Further examination of these specific transcripts by Gene Ontology nomenclature revealed a range of diverse classifications (Fig

Further examination of these specific transcripts by Gene Ontology nomenclature revealed a range of diverse classifications (Fig. in two-channel DNA microarray cIAP1 Ligand-Linker Conjugates 11 hybridization experiments as a common reference for indirect identification of gender-associated transcripts in cercariae, a schistosome life-stage in which there is no cIAP1 Ligand-Linker Conjugates 11 overt sexual dimorphism. This led to the identification of 2,648 gender-associated transcripts. When compared to the 780 gender-associated transcripts identified cIAP1 Ligand-Linker Conjugates 11 by hybridization experiments utilizing a two-channel direct method (co-hybridization of male and female cercariae cDNA), indirect methods using gDNA were far superior in identifying greater quantities of differentially expressed transcripts. Interestingly, both methods identified a concordant subset of 188 male-associated and 156 female-associated cercarial transcripts, respectively. Gene ontology classification of these differentially expressed transcripts revealed a greater diversity of categories in male cercariae. Quantitative real-time PCR analysis confirmed the DNA microarray results and supported the reliability of this platform for identifying gender-associated transcripts. == Conclusions/Significance == Schistosome gDNA displays characteristics highly suitable for the comparison of two-channel DNA microarray results obtained from experiments conducted independently across laboratories. The schistosome transcripts identified here demonstrate, for the first time, that gender-associated patterns of expression are already well established in the cIAP1 Ligand-Linker Conjugates 11 morphologically identical, but chromosomally distinct, cercariae stage. == Author Summary == Infection with parasitic schistosome worms causes schistosomiasis, a major neglected tropical disease currently affecting millions of individuals living in the developing world. A virtually unique characteristic of the schistosome life style in comparison to other members of the Phylum Platyhelminthes is that schistosomes are dioecious, having both male and female individuals. While much is known about the adult dioecious state, virtually nothing has been established with regard to the dioecious larval stages such as the snail-infective miracidium and the human-infective cercaria. To shed some light on this under-studied area of schistosome biology, we first developed a new long-oligonucleotide DNA microarray and used this tool to perfect an indirect hybridization strategy utilizing schistosome genomic DNA for large-scale transcription investigations. Second, we used this tool and strategy to characterize the gene expression profiles of infective male and female cercarial life-stages. This led to the identification of several thousand differentially expressed transcripts and demonstrated that gender-associated patterns of transcription (some associated with adult-specific activities) are surprisingly already established in this short-lived larval life-stage. Further functional interrogation of these transcripts will generate a more complete picture of factors and processes underlying the schistosome’s dioecious state, which may help in control strategies attempting to prevent sexual maturation, inhibit malefemale interactions and limit the production of tissue-damaging eggs. == Introduction == High-throughput molecular helminthology studies of biomedically important trematodes have steadily increased in number throughout the last decade. This has been particularly evident in the field of schistosomiasis, a deadly parasitic disease currently affecting greater than 200 million people worldwide with an annual death rate of approximately 300,000 individuals[1]. Due to major breakthroughs facilitated by the successful elucidation of transcriptomes[2], the increasingly broad use of DNA microarrays[3], the extended utilization of modern proteomic/glycomic tools[3]and the exploitation of post-transcriptional gene silencing (PTGS) and transgenesis technologies[4],[5],[6], the schistosome research community is now poised to make important contributions in varied biological disciplines including vaccine development and chemotherapy. DNA microarray analysis of schistosome transcriptomes has proven to be a major contributor in the identification of novel biological processes, pathways and associations. Most schistosome DNA microarray hybridizations are based on Rabbit Polyclonal to RHG12 the concept of two-channels, where fluorescent signal intensities originating from the co-hybridization of two different cDNA samples labelled with one.