Regulation of Milk Protein Synthesis by Free and Peptide-Bound Amino Acids in Dairy Cows

Zhou, Miaomiao; Xu, Lianbin; Zhao, Feng‐Qi; Liu, H.Y.

doi:10.3390/biology10101044

Cited by 11 publications

(8 citation statements)

References 113 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…Methionine is the limiting amino acid for the ruminants and is essential for the milk protein synthesis whereas, valine, leucine and isoleucine are also essential amino acids that are reported to be potentially limiting for milk protein synthesis 59 . As the genes identified in the study play important role in pathways regulating milk yield either directly or indirectly, they can be considered as candidate genes for milk yield and its composition traits.…”

Section: Discussionmentioning

confidence: 99%

TWAS revealed significant causal loci for milk production and its composition in Murrah buffaloes

Chhotaray,

Vohra,

Uttam

et al. 2023

Sci Rep

View full text Add to dashboard Cite

Milk yield is the most complex trait in dairy animals, and mapping all causal variants even with smallest effect sizes has been difficult with the genome-wide association study (GWAS) sample sizes available in geographical regions with small livestock holdings such as Indian sub-continent. However, Transcriptome-wide association studies (TWAS) could serve as an alternate for fine mapping of expression quantitative trait loci (eQTLs). This is a maiden attempt to identify milk production and its composition related genes using TWAS in Murrah buffaloes (Bubalus bubalis). TWAS was conducted on a test (N = 136) set of Murrah buffaloes genotyped through ddRAD sequencing. Their gene expression level was predicted using reference (N = 8) animals having both genotype and mammary epithelial cell (MEC) transcriptome information. Gene expression prediction was performed using Elastic-Net and Dirichlet Process Regression (DPR) model with fivefold cross-validation and without any cross-validation. DPR model without cross-validation predicted 80.92% of the total genes in the test group of Murrah buffaloes which was highest compared to other methods. TWAS in test individuals based on predicted gene expression, identified a significant association of one unique gene for Fat%, and two for SNF% at Bonferroni corrected threshold. The false discovery rates (FDR) corrected P-values of the top ten SNPs identified through GWAS were comparatively higher than TWAS. Gene ontology of TWAS-identified genes was performed to understand the function of these genes, it was revealed that milk production and composition genes were mainly involved in Relaxin, AMPK, and JAK-STAT signaling pathway, along with CCRI, and several key metabolic processes. The present study indicates that TWAS offers a lower false discovery rate and higher significant hits than GWAS for milk production and its composition traits. Hence, it is concluded that TWAS can be effectively used to identify genes and cis-SNPs in a population, which can be used for fabricating a low-density genomic chip for predicting milk production in Murrah buffaloes.

show abstract

Section: Discussionmentioning

confidence: 99%

TWAS revealed significant causal loci for milk production and its composition in Murrah buffaloes

Chhotaray,

Vohra,

Uttam

et al. 2023

Sci Rep

View full text Add to dashboard Cite

show abstract

“…Milk protein synthesis in the bovine mammary gland is a complex biochemical process. Both free amino acids and small peptides can be taken up by the mammary gland for milk protein synthesis (Tagari et al, 2004 ; Zhou et al, 2021 ). Small peptides play a crucial role in the synthesis of milk proteins (Chen et al, 1987 ; Tagari et al, 2008 ).…”

Section: Introductionmentioning

confidence: 99%

“…Small peptides play a crucial role in the synthesis of milk proteins (Chen et al, 1987 ; Tagari et al, 2008 ). In addition to being used as a nutritional substrate, small peptides can promote milk protein synthesis by enhancing the absorption of amino acids and serving as signaling molecules (Chen et al, 2020 ; Zhou et al, 2021 ).…”

Section: Introductionmentioning

confidence: 99%

Role of peptide transporters in small peptide uptake of bovine mammary epithelial cells cultured in a transwell chamber

