As an adaptor protein of the SCF (Skp1-Cul1-F-box) complex, SKP1 (S-phase kinase-related protein 1) connects with Cullin-1 (Cul1) and F-box proteins, respectively. SKP1 family proteins play their roles in many cytological processes, such as growth and development of plants, transduction of hormone signal and response to biotic/abiotic stresses etc. To uncover the basic biological characteristics and functional mechanism of SKP1 in wheat (Triticum aestivum), a systemic identification and analysis on wheat SKP1 genes in the present study was conducted. 115 sequences were identified in the wheat proteome, which were encoded by 101 SKP1 genes, among them, 9 genes (TSK37, TSK41, TSK44, TSK50, TSK52, TSK59, TSK60, TSK85 and TSK99) were first identified in the present study. The length of 115 deduced SKP1 proteins ranged from 104 to 530 aa, and the theoretical pI showed that all SKP1 members were acidic proteins. The wheat SKP1 proteins were present in the cytoplasm, nucleus and chloroplast by subcellular localization prediction, most of them were localized in nucleus. All members of wheat SKP1 family contained at least one SKP1 and/or SKP1_POZ domain, and the SKP1 domain shared higher conservation when comparing to the SKP1_POZ domain. Phylogenetic analysis of the SKP1 protein from wheat, Arabidopsis thaliana, and rice (Oryza sativa) revealed that the SKP1 sequences from the same plant species were grouped in one branch, which indicated that these sequences shared closer phylogenetic relationship. Location of 101 SKP1 genes was identified on all 21 wheat chromosomes but showed an uneven distribution. The density on chromosome of No. 3 and No. 5 was relatively higher than that of the others. Gene expression patterns indicated that a few SKP1 genes (TSK37, TSK41, TSK54.1, TSK75, TSK97) had higher expression levels in different developmental stages of 5 wheat tissues based on heat map analysis, some of them, such as TSK62, TSK71, TSK56, TSK91.1, and TSK101.1, showed relative higher expression levels in a certain tissue or a specific stage of development, but most of them were not expressed or expressed at lower level in 5 tissues at all developmental stages. The expression patterns of SKP1 family genes in wheat varied greatly under drought and/or heat stresses, and heat stress brought stronger effect on the expression of SKP1 genes in wheat. Three genes TSK41, TSK43.2, and TSK62, which belonged to different type of SKP1 proteins, were obtained from wheat isogenic line TcLr15 based on the strategy of homologous cloning. qPCR showed that these three genes were significantly up-regulated in wheat response to salt stress, and down-regulated with different degrees after treatment by H₂O₂, whereas 3 stress-related hormones ABA, SA and MeJA had little effect on the expression of the three TSK genes (no more than 2.5 times), and inoculation with leaf rust pathogen (Puccinia triticina) caused less effects on their expressions, too, moreover their expression showed no obvious changes to the different virulent strains. Yeast two hybrid (Y2H) was used to screen the target proteins interacting with TSK41, TSK43.2 and TSK62. Results presented that 3 wheat SKP1 proteins and 8 F-box proteins had multiple interaction modes: TSK62 interacted with TaFBK19, TaFBK34, TaFBK71, TaSKP2A, and TaSKIP27, these 5 F-box proteins belong to 3 types: Kelch (FBK), LRR (FBL) and unknown functional domains (FBU), and TSK41 only interacted with 2 Kelch-type proteins TaFBK19 and TaFBK34, but TSK43.2 did not interact with any of these 8 F-box proteins. These findings supplied some basic and important knowledge for further dissecting the detailed mechanism of wheat SKP1 family members in response to biotic and abiotic stresses.

