title: Molecular characterization and mRNA expression of ribosomal protein L8 in Rana nigromaculata during development and under exposure to hormones.
abstract: Like Xenopus laevis, some species of the Rana genus are also used to study endocrine disrupting chemicals (EDCs). Although ribosomal protein L8 (rpl8) is the most-used reference gene for analyzing gene expression by quantitative reverse transcription polymerase chain reaction in Rana, its suitability as the reference gene has never been validated in any species of the Rana genus. We characterized rpl8 cDNA in Rana nigromaculata, a promising native species in East Asia for assaying endocrine disrupting effects. We found that the rpl8 cDNA consisted of 919bp and encoded 257 amino acids, exhibiting high identities of amino acid sequence with known rpl8 in other Rana species. Then, we examined the stability of mRNA expression during development. Compared with elongation factor 1 alpha 1, another common housekeeping gene, neither stage-specific nor tissue-specific expression of the rpl8 gene was found in all tissues examined (brain, liver, intestine, tail, testis and ovary) during R. nigromaculata development. Finally, we investigated rpl8 expression under exposure to hormones. No change in rpl8 mRNA expression was found under exposure to thyroid hormone (T4) and estrogen (estradiol), whereas expression of the corresponding biomarker genes was induced. Our results show that rpl8 is an appropriate reference gene for analyzing gene expression by quantitative reverse transcription polymerase chain reaction for assaying EDCs using R. nigromaculata, and might also provide support for using rpl8 as a reference gene in other Rana species due to the high conservation of rpl8 among the Rana genus.
authors.affiliation: State Key Laboratory of Environmental Chemistry and Ecotoxicology, Research Center for Eco-environmental Sciences, Chinese Academy of Sciences, Beijing 100085, China; College of Environment, Nanjing University of Technology, Nanjing 210009, China. Electronic address: louqinqindy@163.com.
authors.forename: Qinqin
authors.initials: Q
authors.lastname: Lou
authors.affiliation: State Key Laboratory of Environmental Chemistry and Ecotoxicology, Research Center for Eco-environmental Sciences, Chinese Academy of Sciences, Beijing 100085, China; College of Environment, Nanjing University of Technology, Nanjing 210009, China.
authors.forename: Shan
authors.initials: S
authors.lastname: Cao
authors.affiliation: State Key Laboratory of Environmental Chemistry and Ecotoxicology, Research Center for Eco-environmental Sciences, Chinese Academy of Sciences, Beijing 100085, China; College of Environment, Nanjing University of Technology, Nanjing 210009, China.
authors.forename: Wei
authors.initials: W
authors.lastname: Xu
authors.affiliation: State Key Laboratory of Environmental Chemistry and Ecotoxicology, Research Center for Eco-environmental Sciences, Chinese Academy of Sciences, Beijing 100085, China.
authors.forename: Yinfeng
authors.initials: Y
authors.lastname: Zhang
authors.affiliation: State Key Laboratory of Environmental Chemistry and Ecotoxicology, Research Center for Eco-environmental Sciences, Chinese Academy of Sciences, Beijing 100085, China. Electronic address: qinzhanfen@rcees.ac.cn.
authors.forename: Zhanfen
authors.initials: Z
authors.lastname: Qin
authors.affiliation: College of Environment, Nanjing University of Technology, Nanjing 210009, China.
authors.forename: Wuji
authors.initials: W
authors.lastname: Wei
mesh_terms: D000595:Amino Acid Sequence; D000818:Animals; D001483:Base Sequence; D017931:DNA Primers; D052244:Endocrine Disruptors / Q000494:pharmacology; D004958:Estradiol / Q000494:pharmacology; D008969:Molecular Sequence Data; D012333:RNA, Messenger / Q000235:genetics* / Q000378:metabolism*; D011898:Ranidae / Q000254:growth & development / Q000378:metabolism; D012269:Ribosomal Proteins / Q000737:chemistry / Q000235:genetics*; D017386:Sequence Homology, Amino Acid
chemical_list: D017931:DNA Primers; D052244:Endocrine Disruptors; D012333:RNA, Messenger; D012269:Ribosomal Proteins; C075184:ribosomal protein L8, rat; D004958:Estradiol
keywords: Endocrine disrupting chemical; Quantitative RT-PCR; Rana nigromaculata; Reference gene; Ribosomal protein L8