Functional Intronic Variant in the Retinoblastoma 1 Gene Underlies Broiler Chicken Adiposity by Altering Nuclear Factor-kB and SRY-Related HMG Box Protein 2 Binding Sites

Genetic background of walking ability and its relationship with leg defects, mortality, and performance traits in turkeys (Meleagris gallopavo)

This study aimed to explore the genetic basis of walking ability and potentially related performance traits in turkey purebred populations. Phenotypic, pedigree, and genomic datasets from 2 turkey lines hatched between 2010 and 2023 were included in the study. Walking ability data, defined based on a scoring system ranging from 1 (worst) to 6 (best), were collected on 192,019 animals of a female line and 235,461 animals of a male line. Genomic information was obtained for 46,427 turkeys (22,302 from a female line and 24,125 from a male line) using a 65K single nucleotide polymorphism (SNP) panel. Variance components and heritability for walking ability were estimated. Furthermore, genetic and phenotypic correlations among walking ability, mortality and disorders, and performance traits were calculated. A genome-wide association study (GWAS) was also conducted to identify SNPs associated with walking ability. Walking ability is moderately heritable (0.23 ± 0.01) in both turkey lines. The genetic correlations between walking ability and the other evaluated traits ranged from -0.02 to -0.78, with leg defects exhibiting the strongest negative correlation with walking ability. In the female line, 31 SNPs were associated with walking ability and overlapped with 116 genes. These positional genes are linked to 6 gene ontology (GO) terms. Notably, genes such as CSRP2, DDX1, RHBDL1, SEZ6L, and CTSK are involved in growth, development, locomotion, and bone disorders. GO terms, including fibronectin binding (GO:0001968), peptide cross-linking (GO:0018149), and catabolic process (GO:0009057), are directly linked with mobility. In the male line, 66 markers associated with walking ability were identified and overlapped with 281 genes. These genes are linked to 12 GO terms. Genes such as RB1CC1, TNNI1, MSTN, FN1, SIK3, PADI2, ERBB4, B3GNT2, and BACE1 are associated with cell growth, myostatin development, and disorders. GO terms in the male line are predominantly related to lipid metabolism. In conclusion, walking ability is moderately heritable in both populations. Furthermore, walking ability can be enhanced through targeted genetic selection, emphasizing its relevance to both animal welfare and productivity.

Effects of dietary Clostridium butyricum and rumen protected fat on meat quality, oxidative stability, and chemical composition of finishing goats

BACKGROUND

Clostridium butyricum (CB) is a probiotic that can regulate intestinal microbial composition and improve meat quality. Rumen protected fat (RPF) has been shown to increase the dietary energy density and provide essential fatty acids. However, it is still unknown whether dietary supplementation with CB and RPF exerts beneficial effects on growth performance and nutritional value of goat meat. This study aimed to investigate the effects of dietary CB and RPF supplementation on growth performance, meat quality, oxidative stability, and meat nutritional value of finishing goats. Thirty-two goats (initial body weight, 20.5 ± 0.82 kg) were used in a completely randomized block design with a 2 RPF supplementation (0 vs. 30 g/d) × 2 CB supplementation (0 vs. 1.0 g/d) factorial treatment arrangement. The experiment included a 14-d adaptation and 70-d data and sample collection period. The goats were fed a diet consisted of 400 g/kg peanut seedling and 600 g/kg corn-based concentrate (dry matter basis).