MYB-related gene is a subclass of MYB transcription factors, which mainly participates in the processes of secondary metabolism, growth and development, biological and abiotic stress. In order to explore the function of MYB-related transcription factor under drought stress, in the present study, 46 differentially expressed MYB-related genes were identified from the former transcriptome results under drought-rewatering treatment and comprehensive analyses were conducted including phylogenetic tree, motif prediction, gene's structure, cis-acting elements and co-expression analysis. The results showed that 46 genes were unevenly distributed on 8 chromosomes and divided into six sub-groups by phylogenetic analysis. The mainly stress-related cis-acting elements ABRE, MBS, ARE, LTR and hormone response element TCA-element, TGACG-motif, TGA-element were identified in the promoter regions of MYB-related genes. The results of gene expression analysis showed that 9 genes were up-regulated under drought stress, down-regulated after rewatering; 16 genes were down-regulated expression under drought stress while up-regulated expression after rewatering. In addition, 9 core genes responsive to drought stress were identified by co-expression network analysis. The results of qPCR showed that ZmMYBR24, ZmMYBR37, ZmMYBR55 and ZmMYBR89 genes were up-regulated under drought stress, and then down-regulated after rewatering. However, the transcript levels of ZmMYBR41, ZmMYBR78, ZmMYBR87 and ZmMYBR97 exhibited opposite trend. These results provide insight for further functional investigation of MYB-related genes.

Zinc finger protein transcription factors are one of the largest transcription factor families in plants, which participating in various biological processes such as apoptosis, autophagy and dryness maintenance, play an important role in regulating plant growth and development,and in response to adversity stress. In order to study the function of zinc finger protein gene in Brassica campestris, B. campestris variety 'Longyou 7' cDNA and gDNA were used as templates to clone the BrZFP1 gene (GenBank No. OK546027). Bioinformatics analysis of BrZFP1 gene sequence was carried out, and the transient transformation expression vector of Nicotiana tabacum was constructed for subcellular localization. Finally, the expression levels of BrZFP1 in leaves, growth cones and roots under low temperature, drought, high temperature and salt stress were detected by qPCR. The results showed that BrZFP1 encoded 160 amino acids, the predicted molecular weight of the protein was 17.094 kD, and the isoelectric point was 9.34. The gene had no intron and encoding a hydrophilic stable protein with a double conserved domain zf-C2H2_6. PlantCARE analysis results showed that the promoter region of BrZFP1 gene contained multiple cis-acting elements such as low temperature response, light response, meristem-related and hormone-related. The similarity between BrZFP1 amino acid sequence and homologous sequence of B. campestris was 98.75%. Subcellular localization showed that the protein was localized in the nucleus. Under low temperature stress, the change of BrZFP1 gene expression in the growth cone was consistent with the results of transcriptome sequencing, and the expression level showed an upward trend. Under different stress treatments, the expression of BrZFP1 gene in different parts increased to different degrees, drought and high temperature could strongly induce the expression of BrZFP1 gene. These results suggested that BrZFP1 gene might played an important regulatory role in abiotic stress in B. rapa. This study provides reference for further study on the function of BrZFP1 protein.

Brassinolide has a promoting effect on crop growth. In order to clarify the effect of seed soaking on the seedlings of Brassica napus, the dry seeds were soaked in brassinolide, and the soaked in clear water were used as the control. The leaves at the 5~6 leaf stage were used for transcriptome sequencing analysis, and the leaves at young seedling stage, 5~6 leaf stage and budding stage were used for physiological and biochemical analysis. The results showed that transcriptome analysis found 4 066 up-regulated and 4 606 down-regulated differential genes. Three differential genes related to fatty acid synthesis were screened out: Fatty acyl carrier protein thioesterase (BnFAT), biological carboxyl carrier protein (BnBCCP), and stearoy acyl carrier protein desaturase (BnSAD); 3 differential genes related to photosynthesis were screened out: PhotoreactionⅠsystem centerⅤsubunit (BnPSAG), photosystemⅡreaction center protein PSB28 (BnPSB28) and chlorophyll ab-binding protein (BnCab).The qPCR method was used to verify the transcriptome results, and it was found that only BnSAD was inconsistent with the sequencing results, and the other 5 differential genes were consistent with the transcriptome sequencing results. Using the leaves at seedling stage, 5~6 leaf stage and budding stage as materials, the expression level of 6 differential genes was analyzed, and the soluble sugar, soluble protein content, superoxide dismutase (SOD), peroxidase (POD), catalase (CAT) and other physiological functions were analyzed, and the correlation between the differential gene expression in 3 periods and the physiological and biochemical indicators were studied. The results showed that the expression of BnFAT and BnBCCP genes were positively correlated with the content of soluble sugar (both correlation coefficients were 0.69), BnCab expression was positively correlated with the content of soluble protein and SOD activity (correlation coefficients was 0.89 and 0.62, respectively), BnPSAG gene expression was positively correlated with POD activity (correlation coefficient was 0.62). The results of this study indicate that the treatment of seeds with brassinolide could increase the soluble substance content and protective enzyme activity of B. napus, and there was a close correlation between the physiological and biochemical indexes and the differential gene expression. This research could provide theoretical and technical reference for high-yield cultivation of rape.

