摘要：
【目的】探究中华鳖(Pelodiscus sinensis)甘露糖受体C2(Mannose receptor C type 2)基因PsMRC2在应答嗜水气单胞菌(Aeromonas hydrophila)感染中的免疫功...展开更多 【目的】探究中华鳖(Pelodiscus sinensis)甘露糖受体C2(Mannose receptor C type 2)基因PsMRC2在应答嗜水气单胞菌(Aeromonas hydrophila)感染中的免疫功能,为中华鳖抗细菌感染的免疫机制研究提供理论依据。【方法】通过PCR克隆PsMRC2基因开放阅读框(ORF)序列,对其进行生物信息学和系统发育进化分析,并以实时荧光定量PCR检测PsMRC2基因在中华鳖各组织中表达谱及嗜水气单胞菌感染后的时序表达。【结果】PsMRC2基因ORF序列为4086 bp,共编码1361个氨基酸残基。PsMRC2蛋白结构域包括1个纤连蛋白Ⅱ型(FNⅡ)结构域(第61~109位氨基酸)、8个串联的C型凝集素(CLECT)结构域(第116~1276位氨基酸)、1个跨膜结构域(第1295~1317位氨基酸)。通过SOMPA预测得到PsMRC2蛋白二级结构包含706个无规则卷曲(占51.87%)、302个延伸链(占22.19%)、289个α-螺旋(占21.23%)和64个β-转角(占4.70%);SWISS-MODEL预测PsMRC2蛋白三级结构匹配的模板与PsMRC2氨基酸序列相似性为90%,预测结果可信。基于PsMRC2蛋白氨基酸序列相似性构建的系统发育进化树显示,中华鳖与龟类的亲缘关系最近,而与鱼类相距较远。PsMRC2基因在中华鳖的心脏、肝脏、脾脏、肾脏、肠道、肌肉、脑和肺脏组织中均有表达,以脾脏组织中的相对表达量最高。感染嗜水气单胞菌后,PsMRC2基因在中华鳖肝脏、脾脏、肾脏和肠道组织中的相对表达量均呈上调趋势。【结论】PsMRC2基因在进化上较保守,广泛表达于中华鳖各组织中,参与中华鳖抗细菌感染的免疫应答过程。收起
通讯机构：
[Wang, X.] C;[Xiong, G.] D;College of Animal Science & Technology, Hunan, China;Department of Animal Science and Technology, Hunan, China
关键词：
Chinese soft-shelled turtles;embryo development;gonadal sex differentiation;transcriptome
摘要：
<jats:title>Abstract</jats:title>
<jats:p>The Chinese soft-shelled turtle (<jats:italic>Pelodiscus sinensis</jats:italic>) is an economically important and rare freshwater aquaculture species in China. The male turtles have better economic benefits than females due to their faster growth speed. In order to explore the mechanism of sex differentiation and determination of <jats:italic>P. sinensis</jats:italic>, transcriptome analysis was carried out using embryo samples from the sex determination, sex differentiation and shelling stages, respectively. The gender types of embryos were identified by genotyping and histological analysis. In all, 277,230 and 273,859 genes were identified from embryos of male and female turtles, respectively. Cluster analysis of gene expression patterns exhibited trends for all differentially expressed genes (DEGs), which can be classified into three subclusters. In the sex determination, sex differentiation, and shelling stages 975, 43, and 300 DEGs, respectively, were identified by comparing the male and female groups. KEGG analysis was used to explore the function of the DEGs. <jats:italic>Fgf9</jats:italic>, <jats:italic>foxl2</jats:italic>, <jats:italic>mex3</jats:italic>b, <jats:italic>sox7</jats:italic>,<jats:italic>tgfβ</jats:italic>-3, <jats:italic>wnt4</jats:italic>, <jats:italic>wnt7a</jats:italic>, and <jats:italic>wt1</jats:italic> were upregulated in ovary development stages and <jats:italic>chfr</jats:italic>, <jats:italic>ampk</jats:italic>, <jats:italic>aldh2</jats:italic>, <jats:italic>dao</jats:italic>, <jats:italic>glt1d1</jats:italic>, <jats:italic>hvcn1</jats:italic>, <jats:italic>psmd9</jats:italic>, <jats:italic>srsf9</jats:italic> and <jats:italic>ubc</jats:italic> were upregulated in testis development stages, indicating that these genes play important roles in the sex development of <jats:italic>P. sinensis</jats:italic>. The results of this study provide preliminary insights into the sex determination and differentiation of Chinese soft-shelled turtles.</jats:p>
摘要：
Aquatic animals show diverse body coloration, and the formation of animal body colour is a complicated process. Increasing evidence has shown that microRNAs (miRNAs) play important regulatory roles in many life processes. The role of miRNAs in pigmentation has been investigated in some species. However, the regulatory patterns of miRNAs in reptile pigmentation remain to be elucidated. In this study, we performed an integrated analysis of miRNA and mRNA expression profiles to explore corresponding regulatory patterns in embryonic body colour formation in the soft-shelled turtle