Characterizing Oocyte Maturation in Nematodes

One major question in biology is how unspecialized stem cells differentiate into specialized cells. For example, embryonic stem cells can develop into entire organisms and stem cells found in bone marrow can develop into red and white blood cells. Stem cells can also give rise to reproductive cells known as gametes, a process known as gametogenesis. One way to study this process is by using model organisms. Nematodes are an advantageous model organism because their germ cells are linearly arranged in a developmental sequence. In other words, we can see the entire process of specialization at one time. In the best-studied nematode, Caenorhabditis elegans, unspecialized stem cells are present at the distal portion of the germline. These cells undergo mitosis and then subsequently enter meiosis (Corsi et al., 2005).

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Second Week with Mutant Receptors!

During my second week in the Allison lab, I continued my work with the thyroid hormone receptor alpha 1 (TRa1). My transfected HeLa cells from last week had been stained, fixed and were ready to view under fluorescence microscopy. However, during this time I also had to replicate additional DNA plasmids that would express my wild type (wt-TRa1) and mutant receptors (described here and in my future posts as tc-TRa1 and hcc-TRa1)* if I wanted to continue my experiments. I did this through a process known as bacterial transformation, where I inserted the expression vectors for human TRa1 coupled with a gene for antimicrobial resistance into Escherichia coli cells and then allowed them to grow on plates with kanamycin, selecting only for those colonies that had taken up the plasmid. Later on, I isolated and purified the genetic material from the E. coli colonies to obtain a higher amount of my DNA plasmids.

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First Update! Mutant Proteins in Cancer Development

My first week working in Dr. Allison’s lab has been nothing short of incredible. I have had a unique opportunity to develop my laboratory and critical thinking skills while working with the thyroid hormone receptor (TR). As you may recall from my abstract, I am interested in understanding how mutations in this protein may lead to the appearance of cancer; specifically, my project will focus in studying mutations in the THRA gene, linked to thyroid cancer and hepatocellular carcinoma.

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The Role of FBF in Oocyte Maturation in Rhabditis sp. SB347

A fundamental question in biology is how unspecialized stem cells develop into specific and specialized cell types. To address this question, we will investigate the potential role of FBF protein in the nematode species Rhabditis sp. SB347 based on the current understanding of FBF function in C. elegans. In the best studied nematode, C. elegans, FBF down-regulates germline stem cell differentiation by inhibiting translation of mRNAs that promote cell differentiation. Previous studies have shown that in hermaphrodite C. elegans, sperm must be present for oocytes to reach maturation. Based on this C. elegans model, we hypothesize that in SB347, FBF also plays a role in oocyte maturation and that this transition may depend on the presence of sperm. If FBF depends on the presence of sperm, then we predict that FBF will be present in the -1 oocyte in mated female germlines and absent in unmated female germlines. Ultimately, this project will provide more insights in the potential role that FBF plays in oocyte maturation in SB347.