Adipose tissue accumulation represents a significant challenge to both human metabolic health and agricultural productivity. While Ras and Rab Interactor 2 (RIN2) has been characterized as a Rab5 effector protein, its precise role in adipogenesis remains poorly defined. Here, we identified RIN2 as a novel critical regulator of adipogenesis in chicken. We found that RIN2 was widely expressed across various tissues and dynamic expression patterns during adipocyte differentiation. Through comprehensive functional analyses in both ICP-1 cells and primary preadipocytes, we identified that RIN2 overexpression enhances cellular proliferation, cell cycle progression, and adipogenic differentiation, whereas RIN2 knockdown produced contrasting inhibitory effects. Transcriptomic profiling uncovered that RIN2 functions through modulation of the cholesterol metabolic pathway and promotes fatty acid metabolism. Most notably, in vivo knockdown of RIN2 specifically reduced abdominal fat deposition without compromising other carcass characteristics. In summary, our findings identify RIN2 as a key regulator of fat accumulation and highlight its potential as a genetic target for improving poultry carcass composition.

Lutein is an antioxidant that can indicate the oxidative status of organisms through its coloration and may be involved in the development process of chicken skeletal muscle. In this study, after feeding Nanhai Yellow Chickens with lutein-containing feed for 21 d, the lutein group significantly increased the muscle fiber diameter and decreased the fiber density in the chicken's leg muscles compared to the control group. To elucidate the potential regulatory mechanisms by which lutein is involved in muscle development, RNA-seq was used to detect changes in gene expression in chicken leg muscle tissue. After data analysis, a total of 249 significantly differentially expressed genes (DEG) were identified, including TGF-β superfamily (MSTN and TGFB1) and nonreceptor tyrosine kinase c-Src (SRC). Results from GO and KEGG analysis showed that the DEGs were enriched in GO terms such as positive regulation of the ERK1/ERK2 cascade and negative regulation of myoblast differentiation, as well as signaling pathways including the Toll-like receptor signaling pathway and the MAPK signaling pathway. These significantly enriched GO terms and pathways are closely related to muscle development, suggesting that lutein may play an important role in the process of chicken muscle development. This study provides insights into the regulatory mechanisms of dietary lutein on chicken muscle development.

Molecular breeding accelerates animal breeding and improves efficiency by utilizing genetic mutations. Structural variations (SVs), a significant source of genetic mutations, have a greater impact on phenotypic variation than SNPs. Understanding SV functional mechanisms and obtaining precise information are crucial for molecular breeding. In this study, association analysis revealed significant correlations between 198-bp SVs in the GSTA2 promoter region and abdominal fat weight, intramuscular fat content, and subcutaneous fat thickness in chickens. High expression of GSTA2 in adipose tissue was positively correlated with the abdominal fat percentage, and different genotypes of GSTA2 exhibited varied expression patterns in the liver. The 198-bp SVs regulate GSTA2 expression by binding to different transcription factors. Overexpression of GSTA2 promoted preadipocyte proliferation and differentiation, while interference had the opposite effect. Mechanistically, the 198-bp fragment contains binding sites for transcription factors such as C/EBPα that regulate GSTA2 expression and fat synthesis. These SVs are significantly associated with chicken fat traits, positively influencing preadipocyte development by regulating cell proliferation and differentiation. Our work provides compelling evidence for the use of 198-bp SVs in the GSTA2 promoter region as molecular markers for poultry breeding and offers new insights into the pivotal role of the GSTA2 gene in fat generation.

Natural antisense transcripts (NATs) are endogenous RNAs opposite to sense transcripts, and they can significantly contribute to regulating various biological processes through multiple epigenetic mecha-nisms. NATs can affect their sense transcripts to regulate the growth and development of skeletal muscle. Our analysis of third-generation full-length transcriptome sequencing data revealed that NATs repre-sented a significant portion of the lncRNA, accounting for up to 30.19%-33.35%. The expression of NATs correlated with myoblast differentiation, and genes expressing NATs were mainly involved in RNA synthesis, protein transport, and cell cycle. We found a NAT of MYOG (MYOG-NAT) in the data. We found that the MYOG-NAT could promote the differentiation of myoblasts in vitro. Additionally, knockdown of MYOG-NAT in vivo led to muscle fiber atrophy and muscle regeneration retardation. Molecular biology experiments demonstrated that MYOG-NAT enhances the stability of MYOG mRNA by competing with miR-128-2-5p, miR-19a-5p, and miR-19b-5p for binding to MYOG mRNA 3'UTR. These findings suggest that MYOG-NAT plays a critical role in skeletal muscle development and provides insights into the post-transcriptional regulation of NATs.(c) 2023 Elsevier Inc. All rights reserved.

