Project description:Thermal stress alters the transcriptome and subsequent tissue physiology of poultry; thus, it can negatively impact poultry production through reduced meat quality, egg production, and health and wellbeing. The modulation of gene expression is critical to embryonic development and cell proliferation, and growing evidence suggests the role of non-coding RNAs (RNA:RNA interaction) in response to thermal stress in animals. MicroRNAs (miRNAs) comprise a class of small regulatory RNAs that modulate gene expression through posttranscriptional interactions and regulate mRNAs, potentially altering numerous cellular processes. This study was designed to identify and characterize the differential expression of miRNAs in satellite cells (SCs) from the turkey pectoralis major muscle and predict important miRNA:mRNA interactions in these developing SCs under a thermal challenge. Small RNA sequencing was performed on RNA libraries prepared from SCs cultured from 1-week-old male Nicholas commercial turkeys (NCTs) and non-selected Randombred Control Line 2 turkeys during proliferation and differentiation at the control temperature (38°C) or under a thermal challenge (33°C or 43°C). A total of 353 miRNAs (161 known and 192 novel) were detected across the sequenced libraries. Expression analysis found fewer differentially expressed miRNAs in the SCs of NCT birds, suggesting that the miRNA response to heat stress has been altered in birds selected for their modern commercial growth traits. Differentially expressed miRNAs, including those with described roles in muscle development, were detected both among temperature treatments and between genetic lines. A prominent differential expression of miR-206 was found in proliferating turkey SCs with a significant response to thermal challenges in both lines. In differentiating SCs, isoforms of miR-1 had significant differential responses, with the expression of miR-206 being mainly affected only by cold treatment. Target gene predictions and Gene Ontology analysis suggest that the differential expression of miRNAs during thermal stress could significantly affect cellular proliferation and differentiation.
Project description:Thermal stress poses a threat to agricultural systems through increased risk to animal growth, health, and production. Exposure of poultry, especially hatchlings, to extreme temperatures can seriously affect muscle development and thus compromise subsequent meat quality. This study was designed to characterize transcriptional changes induced in turkey muscle satellite cells (SCs) cultured from commercial birds under thermal challenge to determine the applicability of previous results obtained for select research lines. Satellite cells isolated from the pectoralis major muscle of 1-week old commercial fast-growing birds (Nicholas turkey, NCT) and from a slower-growing research line (RBC2) were proliferated in culture at 38°C or 43°C for 72 h. RNAseq analysis found statistically significant differences in gene expression among treatments and between turkey lines with a greater number of genes altered in the NCT SCs suggesting early myogenesis. Pathway analysis identified cell signaling and regulation of Ca2+ as important responses. Expression of the intercellular signaling Wnt genes, particularly Wnt5a and 7a was significantly altered by temperature with differential response between lines. The peripheral calcium channel RYR3 gene was among the genes most highly upregulated by heat stress. Increased expression of RYR3 would likely result in higher resting cytosolic calcium levels and increased overall gene transcription. Although responses in the calcium signaling pathway were similar among the RBC2 and NCT lines, the magnitude of expression changes was greater in the commercially selected birds. These results provide evidence into how SC activity, cellular fate, and ultimately muscle development are altered by heat stress and commercial selection.
Project description:Early muscle development involves the proliferation and differentiation of stem cells (satellite cells, SCs) in the mesoderm to form multinucleated myotubes that mature into muscle fibers and fiber bundles. Proliferation of SCs increases the number of cells available for muscle formation while simultaneously maintaining a population of cells for future response. Differentiation dramatically changes properties of the SCs and environmental stressors can have long lasting effects on muscle growth and physiology. This study was designed to characterize transcriptional changes induced in turkey SCs undergoing differentiation under thermal challenge. Satellite cells from the pectoralis major (p. major) muscle of 1-wk old commercial fast-growing birds (Nicholas turkey, NCT) and from a slower-growing research line (Randombred Control Line 2, RBC2) were proliferated for 72 h at 38 °C and then differentiated for 48 h at 33 °C (cold), 43 °C (hot) or 38 °C (control). Gene expression among thermal treatments and between turkey lines was examined by RNAseq to detect significant differentially expressed genes (DEGs). Cold treatment resulted in significant gene expression changes in the SCs from both turkey lines, with the primary effect being down regulation of the DEGs with overrepresentation of genes involved in regulation of skeletal muscle tissue regeneration and sarcomere organization. Heat stress increased expression of genes reported to regulate myoblast differentiation and survival and to promote cell adhesion particularly in the NCT line. Results suggest that growth selection in turkeys has altered the developmental potential of SCs in commercial birds to increase hypertrophic potential of the p. major muscle and sarcomere assembly. The biology of SCs may account for the distinctly different outcomes in response to thermal challenge on breast muscle growth, development, and structure of the turkey.
