基于SNP标记的滩羊亲子鉴定研究

旨在筛选可用于滩羊亲子鉴定的部分SNP标记，对羊群的保种和繁衍具有重要意义。本试验以宁夏盐池地区的159只滩羊为研究对象，利用600K基因芯片进行SNP测定，通过主成分分析了解样本的遗传背景，依据系统进化树划分家系，最后进行亲子鉴定研究。结果显示，大多数滩羊之间遗传背景相近，系统进化树将其划分为5大家系；亲子鉴定筛选到了211个高质量SNPs，单亲累积排除概率超过99.99%，具有很高的准确性和可靠性；父权鉴定结果表明，在95%置信水平下，观测鉴定率为79%，80%置信度下，观测鉴定率达到87%。在有结果的子代中，大部分真实亲本在疑似父本中找到，即非系谱记录的父本，说明场内应加强系谱管理，尽量避免错误的发生。     

Effects of dietary concentrate level and chromium-methionine supplementation on ruminal fermentation,and ruminal bacterial and fatty acid composition in Tan lambs北大核心CSCD

This study evaluated the effects of dietary concentrate level and chromium methionine(Cr-Met)supplementation on ruminal fermentation and fatty acid composition, and ruminal bacteria abundance in Tan lambs. Forty male Tan lambs [(21.00±1.23) kg body weight, 5 months of age] were randomly assigned to four treatment groups with 10 lambs in each treatment. The treatments were: a low-concentrate (LC) diet (concentrate:forage, 35:65) without Cr-Met supplementation; a high-concentrate (HC) diet (concentrate:forage, 55:45) without Cr-Met supplementation; groups fed the HC diet with 0.75 or 1.50 g·d-1·lamb-1 Cr-Met (HCM and HCH, respectively). Ruminal fluid was collected on day 65 with an oral stomach tube about 3 h after the morning feed and samples used for fermentation analysis, fatty acid composition determination and bacterial DNA extraction. It was found that: 1) Ruminal pH, acetate proportion and acetate:propionate were greater (P<0.05) with the LC diet whereas microbial crude protein, propionate and valerate proportions were greater (P<0.05) with the HC diet. The acetate:propionate was greater (P<0.05) in the HCM group than in the HC group. 2) For the HC diet, the DNA abundances of Butyrivibrio fibrisolvens vaccenic acid subgroup (Butyrivibrio VA) and Ruminococcus flavefaciens were decreased (P<0.05), compared with the LC diet, whereas the DNA abundance of Anaerovibrio lipolytica was increased (P<0.05). For lambs fed the HC diet, DNA abundances of B. fibrisolvens stearic acid subgroup, Butyrivibrio VA, Butyrivibrio proteoclasticus, and A. lipolytica showed a linear decrease (P<0.05) with increasing Cr-Met supplementation level; However, the DNA abundance of R. flavefaciens showed a linear increase (P<0.05). 3) Compared with the LC group, the concentrations of t11 C18:1, trans C18:1, c9t11 CLA, t10c12 CLA, C18:2n6, and C18:3n3 were decreased by the HC diet without Cr-Met supplementation whereas the concentration of C18:0 was increased. There was a linear increase in t11 C18:1 and trans C18:1 with increasing Cr-Met supplementation level in lambs fed the HC diet. The results suggest that the HC diet inhibited the growth of ruminal bacteria involved in the ruminal biohydrogenation process, and the addition of Cr-Met had a potentially positive effect on conjugated linoleic acid (CLA) synthesis in body tissue. © 2022, Editorial Office of Acta Prataculturae Sinica. All rights reserved.     

基于宏基因组分析有氧运动对滩羊瘤胃微生物丰度的影响北大核心

试验旨在探讨有氧运动对育肥期滩羊瘤胃微生物丰度的影响。选取同期断奶体重(16±2) kg的滩羊母羔羊60只,随机分为3组,每组20个重复,每个重复1只羊。10 km组羊除每日在圈舍自由活动外,沿生态牧场运动跑道有氧运动行走10 km;5 km组羊除每日在圈舍自由活动外,沿生态牧场运动跑道有氧运动行走5 km;NC组(对照组)羊每日在圈舍内自由活动。试验期6个月。结果显示,5 km组羊瘤胃OTU独有标识476条,菌群种类变化最大,10 km组次之。与NC组相比,10 km组羊瘤胃酸杆菌门丰度显著增高(P<0.05),5 km组疣微菌门、变形菌门丰度显著增高(P<0.05);5 km组红细菌科、假单胞菌丰度显著增高(P<0.05);5 km组Muri菌108610丰度降低(P<0.05)。基于Kruskal-Wallis方法分析,与NC组相比,10 km组羊瘤胃反刍兽新月单胞菌、埃氏巨型球菌、均匀拟杆菌、酸热脂环酸杆菌、瘤胃梭菌CPB6、嗜酸乳杆菌丰度增加;5 km组羊瘤胃甲烷短杆菌丰度增加。种水平Anosim分析,与NC组相比,10 km组、5 km组羊瘤胃脱硫弧菌丰度降低。研究表明,滩羊育肥期每日有氧运动10 km,可增加瘤胃有益菌菌群丰度,降低有害菌丰度,提升瘤胃健康水平。     

不同月龄滩羊背最长肌组织的基因表达谱分析

为了解析滩羊肌肉生长发育的调控机理，本研究以1月、6月和10月龄滩羊的背最长肌组织为研究对象，采用转录组测序技术构建了其基因表达谱，并通过生信分析筛选与肌肉发育相关的关键候选基因。结果表明：1月龄组和6月龄组相比，表达上调基因为428个，下调基因为236个，1月龄组和10月龄组相比，表达上调基因为1 204个，下调基因为927个，6月龄组和10月龄相比，表达上调基因为254个，下调基因为188个。对不同比较组别的差异表达基因取交集发现：表达逐步上调的基因共10个，包括CSRP3、ARNTL和BDNF等促进肌肉发育的基因，而表达逐步下调的基因共16个，包括IGFBP5和ANGPT1等抑制肌肉发育的基因。qRT-PCR验证结果显示：CSRP3、IGFBP5等基因的表达趋势同转录组分析结果基本一致，提示上述26个基因适合作为下一步研究的候选基因。本研究成功构建了不同月龄滩羊背最长肌的基因表达谱，并通过生信分析筛选得到调控滩羊肌肉发育的关键候选基因，为深入解析滩羊肌肉发育的分子机制提供了可靠信息。     

滩羊C1H3orf33和CNV14基因拷贝数变异与生长性状的关联研究

实验旨在研究C3orf33同源基因（C1H3orf33）和拷贝数14基因（CNV14）拷贝数变异对滩羊生长性状的影响，采用CNVplex检测试剂盒对宁夏地区150只滩羊1号染色体C3orf33同源基因（C1H3orf33）的拷贝数变异（CNV）进行分析并探讨其与生长性状之间的相关关系。结果表明：C1H3orf33基因CNV与滩羊的体重、体高、体长、胸围和管围显著相关，CNV14区域与体重、体高和体长显著相关，系统进化树显示，C1H3orf33基因与人类及其他哺乳动物的同源基因高度相似，说明C1H3orf33基因可能在转录调控中发挥重要作用，CNV14区域可能是绵羊育种中标记辅助选择（MAS）的候选位点。