Project description:Monarch butterflies (Danaus plexippus) rely on milkweeds as larval host plants. Host plant seeking and verification by female butterflies may be mediated by gustatory (GRs) and olfactory receptors (ORs). Here we employed RNA-Seq, bioinformatics and RT-qPCR techniques to identify sex- and tissue-specific gene expression. We focused on chemosensation related genes and pathways, including putative ORs, GRs, ionotropic receptors (IRs), odorant-binding proteins, chemosensory proteins, and steroid hormone mediated signaling in specific chemosensory tissues (i.e., antennae, legs and proboscis). Twelve butterflies evenly split between males and females were caught and used for RNA extraction. Tissue-specific sequencing libraries were prepared and sequenced using Illumina NovaSeq 6000 or HiSeq 3000, generating 2 billion 150-bp, paired-end reads. Many more genes and gene sets were differentially expressed between tissue types than between sexes. A total of 148 chemosensation-related genes exhibited sex- and/or tissue-biased expression. RT-qPCR of a small set of genes confirmed their differential expression between tissue types or between males and females. These findings laid a solid foundation for further investigations into the biological roles of these identified genes underlying chemosensation-mediated behaviors such as foraging and reproduction.
Project description:Purpose: To compare the TnAV-6a1 variant infected Trichoplusia ni larval transcriptome of hemolymph viral vesicles versus those of other major larval tissues specifically, the fat body, epidermis and tracheal matrix (referred to as FET tissues).
Project description:In this study, we evaluated the role of the gnathosomoa (mouthpart) in chemosensing of the most devastating honey bee parasite, Varroa destructor mite. Through transcriptomic analysis, we compared the expression of putative chemosensory genes between the body parts containing the main chemosensory organs (the forelegs), gnathosoma and the rest of the body devoid of these two body parts. Furthermore, we checked the presence of chemosensory-related transcripts in the proteome of the gnathosoma. Our comparative transcriptomic analysis revealed the presence of 83 transcripts with known characteristic conserved domains belonging to eight chemosensory gene families in the three Varroa transcriptomes. Among these transcripts, 11 were significantly upregulated in the mite’s forelegs, compared to 8 and 10 in the gnathosoma and body devoid of both organs, respectively. Whilst the gnathosoma and the forelegs share similar expression of some putative lipid carrier proteins, membrane-bound receptors, and associated proteins, they also differ in the expression profiles of some transcripts belonging to these protein families. This suggests two functional chemosensory organs that may differ in their chemosensory function according to specific characteristics of compounds they detect. Moreover, the higher expression of some chemosensory transcripts in the body devoid of forelegs and gnathosoma compared to the gnathosoma alone, may suggest the presence of additional function of these transcripts or alternatively presence of additional external or internal chemosensory organs. Insights into the functional annotation of a highly expressed gustatory receptor present in both organs using RNA interference (RNAi) are also revealed.
Project description:microRNAs (miRNAs) are a class of small non-coding RNAs involved in the coordination and/or fine-tuning of gene expression. As such, miRNAs are thought to be critical cis-acting regulatory factors that control a wide range of physiological processes in the brain. The datasets presented here represent the miRNA transcriptome of the adult and larval Drosophila melanogaster CNS as determined by small RNA deep sequencing (RNA-Seq). They were derived from adult and larval samples explanted from the animal that contain minimal extraneous (non-neuronal) tissues. Here we present a concise summary of our profiling results as well as the original sequencing data. We identify many miRNAs that are expressed at equal levels in both tissues and several that are significantly enriched in the larval and adult brain. Some of these belong to miRNA families with conserved members in mammals. These datasets should provide a good starting point for others interested in characterizing miRNAs with putative functions in Drosophila neurons.
Project description:Marine pelagic larvae from throughout the animal kingdom use a hierarchy of environmental cues to identify a suitable benthic habitat on which to settle and metamorphose into the reproductive phase of the life cycle. The majority of larvae are induced to settle by biochemical cues and many species have long been known to preferentially settle in the dark. Combined, these data suggest that larval responses to light and biochemical cues may be linked, but this is yet to be explored at the molecular level. Here, we track vertical position of larvae of the sponge Amphimedon queenslandica to show that they descend to the benthos at twilight, by which time they are competent to respond to biochemical cues, consistent with them naturally settling in the dark. We then conduct larval settlement assays under three different light regimes (natural day-night, constant dark or constant light), and use transcriptomics on individual larvae to identify candidate molecular pathways underlying the different settlement responses that we observe. We find that constant light prevents larval settlement in response to biochemical cues, likely via actively repressing chemostransduction; this is consistent with the sustained upregulation of a photosensory cryptochrome and two putative inactivators of G-protein signalling in the constant light only. We hypothesise that photo- and chemosensory systems may be hierarchically integrated into ontogeny to regulate larval settlement via nitric oxide (NO) and cyclic guanosine monophosphate (cGMP) signalling in this sponge that belongs to one of the earliest branching of the extant animal lineages.