Project description:The phenotype of an organism results from its genotype and the influence of the environment throughout development. Even when using animals of the same genotype, independent studies may test animals of different phenotypes, resulting in poor replicability due to genotype-by-environment interactions. Thus, genetically defined strains of mice may respond differently to experimental treatments depending on their rearing environment. However, the extent of such phenotypic plasticity and its implications for the replicability of research findings have remained unknown. Here, we examined the extent to which common environmental differences between animal facilities modulate the phenotype of genetically homogeneous (inbred) mice. We conducted a comprehensive multi-center study, whereby inbred C57BL/6J mice from a single breeding cohort were allocated to and reared in five different animal facilities throughout early life and adolescence, before being transported to a single test laboratory. We found persistent effects of the rearing facility on the composition and heterogeneity of the gut microbial community. These effects were paralleled by persistent differences in body weight and in the behavioural phenotype of the mice. Furthermore, we show that environmental variation among animal facilities is strong enough to influence epigenetic patterns in neurons at the level of chromatin organization. We detected changes in chromatin organization in the regulatory regions of genes involved in nucleosome assembly, neuronal differentiation, synaptic plasticity and regulation of behaviour. Our findings demonstrate that common environmental differences between animal facilities may produce facility-specific phenotypes, from the molecular to the behavioural level. Furthermore, they highlight an important limitation of inferences from single-laboratory studies and thus argue that study designs should take environmental background into account to increase the robustness and replicability of findings.

Project description:There is an emerging concern that particulate air pollution increases the risk of cranial nerve disease onset. Small nanoparticles, mainly derived from diesel exhaust particles reach the olfactory bulb by their nasal depositions. It has been reported that diesel exhaust inhalation causes inflammation of the olfactory bulb and other brain regions. However, these toxicological studies have not evaluated animal rearing environment. We hypothesized that rearing environment can change mice phenotypes and thus might alter toxicological study results. In this study, we exposed mice to diesel exhaust inhalation at 90 micro g/m3, 8 hours/day, for 28 consecutive days after rearing in a standard cage or environmental enrichment conditions. Microarray analysis found that expression levels of 112 genes were changed by diesel exhaust inhalation. Functional analysis using Gene Ontology revealed that the dysregulated genes were involved in inflammation and immune response. This result was supported by pathway analysis. Quantitative RT-PCR analysis confirmed 10 genes. Interestingly, background gene expression of the olfactory bulb of mice reared in a standard cage environment was changed by diesel exhaust inhalation, whereas there was no significant effect of diesel exhaust exposure on gene expression levels of mice reared with environmental enrichment. The results indicate for the first time that the effect of diesel exhaust exposure on gene expression of the olfactory bulb was influenced by rearing environment. Rearing environment, such as environmental enrichment, may be an important contributive factor to causation in evaluating still undefined toxic environmental substances such as diesel exhaust. RNA sample was taken from olfactory bulb of 56-day-old mouse received diesel exhaust (DE) inhalation at 90 micro g/m3, 8 hours/day, for 28 consecutive days, while control RNA was taken from mouse received clean air, after rearing in a standard cage or environmental enrichment conditions. Comparisons among groups were made by one-color method with normalized data from Cy3 channels for data analysis.

Project description:The phenotype of an organism results from its genotype and the influence of the environment throughout development. Even when using animals of the same genotype, independent studies may test animals of different phenotypes, resulting in poor replicability due to genotype-by-environment interactions. Thus, genetically defined strains of mice may respond differently to experimental treatments depending on their rearing environment. However, the extent of such phenotypic plasticity and its implications for the replicability of research findings have remained unknown. Here, we examined the extent to which common environmental differences between animal facilities modulate the phenotype of genetically homogeneous (inbred) mice. We conducted a comprehensive multicentre study, whereby inbred C57BL/6J mice from a single breeding cohort were allocated to and reared in 5 different animal facilities throughout early life and adolescence, before being transported to a single test laboratory. We found persistent effects of the rearing facility on the composition and heterogeneity of the gut microbial community. These effects were paralleled by persistent differences in body weight and in the behavioural phenotype of the mice. Furthermore, we show that environmental variation among animal facilities is strong enough to influence epigenetic patterns in neurons at the level of chromatin organisation. We detected changes in chromatin organisation in the regulatory regions of genes involved in nucleosome assembly, neuronal differentiation, synaptic plasticity, and regulation of behaviour. Our findings demonstrate that common environmental differences between animal facilities may produce facility-specific phenotypes, from the molecular to the behavioural level. Furthermore, they highlight an important limitation of inferences from single-laboratory studies and thus argue that study designs should take environmental background into account to increase the robustness and replicability of findings.