Project description:Background: Exposure of poultry to extreme temperatures during the critical period of post-hatch growth can seriously affect muscle development and thus compromise subsequent meat quality. This study was designed to characterize transcriptional changes induced in turkey muscle satellite cells by thermal challenge during differentiation. Our goal is to better define how thermal stress alters breast muscle ultrastructure and subsequent development. Results: Skeletal muscle satellite cells previously isolated from the Pectoralis major muscle of 7-wk-old male turkeys (Meleagris gallopavo) from two breeding lines: the F-line (16 wk body weight-selected) and RBC2 (randombred control line) were used in this study. Cultured cells were induced to differentiate at 38°C (control) or thermal challenge temperatures of 33 or 43°C. After 48 h of differentiation, cells were harvested and total RNA was isolated for RNAseq analysis. Analysis of 39.9 Gb of sequence found 89% mapped to the turkey genome (UMD5.0, annotation 101) with average expression of 18,917 genes per library. In the cultured satellite cells, slow/cardiac muscle isoforms are generally present in greater abundance than fast skeletal isoforms. Statistically significant differences in gene expression were observed among treatments and between turkey lines, with a greater number of genes affected in the F-line cells following cold treatment whereas more differentially expressed (DE) genes were observed in the RBC2 cells following heat treatment. Many of the most significant pathways involved signaling, consistent with ongoing cellular differentiation. Regulation of Ca2+ homeostasis appears to be significantly affected by temperature treatment, particularly cold treatment. Conclusions: Satellite cell differentiation is directly influenced by temperature at the level of gene transcription with greater effects attributed to selection for fast growth. At lower temperature, muscle-associated genes in the satellite cells were among the genes with the greatest down regulation consistent with slower differentiation and smaller myotubes. Fewer expression differences were observed in the differentiating cells than previously observed for proliferating cells. This suggests the impact of temperature on satellite cells occurs primarily at early points in satellite cell activation.
Project description:BackgroundClimate change poses a multi-dimensional threat to food and agricultural systems as a result of increased risk to animal growth, development, health, and food product quality. This study was designed to characterize transcriptional changes induced in turkey muscle satellite cells cultured under cold or hot thermal challenge to better define molecular mechanisms by which thermal stress alters breast muscle ultrastructure.ResultsSatellite cells isolated from the pectoralis major muscle of 7-weeks-old male turkeys from two breeding lines (16 weeks body weight-selected and it's randombred control) were proliferated in culture at 33 °C, 38 °C or 43 °C for 72 h. Total RNA was isolated and 12 libraries subjected to RNAseq analysis. Statistically significant differences in gene expression were observed among treatments and between turkey lines with a greater number of genes altered by cold treatment than by hot and fewer differences observed between lines than between temperatures. Pathway analysis found that cold treatment resulted in an overrepresentation of genes involved in cell signaling/signal transduction and cell communication/cell signaling as compared to control (38 °C). Heat-treated muscle satellite cells showed greater tendency towards expression of genes related to muscle system development and differentiation.ConclusionsThis study demonstrates significant transcriptome effects on turkey skeletal muscle satellite cells exposed to thermal challenge. Additional effects on gene expression could be attributed to genetic selection for 16 weeks body weight (muscle mass). New targets are identified for further research on the differential control of satellite cell proliferation in poultry.
Project description:In this study, we directly compared turkey muscle satellite cell gene expression between satellite cells with the gene Death-Associated Protein (DAP) knocked down by siRNA transfection and those transfected with a lipofectamine control using our 6K Turkey Skeletal Muscle Long Oligo (TSKMLO) microarray (GPL9788). The DAP gene was previously identified as differentially expressed by genetic line and during development of turkey skeletal muscle (Sporer et al., 2011). Gene expression changes were investigated in satellite cells after 72 h of proliferation and after 48 h of differentiation. We identified novel candidate genes and pathways as playing potentially crucial roles in the DAP-mediated attenuation of the normal processes of proliferation and differentiation in turkey satellite cells previously identified by Velleman et al. (submitted).
