GENE PREDICTION AND COUNTING
It has been found out by using the sequencing technique that although the higher mammals are more complex, the number of genes do not increase likewise. The human beings (-30,000 genes) have only 1/3 rd more genes then the worms (-18,000). This phenomenon is still a paradox to scientists and is called C-value paradox. The C-value paradox indicates that despite the increasing complexity in higher mammals the numbers of genes do not increase likewise.
In human genome only less than 5% of the total sequence, codes, rest are either regulatory in nature such as the splice sites, intron and enhancers or they are simply called Junk DNA.
Table showing the genome size and gene predictions between several different organisms
Genome size in base pairs |
Organism |
No. of chromosomes |
The number of predicted genes |
Part of the genome that
encodes for protein |
500,000 |
Bacteria, E.Coli |
1 |
5000 |
90% |
14,000,000 |
Yeast, S. cerevisiae |
12 |
6000 |
70% |
100,000,000 |
Worm, C. elegans |
6 |
18,000 |
27% |
300,000,000 |
Fruit Fly, D. melanogaster |
4 |
14,000 |
20% |
125,000,000 |
Weed, A. thaliana |
5 |
25,500 |
20% |
3,000,000,000 |
Human, H.sapiens |
23 |
30,000 |
<5% |