Abstract
The blue egg is both of biological interest and economic importance for consumers, egg retailers, and scientists. To date, the genetic mechanisms underlying pigment have mainly focused on protein-coding genes. However, the underpinning mechanism of non-coding RNAs on the pigment deposition among different eggshell colors remains unknown. In this study, RNA sequencing was employed to profile the uterine gland transcriptome (lncRNA and mRNA) of 15 Changshun blue eggshell layers, to better understand the genetic mechanisms of deposition of blue eggshell color. Results showed that differentially expressed mRNAs, GO terms, and KEGG pathways among pink-eggshell and blue-eggshell chickens were mainly targeting immune- and transporter-related terms with the SLC family, IgJ, CD family, and MTMR genes. Furthermore, the progesterone-mediated oocyte maturation and cortisol synthesis and secretion pathway with targeted gene PGR and Pbx1 were significantly enriched between blue- and pink-eggshell chickens. Integrating analysis of lncRNA and mRNA profiles predicted 4 and 25 lncRNA–gene pairs by antisense and cis analysis. They were relative to immune, nerve, and lipids and amino acid metabolisms, porphyrin, and chlorophyll metabolism with targeted gene FECH and oxidative phosphorylation and cardiac muscle contraction pathways with targeted gene COX6A1. Within blue-eggshell chickens, the GO terms hindbrain tangential cell migration and phosphatidylinositol monophosphate phosphatase activity with targeted gene Plxna2 and MTRM1 were identified. Integrating analysis of lncRNA and mRNA profiles predicted 8 and 22 lncRNA–gene pairs. Most pathways were mainly enriched on lipid-related metabolisms as found in mRNA sequencing. The lncRNAs did exert similar functions in color formation by modulating pigment disposition and immune- and lipid-related metabolisms. Our results provide a catalog of chicken uterine lncRNAs and genes worthy of further studies to understand their roles in the selection for blue eggshell color layers.
Highlights
The blue egg is both of biological interest and economic importance for consumers, egg retailers, and scientists
With respect to the coding proteins, we found that different Gene ontology (GO) terms between pink-eggshell and blue-eggshell chickens were mainly targeting immune- and transporter-related terms with SLC family, IgJ, CD family, topoisomerase (DNA) III beta (Top3b), and MTMR genes
Targeted SLC family-related genes were not different between the comparison of chickens producing light blue eggshell eggs and pink shell eggs, as well as chickens with light blue shell and brown-blue shell eggs. These imply that the mechanism of deposition of blue pigment is different between the light and dark blue eggshell, of which the deposition of dark and brown-greenish blue is involved with the SLC family gene, but not the light blue pigment
Summary
The blue egg is both of biological interest and economic importance for consumers, egg retailers, and scientists. It has been long known that the primary avian eggshell pigments are protoporphyrin IX, biliverdin IX, and biliverdin IX zinc chelate in both wild birds and poultry [3, 4]. The pink, light red, and brown eggshell colors are involved with the deposition of protoporphyrin IX, while blue and green-blue eggshell colors are associated with that of biliverdin IX and biliverdin IX zinc chelate. Previous studies on the genetic mechanisms underlying pigment deposition have mainly focused on protein-coding genes. The underpinning mechanism of non-coding RNAs on the pigment deposition remains unknown. A major reason is that the functional annotation of long non-coding RNAs (lncRNAs) is largely missing. Figuring out the role of lncRNAs would better understand the underlying genetic aspects of non-coding RNA on the deposition of blue eggshells
Sign-in/Register to view highlights & summary Sign-in/Register to access full text options 
Free) 
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a call
