Sugestão de leitura: confira os artigos publicados pelos membros do GDMA
Postado em 19/ago/2019
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Artigo 1: Genome-wide association studies for heat stress response in Bos taurus × Bos indicus crossbred cattle
Autores: Pamela I. Otto, Simone E.F. Guimarães, Lucas L. Verardo, Ana Luísa S. Azevedo, Jeremie Vandenplas, Claudia A. Sevillano, Daniele B.D. Marques, Maria de Fatima A. Pires, Célio de Freitas, Rui S. Verneque, Marta Fonseca Martins, João Cláudio C. Panetto, Wanessa A. Carvalho, Diego O.R. Gobo, Marcos Vinícius G.B. da Silva, Marco A. Machado
Revista: Journal of Dairy Science (2019)
Abstract: Heat stress is an important issue in the global dairy industry. In tropical areas, an alternative to overcome heat stress is the use of crossbred animals or synthetic breeds, such as the Girolando. In this study, we performed a genome-wide association study (GWAS) and post-GWAS analyses for heat stress in an experimental Gir × Holstein F2 population. Rectal temperature (RT) was measured in heat-stressed F2 animals, and the variation between 2 consecutive RT measurements (ΔRT) was used as the dependent variable. Illumina BovineSNP50v1 BeadChip (Illumina Inc., San Diego, CA) and single-SNP approach were used for GWAS. Post-GWAS analyses were performed by gene ontology terms enrichment and gene-transcription factor (TF) networks, generated from enriched TF. The breed origin of marker alleles in the F2population was assigned using the breed of origin of alleles (BOA) approach. Heritability and repeatability estimates (± standard error) for ΔRT were 0.13 ± 0.08 and 0.29 ± 0.06, respectively. Association analysis revealed 6 SNP significantly associated with ΔRT. Genes involved with biological processes in response to heat stress effects (LIF, OSM, TXNRD2, and DGCR8) were identified as putative candidate genes. After performing the BOA approach, the 10% of F2 animals with the lowest breeding values for ΔRT were classified as low-ΔRT, and the 10% with the highest breeding values for ΔRT were classified as high-ΔRT. On average, 49.4% of low-ΔRT animals had 2 alleles from the Holstein breed (HH), and 39% had both alleles from the Gir breed (GG). In high-ΔRT animals, the average proportion of animals for HH and GG were 1.4 and 50.2%, respectively. This study allowed the identification of candidate genes for ΔRT in Gir × Holstein crossbred animals. According to the BOA approach, Holstein breed alleles could be associated with better response to heat stress effects, which could be explained by the fact that Holstein animals are more affected by heat stress than Gir animals and thus require a genetic architecture to defend the body from the deleterious effects of heat stress. Future studies can provide further knowledge to uncover the genetic architecture underlying heat stress in crossbred cattle.
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Artigo 2: Nutrition influence on sow reproductive performance and conceptuses development and survival: a review about L-arginine supplementation
Autores: Karine Assis Costa, Daniele Botelho Diniz Marques, Carolina Filardi de Campos, Alysson Saraiva, José Domingos Guimarães, Simone Eliza Facioni Guimarães
Revista: Livestock Science (2019)
Abstract: During gestation, nutrition is the main environmental factor that influences the intrauterine environment and, consequently, development of embryos and fetuses. In this context, L-arginine supplementation of pregnant sows has been shown to be efficient to improve females’ reproductive performance and conceptuses development. Among the products of arginine metabolism, nitric oxide and polyamines play important roles in placenta and pig conceptuses growth and development, through vascularization and blood flow regulation, cell proliferation, migration and differentiation, tissue formation, among other processes. In this review, we aimed to approach current knowledge about the nutrition influence on sow gestation, emphasizing how L-arginine supplementation may affect reproductive performance and conceptuses development and survival.
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Artigo 3: Dietary L-arginine supplementation during early gestation of gilts affects conceptuses development
Autores: Karine Assis Costa, Alysson Saraiva, José Domingos Guimarães, Daniele Botelho Diniz Marques, Mariana Machado Neves, Lívia Maria Reis Barbosa, Faider Alberto Castaño Villadiego, Renata Veroneze, Letícia Fernanda de Oliveira, Ingrid Soares, Garcia, Susana Amaral Teixeira, Simone Eliza Facioni Guimarães
Revista: Theriogenology (2019)
Abstract: l-arginine supplementation of sows has led to improvement of reproductive performance, but the mechanisms responsible for the positive effects of arginine during gestation on conceptuses survival and development are still poorly understood. Thus, we aimed to evaluate effects of 1.0% l-arginine supplementation (ARG) on phenotypic traits of commercial gilts, embryos and fetuses, concentration of gilts’ blood metabolites, expression of developmental and cellular apoptosis genes in conceptuses of 25 and 35 days. At 25 days, IGF1gene was more expressed in embryos from ARG than in embryos from control gilts (CON) (P = 0.05). At this same gestational age, ARG embryos tended to be heavier compared to CON (P = 0.07) and ARG gilts showed a trend to have a greater arginine concentration in blood plasma (P = 0.06). However, at 35 days of gestation, arginine concentration in blood plasma of ARG gilts tended to be lower compared to CON (P = 0.06) and ARG fetuses showed smaller cephalic-caudal length (P = 0.05). These results indicate that duration of supplementation is determinant for arginine effects, not only on the females performance but also on the conceptuses, since supplementation upregulated IGF1 expression at 25 days, in addition to the reduction of cephalic-caudal length of 35-day fetuses.