What stage does the sponge move?9/16/2023 Therefore the ability to receive signals to coordinate behaviour and the mechanism of transmitting signals between cells has come about many times in very different lineages. Unicellular eukaryotes have a huge number of complex behaviours ( Boenigk and Arndt, 2002) and even bacteria can coordinate to form multicellular arrays ( Claessen et al., 2014). The elements described do not fit the scheme of a loss of sophistication, but seem rather to reflect an early specialization for suspension feeding, which fits with the presumed ecological framework in which the first animals evolved.Īll animals and plants have tissues that conduct signals. Here, I examine the elements of the sponge neural toolkit including sensory cells, conduction pathways, signalling molecules and the ionic basis of signalling. Comparative transcriptome data can be informative but need to be assessed in the context of knowledge of sponge tissue structure and physiology. The sponge genomic ‘toolkit’ either reflects a simple, pre-neural system used to protect the sponge filter or represents the remnants of a more complex signalling system and sponges have lost cell types, tissues and regionalization to suit their current suspension-feeding habit. Genomic and transcriptomic analyses show that sponges possess a large repertoire of genes associated with neuronal processes in other animals, but what is the evidence these are used in a coordination or sensory context in sponges? The very different phylogenetic hypotheses under discussion today suggest very different scenarios for the evolution of tissues and coordination systems in early animals.
0 Comments
Leave a Reply.AuthorWrite something about yourself. No need to be fancy, just an overview. ArchivesCategories |