Project description:Lake Apopka (Fl, USA) experienced heavy uses of organochlorine pesticides (OCPs) in the 1950s-1970 during an intense agricultural period. As a result, the region remains heavily contaminated and was declared a Superfund site by the US Environmental Protection Agency. Aquatic organisms inhabit the freshwater systems in and around Lake Apopka, however the impacts of sub chronic exposure to OCPs in this natural environment are not known. The objectives of this study were to determine the effects of the contamination on the reproductive axis of largemouth bass (LMB) (Micropterus salmoides). In October (2007), healthy LMB were stocked into natural mesocosms and remained in mesocosms before being sampled in January 2008 (at early oogenesis). Additional LMB were placed into mesocosms for 2 months in February (2008) and sampled in April (2008) (oocyte maturation). LMB placed in these mesocosms for four months had a 2-20X higher contaminant load for OCPs (e.g. DDE, dieldrin, methoxychlor) than LMB collected from reference sites. Gonadosomatic index for LMB collected in April from the mesocosms were not different that LMB from reference sites. Vitellogenin levels in LMB collected from the mesocosms in January and April were not significantly different than fish collected from Welaka in late vitellogenin or early maturation respectively. Steroids were depressed in mesocosm fish. Microarray analysis revealed that the expression profiles of genes in the LMB ovary were unique compared to LMB collected form reference sites. Transcripts that showed altered abundance in LMB from the mesocosms were insulin-like growth factor I and steroidogenic acute regulatory protein. Interestingly, differentially expressed transcripts showed a significant and positive correlation for LMB sampled in January and April despite the 3 month period in between samplings. Sub-network enrichment analysis for cellular processes showed that retinoic acid metabolism and germ-cell development were decreased in mesocosm-exposed fish but processes such as vitellogenesis, amino acid catabolism, granulosa cell function, vitamin D metabolism, and hormone biosynthesis were increased in mesocosm-exposed fish. These data suggest that (1) LMB from the mesocosms are exhibiting unique gene profiles that may impair normal reproduction and that (2) microarray analysis in the field can provide site specific information by discriminating LMB from reference and polluted sites.
Project description:Lake Apopka (Fl, USA) experienced heavy uses of organochlorine pesticides (OCPs) in the 1950s-1970 during an intense agricultural period. As a result, the region remains heavily contaminated and was declared a Superfund site by the US Environmental Protection Agency. Aquatic organisms inhabit the freshwater systems in and around Lake Apopka, however the impacts of sub chronic exposure to OCPs in this natural environment are not known. The objectives of this study were to determine the effects of the contamination on the reproductive axis of largemouth bass (LMB) (Micropterus salmoides). In October (2007), healthy LMB were stocked into natural mesocosms and remained in mesocosms before being sampled in January 2008 (at early oogenesis). Additional LMB were placed into mesocosms for 2 months in February (2008) and sampled in April (2008) (oocyte maturation). LMB placed in these mesocosms for four months had a 2-20X higher contaminant load for OCPs (e.g. DDE, dieldrin, methoxychlor) than LMB collected from reference sites. Gonadosomatic index for LMB collected in April from the mesocosms were not different that LMB from reference sites. Vitellogenin levels in LMB collected from the mesocosms in January and April were not significantly different than fish collected from Welaka in late vitellogenin or early maturation respectively. Steroids were depressed in mesocosm fish. Microarray analysis revealed that the expression profiles of genes in the LMB ovary were unique compared to LMB collected form reference sites. Transcripts that showed altered abundance in LMB from the mesocosms were insulin-like growth factor I and steroidogenic acute regulatory protein. Interestingly, differentially expressed transcripts showed a significant and positive correlation for LMB sampled in January and April despite the 3 month period in between samplings. Sub-network enrichment analysis for cellular processes showed that retinoic acid metabolism and germ-cell development were decreased in mesocosm-exposed fish but processes such as vitellogenesis, amino acid catabolism, granulosa cell function, vitamin D metabolism, and hormone biosynthesis were increased in mesocosm-exposed fish. These data suggest that (1) LMB from the mesocosms are exhibiting unique gene profiles that may impair normal reproduction and that (2) microarray analysis in the field can provide site specific information by discriminating LMB from reference and polluted sites.
