differences in different versions of genomic assemblies

Question

[Javad]

Hello everybody,

Could you please explain what is the difference between different versions of genomics assemblies. I am particularly interested to know when a new version of genomic assemblies is published (for example GRCh37 vs GRCh38), does the coordinates of different genomic features change or do they stay the same?

Thanks a lot.

Answer 1

[Bastien Hervé]

In UCSC you have the Assembly details of each version : https://genome-euro.ucsc.edu/cgi-bin/hgGateway?redirect=manual&source=genome.ucsc.edu

For example, if your choose GRCh38 and you go to Asssemby Details -> GRCh38 Highlights

You got these informations :

Sequence updates - Several erroneous bases and misassembled regions in GRCh37 have been corrected in the GRCh38 assembly, and more than 100 gaps have been filled or reduced. Much of the data used to improve the reference sequence was obtained from other genome sequencing and analysis projects, such as the 1000 Genomes Project.

Etc...

If you need more information about patches you can find it here : https://www.ncbi.nlm.nih.gov/grc/human

Answer 2

[GenoMax]

Genome reference consortium is your official source of such information.
Coordinates will change between major genome builds. On the other hand patch releases (updates) don't result in changes to chromosome coordinates.