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| Where are they? |
This series is a response to an analysis of a paper in the journal Nature about the emergence of "eDNA" a.k.a. environmental DNA (A 2-million-year-old ecosystem in Greenland uncovered by environmental DNA).
The interesting question is why would human DNA segments be found in 2-3 million year old eDNA from Greenland?
And just what a "human gene" is still "rocket science" in some ways:
"More problematic is the reality that the human genome is still a vast catalogue of the unknown and scarcely known. The Human Genome Project’s most startling finding was that human genes, as currently defined, make up less than 2 percent of all the DNA on the genome, and that the total number of genes is relatively small. Scientists had predicted there might be 80,000 to 140,000 human genes, but the current tally is fewer than 25,000 — as one scientific paper put it, somewhere between that of a chicken and a grape. The remaining 98 percent of our DNA, once dismissed as “junk DNA,” is now taken more seriously. Researchers have focused on introns, in the gaps between the coding segments of genes, which may play a crucial role in regulating gene expression, by switching them on and off in response to environmental stimuli."
(Lost on the Gene Map). The discipline of "human DNA" is somewhat in flux.
In today's post four entities of Bioproject PRJEB55522 are considered in the search for human DNA in Greenland eDNA: (GCF_000181275.1 Sorex, GCF_000233375.1 Salmo, GCF_000260355.1 Condylura, and GCF_000292845.1 Ochotona).
The results are:
Ochotona eDNA version GCF_000292845.1 was found in human DNA:
|ATG*GGA*CAG*AGG*CCT*GGG*GAA*GCT*CTG*CAA*CAC*AGA*CTT*TTA*ACT*CAG*GGG*CAT*GTA*TAG|
|ATG*GCC*GAG*CGG*TCT*AAG*GCG*CTG*CGT*TCA*GGT*CGC*AGT*CTC*CCC*TGG*AGG*CGT*GGG*TTC*GAA*TCC*CAC*TCC*TGA|
Condylura eDNA version GCF_000260355.1 was found in human DNA:
|ATG*TCT*TCT*AGT*ATT*TTG*CTT*TCA*AAT*TGT*GTC*TCC*TGC*CAT*TTG*TGC*CAC*ATT*TAA|
|ATG*CAA*TTA*ACG*GCA*CCA*ACA*TTT*ACA*AAA*TAT*GAT*TAC*AAG*CGC*TTT*GGT*TAA|
|ATG*TGC*ATT*TTT*TCG*AGA*GAC*TTG*CAT*TTT*CTT*TGT*GCA*AAT*AAA*GAG*GCC*CTA*AAT*TCT*CCA*TAG|
|ATG*CAG*TGG*AAC*CAT*GAT*AAC*AAA*CAC*AGG*CTC*CAC*TTT*TTG*CTA*CAT*CCC*CCA*ATT*AAT*TAA|
|ATG*AGA*ACA*TAT*GAG*AGA*GTA*TTA*ACA*GAA*AGG*CAC*ACT*TTG*ATT*TAC*TGA|
|ATG*AAC*TCA*GGG*GGC*AGG*GAG*GGC*AGC*TGG*ATG*AGG*GTG*GAG*CCT*GGG*GGG*CGG*GTC*TGA|
Sorex eDNA version GCF_000181275.1 was found in human DNA:
|ATG*TCA*CAA*ACT*ATA*AAG*CTA*CAG*GGA*GGT*AAT*TCA*ATT*ACC*AAT*TTA*GAG*GTT*TTC*TTT*TTA*TTT*AAA*TAA|
|ATG*TCA*TTA*AGG*CTT*TTG*TCT*GCG*CTG*TTT*TTG*TTT*CAG*AAC*TTT*TCT*CAC*AAT*CCT*ATT*TTT*TGT*TGA|
Salmo (Salmon, fish) eDNA version GCF_000233375.1 was NOT found in human DNA
So, some "human DNA" segments can be found in the ancient environment, in some animals, but none were found in the Salmon, a fish.
The previous post in this series is here.