RESULT

Interaction between CB and RPF was rarely observed on the variables measured, except that shear force was reduced (P < 0.05) by adding CB or RPF alone or their combination; the increased intramuscular fat (IMF) content with adding RPF was more pronounced (P < 0.05) with CB than without CB addition. The pH24h (P = 0.009), a* values (P = 0.007), total antioxidant capacity (P = 0.050), glutathione peroxidase activities (P = 0.006), concentrations of 18:3 (P < 0.001), 20:5 (P = 0.003) and total polyunsaturated fatty acids (P = 0.048) were increased, whereas the L* values (P < 0.001), shear force (P = 0.050) and malondialdehyde content (P = 0.044) were decreased by adding CB. Furthermore, CB supplementation increased essential amino acid (P = 0.027), flavor amino acid (P = 0.010) and total amino acid contents (P = 0.024) as well as upregulated the expression of lipoprotein lipase (P = 0.034) and peroxisome proliferator-activated receptor γ (PPARγ) (P = 0.012), and downregulated the expression of stearoyl-CoA desaturase (SCD) (P = 0.034). The RPF supplementation increased dry matter intake (P = 0.005), averaged daily gain (trend, P = 0.058), hot carcass weight (P = 0.046), backfat thickness (P = 0.006), concentrations of 16:0 (P < 0.001) and c9-18:1 (P = 0.002), and decreased the shear force (P < 0.001), isoleucine (P = 0.049) and lysine content (P = 0.003) of meat. In addition, the expressions of acetyl-CoA carboxylase (P = 0.003), fatty acid synthase (P = 0.038), SCD (P < 0.001) and PPARγ (P = 0.022) were upregulated due to RPF supplementation, resulting in higher (P < 0.001) content of IMF.

CONCLUSIONS

CB and RPF could be fed to goats for improving the growth performance, carcass traits and meat quality, and promote fat deposition by upregulating the expression of lipogenic genes of Longissimus thoracis muscle.

A Functional Variant Alters the Binding of Bone morphogenetic protein 2 to the Transcription Factor NF-κB to Regulate Bone morphogenetic protein 2 Gene Expression and Chicken Abdominal Fat Deposition

In this study, we employed a dual-luciferase reporter assay and electrophoretic mobility shift analysis (EMSA) in vitro to explore whether a 12-base pair (bp) insertion/deletion (InDel) variant (namely g.14798187_14798188insTCCCTGCCCCCT) within intron 2 of the chicken BMP2 gene, which was significantly associated with chicken abdominal fat weight and abdominal fat percentage, is a functional marker and its potential regulatory mechanism. The reporter analysis demonstrated that the luciferase activity of the deletion allele was extremely significantly higher than that of the insertion allele (p < 0.01). A bioinformatics analysis revealed that compared to the deletion allele, the insertion allele created a transcription factor binding site of nuclear factor-kappa B (NF-κB), which exhibited an inhibitory effect on fat deposition. A dual-luciferase reporter assay demonstrated that the inhibitory effect of NF-κB on the deletion allele was stronger than that on the insertion allele. EMSA indicated that the binding affinity of NF-κB for the insertion allele was stronger than that for the deletion allele. In conclusion, the 12-bp InDel chicken BMP2 gene variant is a functional variant affecting fat deposition in chickens, which may partially regulate BMP2 gene expression by affecting the binding of transcription factor NF-κB to the BMP2 gene.

Identification of mutations in porcine STAT5A that contributes to the transcription of CISH

Identification of causative genes or genetic variants associated with phenotype traits benefits the genetic improvement of animals. CISH plays a role in immunity and growth, however, the upstream transcriptional factors of porcine CISH and the genetic variations in these factors remain unclear. In this study, we firstly identified the minimal core promoter of porcine CISH and confirmed the existence of STATx binding sites. Overexpression and RT-qPCR demonstrated STAT5A increased CISH transcriptional activity (P < 0.01) and mRNA expression (P < 0.01), while GATA1 inhibited CISH transcriptional activity (P < 0.01) and the following mRNA expression (P < 0.05 or P < 0.01). Then, the putative functional genetic variations of porcine STAT5A were screened and a PCR-SSCP was established for genotype g.508A>C and g.566C>T. Population genetic analysis showed the A allele frequency of g.508A>C and C allele frequency of g.566C>T was 0.61 and 0.94 in Min pigs, respectively, while these two alleles were fixed in the Landrace population. Statistical analysis showed that Min piglets with CC genotype at g.566C>T or Hap1: AC had higher 28-day body weight, 35-day body weight, and ADG than TC or Hap3: CT animals (P < 0.05, P < 0.05). Further luciferase activity assay demonstrated that the activity of g.508A>C in the C allele was lower than the A allele (P < 0.05). Collectively, the present study demonstrated that STAT5A positively regulated porcine CISH transcription, and SNP g.566C>T in the STAT5A was associated with the Min piglet growth trait.

