Relative expression of antigen B coding gene of bubaline isolates of Echinococcus granulosus in fertile and sterile cysts

Abstract

This article communicates the relative quantification of five isoforms of antigen B (AgB) of Echinococcus granulosus. Relative expression of the AgB was quantified in active and inactive cysts. Cysts with germinal membrane, clear cyst fluid and protoscoleces showed uniform expression of the five isoforms and were utilized as control. Relative expression of AgB1 was the highest in cysts, where calcification has initiated. AgB2 and AgB4 were expressed more in fertile cysts irrespective of the condition of germinal membrane. The lowest expression of AgB3 was seen in calcified cysts. The relative expression of AgB5 could not be correlated with respect to the condition of the cyst because AgB5 is typically expressed by the adult stage of the parasite.

The Echinococcus granulosus Antigen B Gene Family Comprises at Least 10 Unique Genes in Five Subclasses Which Are Differentially Expressed

“…One sequence (GU166203) was identical to one of the cluster sequences (AF143813 cluster, Fig. S1 ) that is related to a sheep strain sequence [31] . Another two clusters in the EgAgB1 subfamily are related to those from E. granulosus cattle (FJ696924-FJ696928) and buffalo (FJ696936, FJ696923) strains [30] , [31] .…”

“…S1 ). As the sequences have the same intronic and exonic sequence lengths and several nucleotide substitutions, they are likely to be encoded by a polymorphic gene that is strain-related [31] . It is not clear whether the variation of the sequence is due to heterozygosity, which has been shown in the Echinococcus malate dehydrogenase (MDH) gene [32] , or to the presence of host-specific alleles.…”

“…S1 ) that is related to a sheep strain sequence [31] . Another two clusters in the EgAgB1 subfamily are related to those from E. granulosus cattle (FJ696924-FJ696928) and buffalo (FJ696936, FJ696923) strains [30] , [31] . Further study is required to determine whether EgAgB1 can be used as a universal probe for distinguishing the recognized genotypes of E. granulosus [33] .…”

“…We initially used E. granulosus actin II (accession no. L07773) as a house-keeping gene as used in other studies with Echinococcus [31] , [36] – [39] but this gene proved to be highly variable between different stages of the parasite at the transcription level, being expressed 35 and 20 times higher in MAW than in the ONC and CM, respectively ( Fig. 5 ).…”

Validation of Suitable Reference Genes for Expression Normalization in Echinococcus spp. Larval Stages

“…Despite the lack of validated reference genes, several publications involving gene expression analysis on Echinococcus spp. have been published [16]–[19],[30]–[33]. The βACT-1 gene is widely used as a housekeeping gene, but this gene has been shown to be significantly upregulated in immature adult worms and to be variable in the other stages.…”