Purifi cation and identification of anti-inflammatory peptides from sturgeon (Acipenser schrenckii) cartilage

Cartilage is a nonedible byproduct with little saleable value.However,previous studies have proposed the possibility of producing peptides from cartilage with immune function modulation potential.The current study aimed to investigate the potential anti-inflammatory activity of peptides derived from sturgeon(Acipenser schrenckii)cartilage in lipopolysaccharide(LPS)-stimulated RAW264.7 macrophages.Five peptide sequences,including four novel peptides,were identified from ethanol-soluble cartilage hydrolysates.Among these five peptides,LTGP,LLLE,LLEL and VGPAGPAGP reduced the production of nitric oxide(NO)and interleukin-6(IL-6)while increasing interleukin-10(IL-10)excretion.Transcriptome analysis suggested the inhibition of activated mitogen-activated protein kinase(MAPK)and interleukin-17(IL-17)signaling pathways after LLEL intervention.MAPK,which is involved in the IL-17 signaling pathway,was further proved to be blocked by downregulating the phosphorylation of p38,extracellular-signal regulated protein kinase(ERK),and c-jun N-terminal kinase(JNK).This novel peptide offers an attractive approach to develop functional foods.

杂交鲟(Sturgeon cartilage)软骨中硫酸软骨素的提取方法及分析鉴定

采用稀碱浸提、蛋白酶水解与三氯乙酸沉淀相结合脱蛋白的工艺,对杂交鲟软骨提取琉酸软骨素的方法进行了较系统的研究。综合考察各种影响因素,设计了正交试验对提取工艺参数进行了优化,并对产品的质量指标进行了检验。结果表明,最佳提取工艺参数为:碱提取时料液比为1:2.0,碱浓度为4%,碱提温度为40℃;胰蛋白酶的酶解温度为55℃,酶量为2%,酶解时间为10h,制备的硫酸软骨素为白色粉末,得率为28.9%,纯度为92.3%,蛋白质含量为2.59%,各项质量指标完全符合标准要求。与目前已报道的其他软骨素制备工艺相比较,该方法具有工艺简便,提取率高,产品纯度高的特点。光谱分析法结构鉴定结果表明它是一种软骨素肽,其主要成分为硫酸软骨素C。

Impact of the Three Gorges Dam on the spawning stock and natural reproduction of Chinese sturgeon in the Changjiang River,China

Chinese sturgeon(Acipenser sinensis) is the flagship species of the Changjiang River.The migration route of this species is blocked by the first dam,the Gezhou Dam,and its reproduction is affected by the Three Gorges Dam(TGD),one of the largest dams in the world.We studied the impact of the impoundment of the Three Gorges Reservoir(TGR) since 2003 on the spawning stock and the natural reproduction of the Chinese sturgeon by using our monitoring data from 1997 to 2013.Results indicate that TGR impoundment has delayed the first spawning dates of the fish from middle-late October to late November,decreased the amount of spawning activities from twice to only once each year,and significantly reduced egg production.In particular,the fish did not demonstrate any spawning activities in 2013.Therefore,TGR impoundment significantly affects the natural reproduction of the fish downstream of the TGD.The spawning stock size of the fish is also predicted to further decrease in the future,which will lead to a risk of population extinction.Ecological regulations must be imposed on decreasing the water temperature to 20℃before mid-October and increasing water discharge downstream of the TGD in October to induce spawning of the Chinese sturgeon.

