Almiñana Carmen, Argente María-José, Serrano-Jara Daniel, Hamdi Meriem, Bauersachs Stefan, García María-Luz
Institute of Veterinary Anatomy, Vetsuisse Faculty, University of Zurich, Lindau, Zurich, Switzerland.
Department of Reproductive Endocrinology, University Hospital Zurich, Zurich, Switzerland.
Biol Res. 2025 Sep 26;58(1):63. doi: 10.1186/s40659-025-00642-1.
Selection for increased homogeneity of litter size has been proposed to improve resistance to stress and diseases in animals. Previous studies have shown that lines selected for decreased litter size variability (L lines) have higher litter sizes at parity than lines selected for increased litter size variability (H lines), possibly due to higher embryo survival in the oviduct. Thus, the study aimed at examining the effect of the line selection on the oviduct environment and its contribution to embryo development, particularly via extracellular vesicles (EVs). Oviductal EVs (oEVs) and their molecular cargo play essential roles in supporting early embryo development in different species, but little is so far known in rabbits.
Oviductal fluid was collected by flushing oviducts from pregnant (with embryos at 72 h p.c., P) and control does (non-ovulated/non-pregnant, NO) from the two lines, resulting in 4 experimental groups: pregnant H line (H_P); pregnant L line (L_P); non-pregnant H line (H_NO); non-pregnant L line (L_NO). Oviductal EVs were isolated and characterized. RNA cargo of oEVs was analyzed by RNA-sequencing, revealing a high number of differential abundant (DA) genes between P vs. NO does in both lines (1223 DA genes in H line and 1519 in L line, FDR < 0.1%). Additionally, 27 and 25 miRNAs were found as DA between P vs. NO in H and L lines, respectively. Interestingly, functional enrichment analysis of DA genes and predicted target genes of identified miRNAs revealed biological terms such as embryo development, epithelium morphogenesis and differentiation, and cilium movement, which were only associated to L line for P and NO groups. Furthermore, the comparison between H and L lines identified 169 DA RNAs in NO does, but without significant differences in P does. For miRNAs, no differences were detected in H vs. L lines in P or NP does.
This is the first study unveiling the differential oEV RNA cargo between lines selected for low versus high variation in litter size, and in each line, between P and NO does. The changes in protein-coding RNA and miRNA cargo might reflect the different maternal support to the early embryo development in the different lines.
有人提出选择提高窝产仔数的同质性来提高动物对压力和疾病的抵抗力。先前的研究表明，选择降低窝产仔数变异性的品系（L系）在产次时的窝产仔数高于选择提高窝产仔数变异性的品系（H系），这可能是由于输卵管中胚胎存活率较高。因此，本研究旨在研究品系选择对输卵管环境的影响及其对胚胎发育的贡献，特别是通过细胞外囊泡（EVs）。输卵管EVs（oEVs）及其分子货物在支持不同物种的早期胚胎发育中起着至关重要的作用，但目前在兔子中了解甚少。
通过冲洗来自两个品系的怀孕母兔（妊娠72小时，P）和对照母兔（未排卵/未怀孕，NO）的输卵管收集输卵管液，得到4个实验组：怀孕H系（H_P）；怀孕L系（L_P）；未怀孕H系（H_NO）；未怀孕L系（L_NO）。分离并鉴定了输卵管EVs。通过RNA测序分析oEVs的RNA货物，发现在两个品系中P组与NO组之间有大量差异丰富（DA）基因（H系中有1223个DA基因，L系中有1519个，FDR<0.1%）。此外，分别在H系和L系中发现27个和25个miRNA在P组与NO组之间为DA。有趣的是，对DA基因和已鉴定miRNA的预测靶基因的功能富集分析揭示了诸如胚胎发育、上皮形态发生和分化以及纤毛运动等生物学术语，这些术语仅与P组和NO组的L系相关。此外，H系和L系之间的比较在NO组中鉴定出169个DA RNA，但在P组中没有显著差异。对于miRNA，在P组或NP组的H系与L系之间未检测到差异。
这是第一项揭示窝产仔数低变异品系与高变异品系之间以及每个品系中P组与NO组之间oEV RNA货物差异的研究。蛋白质编码RNA和miRNA货物的变化可能反映了不同品系对早期胚胎发育的母体支持差异。