The industrial pollution and the overuse of selenium fertilizer result in selenium pollution in some area, which further inhibit plant growth. Hydrogen sulfide (H₂S), a kind of gaseous signaling molecule in plants, regulates plant development and stress responses. In order to explore the function of H₂S synthesis related genes LCDs/DCDs, In this study, Brassica campestris ssp.chinensis was used to study response of the endogenous H₂S and its related genes to selenium stress. The root length and plant height of seedlings at different selenium concentrations were measured, it was found that selenium stress significantly inhibited the growth of seedlings, and showed concentration and time effects. The effect of H₂S on oxidative damage induced by selenium stress was analyzed by lipid peroxidation and loss of membrane integrity and WSP-1 fluorescent probe technology, the results showed that enhancing endogenous H₂S alleviated selenium-induced oxidative injury in seedlings. qRT-PCR analysis showed that selenium stress induced up-regulation of 12 H₂S-producing family genes (BrLCD1~BrLCD10, BrDCD1~BrDCD2) in the early stage, which might result in the rapid production of endogenous H₂S in the early period of selenium stress. Finally, the full-length cDNA of H₂S-producing genes with relative high expression level in response selenium stress were cloned. Sequence analysis showed that the amino acid sequences encoded by these genes contained the typical characteristics of conserved cysteine dehydrogenase. The results of this study provides new evidences for the revealing the mechanisms of plant response to selenium stress.

The pathogenesis-related protein 10 (PR10) gene plays an important role in plants when resistance to biological and abiotic stresses. In this study, a PR10 gene was cloned from island cotton (Gossypium barbadense) 'Pima90-53' and named GbPR10 (GenBank No. MT612460) based on the transcriptome data of drought stress; To reveal tissue expression specificity, exogenous hormones induction, expression characteristics under different stress for GbPR10 gene by qPCR; Meanwhile the promoter of GbPR10 gene was cloned and analyzed; GbPR10 gene overexpression vector PCAMBIA 1301-GbPR10 was transformed into Arabidopsis thaliana to analyze the tolerance of over expression of GbPR10 gene in drought stress conditions. The results showed that the open reading frame of GbPR10 gene was 486 bp, encoding 161 amino acids, and contained a Bet_v1-like domain with P-loop conserved domain, which belonged to the Bet_v1 family of path-related proteins. The sequence blast analysis showed that the cloned GbPR10 was located on chromosome D02 and exist a homologous gene on chomesome A02 with the similarity of 96.07%. Phylogenetic tree analysis with the reported PR10 sequence showed that GbPR10 was closer with GbPR10-5 and NtPR10. Protein phosphorylation site prediction analysis showed that GbPR10 contains 8 serine phosphorylation sites, 4 threonine phosphorylation sites and 3 tyrosine phosphorylation sites. Tissue specific expression results showed that GbPR10 gene was predominance expressed in seedling and bolling roots, especially in 4 leaf age, which the expression level in 4 leaf age root was more than 1 000 folds than that in leaf. Exogenous hormones induction expression of GbPR10 showed that GbPR10 was significant up-regulated by exogenous ABA (abscisic acid), ET (ethylene), MeJA (salicylic acid) and SA (salicylic acid), and meanwhile GbPR10 was also up-regulated under 20% PEG6000 (polyethylene glycol 6000) as well as 200 mmol/L NaCl stress treament. All these induction expression of GbPR10 indicated that GbPR10 may be involved in abiotic stress responses. The GbPR10 promoter fragment of 2 176 bp was obtained using promoter sequence analysis tools (BDGP, FPROM), and the promoter sequence analysis using New PLACE online tool found that the GbPR10 promoter contains many hormone response, defense respones and abiotic stress reponse elements including ET response element AGCBOX, ABA response element DPBFCOREDCDC3, MYB1AT, MYB2AT, MYCCONSENSUSAT, and several abiotic related regulatory elements CBFHV, MYB1AT, MYB2AT, MYCCONSENSUSAT, WRKY71OS. The result further indicated that GbPR10 could be involved in abiotic stress responses. Over-expression of GbPR10 analysis under drought stress showed that the root length of GbPR10 transgenic A. thaliana lines with 10 d seeding was significantly higher than that of wild type under the PEG MS medium (P<0.05), and under natural drought condition, the drought tolerance of transgenic A. thaliana with GbPR10 gene was significantly higher than wild type lines (P<0.05). In conclusion, GbPR10 gene plays an important role in cotton drought response and this study could provide a theoretical reference for the molecular mechanism of cotton drought resistance.

