Effects of agouti overexpression in the brain and skin transcriptome of zebrafish
Ontology highlight
ABSTRACT: Twenty transgenic fish overexpressing agouti-signaling protein (ASIP, Ceinos et al., Pigment Cell and Melanoma Research 28:196-209, 2015) and wild type (WT) zebrafish were placed in 6-liter tanks and acclimated during 30 days prior to sampling to minimize physiological differences. Animals were sacrificed and the brain+pituitary and the skin dissected under the stereo microscope, placed in trizol and stored at -80C until RNA extraction. Six biological replicates (3 females and 3 males) of each tissue (skin and brain) of each group (ASIP vs WT) were analyzed in a total of 6 slides containing 4 microarrays in the 4 × 44 k format. Global gene expression analyses were performed to search for both sex-dependent and transgene-dependent effects as well as the interaction between both factors (sex x phenotype) on the brain+pituitary and skin transcriptome.
Project description:Twenty transgenic fish overexpressing agouti-signaling protein (ASIP, Ceinos et al., Pigment Cell and Melanoma Research 28:196-209, 2015) and wild type (WT) zebrafish were placed in 6-liter tanks and acclimated during 30 days prior to sampling to minimize physiological differences. Animals were sacrificed and the brain+pituitary and the skin dissected under the stereo microscope, placed in trizol and stored at -80C until RNA extraction. Six biological replicates (3 females and 3 males) of each tissue (skin and brain) of each group (ASIP vs WT) were analyzed in a total of 6 slides containing 4 microarrays in the 4 × 44 k format. Global gene expression analyses were performed to search for both sex-dependent and transgene-dependent effects as well as the interaction between both factors (sex x phenotype) on the brain+pituitary and skin transcriptome. Wild type (Tu) or transgenic zebrafish overexpression agouti-signaling protein (ASIP) were reared in similar conditions. Brain+pituitary and skin were sampled from 6 ASIP (3 males + 3 females) and WT (3 males + 3 females) zebrafish. Samples were individually hybridized in a total of 6 slides containing 4 microarrays in the 4 × 44 k format. Microarrays included 60-mer probes to the unique transcripts from Ensembl and Unigene which were annotated by functional categories of GO and pathways of KEGG with bioinformatics package STARS
Project description:The mouse agouti gene is normally expressed in the skin and regulates coat color pigmentation. Dominant regulatory mutations in the agouti gene, such as viable-yellow (Avy), cause ubiquitous over-expression of the wild-type gene product in every tissue in the body. As a result of this altered agouti expression, viable-yellow mice have solid yellow hair, they are obese and diabetic, and they have increased susceptibility to spontaneous and chemically induced tumors in a wide variety of tissues (e.g., skin, lung, liver, mammary gland and urinary bladder). Additionally, liver-specific expression of the agouti gene was shown to promote hepatocellular carcinogenesis, even in the absence of obesity and diabetes. Our lab recently extended these findings to show that the agouti gene also promotes skin cancer in the absence of obesity and diabetes. In K14-Agouti transgenic mice, the wild-type agouti gene is over-expressed in the skin under the regulatory control of the keratin 14 (K14) promoter. Over-expression of agouti in the skin results in yellow coat color without the obesity and diabetes. In two-stage skin carcinogenesis experiments the agouti protein was shown to act as a tumor promoter since it promotes the development of skin tumors in the K14-Agouti transgenic mice, but only after the skin was initiated with a single dose of 7, 12-dimethylbenz[a]anthrance (DMBA). These experiments set the stage for determining the mechanism of action of agouti protein in tumor promotion, which remains completely uncharacterized. As a first step in determining the role of agouti in skin cancer, we used cDNA microarray and quantitative real time polymerase chain reaction (QRT-PCR) analysis to identify and validate a set of differentially expressed genes in the skin of K14-Agouti transgenic mice at the promotion stage of carcinogenesis. Keywords: promotion stage of carcinogenesis, biological replicates,
Project description:Ultraviolet (UV) light affects endocrinological and behavioral aspects of human sexuality via an unknown mechanism. Using a unique male-female comparative approach, we discovered that the sexual behavioral and hormonal features enhanced by UVB are mediated by the skin. In mice, UV exposure increases hypothalamus-pituitary-gonadal axis hormone levels, resulting in enhanced ovary size, extended estrus days, and anti-Mullerian hormone (AMH) expression. It likewise enhances the sexual responsiveness and attractiveness of females and male-female interactions of both males and females. Conditional knockout of p53 specifically in skin keratinocytes abolished UV’s effects. In humans, UV exposure enhanced romantic passion in both genders increased testosterone levels in men. Our data, revealing that UVB triggers a skin-brain-gonadal axis through skin p53 activation, offers therapeutic opportunities for sex-steroid-related dysfunctions. We speculate that during human furless skin evolution, the skin became the front-line regulator of the response to UVB.
Project description:Brain transcriptome at 0h, 1h, 3h, 6h, 12h, 24h, 48h after hypoxia stress Large yellow croakers (body weight at 90-100 g) were purchased from the mariculture farm in Ningde, Fuzhou, China. The fish were maintained at 25 °C in aerated water tanks (dissolved oxygen concentration: 7.8±0.5 mg per liter) with a flow through seawater supply. After 7 days of acclimation, these fish were used for the following experiments. Hypoxic time-course experiments were conducted at 25 °C using published method 30, by bubbling nitrogen gas into an aquarium. The desired pO2 was controlled by using dissolved oxygen meter (, Canada). At the onset of the time course, the oxygen content of the tank was lowered from an aerated pO2 of 100% (7.8 mg per liter) down to 20% (1.6±0.2 mg per liter) over a 30-min period. At the 1-, 3-, 6-, 12-, 24-, and 48-h time points, fish were sampled and sequenced.
