The Roslin Institute and Royal (Dick) School of Veterinary Studies, University of Edinburgh, Easter Bush Campus, Edinburgh EH25 9RG, UK.
Cells. 2023 Apr 13;12(8):1151. doi: 10.3390/cells12081151.
Primordial germ cells (PGCs) are germline-restricted embryonic cells that form the functional gametes of the adult animal. The use of avian PGCs in biobanking and producing genetically modified birds has driven research on the in vitro propagation and manipulation of these embryonic cells. In avian species, PGCs are hypothesized to be sexually undetermined at an early embryonic stage and undergo differentiation into an oocyte or spermatogonial fate dictated by extrinsic factors present in the gonad. However, chicken male and female PGCs require different culture conditions, suggesting that there are sex-specific differences, even at early stages. To understand potential differences between male and female chicken PGCs during migratory stages, we studied the transcriptomes of circulatory stage male and female PGCs propagated in a serum-free medium. We found that in vitro cultured PGCs were transcriptionally similar to their in ovo counterparts, with differences in cell proliferation pathways. Our analysis also revealed sex-specific transcriptome differences between male and female cultured PGCs, with notable differences in Smad7 and NCAM2 expression. A comparison of chicken PGCs with pluripotent and somatic cell types identified a set of genes that are exclusive to germ cells, enriched in the germplasm, and associated with germ cell development.
原始生殖细胞（PGCs）是具有种系限制的胚胎细胞，它们形成成年动物的功能性配子。禽类 PGC 被用于生物银行和生产基因修饰鸟类，这推动了对这些胚胎细胞的体外增殖和操作的研究。在禽类中，PGCs 在早期胚胎阶段被假设为性未分化，并通过存在于性腺中的外在因素分化为卵母细胞或精原细胞命运。然而，鸡的雄性和雌性 PGC 需要不同的培养条件，这表明即使在早期阶段也存在性别特异性差异。为了了解雄性和雌性鸡 PGC 在迁移阶段的潜在差异，我们研究了在无血清培养基中增殖的循环阶段雄性和雌性 PGC 的转录组。我们发现，体外培养的 PGC 在转录上与其胚胎内对应物相似，细胞增殖途径存在差异。我们的分析还揭示了雄性和雌性培养 PGC 之间的性别特异性转录组差异，Smad7 和 NCAM2 表达存在显著差异。鸡 PGC 与多能性和体细胞类型的比较确定了一组仅存在于生殖细胞中的基因，这些基因在生殖质中富集，并与生殖细胞发育相关。
