Project description:Here, we report on a novel chicken comb phenotype, designated Antler-comb. Using a 600K Axiom® Genome-Wide Chicken Genotyping Array, we separately genotyped 12 and 24 female Hetian Wildtype-comb and Antler-comb chickens, respectively. Meanwhile, we sequenced the genomes of 10 Hetian Antler-comb and 10 Wildtype-comb chickens to interrogate the GWAS results and explore the potential genetic variants underlying this phenotype. After conducting a genome-wide association study (GWAS), a 36.5-kb candidate genomic region (chromosome 19:757,754-794,200) related to the Antler-comb phenotype was identified, which wholly and partially encompassed heat shock factor 5 (HSF5) and ring finger protein 43 (RNF43), respectively. HSF5 was ectopically expressed and RNF43 was up-regulated in Antler-comb chickens at embryo ages 7 and 9 (E7 and E9). We further genotyped the most significant single-nucleotide polymorphism (SNP) site, Chr19:794200, across 222 chickens of 16 breeds. We found that the major allele G in Antler-comb chickens remained highly significant across different breeds, and each Antler-comb chicken harbored an allele G. Whole-genome re-sequencing (WGS) involving 10 Hetian Antler-comb and 10 Wildtype-comb chickens reaffirmed the 36.5-kb candidate genomic region, and revealed a genomic duplication, which was 15.7 kb in length and pertained to the 5’-untranslated region and 5’-flanking region of HSF5 (Chr19:784,335-800,034), suggesting its possible role in inducing ectopic expression of HSF5 and altering expression of RNF43 during comb development (E7 and E9). The present study furthers our understanding of this novel chicken comb phenotype, and likely gives another example regarding interactions between genetic variation and phenotype.
Project description:As the only regenerative organ of mammals, antler could grow rapidly without carcinogenesis. To understand the molecular mechanisms of the growth of sika deer antler, we used de novo RNA-seq analyses to determine the differential expression of unigenes and miRNAs from antler at 15, 60, 90, and 110-day. A total of 55004 unigenes, 208 known miRNAs and 38 novel miRNAs were identified. 10182 unigenes and 35 miRNAs were differentially expressed between 60-day and 15-day antler, 13258 unigenes and 53 miRNAs were differentially expressed between 90-day and 60-day antler, and 10740 unigenes and 27 miRNAs were differentially expressed between 110-day and 90-day antler. GO and KEGG analyses showed that DE unigenes and miRNA were mainly related to chondrogenesis, osteogenesis and inhibition of oncogenesis, that were closely associate with antler growth. We also constructed mRNA-mRNA and miRNA-mRNA interaction networks related to chondrogenesis, osteogenesis and inhibition of oncogenesis of antler. The results showed that mRNA (COL2A1, SOX9, WWP2, FGFR1, SPARC, LOX etc.) and miRNAs (miR-145, miR-199a-3p, miR-140, miR-199a-5p etc.) may play important roles in chondrogenesis and osteogenesis of antler, and mRNA (TP53, Tpm3 and ATP1A1 etc.) and miRNAs (miR-106a, miR-145, miR-1260b and miR-2898 etc.) may have key roles in inhibiting the carcinogenesis of antlers. In this study, we identified miRNAs and unigenes related to chondrogenesis, osteogenesis and inhibition of oncogenesis of antler. This will provide a reference for in-depth analysis of the molecular mechanism of antler growth without carcinogenesis, and also provide valuable information for cartilage- and bone-related disease treatment, cancer treatment.