Isolation and Characterization of Acid-soluble Collagen and Pepsin-soluble Collagen from the Skin of Hybrid Sturgeon

By using the wastes fish skin of sturgeon processed as a raw material, a macromolecule biomaterial of collagen was extracted. Acid-soluble collagen(ASC) and pepsin-soluble collagen(PSC) were successfully isolated from the skin of hybrid sturgeon with two extraction methods. The yields of ASC and PSC based on the wet weight of skin were 5.73 ± 0.11% and 10.26 ± 0.39%, respectively. The denaturation and melting points of ASC(26.83 ℃ and 110.49 ℃) and PSC(26.54 ℃ and 102.99 ℃) were assessed by Circular dichroism(CD) and Differential scanning calorimetry(DSC). ASC and PSC appeared to be dense sheet-like film linked by random-coiled filaments under scanning electron microscopy(SEM). Sodium dodecyl sulfate-polyacrylamide gel electrophoresis(SDS-PAGE) and Fourier transform infrared spectroscopy(FTIR) confirmed that both the ASC and PSC were Type I collagen and maintained a complete triple helix structure. These results indicated that both ASC and PSC possessed good biological activity and could be widely used in medical biomaterials and other fields.

Peptide fraction from sturgeon muscle by pepsin hydrolysis exerts anti-inflammatory effects in LPS-stimulated RAW264.7 macrophages via MAPK and NF-κB pathways

Previous studies have suggested that polypeptides extracted from milk, soybean, fish, eggs, and meat possess potential anti-inflammatory effects. To date, few studies have reported the anti-inflammatory function of sturgeon peptides and their underlying mechanisms are unknown. The current study was therefore to determine the anti-inflammatory potential of sturgeon peptides with lipopolysaccharide (LPS)-induced RAW264.7 inflammatory model. Pepsin hydrolysate (PeH) was purified by ultrafiltration and Sephadex G-15 gel filtration chromatography. PeH significantly reduced the inflammatory mediator (NO) and inflammatory cytokines (IL-6, TNF-α and IL-1β) expression in a dose-dependent manner. Moreover, the purified sturgeon peptide (F2) possessed strong antioxidant potential and effectively inhibited DPPH and ABTS free radicals. F2 significantly suppressed the expression of MAPK, IκBα, and NF-κB p65, indicating that F2 exerted anti-inflammatory influence by the inhibition of MAPK and NF-κB pathways.

Gut Peculiarities of Feed Deprived White Sturgeons (<i>Acipenser transmontanus</i>, Richardson 1836)

In the White sturgeon fish farms, some individuals have difficulty in getting access to food: such sturgeons are called "runts", and they result in a slower growth rate than normally feeding fish. In this paper, we have studied the gut peculiarities of runt sturgeons. Utilizing in paralleling an analysis of diatom populations in both the fish gut tissues and the rearing tank waters, we hypothesized a causative relation between the occurrence of runt sturgeons and periodic diatom blooms. In fact, we have observed that the diatom species identified in the aquatic environment were also detected in organs (Fragilaria spp and Rhoicosfenia spp for both glandular body, mid-intestine) of the runt sturgeon's gut, but not in tissues of normally feeding individuals. Owing to their siliceous wall, diatoms can be responsible for areas of epithetlial detachment in the mucosal surfaces of the alimentary canal and a catharral inflammation in both the gastric pits and intestinal folds which may be the cause of secondary bacterial diseases. We suggest that diatom blooms may contribute to the occurrence of runt sturgeons in the studied Italian fish farm.

Determining the specific status of the Iberian sturgeons by means genetic analyses of old specimens

To clarify the species status of sturgeon from rivers of the Iberian Peninsula, eight molecular markers (4 nuclear and 4 mitochondrial) have been analysed in different specimens from historical museum samples and prehistoric samples from archaeological sites. These analyses indicate that one of these specimens (UGP captured in the Guadalquivir River in the 19th century) is A. sturio, based on all the eight molecular markers, four of them used from the first time in this study. In previous analyses based on 5 genetic markers, our group assigned two specimens captured in this river in the 1970-80s (EBD8173 and EBD8401) to the species A. naccarii, suggesting the presence of this species in the Iberian Peninsula. In this work, this conclusion is drawn after successfully obtaining a mitochondrial marker in a very old scute from a prehistoric site (Acinipo, about 1500 BC, from the Guadalquivir River basin). On the other hand, in the specimen EBD8174 captured in the Guadalquivir in 1975, we have obtained two new mitochondrial markers confirming that it can be considered A. sturio for all the mitochondrial markers, but nuclear ones identify it as A. naccarii. Finally, two very old samples (Nerja E-VI and Nerja N/62-63) were not successfully characterized by any molecular markers. Some aspects and consequences of our results are discussed, such as the origin of the “mosaic” specimen EBD8174 and, above all, the native status of A. naccarii in historic and prehistoric times in the southern Iberian Peninsula.