The yellow color of the skin is an important economic trait for yellow chickens. Low and non-uniform skin yellowness would reduce economic efficiency. However, the regulatory mechanism of chicken skin yellowness has not been fully elucidated. In this study, we evaluated the skin yellowness of 819 chickens by colorimeter and digital camera, which are from the same batch and the same age of 2 pure lines with significant differences in skin yellowness. A total of 982 candidate differential expressed genes (DEGs) were detected in duodenal tissue by RNA-seq analysis for high and low yellowness chickens. Among the DEGs, we chose fatty acid translocase (CD36) gene and identified a single nucleotide polymorphism (SNP) upstream of the CD36 gene that was significantly associated with skin yellowness at multiple parts of the chicken, and its different genotypes had significant effects on the promoter activity of the CD36 gene. These findings will help to further elucidate the molecular mechanism of chicken skin yellowness and is helpful for improving chicken skin yellowness.

Molecular breeding can accelerate the process of animal breeding and improve the breeding efficiency. To date, many Indel molecular markers have been identified in livestock and poultry, but how Indels affect economic traits is not well understood. For molecular breeding, it is crucial to reveal the mechanism of action of Indels and to provide more accurate information. The purpose of this study was to investigate how the 52/224-bp multiallelic Indels of the chicken QPCTL promoter area affect the daily weight gain of chickens and the potential regulatory mechanism of the QPCTL gene. The analysis was conducted by association analysis, qPCR, dual-fluorescence assay and Western blotting. The results showed that Indels in the QPCTL promoter region were significantly associated with the daily weight gain in chickens and that QPCTL expression showed a decreasing trend in embryonic breast muscle tissues. Furthermore, QPCTL expression was significantly higher in breast muscle tissues of the AC genotype than in those of the AB and BB genotypes. Based on the transcriptional activity results, the pGL3-C vector produced more luciferase activity than pGL3-A and pGL3-B. In addition, overexpression of QPCTL promoted chicken primary myoblast (CPM) proliferation and inhibited differentiation. The results of this study suggest that Indels in the promoter region of the QPCTL gene may regulate the proliferation and differentiation of CPMs by affecting the expression of QPCTL, which ultimately affects the growth rate of chickens. These Indels have important value for the molecular breeding of chickens, and QPCTL can be used as a candidate gene to regulate and improve chicken growth and development.

Lutein can increase the body's skin color and has antioxidant potential. However, how it affects lipid metabolism and oxidative stress in chickens remains unknown. In this study, 74-day-old male chickens raised on feed supplemented with lutein had higher hip, back, breast, leg, shin and abdominal fat yellowness than the control group, and the livers of chickens in the lutein group had higher superoxide dismutase and glutathione peroxidase and lower malondialdehyde activities. To clarify the potential regulatory network regulated by lutein, we used RNA-seq and nontargeted metabolomics to detect changes in the male chicken liver and plasma, respectively. A total of 243 differentially expressed genes were significantly enriched in cytokine-cytokine receptor interaction signaling pathways, among others. A total of 237 significantly different metabolites were enriched in lysine biosynthesis and degradation and glycerophospholipid metabolism signaling pathways, among others. Finally, we comprehensively analyzed metabolome and transcriptome data and found that many differentially expressed genes and significantly different metabolites play crucial roles in lipid metabolism and oxidative stress. In summary, dietary lutein can improve male chicken skin yellowness and antioxidant indices and affect liver gene expression and plasma metabolites and may help improve the health of chickens.

试验旨在分析GSTA2基因的SNPs和杏花鸡与隐性白洛克鸡F2群体的肉质、生长和屠体性状的相关性.试验采用Sanger测序从359个杏花鸡与隐性白洛克鸡F2群体的基因组序列中筛选到4个GSTA2基因的SNPs,均位于5'UTR区域.利用SPSS 22.0软件对4个SNPs与杏花鸡和隐性白洛克鸡F2群体的经济性状进行了关联分析.结果显示:4个SNPs与杏花鸡和隐性白洛克鸡F2群体的体重、胫长、肤色等性状显著相关.对4个SNPs进行单倍型分析发现SNP1、SNP3、SNP4组成的单倍型AGAGTT与鸡的翅重有显著相关性,SNP2、SNP4组成的单倍型GGTT与鸡的胫长有显著相关性.结果表明GSTA2基因的SNPs显著影响鸡的经济性状,可以作为鸡经济性状选育的候选分子标记.

