Regeneration and tissue turnover require new cell production and positional information.
This observation led to the hypothesis that planarian muscle harbors a positional information coordinate system guiding tissue turnover and regeneration7.
How organs maintain and restore functional integrity during ordinary tissue turnover or following injury represents a central biological problem.
Planarians possess a population of adult dividing somatic cells called neoblasts that mediate constant tissue turnover associated with longevity and regeneration.
Coral tissue turnover rates are not known, but their tissues are unlikely to integrate more than a few months of data.
While increases in some MMPs may be destructive, up-regulation of others may result from increases in normal tissue turnover.
The combined positional information and connective tissue role of planarian muscle is significant for understanding the evolutionary origins of animal connective tissues and the roles of connective tissue in promoting proper tissue architecture in animal regeneration and tissue turnover.
Perhaps differences in other metabolic processes, such as tissue turnover, heat production, or others related to maintenance, can account for more variation in RFI than digestibility.
Furthermore, time series measurement of changes in tissue isotopic signature (δ15N, δ13C) enables modelling of growth dilution and tissue turnover components of isotopic change driven by nutritional sources.
Patterning information from differentiated tissues regulates planarian regeneration and tissue turnover, including neoblast specification and the targeting of neoblast-derived progenitor cells to the correct locations within the animal7,8,9,10.
The main role of adult stem cells is to maintain tissue homeostasis, and to replace cells lost due to normal tissue turnover, injury or disease.
