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是一种耐冻型南极线虫，可在大量细胞内冰晶形成的条件下存活。目前学界对该物种极端耐寒适应性的分子机制仍知之甚少。我们此前的研究证实，经脱水增强的RNA干扰（RNA interference, RNAi）浸泡技术可结合定量聚合酶链式反应（quantitative polymerase chain reaction, qPCR），用于筛选Panagrolaimus sp. DAW1中候选基因表达下调相关的表型。本研究利用该方法，探究了海藻糖合成基因在这一奇特生物中的功能作用。既往研究表明，在冷冻或脱水处理前，将Panagrolaimus sp. DAW1置于5℃环境下进行冷驯化，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及其他海藻糖代谢相关基因，以及lea-1、hsp-70和gpx-1的表达水平。结果显示，Pd-tps-2与Pd-lea-1在冷驯化后显著上调，表明二者在Panagrolaimus sp. DAW1的冷适应过程中呈诱导表达模式。我们进一步通过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信使RNA（messenger RNA, mRNA）水平显著降低，但海藻糖含量与冷冻存活率均未发生明显变化。此外，本研究还对另外两个海藻糖合成基因（tps-2b与gob-1）的功能进行了探究。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。多个具有不同RNAi敏感性的海藻糖合成基因的存在，提示Panagrolaimus sp. DAW1体内存在多重备份系统，凸显了该糖类在冷冻适应准备过程中的关键作用。