Abundantly TSU-68 site transcribed during egg production and linked to an upregulation of protein synthesis and processing in females. The female-enriched set also contained key ribosomal proteins, heat shock proteins and chaperonins, likely to be involved in reproductive processes and possibly host-pathogen-interactions. Interestingly, a gene encoding an endonuclease likely to be intimately involved in switching the state of cells from DNA replication/repair to DNA degradation during apoptosis was highly transcribed in females. This information suggests that selected oocytes might undergo apoptosis during oogenesis to ensure normal development of sister oocytes, consistent with evidence for some other ecdysozoans. Interestingly, transcriptional enrichment in the female also relates to actin and cytoskeletal activity, interpreted to be linked to the contractility in the ovary of O. dentatum, and consistent with the finding of non-striated actin filament networks in the myoepithelial sheath of the proximal ovary of C. elegans – which provides contractile forces essential for the transport of 
eggs in the uterus and “ovulation”. Within the male-enriched set are genes encoding 64 kinases and 71 phosphatases with orthologs in C. elegans as well as other proteins linked to spermatogenesis/sperm, some of which have been identified previously in small-scale molecular studies. For instance, major sperm proteins are molecules that are exclusive to male nematodes, reflected in the present transcription profiles of the majority of 45 msp genes of O. dentatum. Interestingly, there are at least 1,508 gender-enriched genes in O. dentatum that do not have 
orthologs in other strongylid nematodes or C. elegans, indicating the existence of numerous genes and gene products that are unique to reproductive and/or developmental processes in O. dentatum. Although some genes of O. dentatum were not found to be transcribed in any of the five developmental Saracatinib supplier stages investigated here, they may be involved in developmentally regulated processes within particular tissues of the worm. It is possible that low-level transcription in certain cells or tissues might not have been detected by RNA-seq because of Author Manuscript Author Manuscript Author Manuscript Author Manuscript Biotechnol Adv. Author manuscript; available PubMed ID:http://www.ncbi.nlm.nih.gov/pubmed/19854301 in PMC 2016 November 01. Tyagi et al. Page 8 a dilution effect caused by the bulk of other transcripts. For instance, lov-1, a gene required for a mating behavior and vulva location by the male is known to be transcribed/expressed in the HOA and HOB neurons of C. elegans, but was not detectable in any of the five developmental stages of O. dentatum studied here. Another possible reason for the absence of such transcripts might relate to a lack of RNAseq data for stages of O. dentatum other than those included in the present study, such as those undergoing exsheathment, moulting, mating or arrested development Future studies are warranted to explore transcription during short developmental transition periods. Author Manuscript Author Manuscript Author Manuscript Author Manuscript 6. Nematode-host Interactions and immunobiology Many molecules, particularly ES proteins, are recognized to have critical roles in worm establishment, infection, and immune modulation and/or evasion. In O. dentatum, 3,081 of 11,087 genes were inferred to encode ES proteins to be transcribed exclusively in parasitic stages, and fewer only in free-living stages. These percentages are signifi.Abundantly transcribed during egg production and linked to an upregulation of protein synthesis and processing in females. The female-enriched set also contained key ribosomal proteins, heat shock proteins and chaperonins, likely to be involved in reproductive processes and possibly host-pathogen-interactions. Interestingly, a gene encoding an endonuclease likely to be intimately involved in switching the state of cells from DNA replication/repair to DNA degradation during apoptosis was highly transcribed in females. This information suggests that selected oocytes might undergo apoptosis during oogenesis to ensure normal development of sister oocytes, consistent with evidence for some other ecdysozoans. Interestingly, transcriptional enrichment in the female also relates to actin and cytoskeletal activity, interpreted to be linked to the contractility in the ovary of O. dentatum, and consistent with the finding of non-striated actin filament networks in the myoepithelial sheath of the proximal ovary of C. elegans – which provides contractile forces essential for the transport of eggs in the uterus and “ovulation”. Within the male-enriched set are genes encoding 64 kinases and 71 phosphatases with orthologs in C. elegans as well as other proteins linked to spermatogenesis/sperm, some of which have been identified previously in small-scale molecular studies. For instance, major sperm proteins are molecules that are exclusive to male nematodes, reflected in the present transcription profiles of the majority of 45 msp genes of O. dentatum. Interestingly, there are at least 1,508 gender-enriched genes in O. dentatum that do not have orthologs in other strongylid nematodes or C. elegans, indicating the existence of numerous genes and gene products that are unique to reproductive and/or developmental processes in O. dentatum. Although some genes of O. dentatum were not found to be transcribed in any of the five developmental stages investigated here, they may be involved in developmentally regulated processes within particular tissues of the worm. It is possible that low-level transcription in certain cells or tissues might not have been detected by RNA-seq because of Author Manuscript Author Manuscript Author Manuscript Author Manuscript Biotechnol Adv. Author manuscript; available PubMed ID:http://www.ncbi.nlm.nih.gov/pubmed/19854301 in PMC 2016 November 01. Tyagi et al. Page 8 a dilution effect caused by the bulk of other transcripts. For instance, lov-1, a gene required for a mating behavior and vulva location by the male is known to be transcribed/expressed in the HOA and HOB neurons of C. elegans, but was not detectable in any of the five developmental stages of O. dentatum studied here. Another possible reason for the absence of such transcripts might relate to a lack of RNAseq data for stages of O. dentatum other than those included in the present study, such as those undergoing exsheathment, moulting, mating or arrested development Future studies are warranted to explore transcription during short developmental transition periods. Author Manuscript Author Manuscript Author Manuscript Author Manuscript 6. Nematode-host Interactions and immunobiology Many molecules, particularly ES proteins, are recognized to have critical roles in worm establishment, infection, and immune modulation and/or evasion. In O. dentatum, 3,081 of 11,087 genes were inferred to encode ES proteins to be transcribed exclusively in parasitic stages, and fewer only in free-living stages. These percentages are signifi.
