Project description:In the fire ant Solenopsis invicta, a colony queen number is determined by the founding queen's genotypes at the 13 Mb supergene with the non-recombining variants SB and Sb. Single-queen colonies are always headed by SB/SB queens while multiple-queens colonies are always headed by SB/Sb queens. The two variants of the supergene, SB and Sb are completely linked to the two alleles (B and b) of the gene Gp-9. SB/SB and SB/Sb queens differ in many physiological traits including their maturation rate and odor. To explain why SB/SB and SB/Sb queens have different odors, and why SB/SB virgins mature faster and accumulate more fat, we measured expression of ~6000 genes in virgin queens 1 and 11 days after eclosion and in reproductive queens. Keywords: fire ants, Solenopsis invicta, Supergene, queen, Gp-9, social form, maturation, fat storage, queen odor, cuticular hydrocarbon, worker discrimination, monogyne, polygyne, transposon, chemical signaling
Project description:In the fire ant Solenopsis invicta, a colony queen number is determined by the founding queen's genotypes at the 13 Mb supergene with the non-recombining variants SB and Sb. Single-queen colonies are always headed by SB/SB queens while multiple-queens colonies are always headed by SB/Sb queens. The two variants of the supergene, SB and Sb are completely linked to the two alleles (B and b) of the gene Gp-9. SB/SB and SB/Sb queens differ in many physiological traits including their maturation rate and odor. To explain why SB/SB and SB/Sb queens have different odors, and why SB/SB virgins mature faster and accumulate more fat, we measured expression of ~6000 genes in virgin queens 1 and 11 days after eclosion and in reproductive queens. Keywords: fire ants, Solenopsis invicta, Supergene, queen, Gp-9, social form, maturation, fat storage, queen odor, cuticular hydrocarbon, worker discrimination, monogyne, polygyne, transposon, chemical signaling Six-condition experiment: 1-day-old SB/SB virgins, 1-day-old SB/Sb virgins, 11-day-old SB/SB virgins, 11-day-old SB/Sb virgins, SB/SB reproductive queens, SB/Sb reproductive queens. Biological replicates: 8 for 1-day-old SB/SB virgins and 1-day-old SB/Sb virgins that were collected in 2008; 8 for 1-day-old SB/SB virgins, 1-day-old SB/Sb virgins that were collected in 2009; 7 for 11-day-old SB/SB virgins and 11-day-old SB/Sb virgins that were collected in 2008; 8 for 11-day-old SB/SB virgins and 11-day-old SB/Sb virgins that were collected in 2009; 8 for SB/SB and SB/Sb reproductive queens (only collected in 2009). Samples were labeled with Cy3 and were compared to the same common reference RNA labeled with Cy5. Samples from 2008 were hybridized on the microarrays batch I and samples from 2009 were hybridized on the microarrays batch J.
Project description:Hexavalent chromium (Cr(VI)) is a highly toxic contaminant, some bacteria are able to transform it to less toxic and less soluble trivalent chromium (Cr(III)). Klebsiella sp. strain AqSCr, isolated from Cr(VI)-polluted groundwater, reduces Cr(VI) both aerobically and anaerobically, and resists up 35 mM of Cr(VI); Subculturing of AqSCr in the presence of Cr(VI) conduces to adaptation. In this study, we performed RNA-Seq of Cr(VI) adapted stage, finding 255 genes upregulated and 240 downregulated with respect to controls without Cr(VI). Genes differentially expressed are mostly associated with oxidative stress response, DNA repair and replication, sulfur starvation response, envelope-osmotic stress response, fatty acid metabolism, ribosomal subunits and energy metabolism. Among them, genes not previously associated with chromium resistance as cybB, encoding a putative superoxide oxidase, gltA2, encoding an alternative citrate synthase, and des, encoding a fatty acid desaturase were upregulated. The alternative sigma factors fecl, rpoE and rpoS were upredgulated in Cr(VI) adapted cells, then they participate in orchestate the Cr(VI)-resistance mechanisms in AqSCr strain