Reactive oxygen species (ROS) play an important role in intercellular signal transduction between plant cells, while respiratory burst oxidase homologue (RBOH, also known as NADPH oxidase) is a key enzyme that catalyzes the production of reactive oxygen species and widely participates in mediating intra plant signal transmission.Pigeonpea (Cajanus cajan) is a woody leguminous plant which can be used as medicine and food. In this study, the members of CcRboh gene family were screened from the whole genome of pigeonpea by bioinformatics software, and their basic functions including chromosome location, phylogeny, conserved domains and promoter elements were analyzed.The expression of CcRboh in different tissues was screened by transcriptome data, and the response mode of CcRboh gene under abiotic stress was determined by qPCR. Nine Rboh family members were identified named CcRbohA~CcRbohI according to their position on chromosome. They encoded 818~940 amino acid residues with isoelectric point (pI) ranging from 8.76 to 9.36.According to the sequence similarity, they can be clustered into 5 subfamilies, all of which contained 4 domains such as NADPH oxidase structure. Subcellular localization prediction showed that CcRboh proteins were mainly located on the plasma membrane. The cis-element prediction results showed that the promoter region of CcRboh gene contained a variety of hormone and stress response elements. The widespread jasmonate acid response element and light response element indicated that CcRboh gene could respond to the induction of jasmonate and light. The expression pattern analysis results of Rboh in pigeonpea roots and leaves showed that CcRboh gene had a high expression level in roots, indicated that it played an important role in roots. The transcriptome data of jasmonic acid treatment showed that the expression of CcRbohB and CcRbohG were significantly up-regulated (P<0.05), and increased more than 5 folds after 3 h of treatment, indicating that they were indeed more susceptible to jasmonate acid induction. In addition,CcRboh had a good response to high temperature stress, and its expression was significantly up-regulated after 3 h of treatment (P<0.05), The expression levels of CcRbohC, CcRbohF, CcRbohG, CcRbohH and CcRbohI after 3 h treatment were 6.4, 22.5, 21.0, 70.4 and 15.5 times higher than those of the control, respectively.The expression of CcRbohI increased significantly after 12 h treatment (P<0.05), and the highest expression reached 37.4 times; However, for drought and salt stress, CcRboh was induced after 6 h; Moreover, CcRbohG and CcRbohH had the most significant responses to drought, salt and high temperature stress (P<0.05), which indicated that reactive oxygen species may play a crucial role in the response to high temperature stress, especially CcRbohG and CcRbohH genes. In this study, the genes of NAPDH oxidase family were analyzed and screened by bioinformatics,and the key genes CcRbohG and CcRbohH in response to high temperature and drought stress were obtained, which provides candidate genes and research basis for improving the stress resistance of C. cajan.

