肝脏转录组揭示了潜在的关键基因，这些基因可能对牛奶产量的差异有贡献。

Hepatic Transcriptome Reveals Potential Key Genes Contributing to Differential Milk Production.

机构信息

College of Animal Science and Technology, Shihezi University, Shihezi 271018, China.

State Key Laboratory of Animal Nutrition and Feeding, Institute of Animal Science, Chinese Academy of Agricultural Sciences, Beijing 100193, China.

出版信息

Genes (Basel). 2024 Sep 20;15(9):1229. doi: 10.3390/genes15091229.

DOI:10.3390/genes15091229

PMID:39336820

原文链接:https://pmc.ncbi.nlm.nih.gov/articles/PMC11431119/

Abstract

BACKGROUND

Despite the widespread adoption of TMR or PMR and the formulas designed to sufficiently cover the cows' requirements, individual dairy cows' milk production varies significantly. The liver is one of the most important organs in cow lactation metabolism and plays an essential role in the initiation of lactation.

OBJECTIVES

This study aimed to investigate the potential key genes in the liver contributing to the different milk production.

METHODS

We enrolled 64 cows and assigned them to high or low milk yield (MY) groups according to their first 3 weeks of milk production. We performed RNAseq for 35 liver samples with 18 from prepartum and 17 from postpartum cows.

RESULTS

The continuous milk yield observation showed a persistently higher milk yield in high MY cows than low MY cows in the first 3 weeks. High MY cows showed better feed conversion efficiency. We identified 795 differentially expressed genes (DGEs) in the liver of high MY cows compared with low MY cows, with up-regulated genes linked to morphogenesis and development pathways. Weighted gene co-expression network analysis (WGCNA) revealed four gene modules positively correlating with milk yield, and protein and lactose yield ( < 0.05). Using the intersected genes between the four gene modules and DEGs, we constructed the linear mixed-effects models and identified six hub genes positively associated and two hub genes negatively associated with milk yield (Coefficients > 0.25, < 0.05). Random forest machine learning model training based on these eight hub genes could efficiently predict the milk yield ( < 0.001, R = 0.946). Interestingly, the expression patterns of these eight hub genes remained remarkably similar before and after parturition.

CONCLUSIONS

The present study indicated the critical role of liver in milk production. Activated processes involved in morphogenesis and development in liver may contribute to the higher milk production. Eight hub genes identified in this study may provide genetic research materials for dairy cow breeding.

摘要

背景

尽管 TMR 或 PMR 得到广泛应用，且配方旨在充分满足奶牛的需求，但个体奶牛的产奶量差异很大。肝脏是奶牛泌乳代谢中最重要的器官之一，在泌乳启动中起着至关重要的作用。

目的

本研究旨在探讨肝脏中可能对不同产奶量有贡献的关键基因。

方法

我们招募了 64 头奶牛，根据其前 3 周的产奶量将其分为高或低产奶量（MY）组。我们对 35 个肝脏样本进行了 RNAseq，其中 18 个来自产前，17 个来自产后奶牛。

结果

连续的产奶量观察表明，在第 1 至 3 周，高 MY 奶牛的产奶量持续高于低 MY 奶牛。高 MY 奶牛表现出更好的饲料转化率。与低 MY 奶牛相比，高 MY 奶牛肝脏中鉴定出 795 个差异表达基因（DGEs），上调基因与形态发生和发育途径相关。加权基因共表达网络分析（WGCNA）显示，与产奶量、蛋白和乳糖产量呈正相关的四个基因模块（<0.05）。使用四个基因模块和 DEGs 的交集基因，我们构建了线性混合效应模型，鉴定出与产奶量呈正相关的六个枢纽基因和两个负相关的枢纽基因（系数>0.25，<0.05）。基于这八个枢纽基因的随机森林机器学习模型训练可以有效地预测产奶量（<0.001，R=0.946）。有趣的是，这八个枢纽基因的表达模式在产前和产后保持高度相似。