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Proprotein Convertase Subtilisin/Kexin Type 9 (PCSK9) in mammals is a multifunctional protein. In this study, PCSK9 of marine fish Epinephelus coioides was characterized. The full-length cDNA of E. coioides PCSK9 was 2458 bp in length containing 185 bp 5' UTR, 263 bp 3' UTR and 2010 bp open reading frame (ORF) encoding 669 amino acids with the predicted molecular weight of 71 kDa and the theoretical PI of 6.6. Similar to other members of PCSK9 family, E. coioides PCSK9 has three conserved domains: Inhibitor_ I9 super family, Peptidases_ S8_ PCSK9_ Proteinase K_ like, and PCSK9_ C-CRD super family. E. coioides PCSK9 mRNA could be detected in all the tissues examined by real-time quantitative PCR, with the highest expression in the brain, followed by skin, trunk kidney, head kidney, intestine, blood, liver, spleen, gill, muscle and heart. E. coioides PCSK9 was distributed in both the cytoplasm and nucleus. The expression of E. coioides PCSK9 was significantly upregulated during Singapore grouper iridovirus (SGIV) infection. Upregulated PCSK9 could significantly affect the activities of nuclear factor kappaB (NF-κB) promoter, SGIV-induced apoptosis, and the expressions of the key SGIV genes (ICP18, LITAT, MCP, and VP19) and the E. coioides proinflammatory factors (IL-6, IL-1β, IL-8, and TNF-α). The results illustrated that E. coioides PCSK9 might be involved in the pathogen infection by regulating the innate immune response.

The restocking of the endangered Kanglang white minnow (Anabarilius grahami) in Lake Fuxian, China, has been conducted for 13 years. However, few studies have reported on the effectiveness of the captive breeding and release of this species. Here, we investigated variations in morphology, including body shape and skeletal deformities, and genetic features among hatchery-born and recaptured A. grahami from Lake Fuxian. Results showed that current hatchery-reared fish displayed a stubbier body shape than their wild conspecifics from the 1980s. Furthermore, high skeletal deformity ratios were found in two aquafarms (Luchong, 50%; Haikou, 45.2%), and the release of malformed fish elevated the skeletal deformity rate of wild stocks found near the Lake Fuxian release sites (west coast, 19.0%; east coast, 12.5%). Based on variations in the cytochrome b (cyt b) gene, existing A. grahami populations showed relatively high haplotype diversity and low nucleotide diversity. Hatchery populations exhibited reduced genetic variations based on microsatellite markers and reintroduction led to markedly lower genetic diversity around the west coast release sites of Lake Fuxian. Analysis of molecular variance (AMOVA) of cyt b and microsatellite analysis showed that the greatest genetic variations were found within populations, and genetic distance and Bayesian clustering analysis showed that the 14 populations clustered into one group. Based on morphological and genetic tests, we discuss corresponding recommendations, including release size, feed formulations, breeding strategies, and release tags, to minimize potential risks and improve hatchery practices for better restocking of this species.

The Dianchi golden-line barbel, Sinocyclocheilus grahami (Regan, 1904), is one of the “Four Famous Fishes” of Yunnan Province, China. Given its economic value, this species has been artificially bred successfully since 2007, with a nationally selected breed (“S. grahami, Bayou No. 1”) certified in 2018. For the future utilization of this species, its growth rate, disease resistance, and wild adaptability need to be improved, which could be achieved with the help of molecular marker-assisted selection (MAS). In the current study, we constructed the first chromosome-level genome of S. grahami, assembled 48 pseudo-chromosomes, and obtained a genome assembly of 1.49 Gb. We also performed QTL-seq analysis of S. grahami using the highest and lowest bulks (i.e., largest and smallest size) in both a sibling and random population. We screened two quantitative trait loci (QTLs) (Chr3, 14.9–39.1 Mb and Chr17, 4.1–27.4 Mb) as the major growth-related locations. Several candidate genes (e.g., map2k5, stat1, phf21a, sox6, and smad6) were also identified, with functions related to growth, such as cell differentiation, neuronal development, skeletal muscle development, chondrogenesis, and immunity. These results built a solid foundation for in-depth MAS studies on the growth traits of S. grahami.

