Ecosystem monitoring - Experimental models - Heavy metal pollution - Metal pollution - Physiological mechanisms - Physiological trait - Spiders - Toxicological effects
Heavy metals can accumulate in the bodies of spiders and affect their physiological and ecological traits and/or show toxicological effects. Spiders are thus considered to be potential bioindicators of heavy metal pollution for ecosystem monitoring, due to their superior resistance to and regulation of heavy metals. The metal loads in spider bodies show considerable variation within and among species, metal types, geochemical sites, exposure pathways, spider physiological traits, and other factors. Moreover, the mechanism of physiological regulation and tolerance in spiders to different kinds of heavy metals also varies significantly; it has been shown that those two differences are synergistic effects. Since the ecotoxicology and differences in physiological mechanisms remain unclear, questions and recommendations for possible further research are suggested.
Cadmium (Cd) is a heavy metal that can cause irreversible toxicity to animals, and is an environmental pollutant in farmlands. Spiders are considered to be an excellent model for investigating the impacts of heavy metals on the environment. To date, the changes at the molecular level in the cerebral ganglia of spiders are poorly understood. Cd exposure leads to strong damage in the nervous system, such as apoptosis and necrosis of nerve cells, therefore we conducted a transcriptomic analysis of Pardosa pseudoannulata cerebral ganglia under Cd stress to profile differential gene expression (DGE). We obtained a total of 123,328 assembled unigenes, and 1441 Cd stress-associated DEGs between the Cd-treated and control groups. Expression profile analysis demonstrated that many genes involved in calcium signaling, cGMP-PKG signaling, tyrosine metabolism, phototransduction-fly, melanogenesis and isoquinoline alkaloid biosynthesis were up-regulated under Cd stress, whereas oxidative phosphorylation-related, nervous disease-associated, non-alcoholic fatty liver disease-associated, and ribosomal-associated genes were down-regulated. Here, we provide a comprehensive set of DEGs influenced by Cd stress, and heavy metal stress, and provide new information for elucidating the neurotoxic mechanisms of Cd stress in spiders.
Since the birth of transgenic crops expressing Bacillus thuringiensis (Bt) toxin for pest control, the public debate regarding ecological and environmental risks as well as benefits of Bt crops has continued unabated. The impact of Bt crops, especially on non-target invertebrates, has received particular attention. In this review, we summarize and analyze evidences for non-target effects of Bt rice on spiders, major predators in rice fields. Bt rice has been genetically modified to express the Bt protein, which has been shown to be transferred and accumulate in spiders as part of their food chain. Moreover, the Bt protein exhibits unintended effects on the physiology of spiders and spreads to higher trophic levels. Spiders possess unique physiological and ecological characteristics, revealing traits of surrogate species, and are thus considered to be excellent non-target arthropod model systems for study of Bt protein impacts. Due to the complexities of Bt protein transfer and accumulation mechanisms, as well as the apparent lack of information about resulting physiological, biochemical, and ecological effects on spiders, we raise questions and provide recommendations for promising further research.
rice field spider;study advances;China;predation function
Many laboratory and field studies have been conducted on rice field spiders in China. There are 375 species, 108 genera, and 22 families of rice field spiders distributed within the major rice growing areas and 17 dominant species. The biological and ecological characteristics of 17 rice field spider species have been reported in detail. The biology and ecology of these species show significant differences among regions, farmland habitats, and agricultural practices. Future research should focus on rice field habitat diversity, enhancing the insecticide resistance of dominant spider populations, implementing large-scale breeding of spiders and augmentative release, breeding more leaf dominant species, conducting biosafety assessment of spiders in transgenic crops.
Cadmium (Cd) generates a variety of physiological and ecological toxicity to spiders. However, little is known about the effects of Cd on symbiotic bacteria of spiders. Metatranscriptomics is increasing our knowledge of microorganisms in environment. To better understand the impact of Cd on the symbiotic bacteria of spiders, we generated and compared the metatranscriptomes of the intestinal microorganisms of Pardosa pseudoannulata with and without Cd stress. The community structure of intestinal microorganisms in P. pseudoannulata was composed of 4 kingdoms, namely bacteria, viruses, eukaryotes and archaea, including 46 phyla, 97 classes, 184 orders, 339 families, 470 genera, and 598 species. The abundance of eukaryotes, bacteria and viruses was decreased by 0.14%, 1.22% and 2.52% respectively while the archaea was increased by 99.16% when under Cd stress. We identified 1519 differentially expressed genes (DEGs), including 770 up-regulated and 749 down-regulated genes. The results of KEGG annotation revealed that the expression of genes that are involved in the carbon metabolism, protein and amino acid metabolism and synthesis, glucose metabolism, oxidative phosphorylation, and glutathione metabolism were influenced by Cd. Collectively, these findings showed that Cd significantly impacted the community structure and expression of related functional genes of intestinal microorganisms in P. pseudoannulata.
Environmental science and pollution research international,2018年25(24):23875-23882 ISSN：0944-1344
[Yang, Huilin] College of Orient Science and Technology, Hunan Agricultural University, No. 1 Nongda Road, Changsha, 410128, Hunan, China;[Yang, Huilin; Shi, Yixue; Wang, Juan] College of Bioscience and Biotechnology, Hunan Agricultural University, No. 1 Nongda Road, Changsha, 410128, Hunan, China;[Peng, Yuande; Xie, Chunliang] Institute of Bast Fiber Crops, Chinese Academy of Agricultural Sciences, Changsha, 410205, Hunan, China;[Wang, Zhi] College of Bioscience and Biotechnology, Hunan Agricultural University, No. 1 Nongda Road, Changsha, 410128, Hunan, China. firstname.lastname@example.org;[Wang, Zhi] College of Life Science, Hunan Normal University, Changsha, 410006, Hunan, China. email@example.com
[Wang, Zhi] College of Bioscience and Biotechnology, Hunan Agricultural University, No. 1 Nongda Road, Changsha, 410128, Hunan, China.;[Wang, Zhi] College of Life Science, Hunan Normal University, Changsha, 410006, Hunan, China.
Due to some similarity of innate immunity between insects and mammals, the study of the molecular mechanism of innate immunity in insects has become a focus of research. However, the exact molecular and cellular basis of immune system in insect remains poorly understood. Characterization of the transcriptomic response to Cd of spider is an effective approach to understanding the innate immunity mechanisms. In this study, we carried out transcriptome sequencing and gene expression analyses to develop molecular resources for Pardosa pseudoannulata venom glands with and without Cd treatments. A total of 92,778 assembled unigenes and 237 Cd stress-associated differentially expressed genes between the Cd-treated and control groups were obtained. Expression profile analysis demonstrated that immunity-related genes involved in bacterial invasion of epithelial cells, leukocyte transendothelial migration, platelet activation, apoptosis, phagosome, and Rap1 signaling pathway were upregulated by Cd exposure, except the genes involved in PPAR signaling pathway were downregulated. Our results provide the first comprehensive transcriptome dataset of venom glands in P. pseudoannulata response to Cd, which is valuable for throws light on the immunotoxicity mechanism of Cd, and the innate immunity complexity.