Low temperature in winter and spring has become an important factor affecting the growth and development of chrysanthemum (Chrysanthemum morifolium). To explore the physiological mechanism of chrysanthemum leaves membrane lipid constituents to low temperature stress response, chrysanthemum variety 'Tangyujinqiu' was used to test the fatty acid composition in cell and thylakoid membrane and its correlation with fatty acids desaturase genes and chlorophyll fluorescence parameters, separately. The results showed in cell membrane that index of unsaturated fatty acid (IUFA) significantly increased with the decrease of temperature. The expression levels of Δ9 stearoyl acyl-carrier-protein desaturase genes (CmSAD), and fatty acid desaturase genes (CmFAD2 and CmFAD7) were not completely consistent with contents of fatty acids. In thylakoid membrane, the content of saturated fatty acids (palmitic acid (C16∶0), stearic acid (C18∶0)) decreased significantly, while the content of unsaturated fatty acids (oleic acid (C18∶1), linoleic acid (C18∶2), linolenic acid (C18∶3)) showed upward trend. Fatty acid desaturase genes regulated unsaturation fatty acid more directly in thylakoid membrane than in cell membrane. The IUFA of thylakoid membrane was significantly correlated with chlorophyll fluorescence parameters, indicated that the unsaturated fatty acids repressed photoinhibition by reducing the electron transfer on the PSⅡ acceptor side and increasing heat dissipation. The expression level of fatty acid desaturase genes were increased by low temperature stress in leaves, meanwhile, unsaturated fatty acid level in cell and thylakoid membrane was promoted by low temperature, and maintained the stability of the membrane, this might alleviate the damage caused by low temperature to photosystem to a certain extent. This study provides a theoretical basis for further exploring the relationship between changes in plant membrane lipid components and photoinhibition under low temperature stress.

Plant cytoskeleton undergoes dynamic remodeling under plant growth and development and different environmental stresses, resulting in changes in the mechanical properties of the cytoskeleton. Cytoskeleton drugs can change the stability of the cytoskeleton, so cytoskeleton drugs can be used to study the viscoelasticity of tobacco (Nicotiana tabacum) BY-2 cells from the level of cellular structure. In this paper, quartz crystal microbalance (QCM) was used to monitor the viscoelastic response of BY-2 cells under the treatments of two cytoskeleton drugs in real time. The results showed that when the cells were treated with low concentrations of paclitaxel (10, 15, 17 μmol/L), the cell viscoelastic index (CVI) of the cells decreased and then increased, and the cells first became softer and then harder. This softening was almost instantaneous, reflecting the rapid force signal participation process. Under the actions of 20 and 25 µmol/L paclitaxel, the CVI of the cells went from negative values to finally close to zero, and the cells became harder and the hardness was greater than that before the drug was added. Under the treatments of lower concentrations of drug cytochalasin D, at low concentrations (50, 100, 150 ng/mL), the CVI of the cells increased from the negative values before adding the drug to greater than zero then dropped, and the cells first became softer and then became harder, the rapid change of CVI's numerical sign reflected the rapid and unstable change of the cells' generated force;and at higher concentrations (200, 250 ng/mL), the CVI of the cells went from negative values to finally slightly greater than zero, and the cells quickly became harder and then became softer, but the hardness was larger than that before adding the drugs. Cellular tensegrity model and the increased plasma membrane tension caused by retraction of the Hechtian strands were used to explain the changes in cells' softness or stiffness under the actions of the two cytoskeleton drugs. In addition, microscopy technology was used to observe the changes in the microfilament structures of tobacco cells under the action of 200 ng/mL cytochalasin D, the result of fluorescence microscopy observation of microfilaments was consistent with the result obtained by QCM real-time monitoring. The method established in this paper provides a new way to study the cellular structure of plant cells based on viscoelasticity measurements, and provides a basis for further research on the mechanical properties of plant cells under the action of cytoskeleton drugs.

