Prevalence And Molecular Biological Indentification Of Nematode Of Snakes In Changsha

The parasitic disease was badly harmed to the health of snake. The species of nematodes was very much which often caused snake weight loss, anemia. Especially, it not only affected the growth and development of serpents, but also leaded to reduce disease resistance. Consequently the serpents were easily infected by other diseases. When disease was more and more serious, the serpents were be died.In part I of the study, an investigation was firstly carried out which the nematode infected snake of Changsha. The investigated snakes have 180. It resulted that infection rate was Total 30.56% Ancylostoma duodenale 68.89%, Ascaridia galli 35%, Oesophagostomum quadrispinulatum 20%. At the same time, the distribution law of nematode of the Hunan snake was discovered. Ancylostoma duodenale of snake was mainly distributed in north area in Changsha. The infection rate was 75%. Oesophagostomum quadrispinulatum of snake was lowest distributed, which infection rate was 15.18%. Ancylostoma duodenale of snake was mainly distributed in west area in Changsha. The highest infection rate was 58.82%. Ascaridia galli of snake was lowest distributed, which infection rate was 27.94%. It provided important data in order to control nematode disease of snake.In part II of the study, mitochondria DNA(mtDNA) cox1 of the snake nematode have been studied. The mtDNA cox1 were cloned and sequenced. The cox1 sequences of twelve nematode samples were obtained. The twelve cox1 sequences were contrasted. It showed that they separated into three species. The difference among three species were bigger,11.6-31%, 40-147bp. The cox1 sequences of Oesophagostomum quadrispinulatum were obtained firstly. The total length of those cox1 sequences was 450-480bp. The content of G+C was 29.01-34.16%. The interspecific differences were 0-1%. It showed that cox1 gene sequence were a section of very conservative gene sequence. So it was very suitable that cox1 was used for genetic marker of parasite classification.In part III of the study, the internal transcribed spacer (ITS) sequences of ribosomal DNA (rRNA) of snake nematode were cloned and sequenced. The ITS sequences of Ancylostoma duodenal, Ascaridia galli and Oesophagostomum quadrispinulatum were obtained. There were ITS sequences of twelve nematoda samples. The total length of those ITS sequence was 650-750bp. The content of G+C was 45.82-47.07%. The twelve ITS sequences were contrasted. They separated into three species. The lowest divergence of three species ITS sequences were 44.7%. The most intraspecific similarity is 3.1%. It showed that there were apparent differences between species and there were certain intraspecific differences. So ITS sequence could be used for genetic marker of nematoda.In this experiment, cox1 genetic variation of nematode were firstly studied. Genetic variation and DNA polymorphism of mitochondria were carried out from mitochondrial gene. So the effective genetic markers were found which studied molecular taxonomy and genetic relationship of nematode. This study have filled in the blank space of research that was related to China's nematode mitochondrial genome research.