Submitted to: PLoS One
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 6/1/2013
Publication Date: 11/6/2013
Citation: Yong-Zhen, H., Li, M., Wang, J., Womack, J.E., Sun, J., Li, C., Lan, X., Lei, C., Zhang, C., Chen, H. 2013. A 5'-regulatory region and two coding region polymorphisms modulate promoter activity and gene expression of the growth suppressor gene ZBED6 in cattle. PLoS One. 8(11):e79744.doi:10.1371/journal.pone.007974, 2013. Interpretive Summary: Muscle growth in animals is controlled by the release of hormones like insulin-like growth factor-2 (IGF-2). Activation of the IGF-2 gene in skeletal muscles is controlled, in part, by a transcription factor called ZBED6. This transcription factor is also important for normal development and growth of mammalian cells. In this study, variation in three different regions of the ZBED6 gene was identified among four Chinese cattle breeds, and the relationship between these variants and differences in body weight among cattle was examined. It was found that specific changes in the DNA sequence of the ZBED6 gene affect the activity of this transcription factor and are associated with superior body weight in two of the Chinese cattle breeds. Knowledge of these variations in the ZBED6 gene of cattle may provide useful genetic markers for breeding strategies to increase cattle production efficiency.
Technical Abstract: Zinc finger, BED-type containing 6 (ZBED6) is an important transcription factor in placental mammals, affecting development, cell proliferation, and growth. Polymorphisms in its promoter and coding regions are likely to impact ZBED6 transcription and growth traits. In this study, a total of three novel single nucleotide polymorphisms (SNPs) were identified. One promoter SNP and two missense mutations in the coding region of ZBED6, as well as eight haplotypes were revealed. The linkage disequilibrium and evolutionary relationship were assessed in 1,522 individuals representing four purebred cattle breeds from China. The three SNPs and 26 and 23 diplotypes were asssociated with body weight in the Nanyang and Jiaxian cattle populations at five different ages (P < 0.05 or P < 0.01). The mutant-type variants and haplotype (Hap 8: AGG; likely to be the beneficial quantitative trait nucleotide [QTN] allele) was superior for body weight; the heterozygote diplotype was associated with higher body weight compared to the wild-type homozygote. The promoter and coding regions are the key regions for gene function; polymorphisms in these regions can alter gene expression. Quantitative real-time PCR (qPCR) analysis showed that ZBED6 has a broad tissue distribution in cattle and is highly expressed in skeletal muscle. The core region of the basal promoter of bovine ZBED6 is located within the region -866 to -556. The activity of WT-826G-pGL3 in driving reporter gene transcription is significantly higher than the M-826A-pGL3 construct (P < 0.01). It was also found that mutant-type Hap-AGG exhibited a lower mRNA level than the wild-type Hap-GCA (P < 0.05) in longissimus dorsi muscle. Moreover, ZBED6 mRNA expression was low in mutant-type ZBED6-overexpression (pcDNA3.1+ -Hap-GG) C2C12 cells (P < 0.01). Our results suggest that the polymorphisms in the promoter and coding regions may modulate the promoter activity and gene expression of bovine ZBED6 in the skeletal muscles of these cattle breeds.