scholarly journals Regulation of Key Genes for Milk Fat Synthesis in Ruminants

2021 ◽  
Vol 8 ◽  
Author(s):  
Tong Mu ◽  
Honghong Hu ◽  
Yanfen Ma ◽  
Xiaofang Feng ◽  
Juan Zhang ◽  
...  

Milk fat is the most important and energy-rich substance in milk and plays an important role in the metabolism of nutrients during human growth and development. It is mainly used in the production of butter and yogurt. Milk fat not only affects the flavor and nutritional value of milk, but also is the main target trait of ruminant breeding. There are many key genes involve in ruminant milk fat synthesis, including ACSS2, FASN, ACACA, CD36, ACSL, SLC27A, FABP3, SCD, GPAM, AGPAT, LPIN, DGAT1, PLIN2, XDH, and BTN1A1. Taking the de novo synthesis of fatty acids (FA) and intaking of long-chain fatty acids (LCFA) in blood to the end of lipid droplet secretion as the mainline, this manuscript elucidates the complex regulation model of key genes in mammary epithelial cells (MECs) in ruminant milk fat synthesis, and constructs the whole regulatory network of milk fat synthesis, to provide valuable theoretical basis and research ideas for the study of milk fat regulation mechanism of ruminants.

2008 ◽  
Vol 101 (7) ◽  
pp. 1006-1019 ◽  
Author(s):  
Kevin J. Shingfield ◽  
Jacques Rouel ◽  
Yves Chilliard

Dietary supplements of conjugated linoleic acid (CLA) containingtrans-10,cis-12 CLA decrease milk fat secretion in the lactating cow and sheep, but their effects on mammary lipogenesis in the goat are less well defined. Eight lactating goats were used in two 4 × 4 Latin-square experiments with 14 d experimental periods to examine the effects of calcium salts of CLA methyl esters (CaCLA) containingtrans-10,cis-12 on milk fat synthesis. Experimental treatments consisted of incremental inclusion of 0, 30, 60 or 90 g of CaCLA/d (corresponding to 7·47, 14·9 and 22·4 g/d oftrans-10,cis-12 CLA) offered during the first 10 d of each experimental period that replaced maize grain in concentrates (Experiment 1) or calcium salts of palm oil fatty acids (Experiment 2). Relative to the control, inclusion of 30, 60 or 90 g CaCLA/d in the diet reduced milk fat yield by 19·8, 27·9 and 32·3 % and 17·5, 39·0 and 49·3 % in Experiments 1 and 2, respectively. Decreases in milk fat were due to reductions in the secretion of fatty acids synthesisedde novorather than the uptake of fatty acids from the peripheral circulation. Indirect comparisons with the studies in the lactating cow indicated a lower efficacy of CaCLA supplements on mammary lipogenesis in the goat. In conclusion, CaCLA in the diet inhibits milk fat synthesis in the goat, responses that are dependent on the supply of dietary fatty acids, with evidence that the caprine is less sensitive to the anti-lipogenic effects oftrans-10,cis-12 CLA compared with the bovine or ovine.


2000 ◽  
Vol 278 (1) ◽  
pp. R179-R184 ◽  
Author(s):  
Lance H. Baumgard ◽  
Benjamin A. Corl ◽  
Debra A. Dwyer ◽  
A. Saebø ◽  
Dale E. Bauman

Conjugated linoleic acids (CLA) are octadecadienoic fatty acids that have profound effects on lipid metabolism. Our previous work showed that CLA (mixture of isomers) markedly reduced milk fat synthesis. In this study, our objective was to evaluate the effects of specific CLA isomers. Multiparous Holstein cows were used in a 3 × 3 Latin square design, and treatments were 4-day abomasal infusions of 1) skim milk (control), 2) 9,11 CLA supplement, and 3) 10,12 CLA supplement. CLA supplements provided 10 g/day of the specific CLA isomer ( cis-9, trans-11 or trans-10, cis-12). Treatments had no effect on intake, milk yield, or milk protein yield. Only the 10,12 CLA supplement affected milk fat, causing a 42 and 44% reduction in milk fat percentage and yield, respectively. Milk fat composition revealed that de novo synthesized fatty acids were extensively reduced. Increases in ratios of C14:0 to C14:1 and C18:0to C18:1 indicated the 10,12 CLA supplement also altered Δ9-desaturase. Treatments had minimal effects on plasma concentrations of glucose, nonesterified fatty acids, insulin, or insulin-like growth factor-I. Overall, results demonstrate that trans-10, cis-12 CLA is the isomer responsible for inhibition of milk fat synthesis.