Project description:In this study, we directly compared turkey muscle satellite cell gene expression between satellite cells with the gene versican (VCAN) knocked down by siRNA transfection and those transfected with a lipofectamine control using our 6K Turkey Skeletal Muscle Long Oligo (TSKMLO) microarray (GPL9788). The VCAN gene was previously identified as differentially expressed by genetic line and during development of turkey skeletal muscle (Sporer et al., 2011). Gene expression changes were investigated in satellite cells after 72 h of proliferation and after 48 h of differentiation. We identified novel candidate genes and pathways as playing potentially crucial roles in the VCAN-mediated effects on the normal processes of proliferation and differentiation in turkey satellite cells previously identified by Velleman et al. (submitted).
Project description:In this study, we directly compared turkey muscle satellite cell gene expression between satellite cells with the gene Matrix Gla Protein (MGP) knocked down by siRNA transfection and those transfected with a lipofectamine control using our 6K Turkey Skeletal Muscle Long Oligo (TSKMLO) microarray (GPL9788). The MGP gene was previously identified as differentially expressed by genetic line and during development of turkey skeletal muscle (Sporer et al., 2011). Gene expression changes were investigated in satellite cells after 72 h of proliferation and after 48 h of differentiation. We identified novel candidate genes and pathways as playing potentially crucial roles in the MGP-mediated effects on the normal processes of proliferation and differentiation in turkey satellite cells previously identified by Velleman et al. (submitted).
Project description:In this study, we directly compared turkey muscle satellite cell gene expression between satellite cells with the gene Matrix Gla Protein (MGP) knocked down by siRNA transfection and those transfected with a lipofectamine control using our 6K Turkey Skeletal Muscle Long Oligo (TSKMLO) microarray (GPL9788). The MGP gene was previously identified as differentially expressed by genetic line and during development of turkey skeletal muscle (Sporer et al., 2011). Gene expression changes were investigated in satellite cells after 72 h of proliferation and after 48 h of differentiation. We identified novel candidate genes and pathways as playing potentially crucial roles in the MGP-mediated effects on the normal processes of proliferation and differentiation in turkey satellite cells previously identified by Velleman et al. (submitted). This experiment was designed to investigate the role of MGP expression in turkey satellite cells during two crucial processes in muscle development: proliferation and differentiation. Satellite cells were isolated from 7-week-old turkeys from the RBC2 line. Cells were transfected with either MGP siRNA or a lipofectamine control; MGP expression was knocked down by over 50% with siRNA transfection (Velleman et al., submitted). Satellite cells were then induced to proliferate for 72h or differentiate for 48h; culture plates from each stage (n=4) were frozen until RNA extraction. Microarrays directly compared the MGP -knockdown to control from each of 4 culture plates and utilized a dye swap to equal 8 arrays for each of the cell developmental stages, proliferation and differentiation, and 16 arrays for the overall experiment investigating the role of MGP expression in satellite cell development and function. Hybridizations were performed in random order.
Project description:In this study, we directly compared turkey muscle satellite cell gene expression between satellite cells with the gene versican (VCAN) knocked down by siRNA transfection and those transfected with a lipofectamine control using our 6K Turkey Skeletal Muscle Long Oligo (TSKMLO) microarray (GPL9788). The VCAN gene was previously identified as differentially expressed by genetic line and during development of turkey skeletal muscle (Sporer et al., 2011). Gene expression changes were investigated in satellite cells after 72 h of proliferation and after 48 h of differentiation. We identified novel candidate genes and pathways as playing potentially crucial roles in the VCAN-mediated effects on the normal processes of proliferation and differentiation in turkey satellite cells previously identified by Velleman et al. (submitted). This experiment was designed to investigate the role of VCAN expression in turkey satellite cells during two crucial processes in muscle development: proliferation and differentiation. Satellite cells were isolated from 7-week-old turkeys from the RBC2 line. Cells were transfected with either VCAN siRNA or a lipofectamine control; VCAN expression was knocked down by over 50% with siRNA transfection (Velleman et al., submitted). Satellite cells were then induced to proliferate for 72h or differentiate for 48h; culture plates from each stage (n=4) were frozen until RNA extraction. Microarrays directly compared the VCAN-knockdown to control from each of 4 culture plates and utilized a dye swap to equal 8 arrays for each of the cell developmental stages, proliferation and differentiation, and 16 arrays for the overall experiment investigating the role of VCAN expression in satellite cell development and function. Hybridizations were performed in random order.