Dataset Information

Microarray analysis of the white muscle transcriptome in feed deprived rainbow trout treated with insulin-like growth factor-I

ABSTRACT: Treatment with insulin-like growth factor-I (IGF-I) during feed deprivation attenuates the weight loss response in both mammals and fish, therefore the reduction in plasma IGF-I concentrations during fasting likely serves as a signal that contributes to the catabolic response. To better understand the physiological mechanisms responsible for this effect rainbow trout were administered IGF-I during a 2 wk period of feed deprivation and changes in gene expression in white muscle were determined using microarray analysis. Weight loss was reduced by 15% (P<0.05) in IGF-I treated fish. A total of 440 transcripts were identified as differentially regulated (P<0.05) between saline and IGF-I treated fish. Genes related to protein degradation were down-regulated and included protease and peptidase genes and genes involved in ubiquitin-proteasome and cathepsin-mediated proteolytic pathways. IGF-I increased expression of myosin binding protein H and coronin-1C, while decreasing expression of other myofibrillar and cytoskeleton-associated genes like troponin-C and parvalbumin-2. Polyadenylate-binding protein 2, a transcription factor that positively regulates myoD and myogenin expression, was upregulated with IGF-I treatment. Additional genes that were differentially regulated are associated with lipid and carbohydrate metabolism, mitochondrial biogenesis and electron transport, gene transcription, signal transduction and regulation of apoptosis. In summary, these data suggest that IGF-I plays a central role in regulating protein degradation, especially via the ubiquitin-proteasomal pathway, and that reductions in protein degradation and the subsequent effects on other physiological systems are largely responsible for the IGF-I-induced reduction in weight loss.

ORGANISM(S): Salmo salar Oncorhynchus mykiss

PROVIDER: GSE31765 | GEO | 2015/02/01

SECONDARY ACCESSION(S): PRJNA145185

REPOSITORIES: GEO

ACCESS DATA

Dataset's files

Source:

			Action	DRS
		Other

Items per page:

1 - 1 of 1

Similar Datasets

Project description:Treatment with insulin-like growth factor-I (IGF-I) during feed deprivation attenuates the weight loss response in both mammals and fish, therefore the reduction in plasma IGF-I concentrations during fasting likely serves as a signal that contributes to the catabolic response. To better understand the physiological mechanisms responsible for this effect rainbow trout were administered IGF-I during a 2 wk period of feed deprivation and changes in gene expression in white muscle were determined using microarray analysis. Weight loss was reduced by 15% (P<0.05) in IGF-I treated fish. A total of 440 transcripts were identified as differentially regulated (P<0.05) between saline and IGF-I treated fish. Genes related to protein degradation were down-regulated and included protease and peptidase genes and genes involved in ubiquitin-proteasome and cathepsin-mediated proteolytic pathways. IGF-I increased expression of myosin binding protein H and coronin-1C, while decreasing expression of other myofibrillar and cytoskeleton-associated genes like troponin-C and parvalbumin-2. Polyadenylate-binding protein 2, a transcription factor that positively regulates myoD and myogenin expression, was upregulated with IGF-I treatment. Additional genes that were differentially regulated are associated with lipid and carbohydrate metabolism, mitochondrial biogenesis and electron transport, gene transcription, signal transduction and regulation of apoptosis. In summary, these data suggest that IGF-I plays a central role in regulating protein degradation, especially via the ubiquitin-proteasomal pathway, and that reductions in protein degradation and the subsequent effects on other physiological systems are largely responsible for the IGF-I-induced reduction in weight loss. Eight approximately 1-year old full-sibling rainbow trout families were housed in individual tanks, according to family, at the National Center for Cool and Cold Water. Each fish was pit-tagged at 7-months of age. At the beginning of the study, fish were anesthetized with tricaine methanesulfonate (MS-222), weighed, and an osmotic pump was surgically inserted into the peritoneal cavity of each fish (n=4 fish/family/treatment, N=16 fish). The osmotic pump contained either recombinant human IGF-I, which released hormone at 25 ug/kg/day, or saline, which was the vehicle used to resuspend IGF-I. Feed was withheld 2-days prior to surgery and for the experimental 2 week period. Fish were harvested using as overdose of MS-222, weighed, and white muscle samples were removed, frozen in liquid N, and stored at -80 C until analysis. Muscle RNA was isolated from muscle of the two families that exhibited the greatest difference in weight loss between IGF-I and saline treatments; families 64 and 107. Hybridizations were performed using a dye-swap design with an IGF-I and saline treated fish within the same family, therefore a total of 16 slides were hybridized using Alexa 647 and Alexa 555 dyes.

