DNA sequencing is used to study the genomes of prokaryotes that are important to humans and to ecosystems. Functional genomics uses gene sequences to determine the functions of the gene products. Comparative genomics compares gene sequences from different organisms to help identify their functions and evolutionary relationships. Transposable elements, including composite transposons, move from one place to another in the genome. Studies of the minimal genome may lead to the creation of artificial species.
learning outcomes
You should be able to:
Describe the characteristic features of prokaryotic genomes
Develop experimental approaches to address metagenomic questions.
Summarize the ways in which transposable elements can move about the genome.
Suggest evolutionary reasons to explain why prokaryotic genomes are small, sometimes contain plasmids, and have genes that move about the genome.
The following characteristics of prokaryotic genomes are essential for organisms that exist in a rapidly changing environment and must adapt rapidly: (1) Small genomes can show large changes with a few mutations. (2) Plasmids allow individual cells to share genomic information rapidly. (3) Transposons shuffle gene locations and therefore the rate of gene expression, and they cause mutations that make evolution possible.
How do transposons move about the genome?
Transposons either splice out of the host chromosome directly and move to a different location, or they make a DNA copy that is inserted at a different location, leaving the original transposon in place.
There are many bacterial species on the skin of the human belly button. How would you use metagenomics to develop a microbial “fingerprint”?
One could take a sample of belly-
Advances in DNA sequencing and sequence analysis have led to the rapid sequencing of eukaryotic genomes. We will now look at some of the new insights that have come from these studies.