Characterizing endocrine and transcriptional determinants of P utilization mediated by the environment-host-microbiota interaction in laying hens and quails

Contact: Prof. Dr. Klaus Wimmers

Duration: 2017-2020

Funding: Deutsche Forschungsgemeinschaft, DFG WI 1754/16-1

The project addresses the host transcriptomic and endocrine endo-phenotypes in the complex interaction of diet × microbiome × host that affect intestinal phytate (InsP6) degradation, inositol phosphate (InsPx) pattern, myo-inositol levels, and phosphorus (P) utilization in laying hens and quails. Variable P supply affecting enteral phytase activity and the metabolism of InsPx provokes adaptive responses of the endocrine, paracrine, and autocrine regulation of P homeostasis that are mirrored also at the transcriptome level. These responses result from the availability of P, InsPx, and myo-inositol found in the feedstuff and digesta as well as the indirect effects of changes in microbiota composition. Furthermore, considerable variation in P utilization exists among and within species highlighting heritability and underlying genetic variation. Based on comprehensive phenotypic and genotypic records of the feeding experiments described in Project 1 and of the breeding experiment described in Project 2 of this Research Unit, we plan holistic expression analyses of gut samples in order to identify genes and molecular pathways that are shifted due to phenotypic divergence in P utilization, variable mineral Ca and P supplements and ontogenetic development from the onset and during the laying period in two laying hen strains. In each of these conditions, the endocrine response to experimental alterations will be recorded and the relationship among endocrine and transcriptomic responses analyzed. This project will provide insight into the molecular routes engaged in the gut to maintain P homeostasis. Endocrine and paracrine regulatory pathways will be elucidated along with the molecular endo-phenotypes that represent the host part of the complex diet × microbiome × host interaction. The data will be analysed and interpreted at the background of the vast amount of information gathered in the other projects of this Research Unit about the host- and the microbiota-mechanisms affecting the intestinal InsP6 degradation, InsPx pattern, myo-inositol levels, and P utilization.