Laboratory of Physiology of Reproduction of Farm Animals, Department of Animal Production, School of Agriculture, Aristotle University of Thessaloniki, Thessaloniki, 54124, Greece.
Vet Res Commun. 2010 Feb;34(2):173-84. doi: 10.1007/s11259-010-9343-z. Epub 2010 Jan 29.
Maternal mRNAs, which are expressed in oocytes, play an important role in the success of early embryo development, as they allow the first cleavages to occur. Zygote arrest 1 (Zar1) is an oocyte-specific maternal-effect gene that functions at the oocyte-to-embryo transition in many vertebrate species including human, pig, cattle, sheep, mouse, rat, frog and zebrafish. Recently, through in silico studies, a gene structurally related to Zar1, called Zar1-like has been identified in many vertebrates, including the chicken. The objectives of this study were to investigate the expression of the chicken Zar1 and Zar1-like genes in chicken tissues and embryos and to determine whether sexual maturation affects their mRNA abundance. RNA was extracted from various organs of chickens aged from one month up to two years old and from chicken embryos until day ten of embryonic development. Expression analysis of the genes was performed using RT-PCR and real-time PCR. RT-PCR analysis revealed that both genes were preferentially expressed in chicken oocytes, ovary and testes and in embryos during embryonic development. Quantitative real-time PCR analysis revealed a significant up regulation of Zar1 in the mature ovary, and also a significant up regulation of Zar1 and Zar1-like genes in the testes of sexually mature roosters, suggesting a key role of these genes in the chicken fertility. In contrast, expression of Zar1-like was not affected by age in the chicken ovary. Our results indicate that the chicken Zar1 and Zar1-like transcripts are co-expressed in high levels in the chicken gonads. In addition their expression beyond the stage of embryonic genome activation suggests an embryonic and not only a maternal origin of these transcripts.
母源 mRNA 在卵母细胞中表达，在早期胚胎发育的成功中发挥重要作用，因为它们允许第一次分裂发生。合子阻滞 1（Zar1）是一种卵母细胞特异性母性效应基因，在包括人类、猪、牛、羊、鼠、大鼠、青蛙和斑马鱼在内的许多脊椎动物物种中，在卵母细胞到胚胎的过渡中发挥作用。最近，通过计算机分析研究，在许多脊椎动物中发现了一种与 Zar1 结构相关的基因，称为 Zar1-like。本研究的目的是研究鸡 Zar1 和 Zar1-like 基因在鸡组织和胚胎中的表达情况，并确定性成熟是否会影响它们的 mRNA 丰度。从 1 个月至 2 岁的鸡的各种器官以及鸡胚胎的第 10 天提取 RNA。使用 RT-PCR 和实时 PCR 进行基因表达分析。RT-PCR 分析表明，这两个基因在鸡卵母细胞、卵巢和睾丸中以及胚胎发育过程中优先表达。定量实时 PCR 分析显示 Zar1 在成熟卵巢中显著上调，Zar1 和 Zar1-like 基因在性成熟公鸡的睾丸中也显著上调，表明这些基因在鸡的生育能力中起着关键作用。相比之下，Zar1-like 的表达在鸡卵巢中不受年龄的影响。我们的结果表明，鸡 Zar1 和 Zar1-like 转录本在鸡性腺中高水平共表达。此外，它们的表达超出了胚胎基因组激活阶段，表明这些转录本具有胚胎起源，而不仅仅是母体起源。
