How have scientists derived the gene sequences known today?

In summary, scientists use a variety of methods, including sequencing and computational prediction, to arrive at gene sequences available in different databases like NCBI. These methods have evolved over time and depend on the data available for the organism. Initially, mRNA was purified and reverse transcribed for Sanger sequencing or next generation sequencing. Later, gene sequences were refined and compared to genomic DNA sequences. For organisms with only genomic DNA available, computational methods are used to predict gene sequences based on known gene features and comparisons to other organisms.
  • #1
TytoAlba95
132
19
I know that human genome sequencing was done by 2001. Inintially there were Maxam-Gilberth technique, then Sanger's technique and then finally NGS techniques have made sequening faster and efficient. My question is, though we are able to sequence the whole genome, how have scientists arrived at the gene sequences available in different databases link NCBI?

Did they compare the mRNA sequences with the known genomic sequence, to arrive at the gene sequences known today?
 
Biology news on Phys.org
  • #2
There are a number of different methods that have changed over time and depend on the data available for the organism. Initially, scientists would purify mRNA from an organism, reverse transcribe to cDNA then clone the cDNA into plasmids or BACs for Sanger sequencing (older methods) or generate libraries for next generation sequencing (modern methods). The gene sequence can later be refined by methods that better identify the ends of the transcripts, and the gene sequence can be compared to genomic DNA sequences from the same organism.

For many organisms, only the genomic DNA sequence is available, so gene sequence are predicted computationally by using information about what gene features look like (e. g. promoters, splice sites, terminators), making use of the fact that protein coding genes have long, statistically detectable stretched lacking stop codons, and comparing the sequence to other organisms with better known genes.

For more information see:
https://www.nature.com/articles/nature24286https://en.m.wikipedia.org/wiki/Gene_prediction
 
  • Like
Likes TytoAlba95
  • #3
Thank you
 

1. How do scientists determine the order of nucleotides in a gene sequence?

Scientists use a process called DNA sequencing, which involves breaking down the DNA into smaller fragments, determining the sequence of nucleotides in each fragment, and then piecing them back together to create the full gene sequence.

2. What technologies are used to sequence genes?

The two main technologies used for gene sequencing are Sanger sequencing and next-generation sequencing (NGS). Sanger sequencing is a slower, but more accurate method, while NGS allows for faster and more cost-effective sequencing of multiple genes at once.

3. How do scientists ensure the accuracy of gene sequences?

Scientists use various quality control measures to ensure the accuracy of gene sequences, such as repeating the sequencing process multiple times and comparing results, using different sequencing technologies, and cross-checking with known gene sequences from databases.

4. How have gene sequencing techniques evolved over time?

The first method of gene sequencing, developed in the 1970s, was Sanger sequencing. Since then, NGS technologies have been developed, allowing for faster and more comprehensive sequencing. Additionally, advancements in computing and bioinformatics have greatly improved the analysis and interpretation of gene sequences.

5. How do scientists use gene sequences in their research?

Gene sequences are used by scientists in a variety of ways, such as studying the function of genes, identifying genetic mutations and variations, and understanding the evolutionary relationships between species. Gene sequences are also used in medical research to develop treatments for genetic diseases and personalize medicine based on an individual's genetic makeup.

Similar threads

Replies
3
Views
2K
Replies
2
Views
3K
Replies
2
Views
3K
  • Biology and Medical
Replies
1
Views
2K
  • Biology and Medical
Replies
11
Views
5K
  • Biology and Medical
Replies
1
Views
3K
Replies
2
Views
3K
Replies
1
Views
1K
Replies
2
Views
2K
  • Biology and Medical
Replies
11
Views
5K
Back
Top