Chinese Giant Salamander Renal Anatomy And Histology Observation And Gonads Occur

Chinese giant salamander (Andrias davidianus) is the biggest and rarest amphibian in actual existed in the world. To investigate the relationship between structure and function on the development of the kidney and gonad in the Chinese giant salamander, we used the Chinese giant salamander as the research object, and the kidney and gonad morphological changes were observed by anatomical and routine histological techniques. The results and conclusion included the following aspects:1. Before hatching and after hatching1day, the kidney of embryo and young giant slamander were small, so we could not differentiate it with stered microscope. After hatching7day, the translucent kidney was located in the center of the back on both sides of the line. After hatching133day, the hoar kidney was fine line and the blood vessels were located in the center of it. After hatching427day, the shallow red kidney formed by fine line into a flat strip and the width of the rear was bigger than the front.2. Before hatching21day, between yolk granules and notochord, the interstitial cells from mesoblast began to gather. Before hatching14day, one pairs of kidneys were obvious. In every section of the kidney,5-6a uriniferous tubule were viewed. After hatching1day, the uriniferous tubule had differentiated from collecting tubule and renal tubule. After hatching49day, renal tubule began to differentiate from proximal tubule and distal tubule. After hatching133day, some renal corpuscles was appeared in the kidney. After hatching343day, there were6-9renal corpuscles in the kidney middle section. After hatching511day, cortex and medulla differentiated obviously. There was more renal corpuscles in the cortex. Proximal tubule and distal tubule distributed in the medulla.3. This paper figures that the time series of giant salamander kidney included the following aspects. Some organization from mesoderm first developed into uriniferous tubule, along with the development, uriniferous tubule became collecting tubule and renal tubule. renal tubule further developed into proximal tubule and distal tubule. Finally, renal corpuscle was appeared.4. Before hatching and after hatching49day, we could not differentiate the gonad of embryo and young giant slamander with stered microscope. After hatching49day, the fine line gonad that was translucent located in the center of the back on both sides of the line. After hatching175day, the length and diameter of gonad increased obviously and the color was shallower than after hatching49day. After hatching343day, the bigger gonad formed by fine line into a flat strip and the length increased obviously. After hatching511day, the flat gonad was milky and the middle and back part of it was obviously bending.5. The gonad of the Chinese giant salamander appeared at the49day after hatching, which only distinguished the peripheral somatic cells from the central germ cells. At the175day after hatching, the original gonad began to appear differentiation. Some somatic cells moved gonad, prompted the primordial follicles preliminary differentiation. At the343day after hatching, morphological structure and relative position of the gonad constituted by somatic cells and the germ cells change greatly. Some somatic cells stretched into germ cells to divide them into3-4lobules, and some parts of the germ cells and somatic cell regularly arranged together to form some ducts, which prompted testes differentiation appeared before343days after hatching. At the511day after hatching, one of the giant salamander’s gonads differentiated from ovary and other differentiated from testes.6. This paper figures that the gonad of the Chinese giant salamander occurred during28～49day after hatching, and the differentiation of the ovary sooner than testes. The giant salamander gonad differentiation process in cytology and histological two layers of differentiation sign, and cytology differentiation sign appear earlier than the histological differentiation icon. According to Yamamoto standard of the gonad differentiated type, the Chinese giant salamander belonged to differentiated unisexual animals.