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Identificação de redes gênicas de coexpressão e dos mecanismos regulatórios associados à composição mineral e qualidade de carne em bovinos
(Universidade Federal de São Carlos, 2019-10-11) Diniz, Wellison Jarles da Silva; Regitano, Luciana Correia de Almeida; https://lattes.cnpq.br/9595338480545794; https://lattes.cnpq.br/7482534979062879
Meat quality and mineral composition are complex traits genetically regulated. Growing evidence suggests that minerals play a central role in regulatory and physiological functions related to meat tenderness and fat deposition in cattle. Furthermore, miRNAs and genes have been identified as potential regulators of these traits. However, there is a lack of knowledge regarding the interplay among miRNA-gene expression-mineral metabolism in cattle. Thus, to explore regulatory pathways, candidate genes and miRNAs, and their relationships to muscle and mineral metabolism in Nelore steers, we integrated gene and miRNA expression data, eQTLs, mineral content, and meat quality traits based on coexpression networks. To this end, the muscle genome-wide expression profiles of mRNAs (n = 200) and miRNAs (n = 50), obtained by RNA-Seq, were used separately to construct co-expression networks using the WGCNA (Weighted gene co-expression network analysis) R package. Phenotypic data of macro (Ca, K, Mg, Na, P, S) and micro minerals (Co, Cr, Cu, Fe, Mn, Se, Zn), as well as meat quality (intramuscular fat, meat pH, and tenderness) were also integrated to identify gene/miRNAs modules associated to these traits. By clustering 11,996 genes and 343 miRNAs, we identified, based on a linear model, 15 and nine modules, respectively, associated with at least one trait (p < 0.05). We identified 82 potential candidate genes based on the module-phenotype association analysis. From the functional analysis, we identified as over-represented biological pathways related to energy and protein metabolism, such as AMPK, mTOR, insulin, and thyroid hormone. We also integrated the gene and miRNA modules, and pointed out 1,815 unique genes targets of 41 miRNAs. Among the minerals, Ca and Fe were strongly regulated, mainly by the miR-29 family. In addition to the pathways previously mentioned, the target genes functional over-representation analysis highlighted signaling pathways such as hypoxia-inducible factor 1, ferroptosis, and p53. Key genes involved in Fe homeostasis, such as transferrin receptor (TFRC), iron responsive element binding protein 2 (IREB2), and transferrin (TF) were identified, as well as those underlying lipid metabolism. Overall, there is a complex relationship between meat quality and mineral metabolism, as well as the fundamental role of miRNAs regulating target genes. Further studies are needed to investigate the effect of different levels of mineral supplementation in gene expression and meat quality traits.
Avaliações histopatológicas de brânquias e fígado de prochilodus lineatus expostos a um novo metalo-inseticida, complexo magnésio-hesperidina-fenantrolina
(Universidade Federal de São Carlos, 2019-10-11) Sachi, Ivelise Teresa de Castro; Fernandes, Marisa Narciso; https://lattes.cnpq.br/3021357484136942; https://lattes.cnpq.br/8402201701060939
Pesticides have been continuously applied in agriculture to control insects considered agricultural pests which increases the likelihood of these products reaching the aquatic environment and affecting the biota, including fish. The present study is of great ecological importance because it evaluated the histopathological lesions and the gills and liver of curimbatá, Prochilodus lineatus (Pisces, Prochilodontidae) after 24 and 96 hours of exposure to increasing concentrations (0, 0,1, 1, 10, 100 and 1000 µg L-1) of the new metallo-insecticide [Mg(hesp)2(phen)] a Mg complex with hesperidin and phenanthroline as a chelating agent called MgHP. In the gills, the most frequent alterations were cell atrophy in the filament epithelium and lamellae, constriction / rupture / dilatation of the marginal canal of the pillar cells, lamellar epithelium hyperplasia, which occurred more frequently after exposure to 100 and 1000 µg. L-1 of MgHP. Gill change index (Iorg) increased significantly after 24 h exposure from 10 to 1000 µg L-1 MgHP and after 96 h exposure to 100 and 1000 µg L-1 MgHP. Chloride (CC) cell proliferation occurred after 96 h of exposure to 100 and 1000 µg L-1 MgHP and was more frequent in the filament epithelium. In the liver, changes in cellular structure were observed, such as hypertrophy, cytoplasmic degeneration and the appearance of intracellular cytoplasmic substances. They were more common and significant at concentrations of 100 and 1000 µg L-1 MgHP in both exposure periods (24 and 96 h). Liver Iorg increased significantly after 24 h exposure at 100 and 1000 µg L-1 MgHP concentrations and after 96 h exposure at 10, 100 and 1000 µg L-1 MgHP concentrations. The data obtained suggest that these lesions may affect the organ structure, altering the physiological functions of the exposed organism and revealed different sensitivity of the gills in relation to the liver. The gills were more sensitive in the first hours of contact with MgHP and showed recovery of gill tissue after 96 h while the liver showed greater changes after 96 h of exposure. Regarding WC, MgHP affected the density of these cells after 24 h, as a reduction was observed, which could cause a transient electrolyte imbalance. On the other hand, an increase in CC density after 96 h suggests a possible compensatory response in order to maintain the ionic balance of the animal. In general, MgHP is not toxic to P. lineatus at low concentrations, such as 0,1 and 1 µg L-1 MgHP, but is potentially toxic at very high concentrations such as 100 and 1000 µg L-1.