Data from: Investigating trehalose synthesis genes after cold acclimation in the Antarctic nematode Panagrolaimus sp. DAW1

Panagrolaimus sp. DAW1 is a freeze-tolerant Antarctic nematode which survives extensive intracellular ice formation. The molecular mechanisms of this extreme adaptation are still poorly understood. We recently showed that desiccation-enhanced RNA interference (RNAi) soaking can be used in conjunction with quantitative polymerase chain reaction (qPCR) to screen for phenotypes associated with reduced expression of candidate genes in Panagrolaimus sp. DAW1. Here, we present the use of this approach to investigate the role of trehalose synthesis genes in this remarkable organism. Previous studies have shown that acclimating Panagrolaimus sp. DAW1 at 5°C before freezing or desiccation substantially enhances survival. In this study, the expression of tps-2 and other genes associated with trehalose metabolism, as well as lea-1, hsp-70 and gpx-1, in cold-acclimated and non-acclimated nematodes was analyzed using qPCR. Pd-tps-2 and Pd-lea-1 were significantly upregulated after cold acclimation, indicating an inducible expression in the cold adaptation of Panagrolaimus sp. DAW1. The role of trehalose synthesis genes in Panagrolaimus sp. DAW1 was further investigated by RNAi. Compared to the controls, Pd-tps-2a(RNAi)-treated and cold-acclimated nematodes showed a significant decrease in mRNA, but no change in trehalose content or freezing survival. The involvement of two other trehalose synthesis genes (tps-2b and gob-1) was also investigated. These findings provide the first functional genomic investigation of trehalose synthesis genes in the non-model organism Panagrolaimus sp. DAW1. The presence of several trehalose synthesis genes with different RNAi sensitivities suggests the existence of multiple backup systems in Panagrolaimus sp. DAW1, underlining the importance of this sugar in preparation for freezing.Panagrolaimus sp. DAW1是一种耐冻南极线虫，可在广泛的细胞内冰形成过程中存活。该极端适应现象的分子机制目前仍不甚明晰。我们此前的研究表明，干燥增强型RNA干扰（RNA interference, RNAi）浸泡法可与定量聚合酶链反应（quantitative polymerase chain reaction, qPCR）联用，用以筛选Panagrolaimus sp. DAW1中候选基因表达下调相关的表型。本研究即采用该方法，探究海藻糖合成基因在这一特殊物种中的功能作用。既往研究表明，在冷冻或干燥处理前，将Panagrolaimus sp. DAW1置于5℃环境进行冷驯化，可显著提升其存活率。本研究通过qPCR分析了冷驯化组与非冷驯化组线虫中tps-2及其他与海藻糖代谢相关的基因，以及lea-1、hsp-70和gpx-1的表达水平。冷驯化后，Pd-tps-2与Pd-lea-1的表达量显著上调，表明二者在Panagrolaimus sp. DAW1的冷适应过程中存在诱导表达现象。本研究进一步通过RNAi技术探究了海藻糖合成基因在Panagrolaimus sp. DAW1中的功能。与对照组相比，经Pd-tps-2a(RNAi)处理的冷驯化线虫的mRNA水平显著降低，但海藻糖含量与冷冻存活率未发生明显变化。本研究同时探究了另外两个海藻糖合成基因（tps-2b与gob-1）的功能。本研究首次针对非模式生物Panagrolaimus sp. DAW1中的海藻糖合成基因开展了功能基因组学研究。存在多个具有不同RNAi敏感性的海藻糖合成基因，这提示Panagrolaimus sp. DAW1存在多重备份系统，凸显了该糖类在冷冻准备过程中的重要作用。