Abstract: Trichoplax adhaerens is one of the earliest-branching extant multicellular animals and represents an important evolutionary model for investigating the origin of animal multicellularity, cell-type evolution, and intercellular coordination. However, under laboratory conditions, Trichoplax cultures are still maintained primarily by manual passaging, and the lack of a reliable medium- to long-term preservation strategy limits both experimental continuity and resource sharing. In this study, we used T. adhaerens Grell strain/H1 to examine temperature-dependent changes in growth, behavior, and gene expression, with the aim of evaluating the feasibility of low-temperature preservation. Compared with conventional culture conditions, cultivation at 16°C markedly reduced locomotor activity and growth rate while preserving basic physiological functions. Behavioral and transcriptomic analyses further indicated that Trichoplax responds to low temperature by downregulating carbohydrate- and lipid-metabolism-related processes, thereby slowing growth and developmental progression. Upon return to standard culture temperature, low-temperature-treated individuals rapidly resumed normal growth activity. Based on these findings, we further optimized a low-temperature preservation strategy that enabled stable survival of Trichoplax for more than two months without manual intervention. This study provides a practical approach for the preservation and long-term maintenance of  Trichoplax, establishing a technical basis for its wider application as an experimental model organism. 

Key words: Trichoplax adhaerens; low-temperature preservation, starvation tolerance, transcriptome, metabolic regulation