Researchers have given us a count of around 37.2 trillion cells in the human body. Each of these mammalian cells constitute a nucleus and a cell membrane.
And as revealed by cytologists, every cell is symmetrical to one another, and that there are 23 pairs of chromosomes found in most of humans. The reason behind this fascinating fact is due to the cell programming, in all probability.
As per this programming, each variety of cell strives to reach a particular, pre-determined target size; and in the process, it adjusts, readjusts itself from time to time assessing whether it has crossed or lagging behind that target. There are molecules that sense its own size and enable the human cell to maintain uniformity.
However, there are certain cells in order to carry out some specific tasks, break out of this uniformity matrix.
Johns Hopkins University School of Medicine researchers conducted on genetically engineered mice, have suggested that the cilia count is dictated by a process observed in non-mammalian species. Known to have appeared first on single-celled organisms, cilia are small hair-like, finger-like primordial structures that serve as motors sensing the environment by shifting the cell or antennae.
What makes these cells noteworthy is that while other cells create 1 cilium per cell, these advanced cells go about creating hundreds of cilia.
In an attempt to answer the burning question, how the multi-cilliated cells are so drastically different from the rest of the body cells, Andrew Holland (PhD), professor of molecular biology and genetics (at the Johns Hopkins University School of Medicine), discovered that cilia’s base, centriole, where organelles are attached, gets formed prior to cell division; thereby leading to 2-parent centrioles in each cell.
Deuterosomes get created by multi-cilliated cells, which serve as a copy machine.
Keeping this theory in mind, Holland conducted experiments, which surprisingly ruled out deuterosomes’ pivotal function in determining cilia’s number. His experiments also disproved the idea that centrioles’ absence would impact the cilia’s number; and showed centrioles can be created spontaneously just like in small flatworm planaria which experiences the same de novo generation of centrioles.
Upon delving deeper, Holland observed that there is an area rich with fibrogranular material in the cell, where centrioles are flocking together. It is this protein concentrated region in the cell, brimming with required elements to create centrioles, which might be responsible for ultimately determining the number of cilia getting created, suspects Holland.
In his opinion, deuterosomes act to mitigate pressure from the parent centrioles. By being free from the activity of creating new centrioles, the parent centrioles thereby get to carry out other necessary activities.
All the experiments helmed by Dr Holland, have been chronicled in Nature Cell Biology, as Dec 2.
Unearthing the mechanisms or causes governing the cilia number, can shed light on treatment of respiratory infection, infertility, hydrocephaly-- all cilia-related ailments.