The restocking of the endangered Kanglang white minnow (Anabarilius grahami) in Lake Fuxian, China, has been conducted for 13 years. However, few studies have reported on the effectiveness of the captive breeding and release of this species. Here, we investigated variations in morphology, including body shape and skeletal deformities, and genetic features among hatchery-born and recaptured A. grahami from Lake Fuxian. Results showed that current hatchery-reared fish displayed a stubbier body shape than their wild conspecifics from the 1980s. Furthermore, high skeletal deformity ratios were found in two aquafarms (Luchong, 50%; Haikou, 45.2%), and the release of malformed fish elevated the skeletal deformity rate of wild stocks found near the Lake Fuxian release sites (west coast, 19.0%; east coast, 12.5%). Based on variations in the cytochrome b (cyt b) gene, existing A. grahami populations showed relatively high haplotype diversity and low nucleotide diversity. Hatchery populations exhibited reduced genetic variations based on microsatellite markers and reintroduction led to markedly lower genetic diversity around the west coast release sites of Lake Fuxian. Analysis of molecular variance (AMOVA) of cyt b and microsatellite analysis showed that the greatest genetic variations were found within populations, and genetic distance and Bayesian clustering analysis showed that the 14 populations clustered into one group. Based on morphological and genetic tests, we discuss corresponding recommendations, including release size, feed formulations, breeding strategies, and release tags, to minimize potential risks and improve hatchery practices for better restocking of this species.

The study is aimed to create seed materials and dissect the molecular mechanism of sexual propagation of Gastrodia elata. In this research, thirteen characteristics of flowers, flower stem, fruits, seeds and embryo of G.elata f. glauca and G.elata f. elata after bolting at room temperature(RT) and constant temperature(CT, 22 ℃) were determined. It was found that the constant temperature condition could prolong the bolting duration of G.elata and increased the number of flowers, while the variety of G.elata only affected the bolting duration, but had no effect on the number of flowers, and the G.elata f. elata was more likely to bolting than the G.elata f. glauca. The variety of G.elata was the main factor affecting the time of dehiscent fruit of G.elata, the temperature was the main factor affecting the fruits number and fruits diameter, and the constant temperature was more conducive to the fruits shape of G.elata than the room temperature. There was no significant difference in seed phenotype of G.elata varieties, but the seed embryo of G.elata seeds cultivated at constant temperature was fuller than that of G.elata cultivated at room temperature, and temperature had less influence on the seed phenotype of G.elata. But it was interesting to find that temperature and varieties had greater influence on the seed embryo of G.elata, constant temperature cultivation was more conducive to the formation of seed embryo of G.elata, and more the seed embryo of G.elata f. elata was easier to form than the seed embryo of G.elata f. glauca. However, the development of seeds and embryos of G.elata was significantly affected, and the development of seeds and embryos of G.elata f. glauca was more sensitive to temperature than G.elata f. elata. The research suggested that it is advisable for G.elata to produce seed materials by bolting at constant temperature(22 ℃).

