Characteristics And Dynamic Distribution Of Gut Microbiota During Embryonic Development In Chicken

The gut microbiota is a complex ecological community,widely investigated and recognized in many aspects of research.It’s highly essential to study the characteristics of gut microbiota in chicken due to its’ involvement in growth and development of an organism.While gut microbiota has been extensively explored in adult chickens and mammals,little is known on the characteristics and dynamic distribution of the gut microbiota and development in chicken embryo.In present study,we detected and analyzed the composition and distribution of gut microbiota in chickens’ embryo during embryonic stages day 3(E3),day 12(E12)and day19(E19)by using the 16 S rRNA gene sequencing approach.The main results and significance are as follows:(1)21 phyla and 601 genera were detected in the chicken embryo,whereby the predominant phylum and genus was Proteobacteria(65.6%)and Ochrobactrum(23.0%)respectively and 96 genera such as Ochrobactrum,Phylobacterium,Amycolatopsis,Fluviicola,Prevotella,and Pseudomonas were core microbiota in the three stages of development.These results suggest that the presence of microbiota in the chicken embryo at varying proportion was affirmed.(2)94 genera of microbes change significantly between E3 and E12(P < 0.05),143 genera change significantly between E12 and E19 of chicken embryonic development(P < 0.05).Moreover,as chicken embryo advanced in age,there is decrease in the proportion of Ochrobactrum and Amycolatopsis.In contrast,high proportion of Phyllobacterium was seen on the E19.The result also revealed an increasing in some gut microbial population as chicken embryo developed.Additionally,the Principal Component Analysis(PCA)revealed distance is short and high level of similarities between E3 and E12 compared to E19.Also,the alpha analysis results showed more diversity of gut microbiota at E19.It’s noteworthy that the E3 and E12 is characterized by numerous gut microbiota in this study which is likely to play prominent role in the growth and health of the chicken embryo.Notably,our results revealed that gut microbiota in chicken embryo significantly and dynamically change with developmental stages.(3)Pathways assigned for genetic information processing(translation),metabolism of cofactors and vitamins,carbohydrate metabolism,membrane transport and energy metabolism were different between the E3 and E12(P < 0.05).Pathways assigned for genetic information processing,amino acid metabolism,replication,translation,xenobiotics biodegradation,metabolism were differentially enriched between E12 and E19 of chicken embryo development(P < 0.05),suggesting their influence on growth,development and immunity of chicken embryo.(4)The richness index of Chao1,Simpson,Shannon,and ACE revealed no difference among the breedss((Beijing You(Y),Shiqiza(S)and Babcock(B)(Specific pathogen free(SPF)).The beta analysis using Non-metric multidimensional scaling(NMDS)weighted analysis revealed that the samples were clustered at the same location,which denoted that there were no differences between the microbiota across different breeds.These results indicated similar microbial colonization in chicken embryo among the three groups(Y,S and B).In summary,there is dynamic shift in the proportion of microbiota as the chicken embryo developed from one stage to another.The findings provide insights to the understanding of functions of gut microbiota during chicken embryonic growth.Also,provide foundational knowledge for the chicken embryonic development and gut microbiota.