https://www.sciencedaily.com/releases/2022/03/220331151517.htm

Most people will think that the human genome was completely sequenced by 2003 in the Human Genome Project.
Not so. There were gaps.
It has taken nearly another 19 years to fill all the gaps to get a truly complete human genome.

March 31, 2022. Scientists have published the first complete, gapless sequence of a human genome.

The full sequencing builds upon the work of the Human Genome Project, which mapped about 92% of the genome. That last 8% includes numerous genes and repetitive DNA and is comparable in size to an entire chromosome.

The cost of sequencing a human genome using “short-read” technologies, which provide several hundred bases of DNA sequence at a time, is only a few hundred dollars, having fallen significantly since the end of the Human Genome Project. However, using these short-read methods alone still leaves some gaps in assembled genome sequences.

Over the past decade, two new DNA sequencing technologies emerged that produced much longer sequence reads. The Oxford Nanopore DNA sequencing method can read up to 1 million DNA letters in a single read with modest accuracy, while the PacBio HiFi DNA sequencing method can read about 20,000 letters with nearly perfect accuracy. Using long-read methods, we have made breakthroughs in our understanding of the most difficult, repeat-rich parts of the human genome.

The package of six papers reporting this accomplishment appears in today’s issue of Science, along with companion papers in several other journals. For more, visit Genome.gov/T2T and follow @Genome_gov.

so now the government want everyone’s séquences

SCIENCE said:

so now the government want everyone’s séquences

We can always hope that they do, and not just the sequences of psychopathic killers.

It’s very difficult to know which species have been sequenced, because of problems like this.

I used to say that a minimum of 4 times coverage of chromosomal DNA was needed in order to count a species DNA as “sequenced”.
But the progress of shotgun methods meant that “4 times coverage” became inappropriate.
And with these new methods further on, the nanopore method and the 20,000 base pair method, it’s harder to know.

How can we tell how complete the neanderthal genome is, or the woolly mammoth, or the thylacine, or reference species (eg. reference marsupial), or these many critically endangered species, or the food futures species?

That’s what concerns me.

mollwollfumble said:

SCIENCE said:

so now the government want everyone’s séquences

We can always hope that they do, and not just the sequences of psychopathic killers.

It’s very difficult to know which species have been sequenced, because of problems like this.

I used to say that a minimum of 4 times coverage of chromosomal DNA was needed in order to count a species DNA as “sequenced”.
But the progress of shotgun methods meant that “4 times coverage” became inappropriate.
And with these new methods further on, the nanopore method and the 20,000 base pair method, it’s harder to know.

How can we tell how complete the neanderthal genome is, or the woolly mammoth, or the thylacine, or reference species (eg. reference marsupial), or these many critically endangered species, or the food futures species?

That’s what concerns me.

According to wikipedia, close to 400 animal species genomes have been sequenced.

But this includes “draft genomes” and there’s no way of knowing (even by looking up each individual research article) how many gaps there are in those drafts.

Here’s part of the list.

Let’s concentrate on the thylacine. How accurate is the genome there?

https://www.nature.com/articles/s41559-017-0417-y

We don’t know for sure if the thylacine is closest to numbat or equally far from several marsupial species.

Thylacine numbers started dropping long before Europeans arrived, long before Tasmania separated from the mainland, even significantly before Aborigines arrived!

SCIENCE said:

so now the government want everyone’s séquences

That could a lot of data from cord blood surely?

Noice