基于区块链的河豚供应链可信溯源优化研究

针对河豚供应链环节复杂、监管要求高以及溯源系统信息传递繁杂、数据查询效率低的问题,以提高河豚溯源查询效率和安全性为目的,建立了基于区块链技术的河豚供应链溯源优化模型,并搭建相应系统。首先,对河豚供应链业务供应链信息进行分析,整理并提取供应链各业务环节溯源码信息和产品信息;然后,基于区块链技术建立河豚供应链可信溯源优化模型架构,设计多链的存储模式和快速查询流程并制定相应的智能合约;最后,基于Hyperledger Fabric实现了一种河豚供应链信息溯源系统,并使用Caliper性能测试工具测试。结果表明,在数据记录条数大于1000条后,本文模型查询效率高于传统单链模型,在10000条数据记录上链后,本文模型较传统单链模型查询效率提高约92.9%。以江苏省某河豚企业为例,实现河豚供应链信息安全传递和快速溯源。所提出的模型可以应用到河豚行业从而提高溯源效率和安全性,为河豚行业提供一个防篡改、查询效率高的模型。     

Tetrodotoxin--distribution and accumulation in aquatic organisms, and cases of human intoxication

Many pufferfish of the family Tetraodontidae possess a potent neurotoxin, tetrodotoxin (TTX). In marine pufferfish species, toxicity is generally high in the liver and ovary, whereas in brackish water and freshwater species, toxicity is higher in the skin. In 1964, the toxin of the California newt was identified as TTX as well, and since then TTX has been detected in a variety of other organisms. TTX is produced primarily by marine bacteria, and pufferfish accumulate TTX via the food chain that begins with these bacteria. Consequently, pufferfish become non-toxic when they are fed TTX-free diets in an environment in which the invasion of TTX-bearing organisms is completely shut off. Although some researchers claim that the TTX of amphibians is endogenous, we believe that it also has an exogenous origin, i.e., from organisms consumed as food. TTX-bearing animals are equipped with a high tolerance to TTX, and thus retain or accumulate TTX possibly as a biologic defense substance. There have been many cases of human intoxication due to the ingestion of TTX-bearing pufferfish, mainly in Japan, China, and Taiwan, and several victims have died. Several cases of TTX intoxication due to the ingestion of small gastropods, including some lethal cases, were recently reported in China and Taiwan, revealing a serious public health issue.     

暗纹东方鲀冻藏品质劣化的原因解析

通过比较冰晶、内源蛋白酶以及氧化对冻藏暗纹东方鲀(Takifugu obscurus)品质的影响,确定冻藏暗纹东方鲀品质劣化的关键因素。实验通过液氮浸渍快速冻结抑制鱼肉组织中冰晶增长、碘乙酸浸泡前处理抑制鱼肉内源蛋白酶活性、复合抗氧化剂浸泡前处理抑制蛋白/脂质氧化作用的设计,区分冰晶、内源蛋白酶和氧化3种因素对冻藏鱼肉品质的影响;并以硬度、解冻流失率、蒸煮损失率、挥发性盐基氮含量、K值、Ca2+-ATPase活性、肌原纤维小片化指数和肌纤维长度作为鱼肉品质的评价指标。结果显示,冻结过程中控制冰晶增长对暗纹东方鲀冻藏品质的改善作用最大,冻藏24周后,速冻组的硬度比内源蛋白酶抑制组和氧化抑制组分别提高了26.8%和20.5%,解冻流失率分别降低了44.2%和44.8%,且该处理组TVB-N、K值和Ca2+-ATPase活性变化更慢,24周后分别为10.5 mg/100 g、6.8%和1.43 μmol Pi/mg/10 min。综合各项指标发现,冰晶、内源蛋白酶和氧化对冻藏暗纹东方鲀品质劣化均有影响;其中,冰晶作用是导致暗纹东方鲀在冻藏过程中品质下降的最主要影响因素,内源蛋白酶和氧化对冻藏暗纹东方鲀品质的影响次之,且二者对品质影响无显著性差异。     

