College of Food Science and Technology, Huazhong Agricultural University, Wuhan 430070, China.
National R&D Center for Egg Processing, Huazhong Agricultural University, Wuhan 430070, China.
Poult Sci. 2019 Nov 1;98(11):6053-6062. doi: 10.3382/ps/pez270.
This experiment was conducted to explore the differences of serum steroid hormones with age and sex in hen eggs during incubation periods for identification of males and females. The concentrations of estrone (E1), estradiol (E2), estriol (E3), testosterone (T), androstenedione (A4), and dihydrotestosterone (DHT) in serum were measured by enzyme-linked immunosorbent assays in chicken embryos on 8, 10, 12, 14, and 16 D, respectively. During the development of chicken embryo, egg weight loss was closely related to age but no sex. However, it was found that both age and sex significantly affected hormones and had obviously more effect on androgens levels. Besides E2 and T, other steroids such as E1, A4, and DHT were also significantly correlated with sex (P < 0.05). Notably, the level of T and the ratio of T to E2 were significantly higher in males than females (P < 0.05). The ratio of E1 to E2 displayed different trends in different sexes, which increased in males but decreased in females. The distribution proportions of androgens and estrogens kept stable level during the late hatching periods of 12 to 16 D. The sex differences of steroids were more obvious at the late hatching stage through PCA. These suggested that the serum hormones differences in male and female embryos played a vital role in sexual differentiation. These findings not only provided the theoretical basis for sex determination of fertilized eggs in egg-laying hen strains, but also contributed to develop a non-invasive way to sex determination of fertilized eggs to meet the modern commercial application.
本实验旨在探讨鸡胚孵化过程中血清类固醇激素随年龄和性别的差异，以鉴定鸡胚的性别。分别在鸡胚孵化第 8、10、12、14 和 16 天，采用酶联免疫吸附法测定血清中雌酮（E1）、雌二醇（E2）、雌三醇（E3）、睾酮（T）、雄烯二酮（A4）和二氢睾酮（DHT）的浓度。在鸡胚发育过程中，卵重损失与年龄密切相关，但与性别无关。然而，研究发现年龄和性别均显著影响激素水平，且对雄激素水平的影响更为明显。除 E2 和 T 外，其他类固醇如 E1、A4 和 DHT 也与性别显著相关（P<0.05）。值得注意的是，T 水平和 T 与 E2 的比值在雄性中明显高于雌性（P<0.05）。E1 与 E2 的比值在不同性别中表现出不同的趋势，在雄性中增加，而在雌性中减少。在 12 至 16 天的孵化后期，雄激素和雌激素的分布比例保持稳定水平。通过 PCA 发现，在孵化后期，类固醇的性别差异更为明显。这些结果表明，雄性和雌性胚胎血清激素的差异在性别分化中起着重要作用。这些发现不仅为蛋鸡品系中受精卵的性别鉴定提供了理论基础，也为开发非侵入性的受精卵性别鉴定方法以满足现代商业应用需求做出了贡献。
