Project 1.3

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

Klaus Wimmers

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.

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.

Results

Knowledge of the molecular mechanisms of phosphorus utilization (PU) is needed to enable targeted approaches to improve PU effciency and thus lower P excretion in animal husbandry. In a previous population study, Japanese quail were subjected to a low P diet lacking mineral P and exogenous phytase. Individual PU was determined based on total P intake and excretion. In the study Oster et al. 2020 a subset of 20 extreme siblings discordant for PU was selected to retrieve gene expression patterns of ileum. Sequencing reads have been successfully mapped to the current Coturnix japonica reference genome with an average mapping rate of 86%. In total, 640 genes were found to be differentially abundant between the low and high PU groups. Transcriptional patterns suggest a link between improved PU and mitochondrial energy metabolism, accelerated cell proliferation of enterocytes, and gut integrity. In assessing indicators of the effcient use of macro- and micronutrients, further research on turnover and proliferation rates of intestinal cells could provide an approach to improve P effciency in poultry species.

Conceptual model of the ileal epithelium of Japanese quail with divergent PU status. The model links gut integrity, energy metabolism, and enterocyte proliferation rate as potential molecular determinants for efficient PU. Pathways and vitamin D responsive hub genes indicate transcriptional up- (orange items) or down-regulation (blue items) in the high PU group compared to the low PU group. Grey boxes indicate transcriptional effects not predicted based on the Ingenuity Pathway Analysis (IPA) z-score.
Project leaders

Prof. Dr. Klaus Wimmers
Research Institute for Farm Animal Biology (FBN), Dummerstorf
+49 38208 68-600
E-mail

Prof. Dr. Jörn Bennewitz
Institut für Nutztierwissenschaften, Fachgebiet für Tiergenetik und Züchtung
+49 711 459 23570
E-mail

Staff

Dr. Michael Oster
Research Institute for Farm Animal Biology (FBN), Dummerstorf
Institute of Genome Biology
+49 38208 68-706
E-mail

Dr. Henry Reyer
Research Institute for Farm Animal Biology (FBN), Dummerstorf
Institute of Genome Biology
+49 38208 68-702
E-mail

Adewunmi Omotoso
Research Institute for Farm Animal Biology (FBN), Dummerstorf
Institute of Genome Biology
E-mail

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