Project description:This study compares gene expression in the testis of three offshore (Pelican Shoal) and three near-shore (Tingler Island) adult male queen conchs (Strombus gigas) collected from the wild on February 15, 2007.
Project description:Gene expression profiling in the ovary of Queen conch (Strombus gigas) exposed to tributyltin-polluted environments in the British Virgin Islands
Project description:Ecotoxicogenomics in field experiments have yielded valuable mechanistic information for organisms present in polluted environments. The Queen conch (Strombus gigas) is a threatened species and populations are declining due to anthropogenic impact that includes pollution from boating activities. In the British Virgin Islands (BVI), local Queen conch populations have exhibited imposex, a condition in which both male and female gonadal characteristics are present and studies in the BVI suggest that tributyl tin (TBT), a chemical used in boat paint, is correlated to increased incidence imposex. This present study utilized a previously validated 8 x 15K Queen conch microarray to characterize the response of the ovarian transcriptome in conch found in polluted environments with high TBT in the BVIs. There polluted sites, Road Harbour (RH) and Trellis Bay (TB), are harbours with high boating activity while the reference sites, Guana Island (GI) and Anegada (AN), are areas with low boating activity. Microarray analysis revealed that there were 17 transcripts with high homology to known genes that were differentially expressed in the environments with high TBT and these included 6 induced and 11 down-regulated transcripts (p<0.01). These differentially expressed transcripts included phosphoenolpyruvate carboxylase, transposase, and high-affinity phosphate transporter PT1. When considering both RH and TB together in comparison to GI, functional enrichment showed that the biological processes and molecular functions of calcium ion binding, immune response, and negative regulation of cell proliferation were over represented in the polluted sites. Gene set enrichment analysis revealed that transcripts involved in the biological processes of general metabolism, immune, lipid metabolism, and stress were affected in polluted environments. Although difficult to directly link changes at the transcriptomics level to TBT in the harbour, this analysis provides novel insight into pathways impacted in regions that experience heavy boating activity in the BVIs.
Project description:Ecotoxicogenomics in field experiments have yielded valuable mechanistic information for organisms present in polluted environments. The Queen conch (Strombus gigas) is a threatened species and populations are declining due to anthropogenic impact that includes pollution from boating activities. In the British Virgin Islands (BVI), local Queen conch populations have exhibited imposex, a condition in which both male and female gonadal characteristics are present and studies in the BVI suggest that tributyl tin (TBT), a chemical used in boat paint, is correlated to increased incidence imposex. This present study utilized a previously validated 8 x 15K Queen conch microarray to characterize the response of the ovarian transcriptome in conch found in polluted environments with high TBT in the BVIs. There polluted sites, Road Harbour (RH) and Trellis Bay (TB), are harbours with high boating activity while the reference sites, Guana Island (GI) and Anegada (AN), are areas with low boating activity. Microarray analysis revealed that there were 17 transcripts with high homology to known genes that were differentially expressed in the environments with high TBT and these included 6 induced and 11 down-regulated transcripts (p<0.01). These differentially expressed transcripts included phosphoenolpyruvate carboxylase, transposase, and high-affinity phosphate transporter PT1. When considering both RH and TB together in comparison to GI, functional enrichment showed that the biological processes and molecular functions of calcium ion binding, immune response, and negative regulation of cell proliferation were over represented in the polluted sites. Gene set enrichment analysis revealed that transcripts involved in the biological processes of general metabolism, immune, lipid metabolism, and stress were affected in polluted environments. Although difficult to directly link changes at the transcriptomics level to TBT in the harbour, this analysis provides novel insight into pathways impacted in regions that experience heavy boating activity in the BVIs. Adult female queen conchs were collected from field sites in the British Virgin Islands with varying levels of TBT contamination and imposex incidence. Contaminated sites included Rhode Harbour (RH, n=3) and Trellis Bay (TB, n=3), and the low-pollution site was Guana Island (GA, n=5). Ovaries were preserved in RNAlater, transported to the laboratory, and RNA was prepared using a phenol-chloroform extraction and a CsCl gradient. RNA was labeled with Cy3 for a single-dye design, per the Agilent protocol.
Project description:Reproduction of queen conchs at nearshore sites in the Florida Keys is known to be impaired (Delgado et al. 2004). A recent microarray study of male queen conchs collected from the Florida Keys during the early part of the reproductive season (February, 2007) indicated that NS conchs show differences in expression of spermatogenesis-related and small GTPase signaling transcripts (Spade et al. 2010). The current study investigates gene expression in the ovary of female queen conchs from the same sampling effort in February, 2007. One-color (Cy3) oligonucleotide array experiment. Each array sample is an individual biological replicate. The study includes four biological replicates offshore and three biological replicate nearshore. Offshore conchs exhibit normal reproduction, and so were considered the reference group in the analysis.
Project description:Reproduction of queen conchs at nearshore sites in the Florida Keys is known to be impaired (Delgado et al. 2004). A recent microarray study of male queen conchs collected from the Florida Keys during the early part of the reproductive season (February, 2007) indicated that NS conchs show differences in expression of spermatogenesis-related and small GTPase signaling transcripts (Spade et al. 2010). The current study investigates gene expression in the digestive gland, which is closely associated with ovary, of female queen conchs from the same sampling effort in February, 2007. One-color (Cy3) oligonucleotide array experiment. Each array sample is an individual biological replicate. The study includes four biological replicates offshore and three biological and one technical replicate nearshore. Offshore conchs exhibit normal reproduction, and so were considered the reference group in the analysis.