Indispensible Nature of Cell Division Protein Questioned

There exist various genetic factors and biological processes that are conserved throughout time due to their essential nature to the biological world. One of those most key is the process of cell division, by which genetic information is transferred from one generation of cells to the next. All organisms rely heavily on the continued functionality of the process of cell division, making it unlikely for change in the procedure for this phenomenon to take place as time progresses. Centromeres prove to play a crucial role in the process of cell division, providing attachment sites for duplicate chromosomes to separate to opposite poles within the cell. Microscopic analysis has continued to show researchers that while always present, centromeres are quite variable in the sequence of their coding DNA across the cells of different species. Regardless of this variability CenH3, a DNA packaging protein, has continued to remain a common factor for all cases of cell division to biologist knowledge until now.

Investigation by researchers at Malik and Henikoff labs has shown that there exist insect species whose cells lack this supposedly essential CenH3 protein. Their course of research into this topic began with the observance that certain species of insect, specifically butterflies and moths, had an abnormal centromere structure. Analysis of insect chromosome structure and centromere organization has allowed for researchers to divide various insects into two groups; these are monocentric and holocentric insects. The monocentric insects have traditional X-shaped chromosomes with singular centromere attachment while the holocentric insects have chromosomes that appear like railroad tracks as the centromeres run along the full span of the chromosomes with multiple attachments. Some insects identified as monocentric are bees, flies, and beetles; some identified as holocentric are moths and butterflies. Through genome sequencing analysis, researchers were able to come to the conclusion that monocentric insects had all conserved the CenH3 protein while holocentric insects had lost coding for this protein at some point in evolution due to its lack of necessity in the cell division process.

This proved an intriguing finding due to the disappearance of a protein thought to be essential to such a necessary process in the biological world as cell division. This discovery raises many questions as to the possibility for other changes in conserved genetic factors and biological processes among various species. This also brings about thoughts regarding implications to the development of defects in cell division.

I found this article to be quite interesting in the questioning of such a fundamental concept in biological studies. With a process like cell division, one would assume all characteristics and factors involved to remain consistent even as various species evolve due to the essential nature of this process. I find it fascinating that the CenH3 protein has been lost in the genetic code for some insects while not for others, and that this has not negatively impacted these species. Findings such as this that challenge prior belief really add excitement to the study of genetics. Maybe other similar discoveries will come about in the near future.

Original Article: http://www.sciencedaily.com/releases/2014/09/140924113748.htm

Related Page: http://www.plantcell.org/content/14/11/2825.full