Project description:Captive rearing programs (hatcheries) are often used in conservation and management efforts for at-risk salmonid fish populations. However, hatcheries typically rear juveniles in environments that contrast starkly with natural conditions, which may lead to phenotypic and/or genetic changes that adversely affect the performance of juveniles upon their release to the wild. Environmental enrichment has been proposed as a mechanism to improve the efficacy of population restoration efforts from captive-rearing programs: in this study, we examine the influence of environmental enrichment during embryo and yolk-sac larval rearing at the level of the transcriptome in Atlantic salmon (Salmo salar). Full siblings were reared in either a M-bM-^@M-^\simpleM-bM-^@M-^] environment devoid of structure or a M-bM-^@M-^\complexM-bM-^@M-^] environment enriched with gravel substrate. At the end of endogenous feeding by juveniles, we examined patterns of gene transcription in head tissues using the cGRASP-designed Agilent 4M-CM-^W44K microarray. Significance analysis of microarrays (SAM) indicated that 808 genes were differentially transcribed between rearing environments and a total of 184 gene ontological (GO) terms were over- or under-represented, several of which are associated with mitosis/cell cycle and muscle and heart development. However, there were also pronounced differences among families in gene transcriptional response to rearing environment, with the number of genes significantly differentially transcribed by juveniles in our independent analyses of each family ranging from zero to 3445 (FDR of 5%). Overall, our results suggest that rearing environment enrichment can profoundly change patterns of gene transcription during salmon development, but that the degree of response depends on genetic background. This was a two-condition experiment in which a total of 30 RNA samples isolated from the heads of developing salmon were analysed: 15 juveniles reared in a traditional hatchery environment and 15 reared in a hatchery environment enriched with gravel substrate.

Project description:Purpouse: Aims of this study were (1) to characterize the endometrial transcriptome, (2) to identify functional pathways, and (3) to molecularly characterize selected pathways overrepresented in the endometrium of day 7 post-ovulation induction of cows treated to ovulate larger versus smaller follicles Methods: Seventy-four multiparous, nonlactating, presynchronized Nelore cows received a progesterone-releasing device and estradiol benzoate on Day–10 (D?10). Animals received cloprostenol (large follicle-large CL group; LF-LCL; N = 35) or not (small follicle-small CL group; SF-SCL; N = 39) on D?10. Progesterone devices were withdrawn and cloprostenol administered 42 to 54 hours (LF-LCL) or 30 to 36 hours (SF-SCL) before GnRH treatment (D0). Tissues were collected at slaughter on D7. Transcriptional profiling of the endometrial tissue was performed by RNA-seq and protein markers for proliferation and apoptosis were identified by immunohistochemistry. Results: Functional enrichment data indicated that LF-LCL endometrium expressed greater abundance of genes associated with biosynthetic and metabolic processes, whereas SF-SCL endometrium .gene expression profile was biased towards cell proliferation. Extracellular matrix-related genes were also upregulated in the SF-SCL endometrium suggesting reorganization of the ECM towards a proliferation permissive phenotype. Immunohistochemistry data confirmed the greater proliferative activity observed in SF-SCL endometrium I comparison to LF-LCL counterparts, and indicated a time-related transition within experimental group. In conclusion, the periovulatory endocrine milieu regulates bovine endometrial gene expression. Furthermore, timing and amplitude of ovarian steroid secretion pattern seem to determine the transition from a proliferation permissive to a biosynthetic and metabolically active endometrial phenotype, which may be associated with the preparation of an optimally receptive uterine environment. Conclusion: the periovulatory endocrine milieu affected D7 endometrial molecular signature. Main pathways affected were related to cell proliferation, ECM composition and remodeling, biosynthetic and metabolic processes. Reported data further suggest that the endometrial tissue from LF-LCL cows experienced an early proliferative phase (D4), whereas the SF-SCL endometrium, exposed to a distinct periovulatory endocrine environment, expressed a delayed onset of the proliferative activity (D7). endometrial mRNA profiles of endocrine manipulated cows were generated by deep sequencing using Illumina HiScanSQ platform

			Action	DRS
	ERR7997520_1.fastq.gz	Fastqsanger.gz
	ERR7997520_2.fastq.gz	Fastqsanger.gz
	ERR7997700_1.fastq.gz	Fastqsanger.gz
	ERR7997700_2.fastq.gz	Fastqsanger.gz
	ERR7997830_1.fastq.gz	Fastqsanger.gz

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Rearing environment persistently modulates the phenotype of mice

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