IOCAS-IR  > 海洋生态与环境科学重点实验室
仿刺参Apostichopus japonicus对微塑料的摄入特征及其生理响应
Mohsen, Mohamed
Subtype博士
Thesis Advisor杨红生
2020-06
Degree Grantor中国科学院大学
Place of Conferral中国科学院海洋研究所
Degree Name博士
Keyword仿刺参 Apostichopus Japonicus 微塑料 摄食 生理响应 时序rna-seq
Abstract

近年来,海洋环境中微塑料(粒径小于5 mm)的污染日益受到广泛关注。微塑料在近海水体和沉积物中已被广泛检出。目前,有关生物摄入微塑料的研究多集中在贝类、鱼类和多毛类生物,棘皮动物的研究鲜有报道。仿刺参Apostichopus japonicus(以下简称刺参)作为一种沉积食性的生物,可能通过吞食沉积物进而摄入大量微塑料,因此是研究微塑料生态风险的理想研究对象。本研究首次定量分析了野外环境中刺参对微塑料的摄入特征,检测了其体内微塑料的浓度、形状和化学组分,查明了其对微塑料的摄入机制及其在体内的转移途径,揭示了微塑料暴露下对刺参的生理响应,以及长期微塑料暴露下对其生长性能的影响。主要研究结果如下:

  1. 不同养殖区刺参摄入微塑料的监测与分析

从中国渤海和黄海沿岸的八个养殖场收集刺参样品,利用密度分离法将微塑料从刺参肠道中分离出来进行检测。结果表明,刺参的摄入微塑料范围为030个每个,刺参体腔内流体中微塑料的范围为019颗每个个体,而沉积物中微塑料的丰度范围为201040kg-1干沉积物。结果表明,刺参在摄食过程中,一定量的微塑料会随之进入刺参体内,并且微塑料可能会转移到刺参的体腔液中。相关性分析表明,刺参肠道内微塑料浓度与周围沉积物中浓度具有一定的正相关性(r=0.767)。因此,该物种可以作为监测沉积物中微塑料污染的潜在指示物种。

  1. 沉积物、微塑料和刺参体内重金属含量之间的关系

微塑料能够从海洋环境中吸收污染物,并且有可能将这些污染物转移到所处环境的生物体中。为了确定微塑料是否能够将重金属等污染物转移至 刺参体内,检测了刺参生长环境沉积物中八种重金属(砷、镉、铬、铜、锰、镍、铅和锌)的含量。结果表明,刺参生长环境周围沉积物中的重金属浓度符合第一类沉积物质量标准。在上述重金属中,刺参体壁中镉和砷的中位数浓度高于相应沉积物中的浓度。微塑料颗粒中的镉、铅和锌的中值浓度高于相应沉积物浓度的中值。沉积物、刺参和微塑料中的重金属浓度之间无显著相关性,这表明微塑料吸附的重金属浓度不能指示刺参或沉积物中重金属的浓度。

  1. 刺参对微塑料摄取机制

在微塑料暴露下,刺参摄入的颗粒物随着水中颗粒物浓度的增加而增加(Pearsonr = 0.808, 且刺参去除颗粒的速率为0.3-0.9 L-1 h-1。结果表明,刺参能够通过口从水中摄入微塑料颗粒,这是刺参摄入微塑料颗粒的一种特殊途径,也从侧面揭示了仿刺参以前未发现的营养摄入途径。

  1. 微塑料在刺参体内转移途径

野外调查结果表明,微纤维(microfiber)形式的微塑料能够转移到刺参的体腔液中。因此,在实验室中检测查了微塑料转移到刺参体腔液中的可能性。结果表明,在呼吸过程中,微纤维随水一起被刺参摄入,而微纤维会滞留在呼吸树中或转移到体腔液里,该结果表明微纤维能够在仿刺参腔液中转移和积累。呼吸树中溶菌酶LZM)的水平随转移的微塑料的增加而增加,这间接反映了LZMs对外源颗粒物的防御作用。在暴露后24小时和48小时后,总抗氧化能力(T-AOC),丙二醛(MDA),过氧化物酶(POD)和苯酚氧化酶(PPO)的水平没有显着降低,表明滞留在呼吸树中的微塑料对刺参呼吸树的氧化胁迫程度较低。

