Ayu （Plecoglossus altivelis） fish, which are an amphidromous species distributed in East Asia, live in brackish water （BW） during their larval stage and in fresh water （FW） during their adult stage. In this stud...Ayu （Plecoglossus altivelis） fish, which are an amphidromous species distributed in East Asia, live in brackish water （BW） during their larval stage and in fresh water （FW） during their adult stage. In this study, we found that FW-acclimated ayu larvae exhibited a slower growth ratio compared with that of BW-acclimated larvae. However, the mechanism underlying FW acclimation on growth suppression is poorly known. We employed transcriptome analysis to investigate the differential gene expression of FW acclimation by RNA sequencing. We identified 158 upregulated and 139 downregulated transcripts in FW-acclimated ayu larvae compared with that in BW-acclimated larvae. As determined by Gene Ontology annotation and Kyoto Encyclopedia of Genes and Genomes pathway mapping, functional annotation of the genes covered diverse biological functions and processes, and included neuroendo- crinology, osmotic regulation, energy metabolism, and the cytoskeleton. Transcriptional expression of several differentially expressed genes in response to FW acclimation was further confirmed by real-time quantitative PCR. In accordance with transcriptome analysis, iodothyronine deiodinase （ID）, pro-opiom- elanocortin （POMC）, betaine-homocysteine S-meth- yltransferase 1 （BHMT）, fructose-bisphosphate aldolase B （aldolase B）, tyrosine aminotransferase （TAT）, and Na＋-K＋ ATPase （NKA） were upregulated after FW acclimation. Furthermore, the mRNA expressions of b-type natriurefic peptide （BNP） and transgelin were downregulated after FW acclimation. Our data indicate that FW acclimation reduced the growth rate of ayu larvae, which might result from the expression alteration of genes related to endocrine hormones, energy metabolism, and direct osmoregulation.展开更多
The countable characters of Qingdao, Zhejiang, Liaoning and Japanese Ayu arecompared. There are no substantial different characters among the former three Ayu, so thecomprehensive values of them are taken as represent...The countable characters of Qingdao, Zhejiang, Liaoning and Japanese Ayu arecompared. There are no substantial different characters among the former three Ayu, so thecomprehensive values of them are taken as representative of Chinese Ayu, which is in turn comparedwith Japanese Ayu ( Plecoglossus altivelis altivelis and Plecoglossus altivelis ryukyuensis). By thecoefficient of difference test, 3 and 4 characters are found to be beyond the subspecies levelbetween Chinese Ayu and nominate subspecies (Plecoglossus altivelis altivelis) and between ChineseAyu (Plecoglossus altivelis chinensis) and Ryukyus subspecies (Plecoglossus altivelis ryukyuensis),respectively, which shows that they belong to different subspecies. The China mainland Ayu is a newsubspecies, Plecoglossus altivelis chinensis Wu and Shan, the establishment of which and its formingcauses are discussed.展开更多
铁蛋白(Ferritin,Fer)是一类广泛存在于生物体内、并与铁代谢密切相关的铁储存蛋白。本研究通过香鱼(Plecoglossus altivelis)单核/巨噬细胞转录组测序获得铁蛋白亚基基因(Pa Fer)c DNA全序列,结果显示,Pa Fer由943个核苷酸组成,开放阅...铁蛋白(Ferritin,Fer)是一类广泛存在于生物体内、并与铁代谢密切相关的铁储存蛋白。本研究通过香鱼(Plecoglossus altivelis)单核/巨噬细胞转录组测序获得铁蛋白亚基基因(Pa Fer)c DNA全序列,结果显示,Pa Fer由943个核苷酸组成,开放阅读框为531bp,编码176个氨基酸,预测相对分子质量为20.4k Da,等电点为5.46。氨基酸序列多重比对结果显示,Pa Fer具有保守的铁蛋白样双铁结构域,与虹鳟(Oncorhynchus mykiss)和大西洋鲑(Salmo salar)Fer M亚基(Fer-M)同源性最高,均为92%;系统进化树分析表明,Pa Fer与胡瓜鱼、大西洋鲑和虹鳟的Fer-M聚为一个小簇,与虹鳟Fer-M进化相关性最高。实时荧光定量PCR(quantitative real-time PCR,q PCR)结果表明,Pa Fer m RNA主要在香鱼脾脏中表达量最高,肾脏、鳃、脑和心脏中次之;鳗弧菌(Vibrio anguillarum)感染后,香鱼肝脏、脾脏和肾脏等组织中Pa Fer m RNA表达显著上调。原核表达了Pa Fer重组蛋白(r Pa Fer),r Pa Fer以包涵体形式表达,镍柱亲和层析纯化重组蛋白,尿素梯度透析法复性r Pa Fer。铁螯合实验结果显示,当r Pa Fer浓度为4μg/m L时,螯合铁的能力最大,为43.96%。抑菌实验结果表明,r Pa Fer对鳗弧菌、溶藻弧菌(Vibrio alginolyticus)和创伤弧菌(Vibrio vulnificus)的最小抑菌浓度分别为1.5625、25.0和100.0μg/m L。综上,Pa Fer与香鱼抗病原感染的免疫反应紧密相关,可能通过调控铁代谢参与鱼类抵抗微生物的宿主自身免疫过程。本研究为进一步研究鱼类Fer的功能及在病原菌感染免疫中的分子机制奠定基础。展开更多