2021 ◽  
Author(s):  
Zhiyun Hao ◽  
Yuzhu Luo ◽  
Jiqing Wang ◽  
Jon Hickford ◽  
Huitong Zhou ◽  
...  

In our previous studies, microRNA-432 (miR-432) was found to be one of differentially expressed miRNAs in ovine mammary gland between the two breeds of lactating sheep with different milk production...


2017 ◽  
Vol 84 (3) ◽  
pp. 283-288 ◽  
Author(s):  
Jung Nam Lee ◽  
Yong Wang ◽  
Ya Ou Xu ◽  
Yu Can Li ◽  
Fang Tian ◽  
...  

This research communication describes the profile of gene expression related to the synthesis of yak milk as determined via quantitative reverse transcription polymerase chain reaction (RT-qPCR). Significant up-regulation during lactation were observed in genes related to fatty acid (FA) uptake from blood (LPL, CD36), intracellular FA transport (FABP3), intracellular FA activation of long- and short-chain FAs (ACSS1, ACSS2, ACSL1), de novo synthesis (ACACA), desaturation (SCD), triacyglycerol (TAG) synthesis (AGPAT6, GPAM, LPIN1), lipid droplet formation (PLIN2, BTN1A1, XDH), ketone body utilisation (BDH1, OXCT1), and transcription regulation (THRSP, PPARGC1A). In particular, intracellular de novo FA synthesis (ACSS2, ACACA, and FABP3) and TAG synthesis (GPAM, AGPAT6, and LPIN1), whose regulation might be orchestrated as part of the gene network under the control of SERBF1 in the milk fat synthesis process, were more activated compared to levels in dairy cows. However, the genes involved in lipid droplet formation (PLIN2, XDH, and BTN1A1) were expressed at lower levels compared to those in dairy cows, where these genes are mainly controlled by the PPARG regulator.


2020 ◽  
Author(s):  
Yu Cao ◽  
Juxiong Liu ◽  
Qing Zhang ◽  
Lijun Ma ◽  
Jiaxin Wang ◽  
...  

Abstract Background Kp-10 is a peptide hormone mainly involved in the initiation tissue development in puberty. Recent studies have shown that Kp-10 is involved in fat synthesis. However, the role of Kp-10 in milk fat synthesis in lactating dairy cows has not been reported. Therefore, this study investigated the correlation between GPR54 and milk fat synthesis in dairy cows and to study the underlying mechanism in BMECs. Results The results showed that the expression of GPR54, SREBP1 and FASN in mammary glands of high-milk fat dairy cows were significantly higher than those in mammary glands of low-milk fat dairy cows. Meanwhile, 10nM Kp-10 can significantly inhibit AMPK/SIRT6 signaling pathway and promote milk fat synthesis in BMECs through its receptor GPR54. Overexpression of SIRT6 significantly reduced the acetylation level of SREBP1 and milk fat synthesis in BMECs.Conclusions These results suggested that Kp-10 inhibits the AMPK / SIRT6 signaling pathway by mediating GPR54, thereby increasing SREBP1 acetylation levels and increasing milk fat synthesis in BMECs.


2020 ◽  
Vol 87 (3) ◽  
pp. 349-355
Author(s):  
Xinyang Fan ◽  
Lihua Qiu ◽  
Xiaohong Teng ◽  
Yongyun Zhang ◽  
Yongwang Miao

AbstractWe hypothesized that insulin-induced gene 1 (INSIG1) affects milk fat synthesis in buffalo. For this reason, the protein abundance of INSIG1 in the mammary tissue of buffalo during the peak period of lactation and dry-off period was evaluated. The results showed that the expression of INSIG1 at the peak of lactation was lower than that in the dry-off period. To explore the role of INSIG1 in milk fat synthesis, the buffalo mammary epithelial cells (BMECs) were isolated and purified from buffalo mammary tissue, and INSIG1 gene were overexpressed and knocked down by constructing the recombinant lentivirus vector of INSIG1 gene and transfecting into BMECs. Results revealed that INSIG1 overexpression decreased the expression of INSIG2, SREBP, PPARG, SCD, GPAM, DGAT2 and AGPAT6, which led to reduction of triglycerides (TAG) content in the cell. In contrast, knockdown of INSIG1 had a positive effect on mRNA expression of the above genes. Overall, the data provide strong support for a key role of INSIG1 in the regulation of milk fat synthesis in BMECs.


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