Nitric oxide-factor, which regulates proliferation and apoptosis in the adult brain of amur sturgeon <i>Acipenser schrenckii</i>

The distribution of proliferative zones, NO-producing cells and apoptosis areas in the medulla oblongata, cerebellum, optic tectum, thalamus and hypothalamus of Amur sturgeon Acipenser schrenckii was investigated, using techniques of immunoperoxidase staining of proliferating cell nuclear antigen (PCNA), neuronal nitric oxide synthase and TU-NEL-labeling of fragmented DNA. It has been established, that in the sturgeon brain NO can act both as a cytotoxic proapoptogenic factor, and as a factor, which stimulates cell proliferation. The presence of NO-producing elements in somato- and viscerosensory areas of medulla oblongata, tectum, cerebellum and thalamus suppose, that in these brain areas NO constitutes apoptogenic factor, which induces the cells death in a territory of postmitotic neuroblasts, renders controlling effect on development and differentiating of chemosensory, visual, motor and hypophysotropic brain areas in postnatal ontogenesis. Maximal proliferating activity and high concentration of NO-ergic cells were revealed in external layers, adjoining to the medullar, cerebellar and tectum membranes, that allow to suppose NO participation in postnatal morphogenesis of these brain structures as a factor, which regulates cell proliferation. In sensory centers (tectum and nuclei of the V, VII, and X nerves), significantly varying ratios of intensities of proliferation and apoptosis were found;this is indicative of dissimilar rates of growth and differentiation in visual and chemosensory centers of the sturgeon brain. Presence of NO-producing elements in the PCNA- immuno-labeling and TUNEL-labeling brain areas allow to consider NO as a factor, which balances processes of proliferation and apoptosis in the sturgeon brain.

Sturgeon (Acipenser gueldenstaedtii) Acclimatization to Optimal Growth Conditions—A Case Study of Adaptation, Nutrition, Reproduction, and Sex Determination

The development of new agricultural industries is an important challenge for a region’s economic establishment. The connection between a research department at MIGAL Institute and biotechnology in aquaculture is an example (case study) of the interrelationships that also exist in other departments. This article describes the research conducted by the institute supporting the development of the aquaculture industry in Israel through the introduction of a relatively new fish species—the Russian sturgeon (Acipenser gueldenstaedtii), with the relevant information to be used for acclimatization to aquaculture conditions in northern Israel. Many aspects related to bringing a new species to Israel and working with this new industry to study its adaptation to existing conditions in the north of the country influenced the economic success of this new type of precision agriculture. This article describes the research on various aspects affecting the successful acclimatization of Russian sturgeon in northern Israel: introduction, food development, reproduction, hormone systems that control reproduction and growth, gonadal development, and molecular markers for sex determination, differentiation, and economic assessment of caviar production.

SAVING A SPECIES Conservation and breeding of the Chinese sturgeon in the Yangtze River

"Chinese sturgeons, safe journeys!""You’ve eaten well but now you’re on your own.""Keep going all the way to the sea,regardless of wind or rain!"So went real-time online comments displayed during the livestream of an April 22 event in Yichang, central China’s Hubei Province。

A review of sturgeon virosis

Sturgeon, as a kind of rare large-scale economic fish, has high scientific research and commercial value. But virosis was a significant cause of mortality among farm-raised juvenile sturgeon, which brought tremendous loss in the last decades. In this paper, we reviewed the studies on four sturgeon viruses: white sturgeon (Acipenser transmontanus) iridovirus (WSIV), white sturgeon herpesvirus-1,2 (WSHV-1,2) and shovelnose sturgeon (Scaphirhynchus Scaphirhynchus) iridovirus (SSIV). The content of this review were mainly focused on clinic symptom of infected fish, diagnostic method, virus isolation, prophylactic and remedy. Based on a detailed conclusion and analysis, it is reasonable that molecular biology techniques might be a potential method for sturgeon virosis diagnosis.

