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Maintaining genomic stability is inevitable for organism survival and it is challenged by mutagenic agents, which include ultraviolet (UV) radiation. Whenever DNA damage occurs, it is sensed by DNA-repairing proteins and thereby performing the DNA-repair mechanism. Specifically, in response to DNA damage, H2AX is a key protein involved in initiating the DNA-repair processes. In this present study, we investigate the effect of UV-C on earthworm, Perionyx excavatus and analyzed the DNA-damage response. Briefly, we expose the worms to different doses of UV-C and find that worms are highly sensitive to UV-C. As a primary response, earthworms produce coelomic fluid followed by autotomy. However, tissue inflammation followed by death is observed when we expose worm to increased doses of UV-C. In particular, UV-C promotes damages in skin layers and on the contrary, it mediates the chloragogen and epithelial outgrowth in intestinal tissues. Furthermore, UV-C promotes DNA damages followed by upregulation of H2AX on dose-dependent manner. Our finding confirms DNA damage caused by UV-C is directly proportional to the expression of H2AX. In short, we conclude that H2AX is present in the invertebrate earthworm, which plays an evolutionarily conserved role in DNA damage event as like that in higher animals.

Maintaining genomic stability is inevitable for organism survival and it is challenged by mutagenic agents, which include ultraviolet (UV) radiation. Whenever DNA damage occurs, it is sensed by DNA-repairing proteins and thereby performing the DNA-repair mechanism. Specifically, in response to DNA damage, H2AX is a key protein involved in initiating the DNA-repair processes. In this present study, we investigate the effect of UV-C on earthworm, Perionyx excavatus and analyzed the DNA-damage response. Briefly, we expose the worms to different doses of UV-C and find that worms are highly sensitive to UV-C. As a primary response, earthworms produce coelomic fluid followed by autotomy. However, tissue inflammation followed by death is observed when we expose worm to increased doses of UV-C. In particular, UV-C promotes damages in skin layers and on the contrary, it mediates the chloragogen and epithelial outgrowth in intestinal tissues. Furthermore, UV-C promotes DNA damages followed by upregulation of H2AX on dose-dependent manner. Our finding confirms DNA damage caused by UV-C is directly proportional to the expression of H2AX. In short, we conclude that H2AX is present in the invertebrate earthworm, which plays an evolutionarily conserved role in DNA damage event as like that in higher animals.

Regeneration is a complex mechanism to restore lost or damaged body parts. In earthworms, regeneration capability varies among different species, and it is important to explore the mechanism behind the regeneration process. Interestingly, regeneration in earthworms is either dependent or independent of clitellum segments. In the present study, juvenile earthworms (Eudrilus eugeniae) were amputated at 3 different sites, namely the head, clitellum, and tail segments (at segments 10, 15, and 30, respectively), and their regeneration ability was documented using a foldscope. The amputated segments having the intact clitellum were able to heal the wounds and form the regenerative blastema. The smaller portions of the amputated segments (segments 1–10 and 1–15) without intact clitellum were unable to heal the wound, and death occurs within 12–24 h. The larger portions of the amputated segments (segments 15 and 30 to anus) without intact clitellum were able to heal the wound but lacked the regeneration capability. In control worms, alkaline phosphatase (ALP) signals were observed at the anterior tip, clitellum, and gut epithelium tissues, whereas, upon amputation, the enriched signals from the clitellum diminished, but profound signals were observed at the amputation site and regenerative blastema. Interestingly, on days 3 and 4, blastemal tips lacked ALP signals due to initiation of the differentiation process in the regeneration blastema. In summary, using a foldscope microscope, the role of the clitellum in the regeneration mechanism was indicated by ALP activity.

Fetal Bovine Serum (FBS) is used as a major supplement in culturing animal cells under in vitro conditions. Due to ethical concern, high cost, biosafety, and geographical as well as batchwise result variations, it is important to reduce or replace the use of FBS in animal cell culture. The major objective of this work is to evaluate the feasibility of heat-inactivated coelomic fluid (HI-CF) of the earthworm, Perionyx excavatus as a possible alternative for FBS in animal cell culture experiments. The coelomic fluid (CF) was extruded from the earthworm using electric shock method and used for the experiments. Electric shock method is a simple non-invasive technique, which has no harmful effect on earthworms. Mouse primary fibroblast and HeLa cell lines were used in this study. Among HI-CF, autoclaved CF and crude CF, the supplement of medium with HI-CF shows positive results. The processed HI-CF (90°C for 5 min) at 10% supplement in cell culture medium promote maximum cell growth but cells need the initial support of FBS for the attachment to the culture flask. Microscopic observation and immunofluorescence assay with actin and lamin A confirm that the cellular and molecular morphology of the cells is maintained intact. The HI-CF of earthworm, P. excavatus has shown better cellular viability when compared with FBS and making it possible as an alternative supplement to minimize the use of FBS.