Department of Anatomy, Faculty of Science, Mahidol University, Bangkok, Thailand.
PLoS One. 2013 Jul 19;8(7):e69893. doi: 10.1371/journal.pone.0069893. Print 2013.
Female birds develop asymmetric gonads: a functional ovary develops on the left, whereas the right gonad regresses. In males, however, testes develop on both sides. We examined the distribution of germ cells using Vasa/Cvh as a marker. Expression is asymmetric in both sexes: at stage 35 the left gonad contains significantly more germ cells than the right. A similar expression pattern is seen for expression of ERNI (Ens1), a gene expressed in chick embryonic stem cells while they self-renew, but downregulated upon differentiation. Other pluripotency-associated markers (PouV/Oct3/4, Nanog and Sox2) also show asymmetric expression (more expressing cells on the left) in both sexes, but this asymmetry is at least partly due to expression in stromal cells of the developing gonad, and the pattern is different for all the genes. Therefore germ cell and pluripotency-associated genes show both sex-dependent and independent left-right asymmetry and a complex pattern of expression.
左侧发育出功能性卵巢，而右侧的性腺退化。然而，在雄性中，睾丸会在两侧发育。我们使用 Vasa/Cvh 作为标记物来检测生殖细胞的分布。在两性中，表达都是不对称的：在第 35 阶段，左侧性腺中生殖细胞的数量明显多于右侧。同样的表达模式也出现在 ERNI（Ens1）的表达中，该基因在鸡胚胎干细胞自我更新时表达，但在分化时下调。其他多能性相关标记物（PouV/Oct3/4、Nanog 和 Sox2）在两性中也表现出不对称表达（左侧表达细胞更多），但这种不对称至少部分是由于发育中的性腺间质细胞的表达，并且所有基因的表达模式都不同。因此，生殖细胞和多能性相关基因表现出性别依赖性和非依赖性的左右不对称性以及复杂的表达模式。
