New constraints on the genesis and geodynamic setting of the Wulong gold deposit, Liaodong Peninsula, northeast China: evidence from geology, geochemistry, fluid inclusions, and C–H–O–S–Pb isotopes

The Wulong lode gold deposit is located in the Liaoning Province, northeast part of North China Craton. Gold orebodies are mainly hosted in the Late Jurassic granite and structurally controlled by the NE-trending faults. Mineralization can be divided into three stages: (1) quartz-pyrite stage, (2) quartz-polymetallic sulfides stage, and (3) quartz-carbonate stage. Gold formed mainly in the middle stage. Quartz formed in two earlier stages contains three compositional types of fluid inclusions, i.e. pure CO2, CO2–H2O and NaCl–H2O, but the late-stage minerals only contain the NaCl–H2O inclusions. The inclusions in quartz formed in the early, main and late stages yield total homogenization temperatures of 317–383 °C, 260–380 °C and 159–234 °C, respectively, with salinities of 5.14-9.44, 2.95-6.20, 1.23-4.34 wt% NaCl equivalent, respectively. Trapping pressures estimated from CO2–H2O inclusions are 200–390 MPa in the main stage. Fluid boiling and immiscibility caused rapid precipitation of sulfides and gold. Through immiscibility and inflow of meteoric water, the ore-forming fluid system evolved from CO2-rich to CO2-poor in composition, and from magmatic to meteoric, as indicated by δ18Owater values (4.5‰–7.3‰). The carbon (-12.2‰ to -11.5‰), sulfur (0.9‰–2.6‰) and lead isotope (207Pb/204Pb of 15.606–15.618) compositions suggest the hostrocks to be a significant source of ore metals. Integrating the data obtained from the studies including ore geology, fluid inclusion and isotope geochemistry, we conclude that the Wulong deposit is a decratonization gold deposit formed during lithospheric thinning associated with destruction of the NCC triggered by the subduction of the Paleo-Pacific Oceanic plate in the Early Cretaceous.The accepted manuscript in pdf format is listed with the files at the bottom of this page. The presentation of the authors' names and (or) special characters in the title of the manuscript may differ slightly between what is listed on this page and what is listed in the pdf file of the accepted manuscript; that in the pdf file of the accepted manuscript is what was submitted by the author

Selection and assessment of reference genes for quantitative PCR normalization in migratory locust Locusta migratoria (Orthoptera: Acrididae).

Locusta migratoria is a classic hemimetamorphosis insect and has caused widespread economic damage to crops as a migratory pest. Researches on the expression pattern of functional genes in L. migratoria have drawn focus in recent years, especially with the release of genome information. Real-time quantitative PCR is the most reproducible and sensitive approach for detecting transcript expression levels of target genes, but optimal internal standards are key factors for its accuracy and reliability. Therefore, it's necessary to provide a systematic stability assessment of internal control for well-performed tests of target gene expression profile. In this study, twelve candidate genes (Ach, Act, Cht2, EF1α, RPL32, Hsp70, Tub, RP49, SDH, GAPDH, 18S, and His) were analyzed with four statistical methods: the delta Ct approach, geNorm, Bestkeeper and NormFinder. The results from these analyses aimed to choose the best suitable reference gene across different experimental situations for gene profile study in L. migratoria. The result demonstrated that for different developmental stages, EF1α, Hsp70 and RPL32 exhibited the most stable expression status for all samples; EF1α and RPL32 were selected as the best reference genes for studies involving embryo and larvae stages, while SDH and RP49 were identified for adult stage. The best-ranked reference genes across different tissues are RPL32, Hsp70 and RP49. For abiotic treatments, the most appropriate genes we identified were as follows: Act and SDH for larvae subjected to different insecticides; RPL32 and Ach for larvae exposed to different temperature treatments; and Act and Ach for larvae suffering from starvation. The present report should facilitate future researches on gene expression in L. migratoria with accessibly optimal reference genes under different experimental contexts

Pairwise variation analysis for an accurate normalization.

<p>The pairwise variation analysis is performed by geNorm to determine the optimal number of internal control genes. Each pairwise variation value is compared with 0.15, below which the inclusion of an additional reference gene is not required.</p

Details of twelve candidate reference genes used for real-time PCR.

<p>Size: size of amplicon length; Tm: melt temperature; E: PCR efficiency; R²: coefficient of determination.</p

Preferable control genes in <i>L. migratoria</i> across different experimental conditions.

<p>Preferable control genes in <i>L. migratoria</i> across different experimental conditions.</p

Average expression stability and ranking of twelve candidate reference genes calculated by geNorm.

<p>(<b>A</b>) embryos samples (<b>B</b>) nymphs samples (<b>C</b>) adults (<b>D</b>) tissue samples (<b>E</b>) third instar nymphs subjected to insecticides (<b>F</b>) third instar nymphs suffering starvation stress (<b>G</b>) third instar nymphs under temperature stress (<b>H</b>) all of the biological samples.</p

Expression stability of the candidate reference genes under biotic conditions.

<p>StdDev, standard deviation; SD, standard deviation; SV, stability value; r, Pearson correlation coefficient; *<i>p</i>≤0.001.</p