Pelodiscus sinensis. We identified 8 866 novel genes and 9 061 mature miRNAs in the skin of Chinese soft-shelled turtles in three embryonic stages (initial period: IP, middle period: MP, final period: FP). A total of 16 563 target genes of the miRNAs were identified. Furthermore, we identified 2 867, 1 840 and 4 290 different expression genes (DEGs) and 227, 158 and 678 different expression miRNAs (DEMs) in IP vs. MP, MP vs. FP, and IP vs. FP, respectively. Among which 72 genes and 25 miRNAs may be related to turtle pigmentation in embryonic development. Further analysis of the novel miRNA families revealed that some novel miRNAs related to pigmentation belong to the miR-7386, miR-138, miR-19 and miR-129 families. Novel_miR_2622 and novel_miR_2173 belong to the miR-19 family and target Kit and Gpnmb, respectively. The quantification of novel_miR_2622 and Kit revealed negative regulation, indicating that novel_miR_2622 may participate in embryonic pigmentation in P. sinensis by negatively regulating the expression of Kit. miRNA act as master regulators of biological processes by controlling the expression of mRNAs. Considering their importance, the identified miRNAs and their target genes in Chinese soft-shelled turtle might be useful for investigating the molecular processes involved in pigmentation. All the results of this study may aid in the improvement of P. sinensis breeding traits for aquaculture.
期刊：
Annales de Limnologie - International Journal of Limnology,2021年57:18 ISSN：0003-4088
通讯作者：
Wang, X.
作者机构：
[Huang, Guojia] Guiyang Univ, Guiyang 550005, Peoples R China.;[Huang, Guojia; Xu, Dajian; Wang, Xiaoqing] Hunan Agr Univ, Coll Anim Sci & Technol, Changsha 410128, Peoples R China.;[Chen, Yushun] Chinese Acad Sci, Inst Hydrobiol, State Key Lab Freshwater Ecol & Biotechnol, Wuhan 430072, Peoples R China.;[Chen, Yushun] Univ Chinese Acad Sci, Beijing 100049, Peoples R China.;[Deng, Long] China Water Environm Grp Ltd, Beijing 101101, Peoples R China.
通讯机构：
[Wang, X.] C;College of Animal Science and Technology, China
关键词：
Phytoplankton functional groups;C-S-R survival strategies;environmental factors;reservoir;drinking water supply
摘要：
In this study, we used the phytoplankton functional group index, survival strategies and environmental conditions in the Zhushuqiao reservoir to detect overall phytoplankton survival strategies (C-S-R) in the entire reservoir water column, and assess quantitative relationships between phytoplankton survival strategies and environment, which may help for future reservoir management. In this study, use survival strategies of phytoplankton functional groups to environmental factors in a drinking water reservoir. Survival strategies of phytoplankton in drinking water reservoirs were rarely analysed. Dynamics and survival strategies of phytoplankton community in Zhushuqiao Reservoir (Changsha, China) were studied bimonthly from April 2016 to February 2017 to fill this gap. In spring, species of CRS-strategy that adapted to low water temperature, light, and nutrient dominated. There were small individuals of opportunistic colonists of C-strategy observed before stratification. With the increase of nutrient and water temperature in summer, slightly bigger, disturbance-tolerant species of R-strategy and species of CS-strategy that adapted to stratification dominated. In winter, some species adapted to low water temperature, which were R-strategists. Key factors driven seasonal phytoplankton succession were water temperature, total phosphorus, and dissolved inorganic nitrogen. Attention should be paid to potential threats from algal bloom species with C-strategy, and future longer-term monitoring of the system and its surrounding watersheds is greatly needed.
