In vivo response of xanthosine on mammary gene expression of lactating Beetal goat.

Xanthosine is hypothesized to increase stem cell number by promoting symmetrical cell division. Stem cells, in particular mammary stem/progenitor cells are important for gland growth and tissue repair. Molecular mechanism of xanthosine effects on mammary tissue is very limited therefore, a detailed study is warranted. The objective of this study was to evaluate transcriptomic changes in mammary gland infused/not infused with xanthosine of lactating goat. Seven primiparous Beetal goats on day 5 after kidding, were selected for the study. One gland of each goat was infused with xanthosine (TRT gland) twice daily for 3 days while the other gland did not receive any xanthosine and served as control (CON gland). Biopsy of mammary tissues was taken from TRT and CON glands, 2 days after the last day of treatment that is on day 10 after kidding. Illumina RNA-sequencing (RNA-seq) was performed for global gene expression analysis of contralateral glands. Of 382 differentially expressed genes (DEGs), 372 genes were annotated to the goat genome. Gene ontology analyses revealed majority of the DEGs to be associated with metabolic pathways (glycan and lipid metabolism), biosynthesis of antibiotics and peroxisome proliferator-activated receptor signalling pathways. These molecular pathways are either directly or indirectly involved with lipid metabolism in mammary tissue and host adaptive immune response. Expression of stem cell marker namely aldehyde dehydrogenase enzymes (ALDH1A1, ALDH3B1) were upregulated in the treatment gland. Real-time quantitative PCR (RT-qPCR) analyses of selected DEGs showed their expression profiles to be in agreement with results of RNA-seq. To our knowledge, this is the first study that describes effects of xanthosine on transcriptomic changes of mammary tissue. This information can be used further to dissect the molecular mechanisms underlying effects of xanthosine to improve production potential and udder health.