The study of sex differentiation genes in chicken embryos

• Main Authors: PENG,AI-YUN, 彭愛勻
• Other Authors: WANG,SHU-YIN
• Format: Others
• Language: zh-TW
• Published: 2016
• Online Access: http://ndltd.ncl.edu.tw/handle/99540839549380607430

碩士 === 中國文化大學 === 生物科技研究所 === 104 === The purpose of this research is to study the gene regulation and the allantoic estrogen levels during embryo development. Currently, poultry sex-determining genes are still not completely explored. DMRT1 gene is located on poultry Z chromosome and is considered to be an important gene responsible for male embryonic development, and also known to be thermosensitive. In addition, many other relevant genes are found to be related to gender development, such as SOX9, FOXL2 and CYP19A1 genes. This study was designed to investigate the gene expression during early embryonic development, also to investigate the effect of incubation temperature on the steroid hormones secretion. Fertilized eggs were divided into two groups, control group was hatched at temperature 100℉, 58% humidity, thermoregulation group was hatched at the same condition except E3-E5, during that time, temperature was raised to 102℉, and the relative humidity was reduced to 54%. From E3 to E6, 24 embryos were removed from the eggs each day, the blood vessels were collected for DNA extraction and for gender determination, and the RNA was extracted from the embryo for DMRT1, SOX9, FOXL2 and CYP19A1 gene expression analysis using Real Time RT-PCR. From E7 to E11, allantoic fluid was drawn from 24 chick embryos for analysis of estrogen. The results show that DMRT1 and SOX9 gene expression at any stage from E3-E5 were stronger in male embryo than that in female embryos. Raising incubation temperature strengthen the expression of DMRT1, but have no effect on SOX9, FOXL2 and CYP19A1 expression. Estrogen can be detected in the female embryo from the E8, yet in male, only until E10 can reach the detectable level. Independent of gender, the estrone levels increased as embryo development, and the rate of increase is more significant in female rather than that in male. Further observation found that raising incubation temperature reduced the estrone levels in female embryos suggesting that there may be some reversed sex embryos occurred that some female embryos converted into male embryos. This study has confirmed some poultry sexual differentiation associated gene expression and estrogen hormone profile. Further efforts need to be done as to refine the experimental design, and to increase the sample size and to study more of the sex differentiation related genes.