Pseudostellaria heterophylla (family Caryophyllaceae) is a perennial herbaceous plant. Its tuberous roots are highly valued in traditional Chinese medicine. It is mainly cultivated in a geo-authentic production zone located in the Guizhou, Anhui, Shandong, and Fujian provinces of China (Zhao et al. 2016). The herb is widely used for treating lung diseases and as a spleen tonic (Pang et al. 2011). A severe leaf black spot disease was observed on P. heterophylla in China, from 2018 to 2020. Plants displayed water-soaking symptoms in the early stage of infection, then the watery areas turned brown-red and a black mold appeared on the lesions. At a later stage, the leaf spots showed concentric rings surrounded by a yellow halo, and the initial infection site became dry and necrotic (Supplementary Figure S1). Nine infected plants were collected from three cultivation fields in Shibing County (N 27°4'21", E 108°8'0"), Guizhou province, on April 13th, 2019. The fungus was consistently isolated from symptomatic leaves on potato dextrose agar (PDA) medium according to the method described by Larran et al (2002). A total of 22 isolates were obtained, including 7 isolates of Arcopilus and 15 isolates of Trichoderma. The growth rates of isolate MJ2-2b on PDA and oatmeal agar (OA) medium were 3 to 5 mm/day at 25 °C (Supplementary Figure S2A and S2B). Mycelium of isolate MJ2-2b was dense, yellowish-brown on PDA, while it was sparse, bright-red on OA. Also, the mycelium secreted brownish-red pigment on both PDA and OA. Ascomata when mature were water drop and limoniform. Lateral hairs were brown, erect or flexuous, tapering towards the tips. Ascospores when mature were greyish-white to grey, limoniform, or fusiform to pyriform (Supplementary Figure S2C and S2D). Further, the beta-tubulin gene (Tub2) of the fungus was amplified by using primer pairs T1 and TUB4Rd as described by Wang et al (2016) and subjected to sequencing. NCBI nucleotide BLAST results showed that sequences from seven isolates had a 99.86% identity with A. aureus (strain ChL-C, GenBank accession No. MG889987.1) (Supplementary Figure S2F). Molecular phylogenetic analysis by maximum likelihood method using MEGA 7 confirmed that the fungal isolate clustered with A. aureus. Hence, the causal agent was identified as A. aureus based on morphological and molecular characteristics. The sequence was deposited in GenBank (accession No. MW531453). Pathogenicity tests were conducted on 15-day old tissue-cultured seedlings according to Ghanbary et al (2018) (Supplementary Figure S3). Leaves of 16 seedlings were inoculated with 1×1 mm 5-day-old PDA-grown mycelial plugsof the fungal isolate. The experiment was repeated 3 times. After 10 days, the inoculated leaves showed the same symptoms observed on plants in the field. The associated fungal pathogen was consistently re-isolated from the inoculated seedlings and identified by Tub2 gene sequencing. At present, there are no reports of A. aureus causing disease of plants. To the best of our knowledge, this is the first report of leaf black spot disease on P. heterophylla caused by A. aureus in China.

In recent years, the tea plant (Camellia sinensis [L.] Kuntze) has been widely planted in Guizhou Province, China, with a cultivated area of 350,000 ha in 2017. In November 2018, leaf spots were observed on tea plants in Yuqing County (27.22°N, 107.88°E). Disease incidence was estimated at 74 to 82%, and disease severity was estimated at 42 to 48% in 12 tea plantations. Early symptoms on infected leaves were light brown lesions, which gradually enlarged to brown, scattered, round, elliptical or irregular lesions. The central area of each lesion later became grayish and surrounded by an inconspicuous yellow halo. Neighboring lesions coalesced to form larger lesions at the margin of the leaves. In order to identify the pathogen(s) causing this disease, lesion margins of the sampled leaves (n = 10) were surface sterilized with 75% ethanol for 30 s, soaked in 0.5% sodium hypochlorite for 5 min, rinsed three times in sterilized water, plated on potato dextrose agar (PDA), and incubated for 3 to 5 days in darkness at 25°C. The hyphal tips from the edge of growing colonies were picked and transferred to fresh PDA plates. Colonies were initially pale yellow and gradually became grayish-white, producing masses of flocculent aerial hyphae. At 22 days postinoculation, black, spherical, scattered or clustered pycnidia were evident, 50 to 290 μm in diameter. Their shape was globose or irregular, with one to two ostioles. Pycnidia were nonpapillate or slightly papillate, with the pycnidial wall consisting of two to three layers of cells. Unicellular and hyaline conidia (n = 50) were ellipsoidal or obovate in shape, with mean ± SD dimensions of 6.1 ± 1.1 (4.1 to 9.0) × 2.9 ± 0.6 (1.8 to 4.1) μm, and were usually rounded at each end. On the basis of these morphological characteristics, the isolates were initially identified as Didymella bellidis (Xu et al. 2016; Zou et al. 2020). To confirm the identity, the internal transcribed spacer (ITS), the partial 28S large subunit rDNA (LSU), and the beta-tubulin (TUB) gene of three representative isolates were amplified and sequenced (Chen et al. 2017), respectively. The sequences were deposited in GenBank with accession numbers MN274963, MN274964, MN274965 (ITS); MN274966, MN274967, MN274968 (LSU); and MN274969, MN274970, MN274971 (TUB). Phylogenetic analysis confirmed these isolates to be identical to D. bellidis reference strain D. bellidis CBS 714.85. To fulfill Koch’s postulates, healthy leaves on tea plant twigs (C. sinensis ‘Fuding-Dabai Cha’) were separately inoculated with mycelial plugs from PDA cultures and conidial suspension (1 × 10⁶ conidia/ml, 20 to 30 μl) for three isolates. PDA plugs without mycelia and buffer with no conidia were used as a control. Each treatment contained five replicates. The pathogenicity test was performed three times independently. Brown leaf spots gradually turned into black irregular lesions at 1 day postinoculation; the center of the lesion became darker and necrotic at 5 days postinoculation. The control groups showed no symptoms. The pathogen was reisolated from inoculated samples and identified by morphology and molecular biology. To the best of our knowledge, this is the first report of this fungus causing a tea leaf spot in China and seriously reducing both the productivity and the quality of tea leaves. Our findings will be useful for its management and further research.

