Christie Joan Toussaint ‘22

Christie Joan Toussaint

Major: Natural Science
Bio: Christie Joan Toussaint is a senior at Fordham University. She is currently majoring in Natural Science. Her passion for studying under this major stem from her interest in studying all aspects of the life of organisms such as the anatomical structure and development. Her research project "The Application of the Allium cepa technique in Biochemistry/Genetics Lab Classes" aims to inform prospective science majors about easy, innovative ways to study cytogenesis, mutagenesis and genotoxicity.

Title of Research: The Application of the Allium cepa technique in Biochemistry/Genetics Lab Classes
Mentor: Dr. Ana Helena Sales, Department of Natural Sciences
Abstract: Introduction. The Allium cepa assay is an easily handled, low-cost test system which has been used to evaluate cytotoxicity and DNA damages, such as chromosome aberrations and disturbances in the mitotic cycle. Objective. Preparation of an educational manuscript promotes the application of this technique in biochemistry/genetics laboratorial classes to assist the apprenticeship of cytogenetic study of mitotic cell division, mutagenesis, chromosomes structure, genotoxicity, phytotomy and microscopy. Methodology. This project applied the root meristems of A. cepa to the cytogenetic study of mitotic cell division and chromosome structure. The chemical agents used in this work are known for disrupting the mitotic cell cycle and promoting chromosomal aberrations. Slide preparation and microscopic analysis were used to examine the effects of different chemicals in A. cepa roots. The biochemical process of the Feulgen technique is used in cytological research to investigate chromosomes in dividing cells with optical microscopy. Results. Both macroscopic and microscopic parameters of cytotoxicity were present in the positive control roots of A. cepa. Positive control roots were thinner and more fragile in comparison to the negative control roots. Positive control roots also were shown to have chromosomal aberrations and arrests in mitosis. Conclusions.  The A. cepa assay was shown to have positive results in this project. The hypotheses for this lab were confirmed by the assay: 1) all the stages of mitosis are visible in both the positive and negative control; 2) it is possible to see chromosome aberrations and disturbances in the mitotic cycle in the positive control.