Date of Award


Document Type

Union College Only

Degree Name

Bachelor of Science



First Advisor

Robert Olberg




urochordate, reproduction, model system, pattern recognition


Botryllus schlosseri is a colonial marine urochordate that reproduces asexually by budding and always has two developing buds, a primary stemming from the adult and a secondary stemming from the primary bud. Each adult individual has a lifespan of five days which concludes in a process called takeover. The entire adult generation undergoes programmed cell death in all of its internal organs, and is reabsorbed by circulating phagocytes within 24 hours simultaneously with the emergence of a new asexual generation. Phagocytes are instrumental in this process, and have the ability to engulf cell corpses and microorganisms through membrane receptors which specifically recognize conserved molecular patterns. Phagocyte pattern recognition receptors are consistently found across many phyla, and include members of the Toll-like receptor family (TLRs), which recognize microbial patterns. Expressed sequence tagging (EST) has been used to isolate candidate phagocyte receptors. In this study, we have investigated the expression and developmental regulation of TLR2 and TLR13 genes through the asexual lifecycle of Botryllus, and compared these to the expression of the housekeeping gene EF1 by semi-quantitative reverse-transcription polymerase chain reaction (RT-PCR). Our findings indicate that the TLR2 and TLR13 orthologs used in this study are expressed throughout the asexual lifecycle and their expression patterns are developmentally regulated. These studies will pave the way to investigate phagocyte function in this model system.