摘要: Musk is a scarce and precious medical resource secreted by male forest musk deer (FMD). Current research to promote musk secretion in FMD has used almost exclusively hormone injections, but this approach can be detrimental to the health of FMD. In order to conserve this endangered species as much as possible while increasing the production of musk, this study first used bioinformatics methods to predict the function of quercetin, a flavonoid that promotes testosterone (T) production and prevents late-onset male hypogonadism. On the basis of good prediction effect, different concentrations of quercetin were added to the diet of FMD. The results showed that quercetin could change the levels of T, luteinizing hormone releasing hormone, luteinizing hormone, and estradiol, and regulate the structure of intestinal microorganisms and musk microorganisms of FMD. Moreover, there is a correlation among musk components, hormones, intestinal microorganisms, and musk microorganisms, which indicates that the production of musk may be regulated by these three at the same time, and the addition of quercetin with 800 mg per kg diet could significantly increase the yield of muscone (P < 0.05), the most effective ingredient in musk. In addition, quercetin decreased the high level of cortisol during musk secretion, which may relieve the stress on FMD in this process. This may help to protect the health of FMD. Combined with the results of software prediction, we finally proposed a possible mechanism for the complex process of musk secretion in FMD with a view to providing ideas for further studies.

摘要: Stathmin 1 ( stmn1 ) gene, which is involved in the control of cell cycle progression, cell proliferation, differentiation and motility, is a crucial relay in the signal transduction of multiple signaling pathways. Reports on the function of stmn1 in fish are scarce. In this study, the characterization and function of stmn1a gene were explored in an important food fish, namely bighead carp ( Hypophthalmichthys nobilis ). The bighead carp stmn1a ( Hynstmn1a ) genomic sequence, which has 2995 bp with an ORF of 447 bp, is evolutionarily conserved in teleost fish. The highest level of expression of Hynstmn1a is in the un-fertilized eggs and spleen of adult bighead carp. The overexpression of Hynstmn1a facilitates cell cycle progression and suppresses apoptosis in EPC cells. In an siRNA assay, disruption of stmn1a in EPC cells resulted in the inhibition of cell cycle progression and promotion of apoptosis. Analysis of promoter activity indicated that an upstream transcription factor (foxo4) regulates Hynstmn1a . Zebrafish mutants with stmn1a knockout by CRISPR/Cas9 exhibited a significant retardation of body length ( p < 0.05). There was no significant difference in body weight between stmn1a -mutant zebrafish and wildtype ( p 1 / 4 0.053). A 22-bp Indel in the promoter region of Hynstmn1a with an observed heterozygosity (Ho) of 0.136 in a bighead carp population ( n 1 / 4 191). The polymorphism of this 22-bp Indel genotype is significantly associated with body length (BL), head length (HL) ( p < 0.05), body weight (BW), head height (HH), and head width (HW) ( p < 0.01), showing its genetic effects on growth promotion. This study sheds light on the function of stmn1a in fish and demonstrates the potential of the 22-bp Indel of Hynstmn1a as a gene marker when selecting breeding individuals for faster growth and a bigger head of bighead carp in aquaculture.

摘要: Suppressors of cytokine signaling (SOCS) proteins are important regulators of the Janus kinase-signal transducer and activator of transcription (JAK-STAT) pathway. Within the SOCS family, SOCS3 is one of the most potent inhibitors of cytokine signaling. However, there is limited knowledge regarding the function of SOCS3 on regulating type I interferon (IFN) signaling in fish. In this study, the complete open reading frame (ORF) of SOCS3 from the large yellow croaker (Larimichthys crocea, LcSOCS3) was cloned and characterized. The ORF of LcSOCS3 was 618 nucleotides in length and encoded a protein containing 205 amino acids. LcSOCS3 had the typical domain architecture of the SOCS family, including an SRC homology 2 (SH2) domain, a SOCS box, an additional kinase inhibition region (KIR), and an extended SH2 subdomain (ESS). Phylogenetic analysis revealed that LcSOCS3 was clustered with other fish SOCS3s and most closely related to the SOCS3 of Collichthy lucidus. LcSOCS3 mRNA was detected in all organs or tissues examined, and its expression was significantly increased in both head kidney and spleen tissues, and primary head kidney leukocytes after poly(I:C) stimulation. Overexpression of LcSOCS3 significantly promoted Spring viremia of carp virus (SVCV) replication, resulting in a more severe cytopathic effect, increased viral titer, enhanced copy number of the SVCV-G gene, and decreased expression levels of IFN1, IRF7, ISG15, Viperin, PKR, and Mx in epithelioma papulosum cyprinid (EPC) cells. Silencing of LcSOCS3 correspondingly up-regulated the expression of IFNi, IFNh, PKR, Viperin, and Mx in large yellow croaker head kidney (LYCK) cells. Additionally, LcSOCS3 was shown to interact with Signal Transducer and Activator of Transcription 1 (STAT1) which may inhibit STAT1 translocating into the nucleus. This speculation was supported by the increased phosphorylation level of STAT1 in head kidney leukocytes after LcSOCS3 silencing. These results indicated that LcSOCS3 functioned as a potential negative regulator of type I IFN signaling in large yellow croaker through its interaction with STAT1.