Research On The Morphology Of Respiratory Organs And Feeding Organs In "All-Fish" GH-Transgenic Common Carp

"All-fish" GH transgenic common carp (transgenic fish) has been a stable line, produced by microinjection of "all-fish" gene included the grass carp GH drivend by theβ-actin gene promoter of common carp into the fertilized eggs of the common carp. The ecological safety has always been the indispensable step on the commercialization of transgenic fish, the key point is to evaluate the fitness of the transgenic fish. Besides accelarating growth performance and increasing food conversion efficiency of the fish, transgenic GH genes could also have direct or indirect effects on the morphology, physiology and behaviour and so on, which could change the survival, feeding and breeding of the fish, then led to the variation of the species survival and breeding rate, finally change the finess of the transgenic fish.Focusing on the fitness of respiratory organs and feeding organs of transgenic fish, in this study we undertook the histological examination and SEM examination of the gill and measured the morphology of the feeding organs. Then we measured the morphology of the gill and the Na+,K+-ATPase activity of the gill tissue in hypoxia. The main results were listed as follows:1. The gill morphology of the transgenic and nontransgenic (control) common carp was meansured, including the number of filaments, total filament length, total number of lamella, spacing of lamella, area of individual lamella and total lamella area. They were compared using one-way analysis of covariance with body weight as the covariate. It was shown that single filament length, total filament length, total number of lamella and total lamella area of the transgenic fish were significantly larger than those of control fish. But, there were no significant differences in all the other variables.2. The feeding organs morphology of the transgenic and control fish was meansured, including the head length, snout length, spacing of eyes, mouth gape width, mouth gape length, length of fist gill arch, gill raker length and distance between gill raker. They were compared using a one-way analysis of covariance with body weight as the covariate. The results were that the head length, snout length, distance between gill raker were significantly smaller than those of control carp. There were no significant differences in all the other variables.3. The exposure to hypoxia triggered the reduction of the ILCM and the gills displayed protruding lamella in transgenic and control fish. After 7 days of hypoxia, the total lamella area of transgenic carp incresed by 96.3%, was significantly larger than that of control fish. However, this morphological change was reversile. After 3 days recovery, the total lamella area of transgenic carp decreased by 78.4%, and 65.3% in control fish.4. Hypoxia trigged the reduction of Na+,K+-ATPase activity in transgenic and control carp. That of transgenic carp changed faster than that of control fish, but there was no significant differerce between the two groups all over the expoure.