OK, a geneticist, I have no effing clue why hair DNA is different from skin or saliva. THEY ARE THE SAME!. In a lot of older DNA samples, since mitochondrial DNA (a cell organalle founded in multiples with in a single cell), it was used. This DNA is maternally passed as semen does not insert any into the egg. The fact it is multi-copies made it very useful initially in DNA testing of degraded, small, or improperly stored sample, therefore a profile could be developed. For reasons too complex to get into, it has a lower mutation rate due to being a "haploid" genome, and not allowing recombination to occur.

Skin and saliva would also contain the mitochondrial DNA, ALL CELLS DO! It will trace the MATERNAL lineage, that is all, and is slow in evolving.

Genomic DNA is the combination of mother and father to form what is considered a "diploid" organism- genes from mom and pop. These can recombine (think of shuffling) so the next generation gets a a combination of both. The Y chromosome in males behaves as a "haploid," with no chromosome to align to allowing for recombination, and also has a slower mutation rate.

As long as the original samples, the reaction end results, or even the "processed reaction" samples have not been thrown away, then new technologies would allow for deep DNA sequencing. With a brother and possibly male children still alive, it could provide the answers. I can go in to more detail if anyone is interested, or point to some cool videos that will clarify this.

-m

And with Ross being cremated, any surviving children or his brother, the Y chromosome could be compared.

Very interesting, thanks for posting this.

The very little I’ve been able to understand regarding DNA (testing) is something like this:

Mitochondrial DNA (which is gathered from outside the cell) is inherited from the maternal side only as you point out – nuclear DNA (which is gathered from inside the cell) from both sides. So the latter is better for identification purposes, being more unique. But what it comes down to, forensically, is to find enough markers (which would be the…erm…things which are particular to the individual in question and which you use for the comparison) to make a meaningful comparison (to another sample, i.e. another set of markers).

Is that about right?

Now, the question would be this: Can you compare markers from a mitochondrial DNA sample to markers from a nuclear DNA sample? I’d guess you can – but that the result would naturally be less conclusive than a nuclear-nuclear comparison. Is this correct?

As far as the particular subject here goes, I have no idea what MB is talking about either – but he might be referring to the fact that the “Zodiac DNA” they supposedly have is a very partial profile (i.e. few markers). Perhaps it can’t be meaningfully compared to the Riverside DNA because the latter too is incomplete/partial – and perhaps it’s also a matter of a mitochondrial versus nuclear comparison:

R = partial mitochondrial
Z= partial nuclear

Just a…vague idea. It certainly can’t be a question of hair versus skin (or whatever) as such. That makes no sense, given the very little I know about the subject.

Would love some more input from someone who actually knows what they’re talking about (unlike yours truly).

N.

As I was writing and rewriting my post yesterday I misspoke when I said haploid genomes like the mitochondria have a lower mutation rate, as with the Y chromosome. Past research has shown them being higher, but estimates are all over the place (0, to 1 every 40 generations to 1 over 200+ generations, though estimates are changing all the time), but the mitochondria has also been more extensively studied due to in part, its small size genome (16kb while the b stands for nucleotide bases- A,T,C,G-, you can think of it like computer memory bytes) and the cumbersome older DNA techniques. A single cell can have 100’s of them in it, making it easier to sequence. (Side note-if you are wondering why the mitochondria has its own genome, it is believed millions of years ago it was a free living, single celled "organism" and somehow was engulfed by another single celled organiasm- forming a symbiotic relationship. The mito gets a nice comfy protected environment and the cell got an amazing energy producer- the mito’s main job. That is why the mitochondria’s genome is reproduced independently of the cell. The chloroplast is plants is thought to have come about in the same way).

Note to Norse: the mitochondria are in the cell, but not the nucleus, where our human genome (chromosomes) are. EDIT: I also meant to answer, no, unfortunately the markers they have cannot be compared to each other, but can be used in an overall profile. The issue I mention below is with Ross dead and cremated, the markers they have done will need to be compared to his family, unless some definitive source of Ross’s DNA can be found (ex- tube of blood from a hospital stay), and we will probably need more done.

