The transcriptomic signature of diteray zinc supplementation in sheep

In the present study, we studied the effect of dietray zinc (Zn) supplementation on the transcriptome profile of lactating ewes. The main objective was to evaluate the effect of Zn-supplementation on the overall transcriptome and the altered pathways and biological processes in lactating ewes. A previously custom-designed oligo microarray platform (GPL20576) was used to profile the transcriptome of 15 ewes at two time points [T0 (before supplementation) and T40 (after 40-days supplementation period; n = 30). The Isolated and purified total RNAs were individually hybridized to the custom (4x44k) DNA microarray. The comparison of control and treated animal transcriptomes revealed a large set of differentially expressed genes. Functional analysis showed several pathways and biological processes that have been altered following Zn-supplementation to the diet. Lactating crossbred ewes (N = 15; 3 to 4 y of age and 55 to 65 kg BW) have been acclimatized (4-wk) on a basal diet containing a maintenance level of Zn (79 mg Zn/animal/day), before being randomly assigned to 2 treatment groups based on their Zn-supplementation status [supplemented (ZINC; n=10) and unsupplemented control (CTR; n =5)]. During the experimental period (40 d), the CTR group kept receiving the basal diet where the ZINC group received a diet supplemented with Zn (212 mg Zn/animal/day). Following completion of the treatment, blood samples were collected from each individual animal directly into Paxgene blood collection tubes, processed and stored at -20˚C till further analyses. All samples yielded high quality RNA that was tested prior the microarray setup.