Project description:Expression profiling of sheep born to Australian industry sires with high and low genetic merit (Estimated Breeding Values or EBVs) for eye muscle depth (EMD). Progeny (40) from six Poll Dorset sires representing well defined extremes of EBVs for Eye Muscle Depth (low EBV EMD and high EBV EMD) were selected for analysis. The six sires were Australian industry sires with three sires representative of low EBV EMD and three representing high EBV EMD. Microarrays were used for transcription profiling of skeletal muscle samples taken from 40 individual progeny belonging to six Poll Dorset industry sires, with 3 sires extreme for high and 3 sires extreme for low muscling (based on EBV for EMD). Overall design: Sheep longissimus dorsi (LD) skeletal muscle samples were collected from 40 individual progeny belonging to six Poll Dorset industry sires, with 3 sires extreme for high and 3 sires extreme for low muscling (based on EBV for EMD).
Project description:Transcriptional profiling of bovine skeletal muscle comparing metabolically efficient steers to metabolically inefficient steers to ascertain what expression differences can be found in muscle tissue that might help explain differences in this economically significant phenotype. Two condition experiment, efficient versus inefficient animals. 8 efficient and 8 inefficient samples were used representing 16 unique individual animals.
Project description:Expression profiling of sheep born to Australian industry sires with high and low genetic merit (Estimated Breeding Values or EBVs) for eye muscle depth (EMD). Progeny (40) from six Poll Dorset sires representing well defined extremes of EBVs for Eye Muscle Depth (low EBV EMD and high EBV EMD) were selected for analysis. The six sires were Australian industry sires with three sires representative of low EBV EMD and three representing high EBV EMD. Microarrays were used for transcription profiling of skeletal muscle samples taken from 40 individual progeny belonging to six Poll Dorset industry sires, with 3 sires extreme for high and 3 sires extreme for low muscling (based on EBV for EMD). Sheep longissimus dorsi (LD) skeletal muscle samples were collected from 40 individual progeny belonging to six Poll Dorset industry sires, with 3 sires extreme for high and 3 sires extreme for low muscling (based on EBV for EMD).
Project description:The objective of this study was to examine changes in muscle gene expression of growing steers during a period of dietary energy restriction followed by a period of realimentation. Crossbred Aberdeen Angus x Holstein Friesian (n = 24) steers were assigned to one of two feeding treatments. Over a 99 d period, 1 group (n=12) was offered a high energy control diet consisting of concentrates ad libitum and 7 kg of grass silage per head daily. The second group (n=12) was offered an energy restricted diet consisting of grass silage ad libitum plus 0.5 kg of concentrate per head per day. From the end of the differential feeding period (99 d), both groups of animals were offered a total mixed ration (grass silage:concentrate ratio of 80:20). This period, which lasted 200 d, was known as the realimentation period. All animals were slaughtered on d 299 of the study. Muscle biopsies were collected at 2 time points (end of the differential feeding period (d 99) and during the realimentation period (d131). RNA was extracted and muscle gene expression was examined using RNA-seq technology and bioinformatic analysis. During the differential feeding period, 17 over-represented pathways were identified, including the peroxisome proliferator activated receptor signalling, glycolysis/ gluconeogenesis and metabolic pathways controlling the metabolism of lipids and lipoproteins which indicate reduced energy intake and fat tissue accumulation occurring in muscle tissue during the restriction phase. During the realimentation period, 164 differentially expressed genes were annotated to 9 over-represented pathways including starch and sucrose metabolism, carbohydrate digestion and absorption and TGF-β signalling pathway. It is hypothesised that the signalling effects of the TGF-β pathway were reduced thereby promoting accelerated cell growth and proliferation in muscle tissue of animals experiencing compensatory growth. This information can be exploited in genomic breeding programmes to assist selection of cattle with a greater ability to compensate following a period dietary restriction. 24 muscle RNA samples were analysed in total. 6 samples were from muscle biopsies collected at the end of a period of dietary restriction (d99) and 6 samples were from muscle biopsies collected at the peak of compensatory growth (d131). In addition, RNA was also analysed from 6 samples collected from animals fed ad libitum at each of these two timepoints.