An Updated Review of Tetrodotoxin and Its Peculiarities

Tetrodotoxin (TTX) is a crystalline, weakly basic, colorless organic substance and is one of the most potent marine toxins known. Although TTX was first isolated from pufferfish, it has been found in numerous other marine organisms and a few terrestrial species. Moreover, tetrodotoxication is still an important health problem today, as TTX has no known antidote. TTX poisonings were most commonly reported from Japan, Thailand, and China, but today the risk of TTX poisoning is spreading around the world. Recent studies have shown that TTX-containing fish are being found in other regions of the Pacific and in the Indian Ocean, as well as the Mediterranean Sea. This review aims to summarize pertinent information available to date on the structure, origin, distribution, mechanism of action of TTX and analytical methods used for the detection of TTX, as well as on TTX-containing organisms, symptoms of TTX poisoning, and incidence worldwide.     

Genetic comparison between torafugu <Emphasis Type="Italic">Takifugu rubripes</Emphasis> and its closely related species karasu <Emphasis Type="Italic">Takifugu chinensis</Emphasis>

Abstract:   Sequence analyses of mitochondrial (mt) and nuclear genes were performed for genetic comparison between two Takifugu pufferfish species: torafugu T. rubripes and karasu T.  chinensis . With a sequence coverage of 20% in mtDNA, 640, 308, 344, 522 and 697 bp encoding mt 16S ribosomal RNA (rRNA), adenosine triphosphatase 6 ( ATPase 6 ), nicotinamide adenine dinucleotide dehydrogenase subunit 4 ( ND4 ), ND5 and cytochrome b (cyt b ), respectively, among 24 wild torafugu, 24 wild karasu and six hybrid-like samples, 15% of the torafugu identified by external color patterns showed nucleotide sequences consistent with karasu. Meanwhile, sequences of 60% karasu were consistent with those registered for torafugu (AJ421455). As for the hybrid-like samples, two possessed karasu-specific sequences in some base positions while torafugu-specific sequences in others. The remaining hybrid-like samples possessed torafugu-specific sequences. On the other hand, the mt control region did not show such type of consistency. Analysis of nuclear melanocortin receptor genes ( MC1R , MC4R ) among 54 samples showed 99–100% inter- and intraspecific sequence identity. Partial nuclear 18S  rRNA, complete internal transcribed spacer 1 ( ITS1 ), partial 5.8S  rRNA and ITS2 genes showed similar levels of identity, indicating a very low level of variation in their respective gene fragments between the two Takifugu species.     

EDCs‐induced glucocorticoid receptor related genes expression of the river pufferfish,Takifugu obscurus

Endocrine disrupting chemicals (EDCs) are of substantial concern when contaminating waters. We studied gene expression of larvae from river pufferfish, Takifugu obscurus exposed to EDCs. We cloned the full‐ or partial‐length cDNA sequence of genes related to the cortisol pathway, such as the glucocorticoid receptor (GR), mineralocorticoid receptor (MR), heat shock protein (HSP) 70 and 90, phosphoenolpyruvate carboxykinase (PEPCK) and the FK506‐binding protein 4 (FKBP52). The tissue and time‐dependent expression of mRNA was studied by real‐time PCR in T. obscurus exposed to two representative EDCs (bisphenol‐A and 4‐tert‐octylphenol). HSP70, HSP90, MR and FKBP52 mRNA expression level was much higher than GR and PEPCK expression. GR mRNA expression level was significantly upregulated after 48 h in both EDC‐treated fish groups compared with the control. Both groups also showed down‐regulation patterns after 48 h. The initial expression of PEPCK in both groups was down‐regulated after 24 h. In the bisphenol‐A treated group, the expression of FKBP52 showed substantially high up‐regulation from 6 to 48 h after exposure, and then strikingly reduced its expression level at 72 h. Our results provide insights into the EDCs metabolizing system of T. obscurus and offers baseline information for further research related to the possible use as a bio‐indicator of this commercially important aquaculture fish species.     