Classical Fc receptors (FcRs) mediate the binding to and recognition of the Fc portion of antibodies and play an important role during immune responses in mammals. Although proteins similar to soluble FcRs have been i...Classical Fc receptors (FcRs) mediate the binding to and recognition of the Fc portion of antibodies and play an important role during immune responses in mammals. Although proteins similar to soluble FcRs have been identified in fish, little is known about the role of such proteins in fish immunity. Here, we cloned a cDNA sequence encoding a soluble Fc receptor for an immunoglobulin G (FcγR) homolog from ayu (Plecoglossus altivelis)(PaFcγRl). The predicted protein was composed of two immunoglobulin C2-like domains but lacked a transmembrane segment and a cytoplasmic tail. The PaFcγRl transcripts were distributed at low levels in all tested tissues, but significantly increased after Vibrio anguillarum infection. The PaFcγRl protein was expressed in the head kidney, trunk kidney, and neutrophils. Recombinant PaFcγRl (rPaFcγRl) was secreted when transfected into mammalian cells and the native protein was also detected in serum upon infection. rPaFcγRl was also demonstrated to bind to ayu IgM, as assessed by cell transfection. Suppressive activity of the recombinant mature protein of PaFcγRl (rPaFcγRlm) on in vitro anti-sheep red blood cell (SRBC) responses was detected by a modified hemolytic plaque forming cell assay. In conclusion, our study revealed that PaFcγRl is closely involved in the negative regulation of IgM production in the ayu spleen.展开更多
基金Foundation items： The project was supported by the Program for the National Natural Science Foundation of China （31201970） and the KC Wong Magna Fund in Ningbo University
文摘Ayu （Plecoglossus altivelis） fish, which are an amphidromous species distributed in East Asia, live in brackish water （BW） during their larval stage and in fresh water （FW） during their adult stage. In this study, we found that FW-acclimated ayu larvae exhibited a slower growth ratio compared with that of BW-acclimated larvae. However, the mechanism underlying FW acclimation on growth suppression is poorly known. We employed transcriptome analysis to investigate the differential gene expression of FW acclimation by RNA sequencing. We identified 158 upregulated and 139 downregulated transcripts in FW-acclimated ayu larvae compared with that in BW-acclimated larvae. As determined by Gene Ontology annotation and Kyoto Encyclopedia of Genes and Genomes pathway mapping, functional annotation of the genes covered diverse biological functions and processes, and included neuroendo- crinology, osmotic regulation, energy metabolism, and the cytoskeleton. Transcriptional expression of several differentially expressed genes in response to FW acclimation was further confirmed by real-time quantitative PCR. In accordance with transcriptome analysis, iodothyronine deiodinase （ID）, pro-opiom- elanocortin （POMC）, betaine-homocysteine S-meth- yltransferase 1 （BHMT）, fructose-bisphosphate aldolase B （aldolase B）, tyrosine aminotransferase （TAT）, and Na＋-K＋ ATPase （NKA） were upregulated after FW acclimation. Furthermore, the mRNA expressions of b-type natriurefic peptide （BNP） and transgelin were downregulated after FW acclimation. Our data indicate that FW acclimation reduced the growth rate of ayu larvae, which might result from the expression alteration of genes related to endocrine hormones, energy metabolism, and direct osmoregulation.
文摘The countable characters of Qingdao, Zhejiang, Liaoning and Japanese Ayu arecompared. There are no substantial different characters among the former three Ayu, so thecomprehensive values of them are taken as representative of Chinese Ayu, which is in turn comparedwith Japanese Ayu ( Plecoglossus altivelis altivelis and Plecoglossus altivelis ryukyuensis). By thecoefficient of difference test, 3 and 4 characters are found to be beyond the subspecies levelbetween Chinese Ayu and nominate subspecies (Plecoglossus altivelis altivelis) and between ChineseAyu (Plecoglossus altivelis chinensis) and Ryukyus subspecies (Plecoglossus altivelis ryukyuensis),respectively, which shows that they belong to different subspecies. The China mainland Ayu is a newsubspecies, Plecoglossus altivelis chinensis Wu and Shan, the establishment of which and its formingcauses are discussed.