  1. 微塑料转移过程中呼吸树的分子响应

为了查明微塑料在转移过程中呼吸树的分子水平响应,采用时序RNA-Seq技术构建刺参对微塑料暴露的响应的动态表达谱。将刺参暴露于微塑料(2 MP mL-1),在0小时(对照),0.5小时(T1)、2小时(T2)、4小时(T3)、8小时(T4)、16小时 (T5) 进行采样分析。基于差异分析结果,我们筛选FDR< 0.05 |log2FC|>1的基因为显著差异基因。结果表明,差异表达基因随时间增加而增加,T1T2T3T4T5差异表达基因分别为238225757183885。基因本体分析表明,差异分析与“生物过程”类别中的细胞、代谢和单一生物过程相关;与“细胞成分”类别中的细胞、细胞组分、细胞器相关的差异分析非常丰富,在分子功能类别中的催化活性也比较丰富。将差异分析映射到富集分析数据库,发现处理组显著富集于细胞凋亡途径。据此,微塑料的暴露会加速细胞凋亡的过程并导致细胞程序性死亡,而且随着微塑料的暴露时间增加,下调基因表达抑制了代谢途径。

  1. 微塑料长期暴露对刺参生长的影响

为了查明微塑料的摄入是否会影响刺参的生长, 采用带有微塑料的沉积物对两种规格刺参大小进行了60天长期暴露。大规格和小规格型仿刺参的初始重量为83.23±1.85mean±SD),小型仿刺参的初始重量为15.47±1.73mean±SD)。刺参长期暴露于环境相关的微塑料浓度(0.6 MF g-11.2 MF g-1)后以及高浓度微塑料(10 MF g-1)后,其生长并不受微塑料暴露影响。结果表明,暴露60天后,小规格处理组,对照和三种处理的比生长速率分别为0.99±0.170.96±0.180.92±0.150.83±0.02 (%/d)mean±SE),粪便产生率为0.6±0.060.7±0.060.5±0.070.6±0.08 (g ind./d) 对照组和三种处理组无显着差异(P > 0.05)。大规格处理组,对照和三种处理的比生长速率分别为0.63±0.110.50±0.150.51±0.080.49±0.14 (%/d) mean±SE),粪便产生率为2.27±0.322.00±0.161.98±0.492.02±0.35 (g ind./d) 对照组和三种治疗组间无显着差异(P > 0.05)。 因此,微塑料的长期暴露不对仿刺参的生长表现产生负面影响。

MOST Discipline Catalogue理学
Language英语
Table of Contents

Table of Contents

... I

Abstract IV

Chapter 1Introduction. 9

  1. Plastics and microplastics 9
  2. The fate of MPs in the marine environment 11
  3. Status of MPs in China. 12
  4. The potential hazard of MPs 13
  5. Effect of MPs on benthic invertebrates 14
  6. Mortality. 15
  7. Development 15
  8. Egestion. 16
  9. Cellular responses 16
  10. Effect of MPs on sea cucumbers: what is known and what is unknown. 17

Chapter 2. Microplastic ingestion by the farmed sea cucumber Apostichopus japonicus in China. 21

Introduction. 22

2.1. Materials and Methods 24

2.1.1. Sediment and sea cucumber sampling. 24

2.1.2. MP extraction from the sediment 25

2.1.3. MP extraction from the intestines of the sea cucumbers 26

2.1.4. MP extraction from the coelomic fluid of the sea cucumbers 26

2.1.5. Prevent contamination by airborne MPs 26

2.1.6. MPs inspection by microscopy. 27

2.1.7. Identification of the polymer type. 27

2.1.8. Statistical analysis 28

2.2. Results 28

2.2.1. MPs abundance in the sediments of the sea cucumber farms 28

2.2.2. MP ingestion by sea cucumbers 30

2.2.3. MPs isolated from the coelomic fluid of the sea cucumbers 32

2.3. Discussion. 34

2.3.1. MP abundance in the sediments of sea cucumber farms 34

2.3.2. MPs ingestion by sea cucumbers 35

2.3.3. MPs isolated from the coelomic fluid of sea cucumber 38

2.3.4. Polymer types identification of the MPs 39

2.4. Conclusion. 41

2.5. Summary. 41

Chapter 3. Heavy metals in sediment, microplastics, and the sea cucumber Apostichopus japonicus from farms in China. 42

Introduction. 43

3.1. Materials and Methods 44

3.1.1. Metals analysis 44

3.1.2. Quality assessment guides 44

3.1.3. Statistical analysis 45

3.2. Results and discussion. 46

3.2.1. Heavy metals in the sediment 46

3.2.2. Heavy metals concentration in the body wall of sea cucumber: 50

3.2.3. Heavy metals associated with MPs 56

3.3. Conclusion. 59

3.4. Summary. 60

Chapter 4. The sea cucumber Apostichopus japonicus ingests suspended particles through the mouth. 61