Diazepam binding inhibitor (DBI) is closely related to cellular fatty acid metabolism, and fatty acids are involved in oocyte maturation and follicle development. In order to explore the potential biological role of maternal secretory factors mediated by DBI in regulating ovarian development and oocyte maturation of yaks (Bos grunniens). Through the isolation and establishment of yak granulosa cells in vitro culture system, different concentrations of exogenous fibroblast growth factor-10 (FGF-10) (0, 20, 50, 100, 150, 200 ng/mL) were added in the process of in vitro culture in different time (12, 24 h). qPCR , Western blot (WB) and immunofluorescence (IF) assays were used to detect the effect of different concentrations of FGF-10 on the expression of DBI in granulosa cells from gene and protein levels. The isolation and culture system of primary yak granulosa cells was successfully established as follows: The granulosa cell inoculation density was 4×10⁵/mL, DMEM/F12 medium+12% FBS+100 U/mL streptomycin+100 U/mL penicillin, changed the liquid once in 36 h, and the purity of the cells was as high as 95%. After treated with 100 ng/mL FGF-10 for 12 h, the expression level of DBI gene and protein was the highest, and the expression level of DBI was decreased in each treatment group at 24 h. Immunofluorescence showed that DBI protein could be expressed in both the nucleus and cytoplasm of granulosa cells in each treatment group. The results showed that FGF-10 was involved in regulating the expression of DBI in yak granulocytes in a concentration-dependent and time-difference manner, which provides a theoretical basis for further exploring the multiple biological mechanisms of maternal cytokines regulating oocyte maturation.

With the improvement of next-generation sequencing technology and the decline of sequencing costs, low-depth resequencing is applied to genome-wide association study analysis because of its cost-effective and ultra-high density of polymorphic loci. Nevertheless, research on low-depth resequencing for pig genome selection is still lack. In this study, 1 097 Large White pigs (Sus scrofa) were genotyped by low-coverage resequencing with an average sequencing depth of 2.4×. The results showed that the mismatch rate, mapping rate, actual depth and coverage between different batches were in stability. Then, the STITCH (Sequencing to Imputation Through Constructing Haplotypes) software was used for genotype calling and imputation from 1× and 2.4× re-sequencing data, and 15 506 511, 15 994 848 SNPs with 99.1% and 99.8% imputation accuracy were identified, respectively. In addition, overlapping or adjacent SNPs between 1× imputation data and 60K SNP chip (PorcineSNP60 v2) reached 47 421, indicating that low-depth resequencing had good compatibility with SNP chips, Further, BLUP (BLUP based on pedigree), GBLUP-WGS (GBLUP based on imputation from whole genome sequencing data), GBLUP-snp60 (GBLUP based on 60K SNP chip data) were used to predict the breeding values of 4 reproductive traits, including total number born (TNB), number born alive (NBA), healthy piglets (HP) and litter weight (LW) in the validation population. The results showed that except TNB, the prediction accuracy of other traits was GBLUP-WGS>GBLUP-snp60>BLUP, and the improvement range was 33.5%~218%, 16.7%~190%, corresponding to comparison between GBLUP-WGS and BLUP as well as between GBLUP-snp60 and BLUP. This results indicate that low-depth whole-genome sequencing offers a reliable and cost-effective method for large-scale livestock and poultry genome research and genome selection breeding.