Project description:Microarray gene expression profiling to identify differentially regulated genes in Musculus longissimus dorsi (MLD) of Japanese Black (JB) steers compared to Holstein steers (HS) Overall design: pair wise comparison of JB and HS Type: paired t-test
Project description:RNA sequencing (RNA-Seq) was performed on rumen papillae from 16 steers with variation in gain and feed intake. Sixteen rumen papillae samples were sequenced by Cofactor Genomics (St.Louis, MO).
Project description:Growing and finishing phases are two important animal production stages, which differ fundamentally in compositional growth. However, the physiological mechanisms altered concomitantly with the shift in whole-body compositional gain as cattle fatten (growing vs. finished steers), are poorly understood. Microarray analysis using the Bovine Gene 1.0 ST Array was conducted to determine shifts in hepatic genomic expression profiles of growing vs. finishing beef steers. The specific overall hypothesis tested was that genes involved in amino acid, carbohydrate and lipid metabolism, antioxidant capacity and immune responses were differentially expressed in growing vs. finishing steers. Overall design: Sixteen weaned Angus steers (BW = 209 ± 29.4 kg) were randomly assigned (n = 8) to develop through growing (final BW = 301 kg) or finished (final BW = 576 kg) growth phases and individually fed enough of a cotton seed hull-based diet to achieve a constant ADG (1.5 kg/d). Steers had ad libitum access to fresh water and an industry standard vitamin-mineral supplement. Liver samples were collected for RNA extraction and microarray analysis.
Project description:Transcripome of longissimus dorsi muscle was compared between Korean cattle bulls and steers by using a customized bovine Combimatrix microarray containing 10,199 genes. A customized bovine Combimatrix microarray containing 10,199 genes were constructed, and transcripome of longissimus dorsi muscle was compared between Korean cattle bulls (3 bulls) and steers (3 high-marbled and 3 low-marbled steers) by using the microarray hybridzation.
Project description:RNA sequencing (RNA-Seq) was performed on rumen papillae from 16 steers with variation in gain and feed intake. Overall design: Sixteen rumen papillae samples were sequenced by Cofactor Genomics (St.Louis, MO).
Project description:The bovine transcriptome dynamics in logissimus muscle (LM) during the post-natal growth remain unknown. Biopsies of LM from Angus steers were harvested at 0, 60, 120, and 220 d from early-weaning. A 13,153 bovine oligonucleotide array was used for transcript profiling. Functional analysis of microarray data was performed using the Dynamic Impact Approach (DIA) by means of KEGG and DAVID databases. During the growing phase, most of the highly-impacted pathways (e.g. Ascorbate and aldarate metabolism, Drug metabolism - cytochrome P450 and Retinol metabolism) were inhibited. The finishing phase, was characterized with the most striking differences with 3,784 differentially expressed genes (DEG; FDR <0.01). The functional analysis of those DEG revealed that the most-impacted KEGG canonical pathway was “Glycosylphosphatidylinositol (GPI) - anchor biosynthesis”. The inhibition of this pathway suggested a unique role of GPI-anchor proteins in intracellular trafficking during the finishing phase. A mechanism regulating muscle growth during the finishing phase was uncovered in which inhibition of calpastatin and activation of tyrosine aminotransferase ubiquitination promote proteasomal degradation, while the concurrent activation of ribosomal proteins promotes protein synthesis, thus, the balance of these processes likely results in a steady state of protein turnover during the finishing phase. Overall, results underscored the importance of transcriptome dynamics in LM to support key biological functions during rapid growth. The study utilized a subset of 14 animals from a larger study encompassing 32 purebred Aberdeen Angus steers