Electronic Northern Analysis of Genes and Modeling of Gene Networks Underlying Bovine Milk Fat Production

Bhaskar Ganguly,Tanuj Kumar Ambwani,Sunil Kumar Rastogi

doi:10.1155/2017/1910530

Bhaskar Ganguly, Tanuj Kumar Ambwani + Show 1 more

Open Access

https://doi.org/10.1155/2017/1910530

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Abstract

Milk fat is one of the most important economic traits in dairy animals. Yet, the biological machinery involved in milk fat synthesis remains poorly understood. In the present study, expression profiling of 45 genes involved in lipid biosynthesis and secretion was performed using a computational approach to identify those genes that are differentially expressed in mammary tissue. Transcript abundance was observed for genes associated with nine bioprocesses, namely, fatty acid import into cells, xenobiotic and cholesterol transport, acetate and fatty acid activation and intracellular transport, fatty acid synthesis and desaturation, triacylglycerol synthesis, sphingolipid synthesis, lipid droplet formation, ketone body utilization, and regulation of transcription in mammary, skin, and muscle tissue. Relative expression coefficient of the genes was derived based on the transcript abundance across the three tissue types to determine the genes that were preferentially expressed during lactation. 13 genes (ACSS1, ACSS2, ADFP, CD36, FABP3, FASN, GPAM, INSIG1, LPL, SCD5, SPTLC1, SREBF1, and XDH) showed higher expression in the mammary tissue of which 6 (ADFP, FASN, GPAM, LPL, SREBF1, and XDH) showed higher expression during adulthood. Further, interaction networks were mapped for these genes to determine the nature of interactions and to identify the major genes in the milk fat biosynthesis and secretion pathways.

Highlights

Milk fat content is regarded as one of the most important economic traits of milch animals; identification of gene networks that regulate lipid biosynthesis and secretion in the mammary gland is essential to our understanding of lactation physiology
Transcript abundance was inferred from UniGene ESTProfile on the basis of normalized transcripts per million” (TPM) values (Table 2) for the 45 genes involved in nine bioprocesses including fatty acid import into cells (CD36, LPL, and VLDLR); xenobiotic and cholesterol transport (ABCA1, ABCG2); acetate and fatty acid activation and intracellular transport (ACSS1, ACSS2, ACSL1, ACBP, and FABP3); fatty acid synthesis and desaturation (ACACA, FADS1, FADS2, FASN, and SCD5); triacylglycerol synthesis (AGPAT6, DGAT1, DGAT2, GPAM, and LPIN1); sphingolipid synthesis (ASAHL, LASS2, OSBP, OSBPL10, OSBPL2, SGPL1, SPHK2, SPTLC1, SPTLC2, and UGCG); lipid droplet formation (ADFP, BTN1A1, PLIN, and XDH); ketone body utilization (BDH1, OXCT1); and transcriptional regulation (INSIG1, INSIG2, PPARG, PPARGC1A, PPARGC1B, SCAP, SREBF1, SREBF2, and THRSP)
As more and more ESTProfiles get submitted to UniGene, it would become possible to use the same approach for analyzing the expression patterns of different genes including those of these 23 genes

Summary

Introduction

Milk fat content is regarded as one of the most important economic traits of milch animals; identification of gene networks that regulate lipid biosynthesis and secretion in the mammary gland is essential to our understanding of lactation physiology. CD36 LPL VLDLR (2) Xenobiotic and Cholesterol transport ABCA1 ABCG2 (3) Acetate and FA activation and intracellular transport ACBP ACSL1 ACSS1 ACSS2 FABP3 (4) Fatty acid synthesis and desaturation ACACA FADS1 FADS2 FASN SCD5 (5) Triacylglycerol synthesis AGPAT6 DGAT1 DGAT2 GPAM LPIN1 (6) Sphingolipid synthesis ASAHL LASS2 OSBP OSBPL10 OSBPL2 SGPL1 SPHK2 SPTLC1 SPTLC2 UGCG (7) Lipid droplet formation ADFP BTN1A1 PLIN XDH (8) Ketone body Utilization BDH1 OXCT1 (9) Regulation of transcription INSIG1 INSIG2 PPARG PPARGC1A PPARGC1B SCAP

Results

Conclusion