miR-23b-3p regulates the differentiation of goat intramuscular preadipocytes by targeting the PDE4B gene / 生物工程学报

This study aimed to explore the effect of miR-23b-3p on the differentiation of goat intramuscular preadipocytes, and to confirm whether miR-23b-3p plays its roles via targeting the PDE4B gene. Based on the pre-transcriptome sequencing data obtained previously, the miR-23b-3p, which was differentially expressed in goat intramuscular adipocytes before and after differentiation, was used as an entry point. real-time quantitative-polymerase chain reaction (qPCR) was used to detect the expression pattern of miR-23b-3p during the differentiation of goat intramuscular preadipocytes. The effects of miR-23b-3p on adipose differentiation and adipose differentiation marker genes were determined at the morphological and molecular levels. The downstream target genes of miR-23b-3p were determined using bioinformatics prediction as well as dual luciferase reporter assay to clarify the targeting relationship between miR-23b-3p and the predicted target genes. The results indicated that overexpression of miR-23b-3p reduced lipid droplet accumulation in goat intramuscular adipocytes, significantly down-regulated the expression levels of adipogenic marker genes AP2, C/EBPα, FASN, and LPL (P < 0.01). In addition, the expressions of C/EBPβ, DGAT2, GLUT4 and PPARγ were significantly downregulated (P < 0.05). After interfering with the expression of miR-23b-3p, lipid droplet accumulation was increased in goat intramuscular adipocytes. The expression levels of ACC, ATGL, AP2, DGAT2, GLUT4, FASN and SREBP1 were extremely significantly up-regulated (P < 0.01), and the expression levels of C/EBPβ, LPL and PPARγ were significantly up-regulated (P < 0.05). It was predicted that PDE4B might be a target gene of miR-23b-3p. The mRNA expression level of PDE4B was significantly decreased after overexpression of miR-23b-3p (P < 0.01), and the interference with miR-23b-3p significantly increased the mRNA level of PDE4B (P < 0.05). The dual luciferase reporter assay indicated that miR-23b-3p had a targeting relationship with PDE4B gene. MiR-23b-3p regulates the differentiation of goat intramuscular preadipocytes by targeting the PDE4B gene.

Gene cloning and sequence analysis of the RPL29 gene and its effect on lipogenesis in goat intramuscular adipocytes / 生物工程学报

The aim of this study was to clone the goat RPL29 gene and analyze its effect on lipogenesis in intramuscular adipocytes. Using Jianzhou big-eared goats as the object, the goat RPL29 gene was cloned by reverse transcription-polymerase chain reaction (RT-PCR), the gene structure and expressed protein sequence were analyzed by bioinformatics, and the mRNA expression levels of RPL29 in various tissues and different differentiation stages of intramuscular adipocytes of goats were detected by quantitative real-time PCR (qRT-PCR). The RPL29 overexpression vector pEGFP-N1-RPL29 constructed by gene recombination was used to transfect into goat intramuscular preadipocytes and induce differentiation. Subsequently, the effect of overexpression of RPL29 on fat droplet accumulation was revealed morphologically by oil red O and Bodipy staining, and changes in the expression levels of genes related to lipid metabolism were detected by qRT-PCR. The results showed that the length of the goat RPL29 was 507 bp, including a coding sequence (CDS) region of 471 bp which encodes 156 amino acid residues. It is a positively charged and stable hydrophilic protein mainly distributed in the nucleus of cells. Tissue expression profiling showed that the expression level of this gene was much higher in subcutaneous adipose tissue and inter-abdominal adipose tissue of goats than in other tissues (P < 0.05). The temporal expression profile showed that the gene was expressed at the highest level at 84 h of differentiation in goat intramuscular adipocytes, which was highly significantly higher than that in the undifferentiated period (P < 0.01). Overexpression of RPL29 promoted lipid accumulation in intramuscular adipocytes, and the optical density values of oil red O staining were significantly increased (P < 0.05). In addition, overexpression of RPL29 was followed by a highly significant increase in ATGL and ACC gene expression (P < 0.01) and a significant increase in FASN gene expression (P < 0.05). In conclusion, the goat RPL29 may promote intra-muscular adipocyte deposition in goats by up-regulating FASN, ACC and ATGL.