Myostatin (mstn) is a negative regulator of muscle growth and belongs to transforming growth factor β (TGF-β family members), which play a role by inhibiting myoblast proliferation. In order to study the mechanism of mstn in the compensatory growth of Acipenser dabryanus, the CDS region of mstn was cloned according to the results of previous transcriptome sequencing, and the expression of mstn in various tissues and starvation and refeeding conditions was analyzed. The results showed that the total length of mstn (GenBank No. MZ666180) was 2 552 bp, and the CDS region was 1 122 bp, encoding 373 amino acids. The highest expression was in muscle, followed by skin, gill and eye. Under starvation condition, the expression of mstn in muscle of A. dabryanus gradually decreased with the prolongation of starvation time; after 14 d of refeeding, the expression of mstn in 3 d group was significantly higher than that in control group (P<0.05), and there was no significant difference between 7 or 14 d groups and control group (P>0.05). The results showed that starvation could inhibit mstn transcription of A. dabryanus. It showed that starvation could inhibit the transcription of mstn in A. dabryanus, and supplement of nutrients after short-term starvation could activate the muscle mstn function of A. dabryanus. It provides a reference for evaluating the physiological adaptation mechanism of A. dabryanus to environmental stress, and helps us to understand the growth and growth regulation mechanism of A. dabryanus, and provides a reference for future production practice.

From August to September 2020, an outbreak of hemorrhagic disease in the great blue-spotted mudskipper (Boleophthalmus pectinirostris) occurred in a farm in Cixi City, Zhejiang Province, causing serious economic losses to farmers. In order to identify the pathogen of the disease, methods including the anatomical observation, bacterial isolation and culture, electron microscope observation, biochemical test, drug sensitivity test, artificial infection test, and phylogenetic analysis of the 16S rRNA and DNA gyrase subunit B gene (gyrB) were used for identification of the pathogen. The results showed that one dominant strain, named AV20211212, was isolated from the diseased fish. Observation by light microscope with gram staining and ultrastructural observation by scanning and transmission electron microscope showed that the isolated strain AV20211212 was Gram-negative with blunt round ends and hollow polar monotrichous flagella. Results from physiological and biochemical characteristics identification showed that AV20211212 had the similar physiological and biochemical characteristics to Aeromonas veronii. Homology analysis demonstrated that the 16S rRNA of the isolated strain shared 93.6%~99.4% homology with those of other A. veronii and the amino acid sequence of the gyrB from the isolated strain shared 99.5%~99.7% homology with those of other A. veronii. Phylogenetic analysis showed that the isolated strain was closely clustered with A. veronii. The isolated strain was highly resistant to 7 antibiotics such as penicillin and ampicillin, moderately sensitive to azithromycin, and sensitive to 12 antibiotics such as norfloxacin and amikacin. The mudskipper infected by the isolated strain AV20211212 showed the same symptoms with naturally diseased mudskipper on the farm, and its medium lethal dose (LD₅₀) was 4.56×10³ CFU/g to mudskipper. In the present study, A. veronii was identified as the pathogen of mudskipper for the first time. All the results provided theoretical basis and technical support for the effective prevention and rational medicine use for bacterial fish diseases in Cixi City.

Bovine mammary epithelial cells (bMECs) are the main cell type of mammary gland, they not only play the role of lactation, but also regulate the innate immune response of mammary gland. The proliferation and apoptosis of bMECs are regulated by enzymes, hormones, cytokines and other molecules, it is a cellular metabolic process of breast tissue in a specific physiological environment and affects the development and function of breast. In order to explore the function of mammary gland in dairy cows(Bos taurus), a lot of studies on the proliferation and apoptosis of bMECs have been carried out in recent years, and excellent results have been achieved. This paper mainly introduces the signaling pathways related to the cell proliferation and apoptosis, and focuses on the latest research progress of the regulation mechanism of proliferation and apoptosis by coding and non-coding genes (miRNA, lncRNA and circRNA) in bMECs, so as to provide reference for the further research of molecular breeding of high-yield and anti-mastitis dairy cows.

In recent years, with consumers' pursuit of chicken (Gallus) meat quality, breeders have done more and more research on chicken meat quality traits. Inosine monophosphate (IMP) and intramuscular fat (IMF) are significant flavor substances affecting chicken flavor. In depth study of their mechanism is of great significance to improve chicken quality. In this paper, the candidate genes in the synthetic metabolism pathway of IMP and IMF were analyzed in order to explore their mechanism and function, improve selection efficiency, improve chicken quality, and provide reference basis for the genetic improvement of chicken meat quality traits.