4.1. Introduction. 62

4.2. Materials and Methods 63

4.2.1. Experimental animals 63

4.2.2. Examine the particles in the intestines of the sea cucumber 63

4.2.3. The mechanism of particles uptake by the sea cucumber 64

4.2.4. Clearance rate. 64

4.2.5. Statistical analysis 65

4.3. Results and discussion. 65

4.4. Conclusion. 68

4.5. Summary. 69

Chapter 5. Microplastic fibers transfer from the water to the internal fluid of the sea cucumber Apostichopus japonicus 70

5.1. Introduction. 71

5.1. Materials and Methods 72

5.1.1. Experimental Animals 72

5.1.2. Synthetic MFs preparation. 72

5.1.3. A. japonicus exposure to MFs from the water 73

5.1.4. A. japonicus exposure to MFs from the ingested sediment 74

5.1.5. Enzyme analysis of the coelomic fluid due to MF transfer 74

5.1.6. Behavior recording post MF transfer 76

5.1.7. Statistical analysis 76

5.2. Results 76

5.2.1. A. japonicus exposure to MFs from the water 76

5.2.2. A. japonicus exposure to MFs from the ingested sediment 77

5.2.3. Enzymatic responses of the coelomic fluid due to MF transfer 78

  1. Behavior response of the sea cucumber after MFs transfer 84
  2. Discussion. 85
  3. A. japonicus exposure to MFs from the water 85
  4. A. japonicus exposure to MFs from the ingested sediment 86
  5. Enzymatic responses of the coelomic fluid due to MF transfer 87
  6. Conclusion. 89
  7. Summary. 89

Chapter 6. Molecular responses of the respiratory tree during the microplastic transferring process in the sea cucumber Apostichopus japonicus 90

6.1. Introduction. 91

6. 2. Materials and Methods 92

6.2.1. Experimental animals 92

6.2.2. Experimental design. 92

6.2.3. RNA Extraction, library construction, and sequencing. 92

6.2.4. Bioinformatics analysis 93

6.2.5. Relationship analysis of samples 94

6.3. Results 95

6.3.1. Number of the transferred MFs overtime. 95

6.3.2. Analysis of the sequencing data quality. 96

6.3.3. Hierarchical clustering analysis 99

6.3.4. Determine differentially gene expressed genes in response to MFs exposure. 100

6.3.5. Gene Ontology Enrichment Analysis of Identified DEGs 104

6.3.6. KEGG classifications 110

6.4. Discussion. 114

6.5. Conclusion. 117

6.6. Summary. 117

Chapter 7. Chronic exposure to microplastic ingestion in the sea cucumber Apostichopus japonicus 119

7.1. Introduction. 120

7.2. Materials and Methods 121

7.2.1. Experimental animals 121

7.2.2. Measurements and data calculation. 121

7.2.3. Statistical analysis 122

7.3. Results 122

7.3.1. Growth performance. 122

7.4. Discussion. 124

7.5. Conclusion. 125

7.6. Summary. 125

Chapter 8. Conclusion. 126

8.1. Main results 126

8.2. Current problems 127

8.3. Future directions 127

References 128

Publications 150

Acknowledgements 151

 

 

 

 

Document Type学位论文
Identifierhttp://ir.qdio.ac.cn/handle/337002/164712
Collection海洋生态与环境科学重点实验室
Corresponding AuthorMohsen, Mohamed
Recommended Citation
GB/T 7714
Mohsen, Mohamed. 仿刺参Apostichopus japonicus对微塑料的摄入特征及其生理响应[D]. 中国科学院海洋研究所. 中国科学院大学,2020.
Files in This Item:
File Name/Size DocType Version Access License
Mohsen's PhD.pdf(8588KB)学位论文 暂不开放CC BY-NC-SA
Related Services
Recommend this item
Bookmark
Usage statistics
Export to Endnote
Google Scholar
Similar articles in Google Scholar
[Mohsen, Mohamed]'s Articles
Baidu academic
Similar articles in Baidu academic
[Mohsen, Mohamed]'s Articles
Bing Scholar
Similar articles in Bing Scholar
[Mohsen, Mohamed]'s Articles
Terms of Use
No data!
Social Bookmark/Share
All comments (0)
No comment.
 

Items in the repository are protected by copyright, with all rights reserved, unless otherwise indicated.