Stocking density affects the growth performance and metabolism of Amur sturgeon by regulating expression of genes in the GH/IGF axis

The effects of stocking density on the growth and metabolism of Amur sturgeon were assessed. Amur sturgeon were grown for 70 days at three dif ferent stocking densities(low stocking density, LSD: 5.5 kg/m^3; medium stocking density, MSD: 8.0 kg/m^3; and high stocking density, HSD: 11.0 kg/m^3), and the biometric index, muscle composition, and serum biochemical parameters were evaluated. In addition, pituitary, liver, and muscle samples were collected for gene cloning and expression analyses. After 70 days of growth, the fish maintained at HSD had significantly lower fi nal body weight and specifi c growth rate, and a higher feed conversion ratio than those of the fish in the MSD and LSD groups. The HSD group had the lowest lipid and protein concentrations in serum and muscle. The serum cortisol concentration increased significantly in the HSD group, indicating that the stress-response system was activated in these fish. There was no change in the concentration of serum insulin-like growth factor 2(IGF-2), while the concentrations of serum growth hormone(GH) and insulin-like growth factor 1(IGF-1) decreased in the HSD group. The full-length cDNAs of G H and IGF-2 genes(995-bp and 1 207-bp long, respectively), were cloned and analyzed. In the HSD group, the expressions of GH in the pituitary and growth hormone receptor( GHR) and IGF-1 in the liver were down-regulated at the end of the 70-day experiment. In the HSD group, the transcript level of IGF-2 significantly decreased in the liver, but did not change in muscle. Overall, our results indicated that a HSD negatively af fects the growth performance and leads to changes in lipid and protein metabolism in Amur sturgeon. The down-regulated expression of genes related to the GH/IGF axis may be responsible for the poor growth performance of Amur sturgeon under crowding stress.

Changes in growth and osmoregulation during acclimation to saltwater in juvenile Amur sturgeon Acipenser schrenckii

We evaluated the ability of juvenile Amur sturgeon (Acipenser schrenckii) to osmoregulate and grow in saltwater. Hatchery-reared juveniles (mean weight 106.8 g, 5-month old) were transferred from freshwater to 10, 20, and 25 salinity saltwater over a period of 20 d. We measured the growth, serum osmolality, ion concentrations, and Na+/K+-ATPase activity. In addition, we prepared samples of gill tissue to quantify morphological changes in gill ultrastructure. Rearing in up to 25 saltwater for 30 d had no significant effect on growth. Similarly, serum osmolality and ion concentrations were similar to levels reported in other teleosts following acclimation to saltwater. Serum osmolality and Na+, Cl- concentrations increased significantly with the initial increase in salinity. Afterwards, levels tended to stabilize and then decrease. Serum K+ levels did not change during acclimation to saltwater. Gill Na+/K+-ATPase activity increased initially as salinity was increased. However, the activity later decreased and, finally stabilized at 3.7±0.1 μmol Pi/mg·prot·h in 25 saltwater (1.6 times higher than the level in those in freshwater). In fish that were held only in freshwater, the chloride cells were located in the interlamellar regions of the filament and at the base of the lamella. Following acclimation to 25 saltwater for 30 d, the number and size of chloride cells increased significantly. Our results suggest that juvenile Amur sturgeon is able to tolerate, and grow in, relatively high concentrations of saltwater.

