| In this study,120 healthy Chinese yellow feather quails were divided into 12 groups according to the week age (0,1,3,5,9,13,17,21,25,29,32,36 week-old) and each group has 10 samples. During the bursal post-embryonic development of Chinese yellow-feathered quails, morphological method, light microscopy, flow cytometry, immunohistochemical techniques were employed to observe and study its morphological structure, cell proliferation and apoptosis and Vasoactine Intrestinal Peptide (VIP) expression. All results are shown as follows:The weight, length and width of the Chinese yellow-feathered quails’bursa grew during the given period (0 to 5 week-old) and reached the largest in the 5th week, then reduced gradually from the 9th week; while in 0-1 week the bursa organ index rapidly increased and significant difference emerged between groups (P< 0.05) and reached its maximum in the 3 rd week, after which time the bursa organ index was on a decrease. At the same time, the morphological structure of Chinese yellow-feathered quails bursa grew almost perfect at the very beginning (0 week-old), and turned into perfect at the age of 3-5 weeks. While at the age of 9 weeks, its lymphoid nodules began to reduce and bubbled a lot, and its mucinous bursa and corticomedullary differentiation were unclear. Further, the bursa degenerated basically completely at the age of 36 weeks, leaving only a small amount of lymphoid nodules.While the week age increased, the cell dormant stage (Phase G0/G1), DNA synthesis (Phase S), DNA cleavage (Phase G2M) and proliferation index (PI) of Chinese yellow-feathered quail bursa showed some differences. After 0 week, the difference of bursal cells in Phase G0/G1 significantly increased (P< 0.05); while in Phase S reduced (P < 0.05), such difference gradually increased at the age of 5 weeks, and reached its maximum at the age of 9 weeks, after which period the difference began to decrease slowly. In Phase G2M, the significance of bursal cells decreased (P< 0.05) after 0 week and reduced to its minimum at the age of 9 weeks, and the phase value decreased slowly at the age of 13-16 weeks, with insignificant difference (P> 0.05). At 0 week, the proliferation index (PI) of bursal cells significantly decreased (P< 0.05), then increased gradually at the age of 5-9 weeks, and decreased slowly at the age of 13-36 weeks (P> 0.05). The apoptosis rate of bursal cell began to increase significantly (P< 0.05) in 0-9 weeks and reached its maximum at the age of 9 weeks; such rate significantly reduced (P< 0.05) at the age of 13 weeks, and then slowly increased at the age of 17 weeks, dropped after 21 week-old, then decreased significantly (P< 0.05) after 25 weeks.During different weeks of age, VIP positive reaction was observed in the healthy Chinese yellow-feathered quails’ bursa (mainly in the bursa mucosa, submucosa and muscular) and differences in the VIP positive histological distribution and morphology features were also studied.VIP positive reaction were mainly distributed in the bursa muscle, submucosa and blood vessel wall of submucosa (at the age of 0,1,5,9,13,17,21, 25,29,32,36 weeks separately). However, no positive reaction was observed in the bursa mucosa. In the 3rd week, VIP positive reaction was widely distributed in the bursa lymphoid nodules, Laminapropria, mucosal epithelium and submucosa and myometrium.The results showed that different growth indexes histological morphological structure, cell proliferation and apoptosis, and its VIP expression of Chinese yellow-feathered quail bursal showed significant aging changes at different week of age. The development of bursal proliferation and apoptosis was basically the same as the study of the measurement of its development and dynamic changes.VIP was found at all phases of growth in the Chinese yellow-feathered quails’bursa and showed some certain rules with the development and functional changes in bursal. Thus this paper suggests that VIP should play the role of immune regulation in the typical central immune system of poultry and, as a signial molecule, link the interaction of neuroendocrine system with the immune system. |
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