First molecular description, phylogeny and genetic variation of Taenia hydatigena from Nigerian sheep and goats based on three mitochondrial genes

Abstract

AbstractBackgroundCysticercosis caused by the metacestode larval stage ofTaenia hydatigenais a disease of veterinary and economic importance. A considerable level of genetic variation among isolates of different intermediate hosts and locations has been documented. Generally, data on the genetic population structure ofT. hydatigenais scanty and lacking in Nigeria. Meanwhile, similar findings in other cestodes likeEchinococcusspp. have been found to be of epidemiological importance. Our aim, therefore, was to characterize and compare the genetic diversity ofT. hydatigenapopulation in Nigeria based on three mitochondrial DNA markers as well as to assess the phylogenetic relationship with populations from other geographical regions.MethodsIn the present study, we described the genetic variation and diversity ofT. hydatigenaisolates from Nigerian sheep and goats using three full-length mitochondrial genes: the cytochromecoxidase subunit 1 (cox1), NADH dehydrogenase subunit 1 (nad1), and NADH dehydrogenase subunit 5 (nad5).ResultsThe median-joining network of concatenatedcox1-nad1-nad5 sequences indicated thatT. hydatigenametacestodes of sheep origin were genetically distinct from those obtained in goats and this was supported by high FSTvalues ofnad1,cox1, and concatenatedcox1-nad1-nad5 sequences. Genetic variation was also found to be higher in isolates from goats than from sheep.ConclusionsTo the best of our knowledge, the present study described the genetic variation ofT. hydatigenapopulation for the first time in Nigeria using full-length mitochondrial genes and suggests the existence of host-specific variants. The population indices of the different DNA markers suggest that analysis of long mitochondrial DNA fragments may provide more information on the molecular ecology ofT.hydatigena.We recommend that future studies employ long mitochondrial DNA sequence in order to provide reliable data that would explain the extent of genetic variation in different hosts/locations and the biological and epidemiological significance.