The effects of osmotic pressure, temperature and stocking density on medusae survival of Craspedacusta sowerbii were examined. The medusae were shown to be sensitive to the variations of osmotic pressure. And the survival time was < 90 h at 34 mOsm/L and it declined rapidly with rising osmotic pressure. The peak survival time of >200 h was recorded at 0.2 mOsm/L. Comparing with 27 °C and 32 °C treatments, 23 °C treatment yielded lower activities at a range of 8-13/min. However, there was a longer survival time. A non-linear relationship existed between survival time and stocking density. Lower density resulted in larger body size. And sexual reproduction resumed after breeding for >22 days. Newly-formed polyps and medusae appeared subsequently but only in the higher-density groups of 10, 14 and 18 ind./L. It suggested that the number of newly-formed polyps and medusae was highly dependent on stocking density. That is, a higher stocking density produced more organisms. However, newly-formed medusae died within one month and none grew a diameter of >5 mm.

In this study, we investigated the nutritive composition in the muscle of Sinocyclocheilus grahami and S. tingi. The contents of crude protein in the fresh muscle of S. grahami and S. tingi can be described as being 21.7% and 20.6%, crude fat were 3.43% and 2.66%, and total amino acid were 19.23% and 17.67%, respectively. Essential amino acids accounted for 44.08% and 43.69% of total amino acids of S. grahami and S. tingi, respectively. The values of essential amino acid index (EAAI) of the two species were 70.00% and 65.99%, respectively, with S. grahami being better than S. tingi. Ultimately, the amino acid composition of S. grahami and S. tingi muscle tissue met the standards of the Food and Agriculture Organization of the United Nations as well as those of the World Health Organization (FAO/WHO). According to the nutritive evaluation in amino acid score (AAS), the first limited amino acids of both fish were cystine+methionine. Compared with other commercial fish, the nutrition value of the muscle of Sinocyclocheilus fish can generally be considered as being better.该文对滇池金线鲃(

In the present study, we examined the potential uses of Alizarin complexone and Alizarin red S to mark S. grahami larvae and juveniles. Individuals of different ages (6 days, 20 days, 90 days) were immersed in four concentrations of a solution of each chemical (50, 100, 150 and 200 mg/L) for different periods of time (4-36 h). Marked individuals were euthanized 4-27 days after immersion, and the lapillus was removed and used to determine mark quality. After marking with 50-150 mg/L ALC and ARS, violet marks were visible under normal light, and scarlet fluorescent marks were visible under 510-560 nm green light. The clear marks under normal light were recorded, and a 100% survival rate was guaranteed under the following conditions: 6 day old larvae immersed in 50 mg/L ALC or ARS for 8h; 20 day old larvae immersed in 50 mg/L ALC or 100 mg/L ARS for 24h; 90 day old juveniles immersed in 100mg/L ALC or 150 mg/L ARS for 24 h.该文使用不同浓度梯度(50~200 mg/L)和浸泡时间(4~24 h)的茜素络合物(ALC)及茜素红(ARS)水溶液对6、20及90日龄滇池金线鲃(

