鸽乳的组成及其生成调控机制的研究进展

鸽乳是由鸽嗉囊组织生成并分泌的半固态营养物质，是乳鸽唯一的营养来源。乳鸽出生后不能自主觅食，需由亲鸽哺育，鸽乳对其生长发育极为重要。鸽乳的生成及分泌是一种特殊的生理过程，在禽类中极为少见，也不同于哺乳动物的泌乳过程。鸽乳主要由蛋白质、脂质、碳水化合物和矿物质等物质组成，其合成与分泌受催乳素、胰岛素和松弛素等多种激素共同调控，通过激活JAK/STAT、PI3K/Akt/TOR、AMPK和Wnt等信号通路，调控相关基因的表达，进而调节嗉囊上皮细胞增殖、变性和营养物质合成、富集等过程。本文综述了鸽乳的组成及其生成调控机制，并与哺乳动物进行了比较，进一步明确了嗉囊产生鸽乳的生理机制及与哺乳动物乳腺泌乳的异同。通过研究鸽乳的组成，可为种鸽营养需要标准制定及人工鸽乳研发提供参考；通过研究鸽乳生成的调控机制，进一步深入挖掘调控泌乳的基因，结合分子标记辅助育种技术，应用于提高种鸽的泌乳能力。

Research Progress on the Composition and Production Regulatory Mechanism of Pigeon Milk

Pigeon milk (PM) is a semi-solid nutrient substance produced and secreted by the crop of pigeon and it is the only nutritional source of squab. Squabs should be fed by their parents because they could not eat by themselves, so PM is very important for their growth and development. The production and secretion of PM is a special physiological process, which is rare in birds and different from the lactation process of mammals. PM is mainly composed of proteins, lipids, carbohydrates and minerals. Synthesis and secretion of PM are regulated by numerous hormones such as prolactin, insulin and relaxin. The signaling pathways such as JAK/STAT, PI3K/Akt/TOR, AMPK and Wnt are activated by these hormones and then the expression of related genes are regulated. The processes of crop epithelial cell proliferation, degeneration, nutrient synthesis and enrichment are regulated. The composition of pigeon milk and its production regulatory mechanism are reviewed, we compare these characteristics of PM with mammalian milk, and the physiological mechanism of pigeon milk production by crop and its similarities and differences with mammalian mammary lactation are further clarified. Research on the composition of PM will provide reference for the formulating of breeding pigeon nutrition requirements and research of artificial PM. The regulation mechanism of PM production will further find out genes regulating lactation and select breeding populations with high yield of PM by using molecular marker-assisted breeding technology.