Microarray analysis of the Asian seabass (Lates calcarifer) brains
ABSTRACT: In this study, we attempt to characterize the transcriptomic profile of the Asian seabass brains collected from the male and female sexes. The objective is to identify genes that show sexually dimorphic expression in the brain of this species. For this experiment, Asian seabass were collected from the Marine Aquaculture Center of the Agri-Food & Veterinary Authority of Singapore. There were no treatments carried out in this experiment. Four brains from adult male seabass (5 years old) with M3-type testis and four brains from adult female seabass (5 years old) with F3-type ovaries were used in this experiment. (Gonads were examined by histology and classified according to sexual maturation status as described by Guiguen and colleagues (Guiguen et al. Environmental Biology of Fishes, 1994)). Total 8 samples. Male Brain : 4 Female Brain : 4
Project description:In this study, we attempt to characterize the transcriptomic profile of the Asian seabass brains collected from the male and female sexes. The objective is to identify genes that show sexually dimorphic expression in the brain of this species. For this experiment, Asian seabass were collected from the Marine Aquaculture Center of the Agri-Food & Veterinary Authority of Singapore. There were no treatments carried out in this experiment. Four brains from adult male seabass (5 years old) with M3-type testis and four brains from adult female seabass (5 years old) with F3-type ovaries were used in this experiment. (Gonads were examined by histology and classified according to sexual maturation status as described by Guiguen and colleagues (Guiguen et al. Environmental Biology of Fishes, 1994)). Overall design: Total 8 samples. Male Brain : 4 Female Brain : 4
Project description:In this study, we attempt to characterize the transcriptomic profile of the Asian seabass gonads at various developmental stages. The protandric Asian seabass or barramundi (Lates calcarifer) typically matures as a male at approximately 2–4 years of age and then changes sex to a female in later years. For this experiment, Asian seabass of several ages were collected from the Marine Aquaculture Center of the Agri-Food & Veterinary Authority of Singapore and from farms around Singapore. There were no treatments carried out in this experiment. The gonads were examined by histology and classified according to sexual maturation status as described by Guiguen and colleagues (Guiguen et al. Environmental Biology of Fishes, 1994). Altogether, we analyzed 22 gonadal samples that could be classified into six different types of gonads. Total 22 samples: Adult Ovaries (F3-stage; 5 years old fish) : 4 Adult Testes (M3-stage; 5 years old fish) : 4 Early Testes (M3-stage; 8-9 months old fish) : 3 Early Transforming Gonads (>2 years old fish) : 3 Late Transforming Gonads (>2 years old fish) : 4 Undifferentiated Gonads (4.5 months old fish) : 4
Project description:In this study, the relative effect of consuming five different commercial feeds (Feed B-F) and and frozen fish (control; Feed A) for two months on our selected juvenile Asian seabass (77.3g ± 22.4g) were investigated. The growth performance, the biochemical analysis of their flesh, the histology of their midgut and the transcriptome of their midgut and liver were compared to each other and controls. Our customised agilent microarray platform (GPL17855), were used to investigate the liver transcriptomic expression of the different Groups fed with different Feeds. No differential expression were detected between commerical Feeds (B, C, E and F). A total of 397 differentially expressed transcripts (Foldchange cutoff: -1.5≤ or ≥1.5, Pvalue with FDR (<0.05) were detected between Feed D and control Feed A. Total: 24 samples (4 biological samples per Group; 6 Different Groups in total). Groups (A-F) were fed with Feeds (A-F) respectively for 61 days.
Project description:Newly-hatched domestic chick serves as an important model for studies of neural and behavioral plasticity, particularly with respect to learning and memory such as filial imprinting. Imprinting is assumed to be a unique case of recognition learning with some characteristic features, such as sensitive period and irreversibility. However, the molecules involved in the memory process are yet to be fully identified. To address this issue, we attempted to identify the genes differentially expressed at an earlier phase of filial imprinting than described in our previous report (Brain Res. Bull.76, 275-281 (2008)). One-day-old chicks were trained for imprinting for 1 h and whole brains were collected and used for cDNA microarray analysis and quantitative RT-PCR. We identified 18 genes upregulated accompanying filial imprinting. These results suggested that the increase of these 18 genes associated with filial imprinting might play an important role in the acquisition of memory in the filial imprinting. Total RNA was extracted from whole brains of trained chicks (n=16) and control dark-reared chicks (n=16). Using these total RNAs, we performed RT-PCR to distinguish male chicks from females. Then total RNAs were separated and mixed in four groups (1, male trained (n=8); 2, female trained (n=8); 3, male dark-reared (n=8); and 4, female dark-reared chicks (n=8)), and we performed cDNA microarray expression analysis to identify the upregulated genes following imprinting (1 versus 3 and 2 versus 4).
