A STUDY OF CHROMOSOME ORIENTATION DURING MITOTIC METAPHASE

Abstract

This study was conducted to investigate whether chromosomes are misaligned or aligned during mitotic metaphase. Chromosomes that are touching or overlapping are considered misaligned. This study is significant because if chromosomes are misaligned prior to cell division, they may become entangled or break during anaphase separation. Entanglement or breakage could result in chromosome mal-segregation manifesting as aneuploidy leading to cell death, tumorigenesis, or non-cancerous diseases associated with this chromosomal abnormality, or increased energy expenditure by the cell as microtubules try to separate entangled chromosomes. This study was conducted by observing the orientation of chromosomes stained with 4',6-diamino-2-phenylindole (DAPI) within metaphase cells in solution. It was found that 16% of the time, cells had misaligned chromosomes. Another significant finding was microtubules mediate chromosome alignment in metaphase. Future studies will use mutagens to induce chromosome misalignment and cells with misaligned chromosomes will be studied post cell division to investigate the fate of chromosome segregation.