The Ras and Rab interactor 2 ( RIN2 ) gene, which encodes RAS and Rab interacting protein 2, can interact with GTP-bound Rab5 and participate in early endocytosis. This study found a 61-bp insertion/deletion (indel) in the RIN2 intron region, and 3 genotypes II , ID , and DD were observed. Genotype analysis of mutation sites was performed on 665 individuals from F 2 population and 8 chicken breeds. It was found that the indel existed in each breed and that yellow feathered chickens were mainly of the DD genotype. Correlation analysis of growth and carcass traits in the F 2 population of Xinghua and White Recessive Rock chickens showed that the 61-bp indel was significantly correlated with abdominal fat weight, abdominal fat rate, fat width, and hatching weight ( P < 0.05). RIN2 mRNA was expressed in all the tested tissues, and its expression in abdominal fat was higher than that in other tissues. In addition, the expression of the RIN2 mRNA in the abdominal fat of the DD genotype was significantly higher than that of the II genotype ( P < 0.05). The transcriptional activity results showed that the luciferase activity of the pGL3-DD vector was significantly higher than that of the pGL3-II vector ( P < 0.01). Moreover, the results indicate that the polymorphisms in transcription factor binding sites (TFBSs) of 61-bp indel may affect the transcriptional activity of RIN2 , and thus alter fat traits in chicken. The results of this study showed that the 61-bp indel was closely related to abdominal fat-related and hatching weight traits of chickens, which may have reference value for molecular marker-assisted selection of chickens.

Background G-protein subunit beta 1 like (GNB1L) can encode a G-protein beta-subunit-like polypeptide, the chicken GNB1L gene is up-regulated in the breast muscle of high-feed efficiency chickens, and its expression is 1.52-fold that of low-feed efficiency chickens. However, there are no reports describing the effects of GNB1L gene Indel on the growth and carcass traits of chickens. Results This study identified a 31-bp Indel in 5' UTR of the GNB1L gene and elucidated the effect of this gene mutation on the growth and carcass traits in chickens. The results indicated that the 31-bp Indel was highly significant associations with body weight at 8 different stages, and also significantly correlated with daily gain of 0 to 4 weeks and 4 to 8 weeks. Similarly, the mutation was significantly associated with small intestine length, breast width, breast deep and breast muscle weight in carcass traits. Moreover, DD and ID are inferior genotypes for the growth and carcass traits of chickens. Conclusions In a word, these findings suggest that the 31-bp Indel of GNB1L gene is significantly affected body weight and carcass traits in chickens, and can serve as a potential molecular marker for chicken genetics and breeding programs.

Background : Ras and Rab interactor 2 ( RIN2 ) gene, encoding RAS and Rab interacting protein 2, can interact with GTP-bound Rab5 and participate in early endocytosis. Deletion of RIN2 may impair Rab5-related endosome signaling, leading to abnormal phenotypes. However, no research has been reported on the functions of RIN2 related to animal production. Results: A 61-bp insertion/deletion (indel) in the RIN2 intron region in this study. The genotype analysis of mutation sites was performed on 550 individuals from 7 different chicken breeds, and it was found that the indel exists in each breed and the local breed chickens are mainly DD genotypes. Correlation analysis of the indel with growth traits and carcass traits of the F 2 population of Xinghua and White Recessive Rock chicken showed that the RIN2 61-bp deletion mutation site was significantly correlated with abdominal fat weight, fat width and hatching weight traits ( P < 0.05). RIN2 mRNA was expressed in all test tissues, and the expression level of abdominal fat was higher than that in other tissues. In addition, it was further found that the expression level of type II RIN2 mRNA in abdominal fat was significantly different from that of ID type and DD type ( P < 0.05). Conclusion: The results showed that the mutation was closely related to the abdominal fat-related and hatching weight traits of chickens, which may have certain reference value for molecular marker-assisted selection of chickens.