from the University of Illinois beef cattle herd. Steer calves were early-weaned (134 ± 10 d age) and after weaning were placed on a diet of 85% corn silage and 15% wet distiller’s grains (as-fed basis) for 3 wk. Subsequently, one half of Angus (n = 16) steers was randomly assigned to a high-byproduct or high-grain diet for a 112 d growing phase. The high-byproduct diet contained (dry matter basis) 35% corn silage, 20% corn gluten feed, 38% soyhulls, 3% cracked corn, and 3% soybean meal (49% crude protein). The high-grain diet contained 20% corn silage, 68% cracked corn, and 11% soybean meal (49% crude protein). Both diets contained 1% limestone/dicalcium phosphate/mineral/vitamin/urea/dry molasses mixture. Calculated NEG for the high-byproduct diet was 1.19 Mcal/kg and 1.43 Mcal/kg for the high-grain diet. At the end of the growing phase, steers on each group were fed “step-up diets” for 10 d. Step-up diet for high-byproduct-fed steers contained 1.37 Mcal NEG/kg. Step-up diet for high-grain-fed steers contained 1.43 Mcal NEG/kg but contained distiller’s dried grains (16% of dry matter). After the “step-up” period, all steers were finished on a common high-grain finishing diet containing 1.44 Mcal NEG/kg (15% corn silage, 58% cracked corn, 25% dried distiller’s grains, 1% limestone, and 1% urea/mineral/vitamin mixture). All diets were offered on an ad libitum basis. Steers had an individual electronic identification ear tag and individual feed intake data were collected using the GrowSafe system (GrowSafe Systems Ltd., Alberta, Canada). Cattle were harvested at approximately 13 mo age. A bovine oligonucleotide (70-mers) microarray with >13,000 annotated sequences developed at the University of Illinois, was used for transcript profiling. Details on the development, annotation, and use of this microarray have been reported previously by Loor et al., 2007 (http://physiolgenomics.physiology.org/content/32/1/105.abstract). Methods for microarray hybridization and scanning were as reported by Loor et al. (2007). Briefly, slides were hydrated, dried, and placed in a UV Stratalinker 1800 (Stratagene, La Joya, CA) for ~5 min. Slides were washed with 0.2% SDS solution, rinsed with MilliQ (Millipore) H2O, and placed in warm prehybridization soln for 45 min at 42 C. The same amount of Cy3- or Cy5-labelled cDNA from muscle and a reference standard RNA pool (made of different bovine tissues) were co-hybridized using a dye-swap design (i.e., two microarrays per sample). Slides were incubated for 48 h at 45 C prior to scanning. Criteria for evaluation of slide quality included: identification of number of spots with a minimum median signal intensity of 3 SD above background; keeping slides with a minimum of 20,000 spots with minimum median signal intensity of 3 SD above background in both Cy3 and Cy5 channels; and keeping slides with a minimum mean intensity of 400 relative fluorescent units in both Cy3 and Cy5 channels across the entire slide. Data from a total of 112 microarrays were normalized for dye and microarray effects (i.e., Lowess normalization and microarray centering) and used for statistical analysis. Data were analyzed using the Proc MIXED procedure of SAS (SAS, SAS Inst. Inc., Cary, NC). Fixed effects were treatment (high-byproduct, high-grain) and time (0, 56, 120, and 220 d), and dye. Random effects included steer and microarray. A covariate adjustment was used to assess treatment and treatment × time interactions, but time effects on gene expression were assessed without covariate adjustment. Raw P values were adjusted using Benjamini and Hochberg’s false discovery rate (FDR). Differences in relative expression due to treatment × time interactions were considered significant at an FDR-adjusted P < 0.25 or at P < 0.01 for time effects. qPCR data were normalized using the median of 4 suitable internal control genes, and were analyzed using the same statistical model described above. Differences were considered significant at P-value of 0.05.