we investigated the gene expression profile during early and late stages of fasciola hepatica infection in balb / c mice . for this purpose , we have selected three experimental groups , each containing 3 mice . mice from group 1 served as controls and did not receive any treatment ; mice from groups 2 and 3 were orally infected with f. hepatica metacercariae and humanely euthanized and necropsied at 7 and 21  days after infection , respectively . we investigated the success of the infection by means of the detection of specific antibodies raised against the excretory / secretory antigen from f. hepatica at the time of necropsy . histopathological studies were performed from representative samples from the right and left liver lobes coming from each individual mouse . sections ( 4  m ) were stained with hematoxylin and eosin to determine the liver damage areas . the gen elute mammalian total rna miniprep kit ( sigma , san louis , usa ) was used to isolate the rna , following the manufacturer 's recommendations . both the quantity and quality of each rna sample was assessed with the agilent 2100 bioanalyzer ( agilent tech , palo alto , ca , usa ) . furthermore , only those samples with a rna integrity number ( rin ) higher than 7 were selected . the ambion wt expression kit for affymetrix genechip ( invitrogen ) was used to amplify and label the rna . after , it was hybridized to the genechip mouse gene 1.0 st array ( lot . washing and scanning were performed using the genechip instrument system of affymetrix ( genechip hybridization oven 640 , genechip fluidics station 450 and genechip scanner 3000 7  g ) . the 169-format genechip mouse gene 1.0 st array contained approximately 25 probes that were designed across the full length of 28,853 well - annotated genes for mouse . the design of the array was based on the february 2006 mouse genome sequence ( ucsc mm8 , ncbi build 36 ) with comprehensive coverage of refseq , putative complete cds genbank transcripts , all ensembl transcript classes and synthetically mapped full - length mrnas and refseq nms from humans and rats . the genechip mouse gene 1.0 st array has 100% coverage of nm sequences present in the april 3 , 2007 refseq database . the babelomics v4.2 platform was used to analyze raw data ( .cel files ) , which were generated after hybridization scanning , and image acquisition . after , the affymetrix raw data files ( .cel files ) were background - adjusted , normalized and log - transformed of the perfect match ( pm ) values using a robust multi - array average ( rma ) methodology   for data normalization . differential gene expression , limma moderated t - statistics , reporting a t - test statistic for each gene together with its corresponding p - value ( generally called raw p - values ) was used . these raw p - values were further corrected for multiple testing to minimize the number of false positives in the study . in this analysis , we used the conventional multiple testing p - value correction procedures proposed by benjamini & hochberg   to derive adjusted p - values . for functional profiling , each of the comparisons used here ( t0 vs t7 ; t0 vs t21 and t7 vs t21 ) wasanalyzed using logistic regression models to identify the functional blocks that were enriched in any of the conditions , . finally , the functional blocks from two databases , go biological process and kegg pathways , were used in the study . the ingenuity pathways analysis ( ipa ) software v6.0 was used to organize the genes that were regulated during the infection into networks of interacting molecules . the gene identifiers of the genes with a statistically significant change in expression ( p - value  <  0.05 ) and with a calculated positive or negative fold change of at least two - fold were uploaded in the software . in addition , ipa was used for a functional analysis to identify the biological functions that were most significant to the uploaded datasets ( table 1 ) . the 1st strand cdna synthesis kit for rt - pcr ( amv ) ( cat . 1148318801 , roche ) was used to reverse transcribe each rna sample , according to manufacturer 's recommendations . for this purpose , six genes ( up- and down - regulated ) were randomly chosen and specific primers were designed using the primer - blast software ( http://www.ncbi.nlm.nih.gov/tools/primer-blast ) . a touchdown pcr ( td - pcr ) was performed with an initial denaturation at 94  c for 1  min , which was followed by a touchdown program for 16  cycles with successive annealing temperature decrements of 1.0  c every 2  cycles . for these 2  cycles , the reaction was denatured at 94  c for 20  s , which was followed by annealing at 61  c54  c for 30  s and polymerization at 72  c for 30  s. the subsequent 15  cycles of amplification were similar , except that the annealing temperature was 53  c . the td - pcr amplification was performed in a mastercycler gradient ( eppendorf ) and confirmed by electrophoresis . genomic dna contamination was ruled out for each rna sample by amplification of each rna sample without previous reverse - transcription step . we investigated the gene expression profile during early and late stages of fasciola hepatica infection in balb / c mice . for this purpose , we have selected three experimental groups , each containing 3 mice . mice from group 1 served as controls and did not receive any treatment ; mice from groups 2 and 3 were orally infected with f. hepatica metacercariae and humanely euthanized and necropsied at 7 and 21  days after infection , respectively . we investigated the success of the infection by means of the detection of specific antibodies raised against the excretory / secretory antigen from f. hepatica at the time of necropsy . histopathological studies were performed from representative samples from the right and left liver lobes coming from each individual mouse . sections ( 4  m ) were stained with hematoxylin and eosin to determine the liver damage areas . the gen elute mammalian total rna miniprep kit ( sigma , san louis , usa ) was used to isolate the rna , following the manufacturer 's recommendations . both the quantity and quality of each rna sample was assessed with the agilent 2100 bioanalyzer ( agilent tech , palo alto , ca , usa ) . furthermore , only those samples with a rna integrity number ( rin ) higher than 7 were selected . the ambion wt expression kit for affymetrix genechip ( invitrogen ) was used to amplify and label the rna . after , it was hybridized to the genechip mouse gene 1.0 st array ( lot . washing and scanning were performed using the genechip instrument system of affymetrix ( genechip hybridization oven 640 , genechip fluidics station 450 and genechip scanner 3000 7  g ) . the 169-format genechip mouse gene 1.0 st array contained approximately 25 probes that were designed across the full length of 28,853 well - annotated genes for mouse . the design of the array was based on the february 2006 mouse genome sequence ( ucsc mm8 , ncbi build 36 ) with comprehensive coverage of refseq , putative complete cds genbank transcripts , all ensembl transcript classes and synthetically mapped full - length mrnas and refseq nms from humans and rats . the genechip mouse gene 1.0 st array has 100% coverage of nm sequences present in the april 3 , 2007 refseq database . the babelomics v4.2 platform was used to analyze raw data ( .cel files ) , which were generated after hybridization scanning , and image acquisition . after , the affymetrix raw data files ( .cel files ) were background - adjusted , normalized and log - transformed of the perfect match ( pm ) values using a robust multi - array average ( rma ) methodology   for data normalization . differential gene expression , limma moderated t - statistics , reporting a t - test statistic for each gene together with its corresponding p - value ( generally called raw p - values ) was used . these raw p - values were further corrected for multiple testing to minimize the number of false positives in the study . in this analysis , we used the conventional multiple testing p - value correction procedures proposed by benjamini & hochberg   to derive adjusted p - values . for functional profiling , each of the comparisons used here ( t0 vs t7 ; t0 vs t21 and t7 vs t21 ) wasanalyzed using logistic regression models to identify the functional blocks that were enriched in any of the conditions , . finally , the functional blocks from two databases , go biological process and kegg pathways , were used in the study . the ingenuity pathways analysis ( ipa ) software v6.0 was used to organize the genes that were regulated during the infection into networks of interacting molecules . the gene identifiers of the genes with a statistically significant change in expression ( p - value  <  0.05 ) and with a calculated positive or negative fold change of at least two - fold were uploaded in the software . in addition , ipa was used for a functional analysis to identify the biological functions that were most significant to the uploaded datasets ( table 1 ) . the 1st strand cdna synthesis kit for rt - pcr ( amv ) ( cat . no . 1148318801 , roche ) was used to reverse transcribe each rna sample , according to manufacturer 's recommendations . for this purpose , six genes ( up- and down - regulated ) were randomly chosen and specific primers were designed using the primer - blast software ( http://www.ncbi.nlm.nih.gov/tools/primer-blast ) . a touchdown pcr ( td - pcr ) was performed with an initial denaturation at 94  c for 1  min , which was followed by a touchdown program for 16  cycles with successive annealing temperature decrements of 1.0  c every 2  cycles . for these 2  cycles , the reaction was denatured at 94  c for 20  s , which was followed by annealing at 61  c54  c for 30  s and polymerization at 72  c for 30  s. the subsequent 15  cycles of amplification were similar , except that the annealing temperature was 53  c . the td - pcr amplification was performed in a mastercycler gradient ( eppendorf ) and confirmed by electrophoresis . genomic dna contamination was ruled out for each rna sample by amplification of each rna sample without previous reverse - transcription step .
fasciolosis is listed as one of the most important neglected tropical diseases according with the world health organization and is also considered as a reemerging disease in the human beings . 
 despite there are several studies describing the immune response induced by fasciola hepatica in the mammalian host , investigations aimed at identifying the expression profile of genes involved in inducing hepatic injury are currently scarce . 
 data presented here belong to a time - course investigation of the gene expression profile in the liver of balb / c mice infected with f. hepatica metacercariae at 7 and 21  days after experimental infection . 
 the data published here have been deposited in ncbi 's gene expression omnibus and are accessible through geo series accession number gse69588 , previously published by rojas - caraballo et al . 
 ( 2015 ) in plos one [ 1 ] .