通过对新种河南高生熊虫（Hypsibius henanensis）的基因组、转录组和蛋白质组分析，研究人员探讨了导致该生物耐辐射的分子基础。一个假定的水平转移基因DOPA二氧化酶1（DODA1）对辐射产生反应，通过合成甜菜碱（一种具有清除自由基特性的植物色素）来赋予辐射耐受性。
缓步动物特异性辐射诱导的无序蛋白TRID1，通过相分离机制促进DNA损伤修复。两种线粒体呼吸链复合物组装蛋白BCS1和NDUFB8的积累，加速了烟酰胺腺嘌呤二核苷酸（NAD+）的再生，以进行聚（腺苷二磷酸-核糖基化）（PARylation）和随后由聚（腺苷二磷酸-核糖）聚合酶1（PARP1）介导的DNA损伤修复。这三项观察扩展了人们对缓步动物耐辐射机制的理解。
研究人员表示，缓步动物是令人着迷的生物，以其在极端环境下的韧性而闻名，包括超高剂量辐射，但这种韧性的基本机制仍然大量未知。
附：英文原文
Title: Multi-omics landscape and molecular basis of radiation tolerance in a tardigrade
Author: Inge Seim
Issue&Volume: 2024-10-25
Abstract: Tardigrades are captivating organisms known for their resilience in extreme environments, including ultra-high-dose radiation, but the underlying mechanisms of this resilience remain largely unknown. Using genome, transcriptome, and proteome analysis of Hypsibius henanensis sp. nov., we explored the molecular basis contributing to radiotolerance in this organism. A putatively horizontally transferred gene, DOPA dioxygenase 1 (DODA1), responds to radiation and confers radiotolerance by synthesizing betalains—a type of plant pigment with free radical–scavenging properties. A tardigrade-specific radiation-induced disordered protein, TRID1, facilitates DNA damage repair through a mechanism involving phase separation. Two mitochondrial respiratory chain complex assembly proteins, BCS1 and NDUFB8, accumulate to accelerate nicotinamide adenine dinucleotide (NAD+) regeneration for poly(adenosine diphosphate–ribosyl)ation (PARylation) and subsequent poly(adenosine diphosphate–ribose) polymerase 1 (PARP1)–mediated DNA damage repair. These three observations expand our understanding of mechanisms of tardigrade radiotolerance.
DOI: adl0799
Source: https://www.science.org/doi/10.1126/science.adl0799