IL1R2 polymorphisms and their interaction are associated with osteoporosis susceptibility in the Chinese Han population

AIMS

Interleukin 1 (IL-1) inhibitory receptor type 2 (IL1R2) serves as a negative regulator of IL-1 signalling and is involved in the pathogenesis of osteoporosis. This study aimed to determine the correlation between IL1R2 polymorphism and osteoporosis susceptibility in the Chinese Han population.

METHODS

We recruited 594 osteoporosis patients and 599 healthy controls. Six single nucleotide polymorphisms (SNPs) in IL1R2 were selected for genotyping using the Agena MassARRAY platform. The odds ratios (ORs) and 95% confidence intervals (CIs) were calculated using logistic regression analysis with adjustment for age and sex. Linkage disequilibrium analysis was plotted using Haploview v4.2. Multifactor dimension reduction (MDR) was performed to estimate the SNP-SNP interactions of IL1R2 variants.

RESULTS

Rs11674595 (OR = 1.86, p = 0.020), rs2072472 (OR = 1.26, p = 0.019) and rs4851527 (OR = 0.78, p = 0.007) were related to the risk of osteoporosis. Moreover, the contribution of IL1R2 polymorphisms to osteoporosis risk was associated with age, sex and body mass index. We found the relationships of T_rs11674595 A_rs4851527 (OR = 0.80, p = 0.015), C_rs11674595 G_rs4851527 (OR = 1.22, p = 0.043) and A_rs3218977 G_rs2072472 (OR = 1.25, p = 0.022) haplotypes to osteoporosis occurrence, and a potential accumulated effect of IL1R2 SNPs (testing accuracy = 0.5783 and cross validation consistency = 10/10) on osteoporosis susceptibility.

CONCLUSION

IL1R2 polymorphisms (rs11674595, rs4851527, rs2072472 and rs3218977) may contribute to osteoporosis risk in the Chinese Han population. Our findings may increase our understanding of the effects of IL1R2 polymorphisms on the predisposition to osteoporosis.

Chicken C/EBPζ gene: Expression profiles, association analysis, and identification of functional variants for abdominal fat

CCAAT enhancer binding protein ζ (C/EBPζ) plays an important role in adipose proliferation and differentiation in humans. However, very little is known about the effect of C/EBPζ on the growth and development of adipose tissues in domesticated animals. The present study attempted to investigate the mRNA expression profiles of chicken C/EBPζ in a variety of tissues; analyze the association of its variants with abdominal fat; and identify the functional variants for abdominal fat. The tissue expression profiles revealed that C/EBPζ was highly expressed in 19 tissues obtained from broilers. The expression level of C/EBPζ in fat broilers was significantly lower than that in lean broilers in the duodenum, ileum, cecum, kidney, pectoral muscle, and liver (P < 0.05). Among 170 polymorphic loci of C/EBPζ, 9 single nucleotide polymorphisms (SNPs) demonstrated a significant association with chicken abdominal fat traits (P < 0.05) as well as significant discrepancies in their allelic frequencies between fat and lean birds. Particularly, only C/EBPζ g.7085A>C exhibited significant correlation with abdominal fat traits (P < 0.00015) using the Bonferroni method. The results revealed that, in preadipocyte immortalized cells (ICPI), the luciferase activity of the A allele of g.7085A>C locus was remarkably stronger than that of the C allele (P < 0.05). In silico analysis showed that g.7085A>C locus was located in the binding region of the transcription factor SOX5, which possesses the ability to transform C/EBPζ transcription efficiency through binding with SOX5. In summary, the data obtained from this study suggested that C/EBPζ is a potential candidate gene responsible for abdominal fat deposition in chicken and that g.7085A>C is a functional SNP that can be promisingly leveraged for marker assisted selection (MAS) in future chicken breeding programs.