Differential gene expression in normal and intersex Crustacea: New horizons for investigating impacts of pollution, parasitism and climate change.

间性是指当一个生物体同时表现出男性和女性的特征时的一种异常状态。野生动物间性行为的研究为研究生殖决定和/或分化中异常情况的比较生物学提供了极好的手段。甲壳类动物的间性生殖可通过遗传突变、寄生、环境性别决定中断(ESD)和化学暴露而发生。甲壳动物群体的遗传知识目前非常有限，这使得对环境性别决定、雌性化寄生虫和污染背后的机制的评估在这一生态重要群体中非常有限：因此，如果不清楚了解生态相关物种的生物学，就很难评估环境科学中的热点话题，如内分泌干扰和气候变化。在生理、个体和种群水平上，温度、光周期和寄生对两足类性别决定的影响方面存在着大量的信息。此外，一些研究表明，暴露在环境污染物中后，这一群体也可能发生性行为中断。在NERC 454对正常和两性性腺组织中基因表达的初步研究之后，该项目将利用高通量测序技术来完成一套存档的生物组织，以研究雄性和雌性两种两足类动物和两种双性表型(两性雄性和雌性)的特定基因表达；大大增加对这一群体和一般甲壳类群体的遗传知识。雄性、雌性、两性雄性和两性雌性器官的种内和种间差异将通过数字转录学进行比较。此前有证据表明，雄性甲壳类动物可能受到污染的影响，影响了它们的雄性荷尔蒙，导致了去血管化(更像雌性的外表)。进一步的研究将使用三种方法实验地诱导潮间带圆足类动物去雄性化；第一，物理解剖雄性(雄激素)腺体；第二，通过感染雌性寄生虫；第三，通过化学暴露于一些已知的内分泌干扰化学物质。这些实验将被用来检查在每次实验操作后上调/下调的基因的比较。将选择关键基因并利用其开发化验方法，以评估从清洁和受污染地点现场收集的样本是否正在发生血管丧失。在这些研究期间获得的所有基因数据将通过一个名为AmphiBASE的特别设计的数据库向公众公布。

Intersexuality is the abnormal condition when an organism displays characteristics of being both male and female. The study of intersexuality in wildlife provides excellent means for studying comparative biology of abnormal conditions in reproductive determination and/or differentiation. Intersex in crustaceans can occur through genetic abberations, parasitism, disrupted environmental sex determination (ESD) and through chemical exposure. The genetic knowledge of crustacean groups is currently very limited making the assessment of mechanisms behind environmental sex determination (ESD); feminsing parasites; and pollution very limited in this ecologically important group: thus hot-topics in environmental sciences such as endocrine disruption and climate change are difficult to assess without a clear understanding of the biology of ecologically relevant species. Considerable information exists at the physiological, individual and population level impacts of temperature, photoperiod, and parasitism on the sex determination in amphipods. In addition, several studies have suggested sexual disruption might also be occuring in this group following exposure to environmental contaminents. Following on from a NERC 454 pilot study into gene expression in normal and intersex gonadal tissues, this project would utilise high-throughput sequencing technologies to complete a suite of archived biological tissues for specific gene expression in male and female amphipods and two intersex phenotypes (intersex males and females); increasing substantially the genetic knowledge for this and crustacean groups in general. Intra and inter specific differences between organs of males, females, intersex males and intersex females would be compared by digital transcriptmics. Following some evidence that suggests that male crustaceans maybe impacted by pollution in a way that effects their male hormones and cause demasculinisation (a more female-like appearance). Further studies would experimently induce de-masculinisation in an intertidal amphipod using three methods; firstly, physically dissecting the male (androgenic) glands; secondly, through infection with feminising parasites; and thirdly, through chemical exposure to some known endocrine disrupting chemicals. These experiments would be used to examine comparisons in the genes being up/down regulated following each experimental manipulation. Key genes would be selected and utilised to develop assays to assess whether demasculinisation is occuring in field collected specimens from clean and polluted sites. All genetic data acquired during these studies would be made publically available through a specially designed database entitled AmphiBASE.