Lenha Mobuchon, INRA, France
Mobuchon L1,2,3, Marthey S2, Le Guillou S2, Laloë D2, Le Provost F2 and Leroux C1,3
1INRA, UMR1213 Herbivores, F-63122 Saint-Genès-Champanelle, France
2INRA, UMR1313 Génétique Animale et Biologie Intégrative, F-78150 Jouy-en-Josas, France
3Clermont Université, VetAgro Sup, UMR1213 Herbivores, BP 10448, F-63000, Clermont-Ferrand, France
Animal nutrition considerably affects milk composition, influencing its nutritional quality for consumers. Milk components synthesis and secretion involve numerous genes some of which are nutri-regulated. Especially, a 48h food deprivation applied to lactating goats modifies the expression of 161 genes, including genes coding for major milk proteins and for lipogenic enzymes related to milk components synthesis and secretion (Ollier et al., 2007). However, the mechanism of their regulation remains unsolved. MicroRNA (miRNA) are small non coding RNA that regulate genes expression at a post-transcriptional level, conferring a crucial role in most of the biological processes. Due to their pleiotropic role, miRNA could provide new possibilities to decipher these regulations. Thus this study aims to identify miRNA which expression is regulated by food deprivation and could control differentially expressed genes (DEG).
Here, we established the exhaustive list of miRNA expressed (the miRNome) of the lactating mammary gland from goat receiving an ad libitum diet and from goat 48h food deprived, using Solexa (Illumina) sequencing. The mammary miRNA were localized and clustered on the caprine chromosomes allowing an enrichment of the annotation of goat genome. The intragenic location of some miRNA genes was showed to be conserved in different species. Then, a differential analysis between the 2 nutritional trials was performed and showed significant changes in the expression of 30 miRNA, 19 miRNA already annotated in others species and 11 putative miRNA. It is the first study reporting miRNomes whose profiles are affected by nutrition in the mammary gland. Links between the nutriregulated miRNA and DEG identified using transcriptomic mentioned above were analyzed, revealing 47 DEG potentially targeted by nutriregulated miRNA.
To decipher the function of some of those nutriregulated miRNA and to determine their targets, their expression will be deregulated in mammary epithelial cells.