Botryllus schlosseri transcriptome of three colonial developmental stages. Botryllus schlosseri

This is a collection of RNA-seq experiments focused on the study of the asexual reproduction of the tunicate Botryllus schlosseri. Tunicates are the only known chordates that can reproduce both sexually and asexually. Among them, B. schlosseri forms colonies characterized by the coexistence of three blastogenetic generations: filter-feeding adults, buds on adults, and budlets on buds. During asexual reproduction, colonies undergo synchronized and cyclical generation changes where adult zooids die, are progressively resorbed and then replaced by their buds which reach the functional maturity in a process called take-over. In the meantime, budlets become buds and produce a new generation of budlets. Each blastogenetic cycle (i.e., the process representing the cyclical asexual reproduction of B. schlosseri) starts when adult zooids are resorbed and their primary buds became the new zooids at take-over. Various developmental stages have been defined in the colonial blastogenetic cycle [PLoS One 9, e96434 2014]. The RNA-seq experiments concern three well defined stages, each one representing a key phase of the blastogenetic cycle: the mid cycle, the phase preceding the take-over, and the take-over. The total RNA was extracted from colonies at each developmental condition and then sequenced to produce the RNA-seq data. Finally, the gene expression analysis was performed to study the genetic changes during the development. The results aim to reach a first step comprehension of growth and regression, cell proliferation, colony homeostasis, and competition among different generations in the colony.