Genomic selection (GS) has developed rapidly since it was proposed in 2001. It has become a research and application hotspot in the field of animal and plant breeding, which has brought revolutionary changes to animal and plant breeding. Genomic selection, which makes up for the deficiency of traditional breeding methods, has attracted more and more attention. Theory and breeding practice show that the accuracy of genomic selection is higher than that of traditional breeding, which can speed up breeding progress and improve breeding efficiency. At present, a large number of genomic selection studies have been carried out for aquaculture species, while comparing with livestock and poultry, genomic selection for aquaculture species is still in its infancy. This article reviews the principles and procedures, preconditions, analysis methods, advantages and influencing factors of genomic selection. Furthermore, the research progress of genomic selection technology in aquaculture species breeding is expounded. The problems and challenges in the application of genomic selection in aquaculture species are discussed, and the development prospects of genomic selection are also prospected, aiming to provide reference for the application of genomic selection in aquaculture species.

The utilization value of Pinus massoniana is extremely high, exogenous hormones can promote the secondary growth of its stem and wood formation, and rapidly increase its growth speed. Screening the best internal reference genes for qPCR experiment of P. massoniana stem under hormone treatment can provide technical support for gene expression research of secondary growth of P. massoniana. In this study, 14 candidate internal reference genes were selected from the stem transcriptome database of P. massoniana and gene expression was analyzed by qPCR. The expression stability under different hormone treatment - auxin (IAA), gibberellin (GA₃), and brassinolide (BR) was analyzed by 3 softwares: GeNorm, NormFinder and BestKeeper. The selected internal reference genes were verified by the target gene cellulose synthase 2 (CESA2). The results showed that, under different hormone treatments, the internal reference genes with the best expression stability were phosphoate cytidine transferase 1 (PCYT1), ubiquitin-conjugating enzyme E2D(UBE2D), and phosphoglucomutase (PGM). The expression pattern of target gene CESA2 under hormone treatment confirmed the reliability of the above internal reference gene combination. The internal reference genes screened in this study would be helpful to improve the accuracy and reliability of qPCR experiment in P. massoniana, which provides a solid foundation for the analysis of differential gene expression of P. massoniana under hormone treatment.

Porcine deltacoronavirus (PDCoV) is a new swine (Sus scrofa) enteropathogenic coronavirus, which can cause severe dehydration, vomiting and watery diarrhea in piglets, with worldwide distribution. In order to develop an indirect ELISA method for rapid detection of PDCoV antibody, based on the bioinformatics analysis of PDCoV M gene sequence, the M gene located at 76~651 bp was amplified and inserted into the expression vector pET-32a to construct the recombinant plasmid pET-32a-M. The pET-32a-M was transformed into Escherichia coil Transetta (DE3) and the recombinant M protein was expressed, and a target truncated protein with a size of 35 kD was obtained. Western blot test showed that M protein had good reactivity with porcine PDCoV positive serum. An indirect ELISA method was constructed based on purified recombinant M truncated protein, and the critical value was determined to be 0.271, and had no cross reaction with Classical swine fever virus (CSFV), Porcine reproductive and respiratory syndrome virus (PRRSV), Porcine circovirus type 2 (PCV-2), Pseudorabies virus (PRV), Foot-and-mouth disease virus (FMDV), Porcine epidemic diarrhea virus (PEDV), Swine transmissible gastroenteritis virus (TGEV). The coefficient of variation of intra- and inter-batch repeatability tests were less than 10%, and the total coincidence rate with the indirect ELISA based on PDCoV recombinant S1-CTD protein as coating antigen was 96%. The above results showed that the established indirect ELISA method had good specificity, sensitivity, and repeatability. The positive rate of PDCoV antibody was 49.11% in 507 pig serum samples collected in some areas of Sichuan province from 2012 to 2018, which preliminarily proved that the disease had been seriously infected in Sichuan. This study established an indirect ELISA method based on recombinant M truncated protein, which could provide technical support for PDCoV epidemic diagnosis and serum epidemiological investigation, and is of certain significance for PDCoV prevention and control.