Project description:Genetic loci displaying environmentally responsive epigenetic marks, termed metastable epialleles, offer a solution to the paradox presented by genetically identical yet phenotypically distinct individuals. The murine viable yellow agouti (Avy) locus is a well-described metastable epiallele that serves as a visual epigenetic biosensor. The Avy locus exhibits a high R-value or ratio of inter-individual (Vi) to inter-tissue (Vt) variance in gene expression, characteristic of what we term the ‘Agouti Expression Fingerprint.’ We propose a novel method for identification of candidate metastable epialleles based on the Agouti Expression Fingerprint, defining candidates as loci with R-values greater than 1.5 on expression microarray. Using Expression data from tissues of the three germ layers (liver, kidney, brain), high variance in agouti RNA levels among isogenic animals coupled with low variance among tissue types in individual animals is demonstrated. Here, we provide proof of concept for the ‘Agouti Expression Fingerprint’; the characterization of epigenetically labile loci in humans will be crucial to the development of novel screening and therapeutic targets for human disease prevention. For expression microarray studies, total RNA was isolated from liver, kidney, and brain tissue from 10 male Avy/a mice (2 per each of the 5 coat color classes) at time of weaning and coat color determination (day 22). Using Affymetrix GeneChip Mouse Genome 2.0 arrays (Santa Clara, CA), we queried the entire mouse genome for candidate metastable epialleles that display the Agouti Fingerprint. Approximately 100 of the greater than 40,000 transcripts on the mouse array displayed an expression pattern characterized as high inter-individual variation coupled with low inter-tissue variation (R-value > 1.5).
Project description:Addictive drugs including opioids activate signal transduction pathways that regulate gene expression in the brain. However, changes in CNS gene expression following morphine exposure are poorly understood. We studied the effect of short- and long-term morphine treatment on gene expression in the hypothalamus and pituitary using genome-wide DNA microarray and real-time reverse transcriptase polymerase chain reaction (RT-PCR) analyses. In the hypothalamus, we found that short-term morphine administration up-regulated (at least 2-fold) 39 genes and down-regulated six genes. Long-term morphine administration up-regulated 35 genes and down-regulated 51 hypothalamic genes. In the pituitary, we found that short-term morphine administration up-regulated (at least 2-fold) 110 genes and down-regulated 29 genes. Long-term morphine administration up-regulated 85 genes and down-regulated 37 pituitary genes. Strikingly, microarray analysis uncovered several genes involved in food intake (neuropeptide Y, agouti-related protein, and cocaine and amphetamine-regulated transcript) whose expression was strongly altered by morphine exposure in either the hypothalamus or pituitary. Subsequent RT-PCR analysis confirmed similar gene regulation of noteworthy genes in these regions. Finally, we found functional correlation between morphine-induced alterations in food intake and regulations of genes involved in this process. Changes in genes related to food intake may uncover new pathways related to some of the physiological effects of opioids. Keywords: Comparative treatment versus placebo 8 samples analyzed: 4 from hypothalamus (2 biological replicates and 2 dye swaps) and 4 from pituitary (2 biological replicates and 2 dye swaps) 8 samples analyzed: 4 from hypothalamus short term treatment (2 biological replicates and 2 dye swaps) and 4 hypothalamus long term treatment (2 biological replicates and 2 dye swaps)
Project description:RNA was isolated from mouse skin and pituitary. This was used for gene comparisons with an affymatrix Clariom S array We compared the differences in transcripts expressed in the skin and the pituitary in the presence/absence of MIR205HG- and miR-205, which revealed significant differences in the pituitary and overlap in the skin
Project description:In this study, we used whole genome comparative oligonucleotide microarrays to investigate the brain transcriptomic response to predator cues using the threespine stickleback, Gasteroteus aculeatus. We showed that exposure to olfactory, visual and tactile cues of a predator (rainbow trout, Oncorhynchus mykiss) for six days resulted in subtle but significant transcriptomic changes in the brain of sticklebacks. Gene functional analysis and gene ontology (GO) enrichment revealed that the majority of the transcripts differentially expressed between the fish exposed to predator cues and the control group are primarily related to antigen processing and presentation (involving primarily the major histocompatibility complex (MHC)), transmission of synaptic signals, brain metabolic processes, gene regulation, or visual perception. Pathway analysis identified synaptic long-term depression, RAN signaling, relaxin signaling and phototransduction as the top four pathways that were over-represented. Adult fish were placed in six different 26L tanks with three fish per tank in a partially recirculating flow-through system. Half of the tanks were assigned to the control group and the other half to the experimental group.10 samples were selected for microarray analysis. The ten samples comprised five biological replicates in the experimental group (fish exposed to predator cues) and five biological replicates in the control group (fish not exposed to predator cues), and were evenly distributed across tanks. The cDNA labeling (single color), hybridization, washing and scanning steps were performed in the NimbleGen microarray gene expression service department.
Project description:Gene expression was studied using PancChip5.0 in 15 tissues. Most tissues were from the adult mouse, except for fetal pancreas (e18.5) and placenta. Adult tissues studied were: adrenal gland, pancreas, brain, heart, kidney, liver, lung, ovary, parotid gland, pituitary gland, small intestine, stomach and testis. All were studied in duplicate except for the pituitary, the liver, and the stomach. All samples were pooled samples. Tissues were taken from 3 males and 3 females, with the exception of the gonadal tissues, and the fetal tissues were sex was not determined.