piRNA expression in regenerative tissue of Octopus bimaculoides

Tissue regeneration is present in varying capacities across the animal kingdom. Animals such as Hydra and planarians have the capacity to regenerate entire bodies from extremely small sections of amputated tissue. Others, such as humans, have restricted capacities of regeneration, especially in terms of full appendages and specialized tissues such as cardiac and nervous tissue. One of the primary goals of studying regeneration in other organisms is to achieve the development of regenerative medicine. Interaction of P-element induced WImpy testis (PIWI) proteins and PIWI-interacting RNAs (piRNAs) have been implicated in germline genome maintenance, as well as transposable element silencing. Research has also connected PIWI protein expression to regeneration in model organisms. Octopus bimaculoides is a marine animal of Phylum Mollusca that exhibits great regenerative abilities. In this research study, piRNA expression was examined in the regenerated tentacles of O. bimaculoides, and its somatic tissue used as the control. RepeatMasker analysis showed that piRNAs were targeting repeated elements, most notably DNA transposons, long tandem repeats (LTRs), and long interspersed nuclear elements (LINEs). Gene ontology analysis showed that piRNAs were targeting genes implicated in the regulation of transcription, cell communication, signal transduction, and intrinsic and integral components of the cell membrane.