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Genomics is a study of single organisms genome. Example is human genome project where we study
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the genes of human beings. Whereas metagenomics is a study of collection of genomes from multiple
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organisms recovered directly from an environment or biological sample. So from this soil sample
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we are isolating microorganisms. Study of all these microbes constitute metagenomics. Another example is gut microbiome isolating microbes from the gut. Then DNA is extracted
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and study of all these microorganisms present in the gut constitute metagenomics or gut microbiome
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The basic methodology of genomics is genomic DNA isolation. First the DNA is isolated. Then
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it is separated using gel electrophoresis. Then cutting of DNA using restriction enzyme and
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joining using ligases. Then cloning that DNA into a suitable vector to replicate inside a host
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Then making a recombinant DNA for study of expression patterns. Then DNA amplification by
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PCR and further DNA sequencing. DNA sequencing is involved in both genomics and metagenomics
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In the case of metagenomics let's take an example. Broad sampling by direct sequencing without
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relaying on cultured cells. So this is an example from 67 individuals gut microbiome study is
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conducted. First we will be isolating the sample followed by DNA extraction. Then DNA sequencing
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like shotgun sequencing. Then this is assembled combined short sequences to reconstruct individual
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genomes. This is followed by taxonomic binning. That means the process of grouping sequences
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based on similarity to identify different individual microbes or different species. So after binning you can see that we have a gene pool that belongs to a single species
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And finally gene prediction identifying genes based on sequences and also predicting the function
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of genes. So this is the general procedure of metagenomics. Genomics focuses on single
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organisms genetic makeup understanding the structure function and interactions of all the
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genes that makes up the genome like this human genome project. Whereas metagenomics is involved
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in the study of complete set of genomes in a sample that includes bacteria virus fungi protozoa
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etc. directly from a mixed sample like a soil sample or a gut microbiome. Finally the applications
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of genomics it is involved in gene discovery and diagnosis identification of genetic diseases
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targeted therapy prenatal diagnosis and testing infectious disease research. The advantage of
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metagenomics is it allows studying communities of organisms in their natural environment without
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culturing them. Majority of the microbes cannot be cultured easily so metagenomics is a method
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that bypasses the involvement of culturing microorganisms. Helps to understand microbial diversity or taxonomic profiling of a sample identifying previously unknown species during
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taxonomic profiling we can identify new species. Environmental monitoring studying the population
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of microbes with changing environment for example studying the population of microbes
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at different seasons or when exposed to a pollutant like that then disease ecology
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for example the gut microbiome in an healthy individual compared to a disease condition
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So these are some applications of metagenomics. Hope you are benefited from this video. Take care
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stay blessed. Thank you so much you are with biology exams4u.com