Project description:When puberty starts before males reach harvest size, animal welfare and sustainability issues occur in Atlantic salmon (Salmo salar) aquaculture. Hallmarks of male puberty are an increased proliferation activity in the testis and elevated androgen production. Examining transcriptional changes in salmon testis during the transition from immature to maturing testes may help understanding the regulation of puberty, potentially leading to procedures to modulate its start. Since differences in body weight influence, via unknown mechanisms, the chances for entering puberty, we used two feed rations to create body weight differences. Maturing testes were characterized by an elevated proliferation activity of Sertoli cells and of single undifferentiated spermatogonia. Pituitary gene expression data suggest increased Gnrh receptor and gonadotropin gene expression, potentially responsible for the elevated circulating androgen levels in maturing fish. Transcriptional changes in maturing testes included a broad variety of signaling systems (e.g. Tgfβ, Wnt, insulin/Igf, nuclear receptors), but also, activation of metabolic pathways such as anaerobic metabolism and protection against ROS. Feed restriction lowered the incidence of puberty. In males maturing despite feed restriction, plasma androgen levels were higher than in maturing fish receiving the full ration. A group of 449 genes that was up-regulated in maturing fully fed fish, was up-regulated more prominently in testis from fish maturing under caloric restriction. Moreover, 421 genes were specifically up-regulated in testes from fish maturing under caloric restriction, including carbon metabolism genes, a pathway relevant for nucleotide biosynthesis and for placing epigenetic marks. Undifferentiated spermatogonia and Sertoli cell populations increased at the beginning of puberty, which was associated with the up-regulation of metabolic pathways (e.g. anaerobic and ROS pathways) known from other stem cell systems. The higher androgen levels in males maturing under caloric restriction may be responsible for the stronger up-regulation of a common set of (449) maturation-associated genes, and the specific up-regulation of another set of (421) genes. The latter opened regulatory and/or metabolic options for initiating puberty despite feed restriction. As a means to reduce the incidence of male puberty in salmon, however, caloric restriction seems unsuitable.

Project description:The role of different proteins, Always Early (Aly), Spermatocyte Arrest (Sa), Ubi-p63E (Magn) on the gene expression in spermatocyte differentation was assessed by microarray ABSTRACT: The ubiquitin proteasome system (UPS) regulates many biological pathways by posttranslationally ubiquitinating proteins for degradation. Although maintaining a dynamic balance between free ubiquitin and ubiquitinated proteins is key to UPS function, the mechanisms that regulate ubiquitin homeostasis in different tissues through development are not clear. Here we show that loss of function of Drosophila magellan (magn), the polyubiquitin Ubi-p63E, results in specifically meiotic arrest sterility in males. Expression of ubiquitin from magn/Ubi-p63E contributes predominantly to maintaining the free ubiquitin pool in testes. Function of magn/Ubip63E is required cell autonomously for proper meiotic chromatin condensation, cell cycle progression and spermatid differentiation. magn/Ubi-p63E mutant germ cells develop normally to the spermatocyte stage but arrest at the G2/M transition of meiosis I with lack of protein expression of key meiotic cell cycle regulators Boule and Cyclin B. Loss of function of magn/Ubi-p63E did not strongly affect the spermatocyte transcription program regulated by the tTAF and tMAC genes. Knocking down proteasome function specifically in spermatocytes caused a different meiotic arrest phenotype, suggesting that the magn/Ubi-p63E phenotype may not result from general defects in protein degradation. Our results suggest a conserved role of polyubiquitin genes in male meiosis and a potential mechanism leading to meiosis I maturation arrest. RNA was obtained from whole testes of flies with following mutations: 1) aly[2]/aly[5p], 2) sa[1]/sa[2], 3) magn[12c]/magn[23b] or magn[12c]/magn[12c];pSC2, 4) red[1], e[1] (WT). Each genotype had three biological replicates except magn which had four total biological replicates, two from magn[12c]/[23b] and two from [12c]/[12c]; pSC2

Project description:Sustainable aquaculture, which entails proportional replacement of fish-based feed sources by plant-based ingredients, is impeded by the poor growth response frequently seen in fish fed high levels of plant ingredients. To evaluate the potential to improve, by means of early nutritional exposure, the growth of fish fed plant-based feed, rainbow trout swim-up fry were fed for 3 weeks either a plant-based diet (diet V, V-fish) or a diet containing fishmeal and fish oil as protein and fat source (diet M, M-fish). After this 3-week nutritional history period, all V- or M-fish received diet M for a 7-month intermediate growth phase. Both groups were then challenged by feeding diet V for 25 days during which voluntary feed intake, growth, and nutrient utilization were monitored (V-challenge). The results of the V-challenge showed a higher growth rate and higher feed intake in fish of nutritional history V compared to M (see PMID:24386155). To identify the molecular mechanisms that govern the enhancement of feed acceptance following early-feed exposure of diet V, we performed microarray expression analysis using swim-up fry collected at the end of early-feeding exposure (diet M and diet V), as well as brain and liver of juveniles sampled at the end of the V-challenge (M-his and V-his), and employing a rainbow trout microarray platform with 8 X 60K probes per slide. Persistently differentially expressed genes were identified by isolating probes that were differentially expressed (fold change ≥ 1.5 and p {nutritional history} ≤ 0.05), both at the end of the early exposure, and in either brain or liver of juvenile trout at the end of the V-challenge. Overall, 1787 (3-week + Brain) and 924 (3-week + Liver) mRNA probes were found to be persistently affected by nutritional history of early-feeding exposure. This positive response is encouraging as a potential strategy to improve the use of plant-based feed in fish, of interest in the field of fish farming and animal nutrition in general. Furthermore, the genes associated with mediating this positive early feeding effect, could serve as potential biomarkers to evaluate increasing acceptability of plant-based diets in fish farming.

Dataset Information

Microarray analysis of the white muscle transcriptome in feed deprived rainbow trout treated with insulin-like growth factor-I

Dataset's files

Similar Datasets

OmicsDI is part of the ELIXIR infrastructure

Tweets