Identification of genes expressed differentially in subcutaneous and visceral fat of cattle, pig, and mouse.
ABSTRACT The factors that control fat deposition in adipose tissues are poorly understood. It is known that visceral adipose tissues display a range of biochemical properties that distinguish them from adipose tissues of subcutaneous origin. However, we have little information on gene expression, either in relation to fat deposition or on interspecies variation in fat deposition. The first step in this study was to identify genes expressed in fat depot of cattle using the differential display RT-PCR method. Among the transcripts identified as having differential expression in the two adipose tissues were cell division cycle 42 homolog (CDC42), prefoldin-5, decorin, phosphate carrier, 12S ribosomal RNA gene, and kelch repeat and BTB domain containing 2 (Kbtbd2). In subsequent experiments, we determined the expression levels of these latter genes in the pig and in mice fed either a control or high-fat diet to compare the regulation of fat accumulation in other animal species. The levels of CDC42 and decorin mRNA were found to be higher in visceral adipose tissue than in subcutaneous adipose tissue in cattle, pig, and mice. However, the other genes studied did not show consistent expression patterns between the two tissues in cattle, pigs, and mice. Interestingly, all genes were upregulated in subcutaneous and/or visceral adipose tissues of mice fed the high-fat diet compared with the control diet. The data presented here extend our understanding of gene expression in fat depots and provide further proof that the mechanisms of fat accumulation differ significantly between animal species.
Article: Contrasting cellularity and fatty acid composition in fat depots from Alentejana and Barrosã bovine breeds fed high and low forage diets.[show abstract] [hide abstract]
ABSTRACT: During the finishing phase of bovines, large amounts of subcutaneous and visceral fats are deposited leading to production inefficiencies with major impact on meat quality. A better understanding of the cellularity features of the main fat depots could provide strategies for adipose tissue manipulation. This study assessed the effect of feeding diets with distinct forage to concentrate ratios on the cellularity of two fat depots of beef cattle and their implications on the fatty acid profile. Thus, two phylogenetically distant Portuguese bovine breeds, Alentejana and Barrosã, were selected. The results did not show differences in subcutaneous fat deposition nor in visceral fat depots partitioning. Plasma adipokines concentration failed to show a consistent relationship with fatness, as leptin remained constant in all experimental groups, whereas interleukin-6 was influenced by breed. Fat depot seems to determine the area and number of adipocytes, with larger adipocytes and a lower number of cells in subcutaneous fat than in mesenteric fat. Neither breed nor diet influenced adipocytes area and number. The contents of total fatty acids, partial sums of fatty acids and conjugated linoleic acid isomeric profile were affected by breed and fat depot. The incorporation of saturated fatty acids (SFA), trans fatty acids, polyunsaturated fatty acids (PUFA) and branched chain fatty acids (BCFA) was higher in mesenteric fat depot, whereas subcutaneous fat depot had greater percentages of monounsaturated fatty acids (MUFA). In addition, SFA and MUFA proportions seem to be breed-related. In spite of the less relevant role of diet, the percentages of PUFA and BCFA were influenced by this factor. Under these experimental conditions, the effect of fat depot on cellularity and fatty acid composition prevails over breed or diet, as reinforced by the principal component analysis.International journal of biological sciences 01/2012; 8(2):214-27. · 2.70 Impact Factor
Article: Advances in swine transcriptomics.[show abstract] [hide abstract]
ABSTRACT: The past five years have seen a tremendous rise in porcine transcriptomic data. Available porcine Expressed Sequence Tags (ESTs) have expanded greatly, with over 623,000 ESTs deposited in Genbank. ESTs have been used to expand the pig-human comparative maps, but such data has also been used in many ways to understand pig gene expression. Several methods have been used to identify genes differentially expressed (DE) in specific tissues or cell types under different treatments. These include open screening methods such as suppression subtractive hybridization, differential display, serial analysis of gene expression, and EST sequence frequency, as well as closed methods that measure expression of a defined set of sequences such as hybridization to membrane arrays and microarrays. The use of microarrays to begin large-scale transcriptome analysis has been recently reported, using either specialized or broad-coverage arrays. This review covers published results using the above techniques in the pig, as well as unpublished data provided by the research community, and reports on unpublished Affymetrix data from our group. Published and unpublished bioinformatics efforts are discussed, including recent work by our group to integrate two broad-coverage microarray platforms. We conclude by predicting experiments that will become possible with new anticipated tools and data, including the porcine genome sequence. We emphasize that the need for bioinformatics infrastructure to efficiently store and analyze the expanding amounts of gene expression data is critical, and that this deficit has emerged as a limiting factor for acceleration of genomic understanding in the pig.International journal of biological sciences 02/2007; 3(3):132-52. · 2.70 Impact Factor
Article: Altered microRNA expression in bovine subcutaneous and visceral adipose tissues from cattle under different diet.[show abstract] [hide abstract]
ABSTRACT: MicroRNAs (miRNAs) are a class of molecular regulators found to participate in numerous biological processes, including adipogenesis in mammals. This study aimed to evaluate the differences of miRNA expression between bovine subcutaneous (backfat) and visceral fat depots (perirenal fat) and the dietary effect on miRNA expression in these fat tissues. Fat tissues were collected from 16 Hereford×Aberdeen Angus cross bred steers (15.5 month old) fed a high-fat diet (5.85% fat, n = 8) or control diet (1.95% fat, n = 8). Total RNA from each animal was subjected to miRNA microarray analysis using a customized Agilent miRNA microarray containing 672 bovine miRNA probes. Expression of miRNAs was not equal between fat depots as well as diets: 207 miRNAs were detected in both fat depots, while 37 of these were found to be tissue specific; and 169 miRNAs were commonly expressed under two diets while 75 were diet specific. The number of miRNAs detected per animal fed the high fat diet was higher than those fed control diet (p = 0.037 in subcutaneous fat and p = 0.002 visceral fat). Further qRT-PCR analysis confirmed that the expression of some miRNAs was highly influenced by diet (miR-19a, -92a, -92b, -101, -103, -106, -142-5p, and 296) or fat depot (miR-196a and -2454). Our results revealed that the miRNA may differ among adipose depots and level of fat in the diet, suggesting that miRNAs may play a role in the regulation of bovine adipogenesis.PLoS ONE 01/2012; 7(7):e40605. · 4.09 Impact Factor