Project description:Lake Apopka (Fl, USA) experienced heavy uses of organochlorine pesticides (OCPs) in the 1950s-1970 during an intense agricultural period. As a result, the region remains heavily contaminated and was declared a Superfund site by the US Environmental Protection Agency. Aquatic organisms inhabit the freshwater systems in and around Lake Apopka, however the impacts of sub chronic exposure to OCPs in this natural environment are not known. The objectives of this study were to determine the effects of the contamination on the reproductive axis of largemouth bass (LMB) (Micropterus salmoides). In October (2007), healthy LMB were stocked into natural mesocosms and remained in mesocosms before being sampled in January 2008 (at early oogenesis). Additional LMB were placed into mesocosms for 2 months in February (2008) and sampled in April (2008) (oocyte maturation). LMB placed in these mesocosms for four months had a 2-20X higher contaminant load for OCPs (e.g. DDE, dieldrin, methoxychlor) than LMB collected from reference sites. Gonadosomatic index for LMB collected in April from the mesocosms were not different that LMB from reference sites. Vitellogenin levels in LMB collected from the mesocosms in January and April were not significantly different than fish collected from Welaka in late vitellogenin or early maturation respectively. Steroids were depressed in mesocosm fish. Microarray analysis revealed that the expression profiles of genes in the LMB ovary were unique compared to LMB collected form reference sites. Transcripts that showed altered abundance in LMB from the mesocosms were insulin-like growth factor I and steroidogenic acute regulatory protein. Interestingly, differentially expressed transcripts showed a significant and positive correlation for LMB sampled in January and April despite the 3 month period in between samplings. Sub-network enrichment analysis for cellular processes showed that retinoic acid metabolism and germ-cell development were decreased in mesocosm-exposed fish but processes such as vitellogenesis, amino acid catabolism, granulosa cell function, vitamin D metabolism, and hormone biosynthesis were increased in mesocosm-exposed fish. These data suggest that (1) LMB from the mesocosms are exhibiting unique gene profiles that may impair normal reproduction and that (2) microarray analysis in the field can provide site specific information by discriminating LMB from reference and polluted sites. 12 microarrays on LMB collected from the wild in January. These include St John River (n=4), DeLeon Springs (n = 4), and animals placed in Apopka mesocosms (n=4).
Project description:Lake Apopka (Fl, USA) experienced heavy uses of organochlorine pesticides (OCPs) in the 1950s-1970 during an intense agricultural period. As a result, the region remains heavily contaminated and was declared a Superfund site by the US Environmental Protection Agency. Aquatic organisms inhabit the freshwater systems in and around Lake Apopka, however the impacts of sub chronic exposure to OCPs in this natural environment are not known. The objectives of this study were to determine the effects of the contamination on the reproductive axis of largemouth bass (LMB) (Micropterus salmoides). In October (2007), healthy LMB were stocked into natural mesocosms and remained in mesocosms before being sampled in January 2008 (at early oogenesis). Additional LMB were placed into mesocosms for 2 months in February (2008) and sampled in April (2008) (oocyte maturation). LMB placed in these mesocosms for four months had a 2-20X higher contaminant load for OCPs (e.g. DDE, dieldrin, methoxychlor) than LMB collected from reference sites. Gonadosomatic index for LMB collected in April from the mesocosms were not different that LMB from reference sites. Vitellogenin levels in LMB collected from the mesocosms in January and April were not significantly different than fish collected from Welaka in late vitellogenin or early maturation respectively. Steroids were depressed in mesocosm fish. Microarray analysis revealed that the expression profiles of genes in the LMB ovary were unique compared to LMB collected form reference sites. Transcripts that showed altered abundance in LMB from the mesocosms were insulin-like growth factor I and steroidogenic acute regulatory protein. Interestingly, differentially expressed transcripts showed a significant and positive correlation for LMB sampled in January and April despite the 3 month period in between samplings. Sub-network enrichment analysis for cellular processes showed that retinoic acid metabolism and germ-cell development were decreased in mesocosm-exposed fish but processes such as vitellogenesis, amino acid catabolism, granulosa cell function, vitamin D metabolism, and hormone biosynthesis were increased in mesocosm-exposed fish. These data suggest that (1) LMB from the mesocosms are exhibiting unique gene profiles that may impair normal reproduction and that (2) microarray analysis in the field can provide site specific information by discriminating LMB from reference and polluted sites. 8 microarrays on LMB collected from the wild in April. These include St John River (n=4) and animals placed in Apopka mesocosms (n=4).