暗纹东方鲀TTX的微量、快速检测

采用高效液相色谱法建立快速、微量检测河毒素方法。使用WaterspicoTagTMFAA色谱柱;以5％乙腈中含0．005N三氟乙酸和0．005N乙酸为流动相;荧光检测波长：激发波长为365nm,发射波长为510nm。该方法在25ng／ml～300ng／ml线性范围内峰面积响应值与其浓度呈良好的线性关系,r＝0．9994。最低检测线为1ng。该方法可简便、快速、微量、准确定性、定量检测河毒素。     

Early life history of yellow puffer,Chonerhinos naritus (Richardson, 1848) from Sarawak,Northwestern Borneo

The growth and morphological development including fins, spine distribution and pigmentation of larval and juvenile of hatchery‐reared yellow puffer, Chonerhinos naritus were described to provide essential information on the early life history of this species. The total length (TL) of newly hatched larvae was 3.42 ± 0.23 (mean ± SD) mm, reaching 5.66 ± 0.38 mm on 5 days after hatched (DAH), 7.80 ± 0.28 mm on 11 DAH, 9.88 ± 0.40 mm on 27 DAH and 10.92 ± 0.58 mm on 30 DAH. The yolk was completely absorbed in preflexion larvae at 4 DAH. The mouth opening started at 3 DAH of yolk sac larvae, while the teeth appeared starting from preflexion larvae at 7 DAH. Overall aggregate fin ray numbers including caudal fin attained full complement in postflexion larvae at 27 DAH. Several melanophores with appearance of small stellate were first appeared dorsally on the head of flexion larvae at 13 DAH, expanded at the dorsal region of the head, above the eye in juveniles at 30 DAH. The spines first appeared in preflexion larvae of C. naritus at 7 DAH, covering the ventral skin region below pectoral fin base and expanded to the ventral part of the body and nearly covered the whole abdomen region before the anus and below the eyes in juveniles. C. naritus remain as larvae for approximately 29 days, during which they metamorphose to the juvenile stage prior to sexual maturation. Observations in larvae development of C. naritus revealed similar characteristics with other Tetraodontidae species.     

Individual variations in behavior and free cortisol responses to acute stress in tiger pufferfish Takifugu rubripes

Abstract:   The aim of the present study was for individual variation in behavior to be characterized and related to differences in physiological stress responses in juvenile tiger pufferfish (fugu) Takifugu rubripes . A set of siblings ( n  = 330) from wild parents was subjected to behavior tests, and some were classified into active and inactive groups ( n  = 42 each group). The active animals consisted of those individuals that kept active swimming during 6 min after transfer from one tank to another, and the inactive animals were those that stopped swimming within 6 min. Time-course acute stress responses, which were elicited by anesthesia and subsequent removal of a pectoral fin, were compared between the active and inactive fish. The stress indicators used were free and total plasma cortisol, and plasma glucose. Although no significant difference was observed at each sampling point between groups, the inactive fish required shorter recovery time from acute stress in all three indicators than the active fish. The percentage of free to total plasma cortisol in the pre-stress condition was significantly lower in the inactive group than in the active group. Our findings indicate that fugu has behavioral variation that is associated with stress responsiveness. The inactive fish are expected to be more tolerant of stress and suitable for aquaculture.     

Isolation of microsatellite markers by in silico screening implicated for genetic linkage mapping in Japanese pufferfish Takifugu rubripes

ABSTRACT:   The search for dinucleotide repeat microsatellites within scaffolds 1–25 of genome database JGI Fugu v3.0 for the pufferfish Takifugu rubripes revealed that 80% of microsatellite loci consisted of five to 13-fold repeats with locus-specific differences in density. Eleven out of 15 microsatellite loci isolated from the database with which genotyping using wild pufferfish was successfully performed showed polymorphism; that is, the means of the number of alleles and expected and observed heterozygosities at these 11 loci were 21.8, 0.915 and 0.829, respectively. It was confirmed that eight out of the 11 polymorphic loci were inherited through the Mendelian law and one pair of microsatellite loci derived from the same scaffold was linked. These results demonstrated that these loci are useful for constructing a linkage map in the pufferfish as DNA markers.