<b>Genetic regulation and variation of foetal plasma metabolome in the context of sex, paternal breeds and variable foetal weight</b>

We present data on 1,112 plasma metabolites using untargeted UHPLC-MS/MS methods, of 260 backcross (BC) foetuses from two sires’ breeds at 63 days post-conception (dpc). Eight chemical superclasses have been identified, with lipids accounting for the majority of metabolites. Genomic heritability (h²) was estimated for each metabolite, revealing that 50% had h² values below 0.2, with a higher average in the amino acid class compared to the lipid. We annotated 448 significant metabolite quantitative trait loci (mQTLs) associated with 10 metabolites, primarily lipids, indicating strong genetic regulation. Additionally, metabolite associations with sex, foetal weight, and sire's breed were explored, revealing significant associations for 354 metabolites.Foetal weight influenced the largest number of metabolites, particularly glycerophospholipids and sphingolipids, emphasizing the genetic and metabolic complexity underlying foetal development.本研究报道了基于非靶向超高效液相色谱-串联质谱（untargeted UHPLC-MS/MS）方法检测得到的1112种血浆代谢物的数据，样本为260头来自2个父本品种的回交（backcross, BC）胎仔，采样时胎龄为受孕后63天（days post-conception, dpc）。本研究已鉴定出8大类化学超类代谢物，其中脂类占总代谢物的绝大多数。研究对每种代谢物的基因组遗传力（genomic heritability, h²）进行了估算，结果显示50%的代谢物其h²值低于0.2，且氨基酸类代谢物的平均遗传力高于脂类。本研究共注释得到448个与10种代谢物（主要为脂类）相关的显著代谢物数量性状基因座（metabolite quantitative trait loci, mQTLs），表明代谢物存在较强的遗传调控作用。此外，本研究还探究了代谢物与胎仔性别、胎仔体重及父本品种之间的关联，发现354种代谢物存在显著关联。其中胎仔体重对代谢物的影响数量最多，尤其体现在甘油磷脂与鞘磷脂层面，这凸显了胎仔发育背后遗传与代谢调控的复杂性。