Effects of the Chinese Medicinal Herb Com plex Additives on Non-specific Immunity of Amursturgeon( Acipenser schrencki Brandt)

This study was to investigate the effects of aqueous decotion from three Chinese medicinal herb additives( Cyrtomium fortunei,prescription I and prescription II) on non-specific immunity of 1 + age old Amur sturgeon( Acipenser schrencki Brandt) by oral perfusion. Cyrtomium fortunei,prescription I and prescription II were orally given to 15 fishes for each experimental group once a day,with the concentration of 9,175 and 36 g /50 kg body weight,respectively. The administration was lasted for 14 days. Meanwhile,distilled water was orally given as the control. After the experiment,some of the experimental fishes were stimulated with high temperature( 30 ℃) for two hours. Sampling was performed from fishes treated at 22 ℃ and 30 ℃ for measuring the protein content in the serum,phagocytic activity of leucocytes and the activity of the lysozyme in six tissues. The results indicated that Cyrtomium fortunei and prescription II could help to enhance the content of various proteins and the phagocytic activity of leucocytes. There was no significant change in the effects between these two additives at either the normal temperature or high temperature. Prescription I did not show an obvious effect on the immunity of fishes at the normal temperature,but it did in promoting high-efficiency response and improving immunoregulation of fish shocked by some stimuli.

Effects of Norfloxacin on the Superoxide Dismutase Activities of 2 Sturgeon Species

[Objective]This study was to investigate the effect of different concentrations of Norfloxacin on the superoxide dismutase ( SOD) activities in the blood plasma and liver tissues of Amur sturgeon ( Acipenser schrencki Brandt) and sterlet ( Acipenser ruthenus Linnaeus) . [Method] Using pharmaco-toxicological evaluation method,Norfloxacin with the concentrations of 0,20,40,60,80 and 100 mg /kg,was orally delivered to the Amur sturgeon and sterlet for 5 d,respectively. The SOD activities in the blood plasma and liver tissues were measured after drug withdrawal for 2 d to explore the optimal dosing concentration of Norfloxacin during sturgeon culture,as well as the effect of Norfloxacin on liver injury. [Result] SOD existed in both two sturgeons but with different amounts,and the SOD activities were higher in the livers than in the blood plasma no matter in the control and all drug delivered groups. Under different drug delivery concentrations,the SOD activities first increased and then decreased in the 2 tissues of the 2 sturgeon species,and the SOD activities reached the maximum when the drug delivery concentration was 40 mg /kg. The drug de- livery concentration had little effect on the SOD activities in the blood plasma,which showed stable changes. When the drug delivery concentration was 40 mg /kg,the SOD activities in the blood plasma of Amur sturgeon were higher than that of sterlet,while for the other concentrations,the SOD activities in the plasma of sterlet showed higher performance. However,the SOD activities changed significantly through drug delivery in the liver tis- sues,and the SOD activities were higher in the sterlet than in the Amur sturgeon when the drug delivery concentrations were 0,40 and 100 mg /kg. The SOD activity in the sterlet was the highest under 40 mg /kg,presenting a sharp peak value. The optimal drug delivery concentration of Norfloxa- cin was 30 -50 mg /kg,under which the Norfloxacin presented best effect and had no injury effect on livers. [Conclusion]This study provides theo- retical basis for the reasonable application of Norfloxacin in aquaculture.

Isolation of Sturgeon Peripheral Blood Lymphocytes and the Optimal Proliferation Response Conditions

In this study,sterlet( Acipenser ruthenus) was chosen as the model species of sturgeon,different solutions were used to isolate the sturgeon peripheral blood lymphocytes and study their optimal proliferate response condition. Phytohemagglutinin( PHA),concanavalin A( Con A) and lipopolysaccharide( LPS) were used as lymphocyte proliferation mitogen,respectively. According to L25( 56) five-factor five-level orthogonal experimental design,the conditions for sturgeons proliferation response of peripheral blood lymphocytes were optimized using enhanced cell counting Kit-8( enhanced CCK-8 or WST-8). Five factors were selected to explore the optimal response conditions,including culture time,culture temperature,cell concentration,fetal bovine serum( FBS) concentration,and mitogen concentration. The results showed that 70% Percoll( 1. 092 g/ml) used as the sturgeon lymphocyte separation solution had the best separating effect. The optimal proliferation conditions were as follows: 3. 625 × 10~6 initial cells,20 μg/ml PHA or 50 μg/ml Con A or 10 μg/ml LPS as mitogen,10%-20% FBS,the temperature at 20-25 ℃,and the culture time of 2 d.

