Determining if Mating Type Proteins Play a Role in Immaturity of the Ciliate Tetrahymena thermophila

Abstract

Tetrahymena thermophila is free‐living ciliate, commonly found in freshwater ponds, and is used as a model research organism. Mating type gene expression is induced in mature cells after they have been starved and put in the presence of cells of a different mating type (Tetrahymena Genome Database, November 10, 2018). T. thermophila are known to have developmental stages of maturity, and immature cells are unable to mate, although the scientific processes that prevent mating are unknown. It is known that mating type gene expression increases one‐hundred fold from logarithmic phase growth to three hours of starvation (Tetrahymena Genome Database, November 10, 2018). It is currently unknown if the mating type genes are expressed in immature progeny since immature cells do not mate.The goal of this study was to determine if immature progeny cells expressed mating type proteins under a variety of conditions. We hypothesized that mating type genes would not be expressed in immature progeny because T. thermophila will not mate until they reach an level of maturity, and the expression of the mating type genes is essential for mating (Rogers and Karrer, 1985). We plan to quantify the mating type gene expression using q‐RT PCR and RNA Seq transcriptase analysis.This study mated two strains, one mating type VI and II, of T. thermophila and isolated the progeny based on drug sensitivity differences from parental cells. For the q‐RT PCR experiment, mating type gene expression for the parental strain was tested at log phase, thirty minutes of starvation, and two hours of starvation. The mating type gene expression for the progeny strain was tested at the same three conditions as the parental strain. RNA samples from each of the six conditions were isolated and used to create cDNA. The cDNA was confirmed through a PCR containing a genomic control, mating type primers, starvation versus log primers, and negative control primers. Then qPCR was utilized to quantify the expression of mating type genes in the six previously described conditions. RNA Seq was utilized to quantify the expression of all genes for triplicate samples of parental cells and progeny, each starved for 24 hours.Mating type gene expression will be validated through the cross referencing of quantified results provided by RNA Seq and qPCR for T. thermophila and are hypothesized to be lower or absent in progeny samples. There may also be differences in expression levels of transcription factors between the progeny and mature cells. However, if there is no difference in either mating type gene or transcription factors, then prevention of mating in immature cells occurs after transcriptional processes and needs further investigation.Support or Funding InformationAlbion College Foundation for Undergraduate Research, Scholarship, and Creative ActivityThis abstract is from the Experimental Biology 2019 Meeting. There is no full text article associated with this abstract published in The FASEB Journal.