关键词：
Chinese soft-shelled turtle;Aeromonas hydrophila;hemorrhagic sepsis;molecular immunopathogenesis
摘要：
Simple Summary: The Chinese soft-shelled turtle (Trionyx sinensis) is an important cultured reptile in East Asia. Hemorrhagic sepsis caused by Aeromonas hydrophila infection is the dominant disease in the aquaculture of Chinese soft-shelled turtles, while the molecular pathology is far from clear due to the lag of research on turtle immunology. It has been reported in mammals and fish that the dysfunction of immune responses to pathogen infections causes host tissue hemorrhagic sepsis. In this study, two groups of turtles with different susceptibility to A. hydrophila infection are found. A comparative transcriptome strategy is adopted to examine the gene expression profiles in liver and spleen for these two phenotypes of turtles post A. hydrophila infection, for the first time revealing the full picture of immune mechanisms against A. hydrophila, which provides new insight into the molecular pathology during A. hydrophila infection in T. sinensis. The findings will promote further investigations on pathogenic mechanisms of hemorrhagic sepsis caused by A. hydrophila infection in T. sinensis, and also will benefit their culture industry.<br>Although hemorrhagic sepsis caused by Aeromonas hydrophila infection is the dominant disease in the aquaculture of Chinese soft-shelled turtle, information on its molecular pathology is seriously limited. In this study, ninety turtles intraperitoneally injected with A. hydrophila exhibited two different phenotypes based on the pathological symptoms, referred to as active and inactive turtles. Comparative transcriptomes of liver and spleen from these two groups at 6, 24, and 72 h post-injection (hpi) were further analyzed. The results showed that cytokine-cytokine receptor interaction, PRRs mediated signaling pathway, apoptosis, and phagocytosis enriched in active and inactive turtles were significantly different. Pro-inflammatory cytokines, the TLR signaling pathway, NLR signaling pathway, and RLR signaling pathway mediating cytokine expression, and apoptosis-related genes, were significantly up-regulated in inactive turtles at the early stage (6 hpi). The significant up-regulation of phagocytosis-related genes occurred at 24 hpi in inactive turtles and relatively lagged behind those in active turtles. The anti-inflammatory cytokine, IL10, was significantly up-regulated during the tested periods (6, 24, and 72 hpi) in active turtles. These findings offer valuable information for the understanding of molecular immunopathogenesis after A. hydrophila infection, and facilitate further investigations on strategies against hemorrhagic sepsis in Chinese soft-shelled turtle T. sinensis.
摘要：
Aromatase, encoded by Cyp19a1, is essential in estrogen biosynthesis and crucial in sex differentiation and ovary development. Although aromatase regulates the proliferation, development, maturation and functional maintenance of male germ cells during mammalian spermatogenesis, its role in nonmammalian vertebrates is unclear. In the current study, a polyclonal antibody was prepared and the function of aromatase in testes was determined by administering letrozole. With ELISA detection, the titer of the antibody prepared in this study was more than 1:30000. Western blot analysis showed that the antibody could bind with cyp19a1 specifically. Aromatase was detected in Leydig cells and spermatogonia by immunohistochemistry. Thirty turtles were randomly assigned into three groups and received either letrozole treatment at 0 mg/kg (in control) body weight (BW), 5 mg/kg BW, or 10 mg/kg BW each day for 8 weeks. Histological analysis demonstrated that sperm count decreased in testis after letrozole treatment, and increasing levels of apoptosis were revealed by TUNEL staining. Quantitative real time PCR showed that Esr1, Esr2, and Gper exhibited different expression patterns after letrozole treatment. Dvl2, Cdc20, Dmc1, Sycp3, and Casp3 expression was significantly upregulated with the 10 mg/kg treatment (P < 0.05). Efnb1, Spata6, and Stra8 expression was significantly downregulated with the 5 mg/kg and 10 mg/kg treatments. These findings demonstrate that aromatase might play a functional role in spermatogenesis in the Chinese soft-shelled turtle, Pelodiscus sinensis.
