Faculty of Biosciences and Aquaculture, Nord University, N-8049, Bodø, Norway.
Present address: Sars Center, University of Bergen, N-5006, Bergen, Norway.
BMC Genomics. 2019 Apr 24;20(1):315. doi: 10.1186/s12864-019-5667-4.
Early development of an oviparous organism is based on maternally stocked structural, nutritional and regulatory components. These components influence the future developmental potential of an embryo, which is referred to as egg quality. Until zygotic genome activation, translational activity in a fish early embryo is limited to parentally inherited transcripts only. In this study, we asked whether egg transcriptome is associated with egg quality in Atlantic salmon (Salmo salar), which is capable of storing ovulated eggs in its abdominal cavity for a long time before spawning.
We analyzed messenger RNA (mRNA) and micro RNA (miRNA) transcriptomes throughout the post-ovulatory egg retention period in batches of eggs from two quality groups, good and poor, classified based on the future developmental performance. We identified 28,551 protein-coding genes and 125 microRNA families, with 200 mRNAs and 5 miRNAs showing differential abundance between egg quality groups and/or among postovulatory ages. Transcriptome dynamics during the egg retention period was different in the two egg quality groups. We identified only a single gene, hepcidin-1, as a potential marker for Atlantic salmon egg quality evaluation.
The overlapping effect of post-ovulatory age on intrinsic egg developmental competence makes the quantification of egg quality difficult when based on transcripts abundance only.
卵生动物的早期发育依赖于母体储存的结构、营养和调节成分。这些成分影响胚胎未来的发育潜力，即卵质。在合子基因组激活之前，鱼类早期胚胎的翻译活性仅限于亲本遗传的转录本。在这项研究中，我们询问了大西洋鲑（Salmo salar）的卵转录组是否与卵质有关，因为它能够在产卵前将排卵后的卵储存在腹部很长一段时间。
我们分析了来自两个质量组（根据未来的发育性能分类为好和差）的卵批在排卵后卵保留期间的信使 RNA（mRNA）和 micro RNA（miRNA）转录组。我们鉴定了 28551 个编码蛋白的基因和 125 个 microRNA 家族，其中 200 个 mRNA 和 5 个 miRNA 在卵质量组和/或排卵后年龄之间表现出丰度差异。两个卵质量组在卵保留期间的转录组动态不同。我们只鉴定了一个基因，hepcidin-1，作为评估大西洋鲑卵质的潜在标记基因。
排卵后年龄对内在卵发育能力的重叠影响使得仅基于转录本丰度来定量卵质变得困难。
