Why many organisms even though they possess mitochondrial DNA (mtDNA), it is not typically represented by chromosomes labeled as "mtDNA"?

Question

[George X.]

While I was searching the genomes of some eukariotic organisms (fungi,plants,protists) even though I knew that they had mitochondrial DNA,when I searched their genome structure I couldn't find any "chromosome" labeled as "mtDNA". Here I give some links of genomes that show this: https://www.ncbi.nlm.nih.gov/genome/gdv/browser/genome/?id=GCF_016861865.1 https://www.ncbi.nlm.nih.gov/genome/gdv/browser/genome/?id=GCF_009556855.1

Why does this happens? How can I find if the mtDNA sequence is inluded in these "chromosomes"?

[Ram]

Please keep in mind that posting the same question to multiple sites can be perceived as bad etiquette, because efforts may be made to address a problem that has already been solved elsewhere in the meantime.

The helpful thing to do if you do decide to post on multiple forums is to add a link to the other forum posts on each post so people will look at the other posts before investing their effort.

Link to post on bioinfo SE: https://bioinformatics.stackexchange.com/questions/22246/why-many-organisms-even-though-they-possess-mitochondrial-dna-mtdna-it-is-not

[George X.]

Thank you I will keep that in mind!

[Ram]

Are you sure the sequences don't exist - could it be that the viewer does not show them?

Answer 1

[GenoMax]

Organelle genomes may be separately sequenced and thus may have their own RefSeq entries. Here are five genomes from the organism you refer to : https://www.ncbi.nlm.nih.gov/nuccore/?term=ddbj_embl_genbank%5Bfilter%5D+AND+txid37727%5Borgn%3Anoexp%5D+AND+complete-genome%5Btitle%5D+AND+mitochondrion%5Bfilter%5D