Due to declining fishery resources and the growing development of conservation aquaculture, artificial freshwater fish enhancement and releasing have begun to replace traditional means of recovering endemic and rare fish populations. Artificial proliferation can be beneficial both to endemic fish conservation and technical bottleneck breakthroughs. This overview presents a review of the latest research and the underlying principles behind the conservation implementation processes, as well as the research status of artificial enhancement and release of endangered freshwater fish species in China, such as Mylopharyngodon piceus, Ctenopharyngodon idellus, Hypophthalmichthys molitrix, H. nobilis, Acipenser sinensis, Myxocyprinus asiaticus, and Sinocyclocheilus grahami. The overview also presents evolutionarily significant units, sperm and egg quality, and cryopreservation technologies and cell cultures used in artificial enhancement and release, which help standardize genetic management and minimize the genetic differences between hatched and wild populations. Monitoring fish from cultivation to release is essential to evaluating wild population recovery and adjusting recovery plans. Moreover, the remaining problems of artificial releases are discussed in-depth, touching on issues such as the limitations of domestic hatching, the base number of wild populations necessary to the environment, the proper size at which to release juveniles' into the environment, the geographic confusion of populations, the contradictions in commercial fish selection and fish conservation, and "exotic species" invasion.随着鱼类资源的持续衰退以及保护水产学的兴起, 鱼类人工增殖放流已由传统渔业增殖发展成为特有珍稀鱼类种群恢复的主要技术手段。近年来, 我国淡水鱼类人工增殖放流涉及水系多、规模大且种类丰富, 取得了显著效果并积累了大量基础资料和经验。为深入开展人工增殖放流基础研究, 规范技术并提升生态效益, 该文收集整理了国内、外相关文献资料, 分别从基础理论、塘养种群管理及效果评价等方面阐述人工增殖放流的理论背景, 并结合我国“四大家鱼”、中华鲟、胭脂鱼、滇池金线鲃及其他珍稀濒危鱼类人工增殖放流现状, 讨论了野外监测和效果评价的作用和意义, 提出放流种群遗传局限性、数量和规格权衡以及经济效益与生态效益权衡等问题, 旨在为相关研究和人工放流实践提供系统资料。

Though Yunnan province contains some 562 known species of fish, no cell lines from any of these have been made available to date. To protect germplasm resources and provide an effective tool in solving problems at cellular level of Anabarilius grahami, a fish endemic to Fuxian Lake, Yunnan, China, we established and characterized the major features of a continuous cell line (AGF II) from the caudal fin tissue of A. grahami. This AGF II cell line consists of fibroblast-like cells and has been subcultured more than 60 times over the course of a year. The cell line was maintained in DMEM/F12 supplemented with 10% FBS, with a cellular doubling time of 51.1 h. We continued with more experiments to optimize the culture and storage conditions, and found a variety of interesting results: cells could grow at temperature between 24 Degrees Celsius and 28 Degrees Celsius, with the optimal temperature of 28 Degrees Celsius. Likewise, the growth rate of A. grahami fin cells increased when the FBS proportion increased from 5% to 20%, with the optimal growth at the concentrations of 20% FBS; cells were able to grow in L-15 and DMEM/F12 with optimal growth at L-15; DMSO is a better cryoprotectant than Glycerol, EG and MeOH for AGFII cells with optimal concentration of 5% DMSO. Chromosome analysis also showed that the distribution of chromosome number varies from 38 to 52, with a modal peak at 48 chromosomes, accounting for 39.8% of all cells. Using the same primer pairs specific to mtDNA, the AGF II cell sequences obtained by PCR were identical to those from muscle tissues of A. grahami. Both chromosome analysis and PCR amplification confirmed the AGF II cells were from A. grahami, also indicating that that current long-term artificial propagation of A. grahami has been successful. Finally, we noted that when cells were transfected with pEYFP-N1 and pECFP-N1 plasmid, bright fluorescent signals were observed, suggesting that this cell line may be suitable for use in transfection and future gene expression studies.