Temporal regulation of planarian eye regeneration

Abstract

While tissue regeneration is typically studied using standard injury models, in nature injuries vary greatly in the amount and location of tissues lost. Planarians have the unique ability to regenerate from many different injuries (including from tiny fragments with no brain), allowing us to study the effects of different injuries on regeneration timelines. We followed the timing of regeneration for one organ, the eye, after multiple injury types that involved tissue loss (single‐ and double‐eye ablation, and decapitation) in Schmidtea mediterranea. Our data reveal that the timing of regeneration remained constant despite changing injury parameters. Optic tissue regrowth, nerve re‐innervation, and functional recovery were similar between injury types (even when the animal was simultaneously regrowing its brain). Changes in metabolic rate (i.e., starving vs. fed regenerates) also had no effect on regeneration timelines. In addition, our data suggest there may exist a role for optic nerve degeneration following eye ablation. Our results suggest that the temporal regulation of planarian eye regeneration is tightly controlled and resistant to variations in injury type.

Positional information specifies the site of organ regeneration and not tissue maintenance in planarians

“…We next examined the regenerative properties of pre-existing versus supernumerary eyes generated by notum RNAi. Resection of normal planarian eyes results in eye regeneration over approximately 2 weeks ( Deochand et al, 2016 ; LoCascio et al, 2017 ). In notum(RNAi) animals, resection of newly formed supernumerary eyes consistently resulted in regeneration of new eyes in the same position.…”

The planarian TRPA1 homolog mediates extraocular behavioral responses to near ultraviolet light

“…6 ). For these experiments, we used an eye ablation technique we previously developed that removes the eyes without disturbing the underlying brain tissues ( Deochand et al, 2016 ). We found that sham surgery controls (where two pieces of anterior tissue outside the eye field were excised) displayed similar responses to uninjured wild-type worms for both green ( P =0.98, Fig.…”

“…Double eye ablations and sham ablations were performed as previously described ( Deochand et al, 2016 ). After 24 h, behavioral responses to green and near-UV light were tested and analyzed using the avoidance assay described above.…”

“…Whole-mount in situ hybridization was performed as described in Pearson et al (2009) , with modifications as described in Deochand et al (2016) except that samples were incubated in formamide-bleaching solution for 4 h as described in King and Newmark (2013) . The Smed-TrpA probe was used at 4 ng μl −1 .…”

Avaliação Sensorial E Microbiológica Na Produção De Geleia Tipo Extra De Manga Com Cravo-Da-Índia

“…Avaliando a capacidade de formação de brotos e raízes em segmentos nodais, Santos et al (2006) utilizaram diferentes combinações de BAP e ANA em meio de cultura WPM contendo 800 mg L -1 de PVP, 30 mg L -1 de sacarose, 7 mg L -1 de ágar e carvão ativado (0 g L -1 e 4 g L -1 ). De acordo com estes autores melhores brotações foram obtidas com 0,05 mg L -1 de ANA combinada 0,75 mg L -1 de BAP (média de 6 brotações por explante), induzindo maior número de gemas por explante (17,4), o que proporcionou a maior taxa de multiplicação (8,7). is a fruit rich in bioactive compounds.…”