Comparative Approach of the de novo Fatty Acid Synthesis (Lipogenesis) between Ruminant and Non Ruminant Mammalian Species: From Biochemical Level to the Main Regulatory Lipogenic Genes

Abstract

Over the second half of 20(th) century much research on lipogenesis has been conducted, especially focused on increasing the production efficiency and improving the quality of animal derived products. However, many diferences are observed in the physiology of lipogenesis between species. Recently, many studies have also elucidated the involvement of numerous genes in this procedure, highlighting diferences not only at physiology but also at the molecular level. The main scope of this review is to point out the major differences between ruminant and non ruminant species, that are observed in key regulatory genes involved in lipogenesis. Human is used as a central reference and according to the findinggs, main differences are analysed. These findings could serve not only as basis for understanding the main physiology of lipogenesis and further basic research, but also as a basis for any animal scientist to develop new concepts and methods for use in improving animal production and modern genetic improvement.

Keywords: Fatty acids; genes; lipogenesis; ruminants; sheep..

Fig. (1)

Regulator molecules secreted by adipose tissue.

Fig. (2)

Ovine ACC transcripts formation [25]. Ovine ACC gene consists of three distinct promoter regions which give rise to different transcripts according to tissue.

Fig. (3)

Ovine G6PD protein model [72]. (A) Theoretical three-dimensional molecular model of ovine G6PD protein (left and centre figure) and human protein (right figure). The colored segments of the backbone structure mark the location of α-helix (red), β-sheet (green) and coil (white). (B) Structural representation of catalytic motif of OG6PDA isoform and human G6PD protein. (C) Structural representation of catalytic motif of OG6PDB isoforms.

Fig. (4)

Comparative approach of the 5΄ regulatory region of G6PD gene between ruminant and non ruminant species. The most important motifs such as TATA box, E-box, GC-box, SREBP, SP1 (Stimulating Protein 1), AP1 (Activator Protein 1) and AP2 (Activator Protein 2) are present in the promoter region of the three mammals (sheep, human, mouse). However, some differences were noted. For example, AP1 was only present in murine sequence, E-box 2 and 3 were conserved only in sheep and human regions, while a variation in the location of SREBP binding site was observed among the promoter region of the three analyzed mammals.