Sarcocvstis Sarcocvst Morohology And Genetic Markers In Bos Taurus And Gallus Gallus

Sarcocystis is an intracellular protozoan,widely parasitic on endotherms and ectotherms.Bos taurus and Gallus gallus are intermediate hosts of Sarcocystis.Muscle inflammation and growth retardation may occur after infection.The identification of Sarcocystis species based on its various genetic markers and the analysis of its phylogenetic relationship with other Sarcocystis species are the basis of the research work of Sarcocystis.In this paper,in the basis of morphological species identification,for Sarcocystis in Bos taurus and Gallus gallus,many kinds of molecular markers were analyzed,the results are as follows.(1)On the basis of morphological and molecular marker analysis,five species of Sarcocystis spp.were isolated from the muscle of cattle in Kunming,and identified as S.cruzi,S.hominis,S.rommeli,S.hirsuta and Sarcocystis sp..(2)The 18 S rDNA,28 S rDNA,mitochondrial COX1 gene,ITS1 and RpoB genes of the above species were sequenced and analyzed,and the intraspecific and interspecific genetic distance was analyzed with their sequences.The phylogenetic tree was constructed with their sequences.The intraspecific variability of the five gene markers of Sarcocystis in cattle was ITS1,mitochondrial COX1,28 S rDNA,18 S rDNA and RpoB from high to low,and the interspecific differentiation was ITS1,mitochondrial COX1,RpoB,28 S rDNA and 18 S rDNA from high to low.Among them,mitochondrial COX1 was the most suitable molecular marker for Sarcocystis identification in cattle.(3)The similarity of COX1 and 18 S rDNA in Sarcocystis sp.and S.dehongensis were 99.5-100% and 96.3-97.5% respectively.In phylogenetic trees,Sarcocystis sp.and S.dehongensis are all clustered together.Therefore,they may the same species.The phylogenetic tree showed Sarcocystis sp.clustered with S.ovalis,the definitive host of Corvidae.It is speculated that the definitive host of Sarcocystis sp.may also be a bird of Corvidae.(4)The genetic sequences(18 S rDNA,28 S rDNA,mitochondrial COX1,ITS1 and RpoB)of the Sarcocystis species in cattle were analyzed with restriction enzyme site analysis.Experiment shows PCR-RFLP method that the restriction enzymes Ava Ⅰ digestion S.cruzi,S.hominis,S.hirsuta and S.heydorni mitochondria COX1 sequences,can get different enzyme map,which distinguish each other.(4)S.wenzeli was found in the tissue of the chickens raised by farmers in Shizong county,Yunnan province.S.wenzeli sarcocysts were found in 7(41.18%)of 17 chickens.The morphology and ultrastructure of the S.wenzeli were observed.S.wenzeli was spindle shaped with the size of 48.93-154.55×381.04-3585.70μm and an average size of 99.35×1723.14μm(n=20).S.wenzeli with short fingerlike protrusions,length of 0.72-2.81μm,and the average length was 1.78 μm(n=176).S.wenzeli filled with myriad lancet-shaped bradyzoites,the average size of 2.53×11.12μm.Under electron microscope,the protrusions of S.wenzeli with microtubules,and a layer of ground substances beneath the protrusions,length of 0.35-0.68 μm,and the surface of protrusions have thin electrondense layer.S.wenzeli electron microscope type is 9k.(5)In this paper,the sequences of five molecular markers(18S rDNA,28 S rDNA,mitochondrial COX1,ITS1 and RpoB)of S.wenzeli were analyzed for the first time.Phylogenetic tree showed that S.wenzeli was closely related to S.albifronsi,S.anasi and S.rileyi.Among the 5 genetic markers,S.wenzeli has low intraspecific variation,and ITS1 was the best genetic marker to identify it.