Transient impacts of UV-B irradiation on whole body regeneration in a colonial urochordate

Dev Biol. 2023 Aug 22;503:83-94. doi: 10.1016/j.ydbio.2023.08.006. Online ahead of print.ABSTRACTWithin the chordates, only some colonial ascidians experience whole body regeneration (WBR), where amputated small colonial fragments containing blood-vessels have the capability to regenerate the entire functional adult zooid within 1-3 weeks. Studying WBR in small colonial fragments taken at different blastogenic stages (the weekly developmental process characteristic to botryllid ascidians) from the ascidian Botrylloides leachii, about half of the fragments were able to complete regeneration (cWBR) three weeks following separation, about half were still in uncomplete, running regeneration (rWBR), and only a small percentage died. cWBR significantly increased in fragments that originated from a late blastogenic stage compared to an early stage. Most B. leachii populations reside in shallow waters, under variable daily natural UV irradiation, and it is of interest to elucidate irradiation effects on development and regeneration. Here, we show that UV-B irradiation resulted in enhanced mortality, with abnormal morphological changes in surviving fragments, yet with non-significant cWBR vs. rWBRs. Further, UV-B irradiation influenced the proportion of blood cells (morula cells, hemoblasts) and of multinucleated cells, a new WBR-associated cell type. At 24-h post-amputation we observed enhanced expression of β-catenin (a signaling pathway that plays indispensable roles in cell renew...

Source: Developmental Biology - August 24, 2023 Category: Biology Authors: Andy Qarri Baruch Rinkevich Source Type: research