Project description:Silkworms show a reproductive behavior induced by sex pheromone. To elucidate the neral mechanism of sex pheromone induced sexual behavior in the silkworm, we attempted to use the neural activity-induced gene as a neural activity marker. Since no neural activity-induced gene was identified in the silkworm, we conducted screening of neural activity-induced gene using the male silkworm brain. By the screening, we identified Bhr38 as a novel neural activity-induced gene, and succeded to comprehensively map the active neruons in the silkworm brain in response to the sex pheromone exposure. Further, we found that Dhr38, the Drosophila homologue of Bhr38, also expressed in a neural activity dependent manner. These results strongly suggest that Hr38 is a highly conserved neural activity-induced gene. The male silkworms were exposed to the female odor for 30 min (group P). Non-treated male silkworms were used as the control group group C. Ten brains were collected for each sample and stored at -80°C until use. Total RNA was isolated by the TRIzol reagent and subjected to microarray experiments using the custam made (8x16k) Oligo Microarray (Agilent Technologies, Inc.).
Project description:Pirarucu (Arapaima gigas, or A. gigas) is a native fish species to Amazon basin and, economically important in the Brazilian Amazonian for its great potential to aquaculture. In the natural environment the A. gigas is captured only in the sustainable development reserves of the State of Amazonas by applying a system of rotation in fishing in order to avoid overfishing of this important fishing resource. The reproductive biology of A. gigas has long been intriguing; however, very little is known about the molecular pathways underlying their sexual differentiation and determination. Using the SOLiD sequencing platform, a total of 432,058,560 short sequencing reads were produced. An average of ~30% of sequencing reads could be mapped to Asian arowana reference cDNAs. 305 genes showed higher expression in female brain against 8 gene with higher expressing in male brain. In gonad, there are 120 genes higher expressed in female against 10 gene higher expressed in male. Overall design: To identify genes representing the sex specific gene expression, a comprehensive transcript dataset for the gonads and brain of A. gigas was produced using SOLiD platform. The sequencing reads were mapped to the genome of a close species Scleropages formosus (Asian arowana). Differential gene expression between male and female were then identified using the quantified gene expression values.
Project description:Methylmercury (MeHg) is a potent neurotoxin and endocrine disruptor that accumulates in aquatic systems. Previous studies have shown suppression of hormone levels in both male and female fish, suggesting effects on gonadotropin regulation in the brain. We investigated the gene expression profile in adult female zebrafish whole brain induced by acute (96 hr) MeHg exposure. Fish were exposed by injection to 0 or 0.5 µg MeHg/g. Gene expression changes in the brain were examined using a two-color 22,000 feature zebrafish microarray. At a significance level of p<0.01, 79 genes were up-regulated and 76 genes were down-regulated in response to MeHg exposure. Individual genes exhibiting altered expression in response to MeHg exposure implicate effects on glutathione metabolism and GABA-A receptors in the mechanism of MeHg neurotoxicity. Gene ontology (GO) terms significantly enriched among altered genes included protein folding, cell redox homeostasis, and steroid biosynthetic process. The most affected biological functions were related to the nervous system development and function, as well as lipid metabolism and molecular transport. These results support the involvement of oxidative stress and effects on protein structure in the mechanism of action of MeHg in the female brain. Future studies will compare the gene expression profile induced in response to MeHg with that induced by other toxins and investigate responsive genes as potential biomarkers of MeHg exposure. Wild-type strain AB-1 zebrafish (Zebrafish International Resource Center, University of Oregon, Eugene, OR) were cultured at the Columbia Environmental Research Center (CERC), USGS, for MeHg exposures. Adult female zebrafish were injected with 0 μg/g or 0.5 μg/g MeHg in 2 µL Na2CO3 (pH 6.98)/g body weight. After 96 hr, fish were anesthetized using ethyl 3-aminobenzoate methanesulfonate (MS-222, Sigma, St. Louis, MO). Whole brains were removed, flash frozen with liquid nitrogen and stored at 80°C. For the microarray experiment, two zebrafish brains were pooled per sample. Four pooled samples were taken from fish treated with 0.5 μg/g of MeHg, and the other five were taken from control fish treated with sodium carbonate. Array hybridizations were performed using a reference design, where each sample was compared to a reference sample. The reference sample consisted of equal amounts of RNA from control and treated female brains. Five replicates for the control and four replicates for the treated were analyzed. cDNA synthesis, cRNA labeling, amplification and hybridization were performed following the manufacturer’s kits and protocols (Agilent Low RNA Input Fluorescent Linear Amplification Kit and Agilent 60-mer oligo microarray processing protocol; Agilent, Palo Alto, CA).
Project description:Biological bases for sexual differences in the brain exist in a wide range of vertebrate species, including the chicken. We examined whether sexually dimorphic gene expression in the brain precedes gonadal differentiation. Using the Affymetrix GeneChip® Chicken Genome Array, we identified many female- and male-enhanced genes that are differentially expressed in sex-specific brains from stage 29 chicken embryos. We postulate that these genes have potential roles in the sexual differentiation of neural function and development in chickens. Experiment Overall Design: All analyses were performed in triplicate. The Affymetrix data from male and female brain samples at stage 29 were generated. The male and female brain samples by genetic sexing were pooled and homogenized. Pooled samples ranged from 5 to 8 embryos. 4g of total RNA from the pooled samples was used for labeling. Probe synthesis from total RNA samples, hybridization, detection, and scanning were performed according to standard protocols from Affymetrix.