Decrypting an achiasmatic segregation pathway in Arabidopsis Thaliana (2014)

Undergraduate: Neelesh Dewan

Faculty Advisor: Gregory Copenhaver
Department: Biology

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Meiotic recombination is the process by which homologous chromosomes exchange genetic material during gamete production by ¿crossing over.¿ This shuffling of parental chromosomes is not only thought to be important for increasing genetic diversity in a population, but also a necessary step in segregating chromosomes appropriately during meiosis. Plant breeders may find it desirable to preserve advantageous gene combinations in their crops through generations and, in this context, manipulation of recombination can have a significant impact in breeding methods. Most eukaryotes, including humans and plants, require at least one crossover (CO) per chromosome to avoid non-disjunction and resulting genetic disorders associated with chromosome mis-segregation. theless, evidence of crossover-independent meioses have been observed in many organisms including insects such as Drosophila males, mammals, and plants.
In all sexually reproducing species studied thus far, including plants, the topoisomerase-like protein SPO11-1 initiates meiotic recombination by catalyzing DNA double-strand breaks (DSBs) to initiate crossing over. Thus in the absence of SPO11-1 recombination does not occur, resulting in a sterile phenotype. My project seeks to find a SPO11-1 mutant that maintains fertility in the absence of recombination through a chemical mutagenesis screen.