MiR-103 controls milk fat accumulation in goat (Capra hircus) mammary gland during lactation.

Xianzi Lin,Liping Zhang,Jun Luo,Deming Gou,Wei Wang,Raul M Luque

doi:10.1371/journal.pone.0079258

Abstract

Milk is the primary source of nutrition for young mammals including humans. The nutritional value of milk is mainly attributable to fats and proteins fractions. In comparison to cow milk, goat milk contains greater amounts of total fat, including much higher levels of the beneficial unsaturated fatty acids. MicroRNAs (miRNAs), a well-defined group of small RNAs containing about 22 nucleotides (nt), participate in various metabolic processes across species. However, little is known regarding the role of miRNAs in regulating goat milk composition. In the present study, we performed high-throughput sequencing to identify mammary gland-enriched miRNAs in lactating goats. We identified 30 highly expressed miRNAs in the mammary gland, including miR-103. Further studies revealed that miR-103 expression correlates with the lactation. Further functional analysis showed that over-expression of miR-103 in mammary gland epithelial cells increases transcription of genes associated with milk fat synthesis, resulting in an up-regulation of fat droplet formation, triglyceride accumulation, and the proportion of unsaturated fatty acids. This study provides new insight into the functions of miR-103, as well as the molecular mechanisms that regulate milk fat synthesis.

Highlights

Milk, one of the most complete foods in nature, is the primary source of nutrition for young mammals
Triglycerides synthesized from numerous fatty acids in mammary gland epithelial cells are the major type (.95%) of lipids present in milk fat globules [4,5]
Goat milk contains a much higher proportion of the short and medium chain fatty acids in comparison to cow milk [7], and it has been reported that these short and medium chain fatty acids are beneficial in the treatment of human dyspepsia and gastrointestinal dysfunction [8]

Summary

Introduction

One of the most complete foods in nature, is the primary source of nutrition for young mammals (including human beings). Triglycerides synthesized from numerous fatty acids in mammary gland epithelial cells are the major type (.95%) of lipids present in milk fat globules [4,5]. In comparison to cow milk, goat (Capra hircus) milk contains much higher levels of fatty acids, as well as higher levels of fats, proteins, carbohydrates, calcium, and vitamins [6]. Improving milk quality through the alteration of milk composition to maximally benefit human health is one of the major goals of milk production. Understanding these mechanisms may lead to novel strategies resulting in further improving the nutritional values of goat milk and genetically modify the milk composition

Methods

Results

Conclusion