Meeting Abstract
Technological advances in DNA sequencing such as Illumina’s Sequencing By Synthesis have made the generation and analyses of transcriptomes a rapid and economical endeavor across life. For crustaceans, characterizations of physiological or developmental mechanisms and processes have mainly focused on a handful of taxa or species of economic interest. Shrimp from the anchialine ecosystem, in contrast, present an opportunity to expand transcriptomic studies to both a novel taxonomic and ecological niche. This ecosystem is comprised of landlocked coastal ponds and caves with subterranean influences from both the ocean and freshwater aquifer. Given this, anchialine shrimp species must physiological cope with continuously fluctuating salinities due to tides, rainfall, and vertical salinity stratifications. Transcriptomic studies of four anchialine shrimps from the Ryukyus Islands, Japan (Antecaridina lauensis, Caridina rubella, Halocaridinides trigonophthalma, Metabetaeus minutus) found that classic crustacean osmoregulatory mechanisms, like up-regulation of ion transporters during salinity change, are characteristic for these species. On the other hand, the endemic Hawaiian anchialine atyid Halocaridina rubra appears to employ unusual osmoregulatory processes via high and constitutive ion transporter expression under all salinities as well as the differential gene expression of unexpected transcripts in its gill tissues. Additionally, developmental transcriptomics of H. rubra identified significant differential expression of transcripts involved in pathways like energy production via peptide and carbohydrate catabolism, mitochondrial function, protein synthesis, respiration and photoreception that correlate to biological differences between life stages of the species.