Zhou

Huang

2023

Food Science & Nutrition

Self Cite

View full text Add to dashboard Cite

Small peptides can be absorbed by the bovine mammary gland for the synthesis of milk protein, but the absorption mechanism still needs further study. In this study, the role of peptide transporters in small peptide uptake by bovine mammary epithelial cells (BMECs) was studied. First, BMECs were obtained and cultured in a transwell chamber. After 5 days of culture, the FITC‐dextran permeability of the cell layer was detected. Then, 0.5 mM methionyl‐methionine (Met‐Met) was added to the medium of the lower and upper transwell chambers, respectively. The culture medium and BMECs were collected after 24 h of treatment. Liquid chromatography‐mass spectrometry (LC–MS) was used to detect the concentration of Met‐Met in the culture medium. Real‐time PCR was used to detect the mRNA abundance of β‐casein, oligopeptide transporter 2 (PepT2), and small peptide histidine transporter 1 (PhT1) in BMECs. Then, the BMECs were transfected with siRNA‐PepT2 and siRNA‐PhT1, respectively, and the uptake of β‐Ala‐Lys‐N‐7‐amino‐4‐methylcoumarin‐3‐acetic acid (β‐Ala‐Lys‐AMCA) in BMECs was detected. The results showed that, after 5 days of culture, the FITC‐dextran permeability of BMECs was 0.6%, which was significantly lower than that of the control group. The absorption rates of Met‐Met in the culture medium of the upper and lower chambers were 99.99% and 99.95%, respectively. The addition of Met‐Met to the upper chamber significantly increased the mRNA abundance of β‐casein and PepT2. The addition of Met‐Met to the lower chamber significantly improved the mRNA abundance of β‐casein, PepT2, and PhT1. The uptake of β‐Ala‐Lys‐AMCA significantly decreased in BMECs transfected with siRNA‐PepT2. These results suggested that the BMECs were successfully cultured in the transwell chamber and formed a cell layer with little permeability. The small peptides in both the upper and lower chambers of the transwell can be absorbed by BMECs in different ways. PepT2 plays an important role in the uptake of small peptides on both the basal and apical sides of BMECs, and PhT1 may be involved in the uptake of small peptides on the basal side of BMECs. Therefore, the addition of small peptides in dairy cow diets may be an effective dietary manipulation to increase milk protein concentration or yield.

show abstract

“…[ 1 ]. Consequently, peptides are becoming more popular in nutrition and pharmaceutical research [ 1 , 2 ]. Methionine dipeptide (MD) is a bioactive peptide consisting of two methionine (Met) residues linked by a peptide bond.…”

Section: Introductionmentioning

confidence: 99%

“…Hence, MD may provide microorganisms with Met and MD together. For dairy cows, Met is the most limiting amino acid [ 2 ]. Met supplementation in a rumen-protected form can improve milk fat [ 13 ], milk protein [ 14 ], and milk production in dairy cows [ 15 ].…”

Section: Introductionmentioning

confidence: 99%

Nutrient Digestibility, Microbial Fermentation, and Response in Bacterial Composition to Methionine Dipeptide: An In Vitro Study

Kong

Liu²,

Wang

et al. 2022

Biology

View full text Add to dashboard Cite

It is well known that the methionine dipeptide (MD) could enhance the dairy cows milking performance. However, there is still a knowledge gap of the effects of MD on the rumen fermentation characteristics, microbiota composition, and digestibility. This experiment was conducted to determine the effect of different nitrogen sources with a total mixed ration on in vitro nutrient digestibility, fermentation characteristics, and bacterial composition. The treatments included 5 mg urea (UR), 25.08 mg methionine (Met), 23.57 mg MD, and no additive (CON) in fermentation culture medium composed of buffer solution, filtrated Holstein dairy cow rumen fluid, and substrate (1 g total mixed ration). Nutrient digestibility was measured after 24 h and 48 h fermentation, and fermentation parameters and microbial composition were measured after 48 h fermentation. Digestibility of dry matter, crude protein, neutral detergent fiber (NDF), and acid detergent fiber (ADF) in the MD group at 48 h were significantly higher than in the CON and UR groups. The total volatile fatty acid concentration was higher in the MD group than in the other groups. In addition, 16S rRNA microbial sequencing results showed MD significantly improved the relative abundances of Succinivibrio, Anaerotruncus, and Treponema_2, whereas there was no significant difference between Met and UR groups. Spearman’s correlation analysis showed the relative abundance of Succinivibrio and Anaerotruncus were positively correlated with gas production, NDF digestibility, ADF digestibility, and acetate, propionate, butyrate, and total volatile fatty acid concentrations. Overall, our results suggested that the microbiota in the fermentation system could be affected by additional nitrogen supplementation and MD could effectively enhance the nutrient utilization in dairy cows.

show abstract

Regulation of Milk Protein Synthesis by Free and Peptide-Bound Amino Acids in Dairy Cows

Cited by 11 publications

References 113 publications

TWAS revealed significant causal loci for milk production and its composition in Murrah buffaloes

TWAS revealed significant causal loci for milk production and its composition in Murrah buffaloes

Role of peptide transporters in small peptide uptake of bovine mammary epithelial cells cultured in a transwell chamber

Nutrient Digestibility, Microbial Fermentation, and Response in Bacterial Composition to Methionine Dipeptide: An In Vitro Study

Contact Info

Product

Resources

About