Cloning and expression profile of ZFP36L1 gene in goat / 生物工程学报

The purpose of this study was to clone and characterize the ZFP36L1 (zinc finger protein 36-like 1) gene, clarify its expression characteristics, and elucidate its expression patterns in different tissues of goats. Samples of 15 tissues from Jianzhou big-eared goats, including heart, liver, spleen, lung and kidney were collected. Goat ZFP36L1 gene was amplified by reverse transcription-polymerase chain reaction (RT-PCR), then the gene and protein sequence were analyzed by online tools. Quantitative real-time polymerase chain reaction (qPCR) was used to detect the expression level of ZFP36L1 in intramuscular preadipocytes in different tissues and adipocytes of goat at different differentiation stages. The results showed that the length of ZFR36L1 gene was 1 224 bp, and the coding sequence (CDS) region was 1 017 bp, encoding 338 amino acids, which was a non-secretory unstable protein mainly located in nucleus and cytoplasm. Tissue expression profile showed that ZFP36L1 gene was expressed in all selected tissues. In visceral tissues, the small intestine showed the highest expression level (P < 0.01). In muscle tissue, the highest expression level was presented in longissimus dorsi muscle (P < 0.01), whereas the expression level in subcutaneous adipose tissue was significantly higher than that in other tissues (P < 0.01). The results of induced differentiation showed that the expression of this gene was up-regulated during adipogenic differentiation of intramuscular precursor adipocytes (P < 0.01). These data may help to clarify the biological function of the ZFP36L1 gene in goat.

Cloning, identification and functional analysis of the goat transcription factor c-fos / 生物工程学报

C-fos is a transcription factor that plays an important role in cell proliferation, differentiation and tumor formation. The aim of this study was to clone the goat c-fos gene, clarify its biological characteristics, and further reveal its regulatory role in the differentiation of goat subcutaneous adipocytes. We cloned the c-fos gene from subcutaneous adipose tissue of Jianzhou big-eared goats by reverse transcription-polymerase chain reaction (RT-PCR) and analyzed its biological characteristics. Using real-time quantitative PCR (qPCR), we detected the expression of c-fos gene in the heart, liver, spleen, lung, kidney, subcutaneous fat, longissimus dorsi and subcutaneous adipocytes of goat upon induced differentiation for 0 h to 120 h. The goat overexpression vector pEGFP-c-fos was constructed and transfected into the subcutaneous preadipocytes for induced differentiation. The morphological changes of lipid droplet accumulation were observed by oil red O staining and bodipy staining. Furthermore, qPCR was used to test the relative mRNA level of the c-fos overexpression on adipogenic differentiation marker genes. The results showed that the cloned goat c-fos gene was 1 477 bp in length, in which the coding sequence was 1 143 bp, encoding a protein of 380 amino acids. Protein structure analysis showed that goat FOS protein has a basic leucine zipper structure, and subcellular localization prediction suggested that it was mainly distributed in the nucleus. The relative expression level of c-fos was higher in the subcutaneous adipose tissue of goats (P < 0.05), and the expression level of c-fos was significantly increased upon induced differentiation of subcutaneous preadipocyte for 48 h (P < 0.01). Overexpression of c-fos significantly inhibited the lipid droplets formation in goat subcutaneous adipocytes, significantly decreased the relative expression levels of the AP2 and C/EBPβ lipogenic marker genes (P < 0.01). Moreover, AP2 and C/EBPβ promoter are predicted to have multiple binding sites. In conclusion, the results indicated that c-fos gene was a negative regulatory factor of subcutaneous adipocyte differentiation in goats, and it might regulate the expression of AP2 and C/EBPβ gene expression.