Toxascaris leonina is a common parasitic nematode of wild mammals and has significant impacts on the protection of rare wild animals. To analyze population genetic characteristics of T. leonina from South China tiger, its mitochondrial (mt) genome was sequenced. Its complete circular mt genome was 14,277 bp in length, including 12 protein-coding genes, 22 tRNA genes, 2 rRNA genes, and 2 non-coding regions. The nucleotide composition was biased toward A and T. The most common start codon and stop codon were TTG and TAG, and 4 genes ended with an incomplete stop codon. There were 13 intergenic regions ranging 1 to 10 bp in size. Phylogenetically, T. leonina from a South China tiger was close to canine T. leonina. This study reports for the first time a complete mt genome sequence of T. leonina from the South China tiger, and provides a scientific basis for studying the genetic diversity of nematodes between different hosts.
Animals ; Animals, Wild ; Bias (Epidemiology) ; China* ; Codon, Initiator ; Codon, Terminator ; DNA, Intergenic ; Genes, rRNA ; Genetic Variation ; Genome ; Genome, Mitochondrial* ; Mammals ; Phylogeny ; RNA, Transfer ; Sequence Analysis* ; Tigers* ; Toxascaris*

Objective To explore the clinical diagnostic value of Doppler flow parameters of right pulmonary artery ( RPA) in the diagnosis of fetal ventricular outflow tract obstruction . Methods Thirty-two cases of fetuses with left ventricular outflow tract obstruction ( LVOTO ) and 35 cases with right ventricular outflow tract obstruction (RVOTO) were enrolled ,and 107 normal singleton fetuses served as control group . The definition of different segments of RPA was as following :the proximal RPA was defined as the first segment just distal to the originating from the main pulmonary artery ( PA 1) ;the mid RPA was the most distal aspect of the RPA in the extraparenchymal segment ,just before the artery entering the right lung parenchyma ( PA2) ; and the distal RPA was defined as the intraparenchymal segment at the first branching point within the right lung ( PA3) . All Doppler parameters were obtained from three RPA segments , and the maximum flow velocity ( Vmax) ,minimum flow velocity ( Vmin) and pulsation index ( PI) of each segment in each group as well as PA1 segment velocity time integral ( VTI-PA1) and PA1 segment flow from three groups were compared . Results The results of comparison of control group with LVOTO and RVOTO demonstrated that there were significant differences in VTI-PA1 ,Vmin and PI among three RPA segments ( P <0 .05) . There were significant differences in PA1 flow volume ( P <0 .05) in LVOTO group comparing with control group and RVOTO group . However , there was no statistics difference in flow volume between RVOTO and control group ( P > 0 .05) . Significant differences were found in Vmax of all three RPA segments between RVOTO group and control group ( P<0 .05) . There were significant differences in Vmin and PI of the PA2 and PA3 segments between LVOTO and RVOTO group ( P < 0 .05) . The PI in PA2 and PA3 segments in the RVOTO group were lower than those in LVOTO and control group ( P <0 .05) . Conclusions The differences of PI in PA2 and PA3 segments of RPA between fetuses with ventricular outflow tract obstruction and normal fetuses can provide a reference for the differential diagnosis of fetal ventricular outflow tract obstruction .