Project description:Samples of perirenal fat tissue from 8 Assaf breed suckling lambs. These animals were selected from a larger group of 17 Assaf suckling lambs for which carcass traits were measured. The 8 selected lambs were those showing the highest and the lowest values, from the larger group, for the percentage of perirenal and cavitary fat relative to the half carcass weight. Hence, considering the values for this trait, we defined the High-PF group (n = 4; average: 3.23 ± 0,.47) and the Low-PF group (n = 4; 1.65 ± 0,.16), respectively.
Project description:The aim of this study was to perform a comparative analysis of the perirenal fat transcriptomes of suckling lambs from two breeds with different growth and carcass characteristics. The perirenal fat tissue from 14 suckling lambs (Assaf= 8, Churra= 6) was used for the RNA-Seq analysis. The functional enrichment analysis of the 670 highly expressed genes (>150 fragments per kilobase of exon per million fragments mapped) in the perirenal fat transcriptome of both breeds revealed that the majority of these genes were involved in energy processes. The differential expression analysis performed identified 373 differentially expressed genes (DEGs) between the two compared breeds. In Assaf lambs, DEGs were enriched in Gene Ontology (GO) biological processes related to fatty-acid oxidation, while in Churra lambs, the majority of the significantly enriched GO terms were related to cholesterol synthesis, which suggests that upregulated DEGs in Assaf lambs are implicated in fat burning, while the Churra upregulated DEGs are linked to fat accumulation.
Project description:In sheep, differences were observed regarding fat accumulation and fatty acid composition between males and females, which may impact the quality and organoleptic characteristics of the meat. The analysis of omics technologies is a relevant approach for investigating biological and genetic mechanisms associated with complex traits. Here, the perirenal tissue of six male and six female Assaf suckling lambs was evaluated using RNA sequencing.
Project description:Purpose: The present study was designed to identify both differentially expressed (DE) genes and differences in proteins accumulated in the liver tissues of suckling female lambs, thus trying to identify modified metabolic pathways as a consequence of milk restriction during the suckling period. Methods: Forty Assaf lambs (average BW 4.7 kg) were penned individually, twenty of them were fed milk replacer (200 g dry matter/L) ad libitum (ADL; 192 mL/kg LBW) whereas the other group (restricted, RES) only received 120 mL/kg LBW. When they were 35 days old, four animals per group were slaughtered (8 lambs in total) and a piece of liver was excised for transcriptomic analysis. The liver transcriptome analysis was carried out using RNA sequencing methodology (RNA-seq). Results: 386 DE genes were identified by RNA-seq, 198 of them being annotated genes in the KEGG pathway. Positive values of log2-fold change (log2FC) indicated that 210 genes were up-regulated in the liver of RES relative to the ADL group, whereas negative log2FC values denoted the down-regulation of 176 genes (P < 0.05). Conclusions: According to the data obtained, a restricted milk intake during the suckling period of replacement lambs affects hepatic transcriptome and proteome associated with an altered metabolism of lipids and proteins, thus reducing feed efficiency of replacement period.
Project description:Worldwide, fetal growth restriction (FGR) affects 7 to 10% of pregnancies, or roughly 20.5 million infants, each year. FGR not only increases neonatal mortality and morbidity but also the risk of obesity in later life. Currently, the molecular mechanisms by which FGR "programs" an obese phenotype are not well understood. Studies demonstrate that FGR females are more prone to obesity compared to males; however, the molecular mechanisms that lead to the sexually dimorphic programming of FGR are not known. Thus, we hypothesized that FGR leads to the sexually dimorphic programming of preadipocytes and reduces their ability to differentiate into mature adipocytes. To test the hypothesis, we utilized a maternal hyperthermia-induced placental insufficiency to restrict fetal growth in sheep. We collected perirenal adipose tissue from male and female near-term FGR and normal-weight fetal lambs (N=4 in each group, 16 total), examined the preadipocytes' differentiation potential, and identified differential mRNA transcript expression in perirenal adipose tissue. Male FGR fetuses have lower cellular density compared to control male fetuses. However, no difference was observed in female FGR fetuses compared to control female fetuses. In addition, the ability of preadipocytes to differentiate into mature adipocytes with fat accumulation was impaired in male FGR fetuses, but this was not observed in female FGR fetuses. Finally, we examined the genes and pathways involved in the sexually dimorphic programming of obesity by FGR. On enrichment of differentially expressed genes in males compared to females, the Thermogenesis KEGG Pathway was downregulated, and the Metabolic and Steroid Biosynthesis KEGG pathways were upregulated. On enrichment of differentially expressed genes in male FGR compared to male control, the Steroid Biosynthesis KEGG Pathway was downregulated, and the PPAR Signaling KEGG pathway was upregulated. No pathways were altered in females in response to growth restriction in perirenal adipose tissue. Thus, the present study demonstrates a sexually dimorphic program in response to growth restriction in sheep fetal perirenal adipose tissue.
Project description:Next Generation Sequencing (NGS) was used to measure the levels of gene transcription in perirenal adipose tissue (PRAT) in late gestation sheep fetuses (~ 2 weeks before birth) and in 12 week old lambs.