MicroRNAs (i.e. miRNAs) are small non-coding RNAs that play essential modulation roles in embryonic development in vertebrates. Paternal and maternal miRNAs contribute to the development of post-fertilization embryo and zygotic genome activation. The pattern of expression and their roles in embryonic development of medaka are not clearly understood. The present study, therefore, examined a temporal expression of seven miRNAs, ola-let-7a, ola-miR-202-3p, ola-miR-126-3p, ola-miR-122, ola-miR-92a, ola-miR-125a-3p and ola-miR-430a in sperm, oocytes, and embryos during early developmental stages. Three unique expression patterns of miRNAs were observed. ola-let7a, ola-miR-202-3p and ola-miR-126-3p showed both paternal and maternal expression, and ola-miR-122, ola-miR-92a, ola-miR-125a-3p showed maternal expression only. The expression of six out of seven miRNAs significantly decreased after maternal-zygotic transition (MZT), whereas ola-miR-430a expression initiated only after MZT. The temporal dynamic expression of these miRNAs suggests their potential roles in early embryogenesis and genome-zygotic activation in medaka.

MicroRNAs (即miRNAs) 是小的非编码RNAs，在脊椎动物的胚胎发育中起着重要的调节作用。父本和母本 miRNA 有助于受精后胚胎的发育和合子基因组激活。表达模式及其在青鳉胚胎发育中的作用尚不清楚。因此，本研究检测了 7 种 miRNA，ola-let-7a、ola-miR-202-3p、ola-miR-126-3p、ola-miR-122、ola-miR-92a、ola-早期发育阶段精子、卵母细胞和胚胎中的miR-125a-3p和ola-miR-430a。观察到三种独特的 miRNA 表达模式。ola-let7a、ola-miR-202-3p和ola-miR-126-3p 同时显示父本和母本表达，ola-miR-122、ola-miR-92a、ola-miR-125a-3p仅显示母本表达. 在母合子转变 (MZT) 后，七个 miRNA 中有六个的表达显着降低，而ola-miR-430a表达仅在 MZT 后才开始。这些 miRNA 的时间动态表达表明它们在青鳉早期胚胎发生和基因组合子激活中的潜在作用。