亚硒酸钠、酵母硒和富硒螺旋藻对杂交鲟幼鱼生长、抗氧化能力及组织硒含量的影响

实验旨在研究饲料中不同类型和水平的硒源对杂交鲟(Acipenser baerii♂×Acipenser schrenckii♀)幼鱼生长、抗氧化能力及组织硒含量的影响。不同类型的硒源为亚硒酸钠、酵母硒和富硒螺旋藻,添加水平为0、0.4和1.2 mg/kg,制作对照饲料(C)、亚硒酸钠添加饲料(S1和S2)、酵母硒添加饲料(Y1和Y2)和富硒螺旋藻添加饲料(P1和P2)。使用实验饲料饲喂初始体重为(7.82±0.12)g的杂交鲟幼鱼,养殖62d。结果表明,不同硒源和硒水平对杂交鲟幼鱼的特定生长率和饲料效率无显著影响(P>0.05)。高水平亚硒酸钠显著提高了全鱼和肝脏硒含量(P<0.05),但对肌肉和脊椎骨硒含量无显著影响(P>0.05)。高水平酵母硒和富硒藻螺旋添加组杂交鲟幼鱼的全鱼、肝脏、肌肉及脊椎骨硒含量均显著高于对照组(P<0.05)。酵母硒添加组的血浆总蛋白(TP)和总胆固醇(TC)含量均显著高于对照组(P<0.05)。同时,高水平硒添加组杂交鲟幼鱼的血浆谷胱甘肽过氧化物酶(GSH-Px)活性显著高于对照组和低水平硒添加组(P<0.05)。亚硒酸钠组肌肉硒含量与全鱼硒含量显著正相关(P<0.05),与肝脏硒含量显著负相关(P<0.05)。血浆GSH-Px活性与肌肉、脊椎骨和肝脏硒含量正相关(P<0.05)。综上所述,高水平硒添加可以提高全鱼及肝脏硒含量,不同类型硒在鱼体的蓄积模式不一致,高水平的有机硒(酵母硒和富硒螺旋藻)添加比无机硒(亚硒酸钠)更易在肌肉和脊椎骨中蓄积;高水平硒添加可显著提高杂交鲟抗氧化能力,不同硒源对杂交鲟的抗氧化能力无显著影响。

鲟鱼重组鱼排3D打印特性的研究

该研究以鲟鱼肉为原料,复配鸭肉和山药并借助3D打印技术制备重组鱼排。通过分析复配物料的流变特性及3D打印效果,考察熟化后鱼排的质构特性、色泽、水分特性、微观结构,结合感官评定结果,探究山药和鸭肉复配比对重组鱼排品质的影响。研究结果表明,当山药和鸭肉总添加量为26.25%时,随山药占比增加,复配物料表观黏度降低,流动性增大。核磁共振结果显示,山药的添加会提高水分迁移率,使得重组鱼排微观网络结构逐渐粗糙不均匀。当山药与鸭肉复配比例为3∶7~4∶6时,重组鱼排的剪切力为456.86~504.19 g,硬度为300.72~391.79 g,此时3D打印鱼排结构紧密,具有良好稳定性且感官接受度高。综上,当山药与鸭肉复配比例在3∶7~4∶6时,对重组鱼排进行加工,鱼排质构特性较为适宜,成型性良好,具有优良的品质。