文摘铁蛋白(Ferritin,Fer)是一类广泛存在于生物体内、并与铁代谢密切相关的铁储存蛋白。本研究通过香鱼(Plecoglossus altivelis)单核/巨噬细胞转录组测序获得铁蛋白亚基基因(Pa Fer)c DNA全序列,结果显示,Pa Fer由943个核苷酸组成,开放阅读框为531bp,编码176个氨基酸,预测相对分子质量为20.4k Da,等电点为5.46。氨基酸序列多重比对结果显示,Pa Fer具有保守的铁蛋白样双铁结构域,与虹鳟(Oncorhynchus mykiss)和大西洋鲑(Salmo salar)Fer M亚基(Fer-M)同源性最高,均为92%;系统进化树分析表明,Pa Fer与胡瓜鱼、大西洋鲑和虹鳟的Fer-M聚为一个小簇,与虹鳟Fer-M进化相关性最高。实时荧光定量PCR(quantitative real-time PCR,q PCR)结果表明,Pa Fer m RNA主要在香鱼脾脏中表达量最高,肾脏、鳃、脑和心脏中次之;鳗弧菌(Vibrio anguillarum)感染后,香鱼肝脏、脾脏和肾脏等组织中Pa Fer m RNA表达显著上调。原核表达了Pa Fer重组蛋白(r Pa Fer),r Pa Fer以包涵体形式表达,镍柱亲和层析纯化重组蛋白,尿素梯度透析法复性r Pa Fer。铁螯合实验结果显示,当r Pa Fer浓度为4μg/m L时,螯合铁的能力最大,为43.96%。抑菌实验结果表明,r Pa Fer对鳗弧菌、溶藻弧菌(Vibrio alginolyticus)和创伤弧菌(Vibrio vulnificus)的最小抑菌浓度分别为1.5625、25.0和100.0μg/m L。综上,Pa Fer与香鱼抗病原感染的免疫反应紧密相关,可能通过调控铁代谢参与鱼类抵抗微生物的宿主自身免疫过程。本研究为进一步研究鱼类Fer的功能及在病原菌感染免疫中的分子机制奠定基础。
基金supported by the Program for the National Natural Science Foundation of China(3177287631402323+6 种基金31372555)Natural Science Foundation of Zhejiang Province(LZ18C190001LY14C190007)Scientific Innovation Team Project of Ningbo(2015C110018)Natural Science Foundation of Ningbo City of China(2018A610225)Ningbo Science and Technology “Fumin Engineering”Project(2017C10037)K.C.Wong Magna Fund in Ningbo University
文摘Classical Fc receptors (FcRs) mediate the binding to and recognition of the Fc portion of antibodies and play an important role during immune responses in mammals. Although proteins similar to soluble FcRs have been identified in fish, little is known about the role of such proteins in fish immunity. Here, we cloned a cDNA sequence encoding a soluble Fc receptor for an immunoglobulin G (FcγR) homolog from ayu (Plecoglossus altivelis)(PaFcγRl). The predicted protein was composed of two immunoglobulin C2-like domains but lacked a transmembrane segment and a cytoplasmic tail. The PaFcγRl transcripts were distributed at low levels in all tested tissues, but significantly increased after Vibrio anguillarum infection. The PaFcγRl protein was expressed in the head kidney, trunk kidney, and neutrophils. Recombinant PaFcγRl (rPaFcγRl) was secreted when transfected into mammalian cells and the native protein was also detected in serum upon infection. rPaFcγRl was also demonstrated to bind to ayu IgM, as assessed by cell transfection. Suppressive activity of the recombinant mature protein of PaFcγRl (rPaFcγRlm) on in vitro anti-sheep red blood cell (SRBC) responses was detected by a modified hemolytic plaque forming cell assay. In conclusion, our study revealed that PaFcγRl is closely involved in the negative regulation of IgM production in the ayu spleen.
文摘对浙江瑞安、福建宁德、福建东张水库3个地理群体共31例香鱼(Plecoglossus altivelis)的线粒体细胞色素b(Cyt b)基因和线粒体D-loop区序列进行了PCR扩增、序列测定、核苷酸组成和多态性分析。Cytb基因中,A、T、C和G4种核苷酸的比例分别为19.72%、29.71%、32.25%和18.32%,A+T含量为49.43%,G+C含量为50.57%。D-loop区序列中,A、T、C和G4种核苷酸的比例分别为29.99%、29.29%、23.80%和16.92%,A+T含量为59.28%,G+C含量为40.72%。在长度为1141bp的Cytb基因序列中,仅存在1个变异位点,核苷酸多样性指数(π值)为0.00028,31个样本中仅出现两种单倍型;857 bp 长的D-loop区序列中,仅存在5个变异位点,核苷酸多样性指数(π值)为0.00199,仅出现5种单倍型。这表明闽浙地区香鱼的遗传多样性水平很低,应当加大对香鱼的保护力度。
