CBET Research Group, Dept. of Zoology and Animal Cell Biology, Centre for Experimental Marine Biology and Biotechnology of Plentzia (PIE), University of the Basque Country (UPV/EHU), PO BOX 644, E-48080 Bilbao, Basque Country, Spain.
Comp Biochem Physiol A Mol Integr Physiol. 2013 Jun;165(2):178-90. doi: 10.1016/j.cbpa.2013.03.001. Epub 2013 Mar 6.
Bivalve molluscs accumulate chemical compounds from the environment that could cause alterations in lipid homeostasis and endocrine system. In vertebrates such cell processes are modulated by transcription factors belonging to the superfamily of nuclear receptors (NRs). The goal of this study was to clone fragments of mussel Mytilus galloprovincialis NR genes that could mediate cell responses such as peroxisome proliferation and endocrine disruption. PCR-based screening of mussel digestive gland cDNA using degenerate primers provided cDNA fragments or whole ORFs of retinoid X receptor (RXR), estrogen receptor (ER) and 5 proteins belonging to the NR1 subfamily highly similar to the arthropod ecdysone inducible protein E75. NR1G, whose whole ORF was cloned, is related to the nematode and trematode G group of NR1 receptors; NR1DEF is related to the D, E and F groups, and NR1Dv1, NR1Dv2 and NR1DΔ belong to the D group. mRNA transcripts for all these receptors were detected in gill, mantle and digestive gland. In all cases, except ER, transcript levels were lower in June than in January. NR1Dv1 and NR1DΔ did not show identical transcription levels, although both were at their lowest in digestive gland in June. On the contrary, NR1Dv2 and NR1DΔ transcription profiles were similar. Further studies are needed to determine the function(s) of mussel RXR, ER and novel NR1 subfamily receptors and their possible role in the regulation of physiological cell responses and/or adaptive response to xenobiotic exposures.
双壳贝类从环境中积累化学化合物，这些化合物可能导致脂质动态平衡和内分泌系统的改变。在脊椎动物中，这些细胞过程受属于核受体（NRs）超家族的转录因子调节。本研究的目的是克隆贻贝 Mytilus galloprovincialis NR 基因的片段，这些片段可以介导细胞反应，如过氧化物酶体增殖和内分泌干扰。使用简并引物对贻贝消化腺 cDNA 进行基于 PCR 的筛选，提供了视黄酸 X 受体 (RXR)、雌激素受体 (ER) 和 5 种属于 NR1 亚家族的蛋白的 cDNA 片段或全长 ORF，这些蛋白与节肢动物蜕皮激素诱导蛋白 E75 高度相似。克隆了全长 ORF 的 NR1G 与线虫和吸虫的 NR1 受体 G 组有关；NR1DEF 与 D、E 和 F 组有关，而 NR1Dv1、NR1Dv2 和 NR1DΔ 属于 D 组。在鳃、套膜和消化腺中都检测到了所有这些受体的 mRNA 转录本。除了 ER 之外，在 6 月份，所有这些受体的转录水平都低于 1 月份。NR1Dv1 和 NR1DΔ 的转录水平并不相同，尽管它们在 6 月份的消化腺中都处于最低水平。相反，NR1Dv2 和 NR1DΔ 的转录谱相似。需要进一步研究来确定贻贝 RXR、ER 和新型 NR1 亚家族受体的功能及其在调节生理细胞反应和/或对外源物质暴露的适应性反应中的可能作用。
