilidade foi possivel observar que todas as variaveis estudadas apresentaram diferenca significativa (P<0,05) entre as especies estudadas. Os resultados que tiveram destaque foram a alta taxa de alongamento foliar (TxAlF) do capim Pangolao, e a alta duracao de vida da folha (DVF) do Braquiaria humidicola superior a 30 dias. DOI:10.15528/2176-4158/rcpa.v14n1p17-20