Project description:Background: Earlobe color is a typical external trait in chicken. There are some previous studies showing that the chicken white/red earlobe color is a polygenic and sex-linked trait in some breeds, but its molecular genetic and histological mechanisms still remain unclear. Methods: We herein utilized histological section, genome-wide association study (GWAS) and RNA-seq, further to investigate the potential histological and molecular genetic mechanisms of white/red earlobe formation in Qiangyuan Partridge chicken (QYP). Results: through histological section analysis, we found the dermal papillary layer of red earlobes had many more blood vessels than that of white earlobes. And we identified a total of 44 SNPs from Chromosome 1, 2, 3, 4, 9, 10, 11, 13, 19, 20, 23 and Z, that was significantly associated with the chicken white/red earlobe color from GWAS, along with 73 significantly associated genes obtained (e.g., PIK3CB, B4GALT1 and TP63), supporting the fact that the white/red earlobe color was also polygenic and sex-linked in QYP. Importantly, PIK3CB and B4GALT1 are both involved in the biological process of angiogenesis, which may directly give rise to the chicken white earlobe formation through regulating blood vessel density in chicken earlobe. Additionally, through contrast of RNA-seq profiles between white earlobe skins and red earlobe skins, we further identified TP63 and CDH1 differentially expressed. Combined with the existing knowledge of TP63 in epithelial development and tumor angiogenesis, we propose that down-regulated TP63 in white earlobes may play roles in thickening the skin and decreasing the vessel numbers in dermal papillary layer, thereby contributing to the white earlobe formation via paling the redness of the skin in QYP, but the specific mechanism remains further clarified. Conclusion: our findings advance the existing understanding of the white earlobe formation, as well as provide new clues to understand the molecular mechanism of chicken white/red earlobe color formation.
Project description:The genetic foundation of chicken tail feather color is not very well studied to date, though that of body feather color is extensively explored. In the present study, we used a synthetic chicken dwarf line (DW), which was originated from the hybrids between a black tail chicken breed, Rhode Island Red (RIR) and a white tail breed, Dwarf Layer (DL), to understand the genetic rules of the white/black tail color. The DW line still contain the individuals with black or white tails, even if the body feather are predominantly red, after more than ten generation of self-crossing and being selected for the body feather color. We firstly performed four crosses using the DW line chickens including black tail male to female, reciprocal crosses between the black and white, and white male to female to elucidate the inheritance pattern of the white/black tail. We found that (i) the white/black tail feather colors are independent of body feather color and (ii) the phenotype are autosomal simple trait and (iii) the white are dominant to the black in the DW lines. Furtherly, we performed a genome-wide association (GWA) analysis to determine the candidate genomic regions underlying the tail feather color by using black tail chickens from the RIR and DW chickens and white individuals from DW lines.
Project description:Dongxiang blue-shelled chicken, an indigenous chicken breed in China, has segregated significantly for the dermal hyperpigmentation phenotype. Two lines of the chicken have been divergently selected with respect to comb color for over 20 generations. The recent selection has also resulted in a significant difference in egg production. The red comb line (RCL) chicken produces significantly higher number of eggs than that by the dark comb line (DCL) chicken. The objective of this study was to explore potential mechanisms involved in the relationship between comb color and egg production among chickens. We performed genome-wide association study to identify candidate genes associated with chicken comb color using SNP array data, and we conducted selective sweep analysis to identify putative regions of selection harboring pleiotropic genes affecting both comb color and egg production.
Project description:Genome-wide association study and transcriptome analysis provide new insights into the white/red earlobe color formation in chicken
Project description:Single-nucleus RNA sequencing (snRNA-seq) was used to profile the transcriptome of 8,413 nuclei in chicken adult testis. This dataset includes two samples from two different individuals. This dataset is part of a larger evolutionary study of adult testis at the single-nucleus level (97,521 single-nuclei in total) across mammals including 10 representatives of the three main mammalian lineages: human, chimpanzee, bonobo, gorilla, gibbon, rhesus macaque, marmoset, mouse (placental mammals); grey short-tailed opossum (marsupials); and platypus (egg-laying monotremes). Corresponding data were generated for a bird (red junglefowl, the progenitor of domestic chicken), to be used as an evolutionary outgroup.
Project description:Boihai Red is new strains of inter-specific hybridizing the bay scallop (Argopecten irradians irradians) with the Peruvian scallop (Argopecten purpuratus). Orange color variant of adductor muscle have been developed through successive selective breeding in this strain. In the present study, transcriptomic was conducted on orange and white adductor muscle tissues. Transcriptomic analysis showeds 416 differentially expressed genes (DEGs) were identified between white and orange adductor muscle tissues in Boihai Red Scallop, with 216 up regulated and 200 down. In DEGs, apolipophorin, CYP450 and tyrosinase were expressed highly in orange adductor muscle tissues, which related to carotenoids or melanin. It is probable that not only carotenoids, but also melanin act on orange color of adductor muscle. This study provides valuable genetic resources for understanding underlying mechanisms and pathways of adductor muscle color.
Project description:Our results revealed that the initial flowering stage plays a critical role in the color change of MN. Metabolome analysis demonstrated that cyanidin was the primary anthocyanin in SZT and MN’s red region, while its content was low in TZM and MN’s white region. According to the transcriptome analysis, the anthocyanins biosynthesis pathway was reconstructed in Yunnan Camellia, and the low expression of CHS was detected in TZM and MN’s white region, while ANR maintained a high expression level, which may lead to the low content of cyanidin in them. Transcription factors MYBs, bHLH, and bZIP may play a key role in regulating anthocyanin-structural genes. The co-expression analysis showed that the meristem tissue may play a crucial role in the formation of the mixed white-red color in MN.
Project description:During the long history of chicken domestication, eyelid color, like skin color and shank color, has been one of the unique physical traits of Chinese indigenous chickens that influence consumer behavior. In China, the Lindian chicken, which has colored feathers, is renowned for the appetizing flavor of its meat and eggs, and its eyelid colors varies from deep to light shades, including black, gray, red, and light yellow. To identify the genes controlling eyelid pigmentation, the expression profiles of black and light-yellow eyelids of Lindian chickens were analyzed with transcriptome sequencing. We detected 13,466 genes expressed in the eyelids, among which 14 were differentially expressed. A KEGG pathway analysis showed that tyrosine metabolism and melanogenesis genes were significantly enriched among these DEGs (corrected P < 0.05). Therefore, we infer that melanin metabolism is one of main factors affecting Lindian chicken eyelid pigmentation. In summary, we have identified the melanin genes responsible for eyelid pigmentation of the Lindian chicken, and also provide a valuable resource for the future study of the physical traits of chickens.