不同生理状态中华鲟体表黏液与生境微生物组成差异分析

为揭示不同生理状态下中华鲟(Acipenser sinensis)体表黏液与生境微生物组成差异,本研究比较了健康和亚健康中华鲟体表黏液菌群的群落结构差异,探讨细菌群落结构与中华鲟生理状态的相关性。本研究采集健康与亚健康中华鲟的体表黏液和养殖水体,利用高通量测序技术分析其菌群结构。结果表明,亚健康组微生物多样性与丰富度显著高于健康组(P<0.05)。序列的统计分析表明,相较于水体,黏液样本存在大量的独有操作分类单元(operational taxonomic unit,OTU),且与水体的共有OTU数目因中华鲟生理状况而发生变化。根据组间的相似性与差异分析,不同组之间的主成分与主坐标分析显示出较强的分离趋势,且组内样本相对距离较小。在门和属水平下,中华鲟体表黏液和水体群落组成和优势种有显著差异。水体中优势菌门为变形菌门(Proteobacteria)(31.84%)和厚壁菌门(Firmicutes)(24.37%);健康组优势菌门为变形菌门(55.23%)和拟杆菌门(Bacteroidetes)(21.00%);亚健康组的变形菌门(40.23%)占比相较于健康组有所下降,但酸杆菌门(Acidobacteria)(18.29%)、芽单胞菌门(Gemmatimonadetes)(10.08%)、放线菌门(Actinobacteria)、疣微菌门(Verrucomicrobia)的比例均有不同程度的增加。水体中优势菌群包括球形发丝菌属(Sphaerochaeta)(10.56%)和下水道菌属(Cloacibacillus)(7.95%)。健康组中的优势菌群包括罗尔斯通氏菌属(Ralstonia)(19.83%)和黏液杆菌属(Mucilaginibacter)(8.11%)。亚健康组的优势菌群则相较于健康组发生了变化,主要由鞘氨醇单胞菌属(Sphingomonas)(16.71%)和WPS-1_genera_incertae_sedis(5.05%)组成。功能预测发现,亚健康组的菌群功能丰度相较于健康组显示出下降的趋势,包括环境适应、生物代谢、信号转导等。通过对不同生理状态中华鲟黏液微生物组与水体的相似性及差异分析发现,随着中华鲟的生理状态的改变,体表黏液核心菌群产生差异,亚健康组中鞘氨醇单胞菌属是黏液菌群的优势属,该属可作为健康检测的标志物。通过对健康和亚健康中华鲟体表黏液微生物群落的比较,发现不同健康状态存在不同的微生物群落结构,为中华鲟的健康养殖与监测提供了新的视角。

基于环境DNA的长江中华鲟分布特征探究

中华鲟(Acipenser sinensis)是我国长江流域的旗舰物种,在长江十年禁渔的大背景下,研究中华鲟无损化检测技术具有重要意义。环境DNA(eDNA)技术是一种环境友好型生物监测技术,可以在不直接观察或捕获生物体的情况下对物种进行检测。从文献中筛选出可以用于检测中华鲟eDNA的特异性引物,于2020年9月在长江中下游选取4个中华鲟常出现的区域,进行各断面立体式采样;提取16个点位的e DNA,使用筛选得到的引物对中华鲟进行eDNA的检测,以探究中华鲟的分布特征。结果显示,成功筛选到1组可以检测中华鲟eDNA的引物,使用该引物成功检测到包括中华鲟在内的长江4种鲟类的eDNA,共计测得约300万条鲟类序列。依据测序结果分析不同断面检测到的中华鲟eDNA的差异,发现宜昌江段断面的中华鲟eDNA最多,洞庭湖口断面最少,且表层和底层水体的中华鲟eDNA检出也有显著差异。筛选得到的引物可以用于中华鲟eDNA的检测,中华鲟e DNA的检测结果与中华鲟的历史调查和洄游特征较为吻合。不同水深条件中华鲟eDNA的检出量有显著差异,表明在今后的调查中采用混合或者立体采样可以更加全面地进行中华鲟eDNA的检测。