Improving the Yields of Blood Cell Extractions from Botryllus schlosseri Vasculature

The urochordate Botryllus schlosseri belongs to the Vertebrata’s closest living invertebrate group. This colonial species represents an invertebrate model system that maintain high capacity of adult stem cell activity, where various blood cell types, expressing multipotent or totipotent phenotypes, circulate in vasculature throughout life. While in vitro cultures of isolated blood cells from Botryllus may serve as indispensable tools for studying stem cells biology, up to date, there is no single established cell line available from Botryllus, since drawn cells stop dividing in vitro within 24-72h after isolation and many of the cultures are commonly contaminated by bacteria and protists. Moreover, low yields of blood cells are of significant hindrance to the development of long-term cultures since lower numbers of cells eventually lead to poor results. Tackling these two critical technical obstacles, we present here methodologies for improved aseptic conditions and for higher yields of cells extracted from colonial vasculature. This study was performed on two colonial stocks (Israel, laboratory stocks; Helgoland, Germany- field collected stocks) which resulted with a significant difference in the numbers of cell extractions between the two stocks and significantly different blood cell yields between various blastogenic stages (laboratory stocks), further revealing differences between field/laboratory-maintained colonies