Project description:This SuperSeries is composed of the following subset Series: GSE38738: High contaminant loads in Lake Apopka mesocosms affect the ovarian transcriptome in largemouth bass [April] GSE38773: High contaminant loads in Lake Apopka mesocosms affect the ovarian transcriptome in largemouth bass [January] Refer to individual Series
Project description:Copper is both essential and toxic to living beings, which therefore tightly control its intracellular concentration. At the host-pathogen interface, copper is used by phagocytic cells to kill invading microorganisms. We investigated copper homeostasis in the whooping cough agent Bordetella pertussis, which lives in the human respiratory mucosa and has no environmental reservoir. B. pertussis has considerably streamlined copper homeostasis mechanisms relative to other Gram-negative bacteria. Its single remaining defense line against copper intoxication consists in a metallochaperone diverted for copper passivation and two enzymes involved in peroxide detoxification, which together fight two stresses encountered in phagolysosomes. The three proteins are encoded by an original, composite operon assembled in an environmental ancestor and which is under sensitive control by copper. Interestingly, this system appears to play a role in persistent infection in the nasal cavity of B. pertussis-infected mice. Combining responses to co-occurring stresses in a tailored operon reveals a new strategy adopted by a host-restricted pathogen to optimize survival at minimal energy expenditure.
Project description:Resistance to oxidative stress plays a vital role in animal physiology, where it influences both life history traits and the ability to tolerate the effects of a myriad of environmental stressors. While stress resistance has previously been shown to share a role in shaping an organism's response to traits as varied as desiccation, thermal tolerance and xenobiotic resistance, heavy metal tolerance presents a particular challenge with regards to adaptation to stress. Heavy metals contamination can result in robust and persistent selection pressure: not only is acute exposure highly toxic, but metals can accumulate in the environment over long periods, prolonging this exposure. However, many heavy metals, such as copper and zinc, are also essential micronutrients, which may constrain adaption in high copper conditions. To determine the genetic basis of copper tolerance in European Drosophila melanogaster, we phenotyped 76 inbred lines sampled from nine locations across Western Europe on copper sulphate, demonstrating that that copper tolerance is a highly variable trait. A combination of long-read nanopore sequencing and high-throughput RNA-seq analysis carried out before and after copper exposure shows that while copper tolerance is a highly heterogenous trait, affected by changes in expression across multiple loci, the greatest changes in expression a seen in the digestive tract. In addition, a large proportion of genes found differentially expressed upon copper exposure have previously shown to be regulated by a number of transcription factors with known roles in a broad range of metabolic processes, indicating that while the initial response may be tissue restricted, long term affects of copper expose are more likely to be systemic.
Project description:Iron and copper are important environmental nutrients for plant growth. However, the molecular mechanisms of both iron and copper signaling that integrate the two pathways remain poorly understood. The Arabidopsis thaliana high affinity copper transporter COPT5, is a tonoplast localized permease involved in copper remobilization. Here, a global expression microarray analysis of the copt5 mutant points out the induction of iron deficiency responses, including NATURAL RESISTANCE-ASSOCIATED MACROPHAGE PROTEIN 4 (NRAMP4), a tonoplast-localized iron transporter. The copper requirement in iron perception and uptake from the media becomes more evident in the double nramp3nramp4 mutant, unable to remobilize iron from vacuoles, that is highly sensitive to copper deficiency. Furthermore, COPT5 expression is altered under iron deficiency and the copt5 mutant is sensitive to iron deficiency and is unable to perceive iron in the media under copper deficiency. Noteworthy, iron deficiency post-transcriptionally restraints the copper-dependent superoxide dismutase protein levels and the subsequent activity. As a consequence of its increased iron deficiency responses, the copt5 mutant present lower levels of both copper- and iron-dependent superoxide dismutase activities. Moreover, the copt5 mutant mobilizes faster its iron storage pools and presents higher levels of iron in cotyledons and seeds. These results underline the importance of internal metal pools in the understanding of copper and iron deficiency responses and their crosstalk that are critical for governing proper plant development in response to combined metal scarcities in soils.