As reference, the size of the human genome is 3.3gigs, which is why it is the preferred DNA to use in DNA testing as there are many more places to look for variation, and recombination allows siblings and other family members to be excluded.

A lot of times now, and will try not to us abbreviations as they cause confusion, but if you read things elsewhere- mtDNA refers to the mitochondrial genome and usually just DNA means the nuclear genome (that which we get from both parents) but sometimes to avoid confusion is written nDNA. The Y chromosome of males is part of the nuclear DNA, and again follows the male lineage, but with the nuclear DNA.

Within either genome, there are "hotspots" for variation, and these are what are looked at in DNA testing and the mutation rates at these locations is really what matters to include and exclude suspects.

Originally, when dealing with old remains, the mitochondrial DNA was very helpful if you can get a DNA sample from a sibling or mother for identification purposes (or depending on their family, an aunt, one of her children, etc. Jut trace the maternal line) and there are millions more copies in the body.

So first we need a DNA profile from what they have of Zodiac- some good mitochondrial markers and some nDNA markers. Then, since Ross has passed, a close relative would be needed to form the comparison to see if it could be him.

I hope I haven’t sufficiently confused anyone yet. And feel free to ask any questions, it can get very confusing.

I hope I haven’t sufficiently confused anyone yet…

Well…

No, seriously – thanks for the reply, it was clarifying for me at least.

I have several further questions, but I think it’s better to start a separate DNA thread (as mentioned above). The DNA stuff which pertains to Ross (who is a known factor) seems more clear cut than the general Zodiac DNA question.

Thanks again for posting on this subject, very much appreciated.

I hope I haven’t sufficiently confused anyone yet…

Well…

No, seriously – thanks for the reply, it was clarifying for me at least.

I have several further questions, but I think it’s better to start a separate DNA thread (as mentioned above). The DNA stuff which pertains to Ross (who is a known factor) seems more clear cut than the general Zodiac DNA question.

Thanks again for posting on this subject, very much appreciated.

So all told, are we looking at a lot of DNA? Or just the hair or two from Riverside? I would love clarification on the total amount from all crime scenes, if anyone has that top of mind.

I don’t think anyone (among us amateurs, that is) actually knows precisely what sort of Zodiac DNA they have, or believe they have.

But what has been suggested in the past is, off the top of my head:

* That they have partial DNA which is insufficient to make a positive match to anyone – but which can be used to clear suspects.

* That this DNA has been extracted from a letter (or letters).

* Some have suggested that the DNA is from a hair sample (possibly found under a stamp). This may have been – sort of – confirmed at one point by the lab in San Francisco that extracted the DNA (need to look for the links), but part of the problem is that there seems to be plenty of uncertainty surrounding exactly WHEN they did what, and how recent their latest efforts are.

* Others have suggested it is a saliva sample.

* Others again have suggested that the Z-DNA is no good. In other words, it can’t be used – even – to clear suspects. Too few markers – or rumors to that effect.

None of the above has ever been properly confirmed as far as I know, and it is – as we see – partly contradictory suggestions.

Lastly, I have been led to believe that if the Z-DNA is from a hair sample, it’s mitochondrial DNA – whereas if it’s from a saliva sample, there’s a chance it could be nuclear DNA (this is a question of cell deterioration, i.e. what type of cells deteriorate more slowly/quickly – I’m sure marie can tell us more about that aspect).

Oh, and thanks for creating the thread, Seagull

PS The above pertains to the so-called "Zodiac DNA". The RIverside DNA is a different animal altogether, presumably extracted from a hair sample. The Z-DNA I refer to was extracted from evidence relevant to the Z case, reportedly one of the Z letters (or more letters). So, two different samples – just to make that clear.

It is furthermore unclear whether the two have been compared – but some (including Butterfield, as mentioned above) have claimed that this is, in fact, impossible to do.

Only if the hair follicle is present is there a chance of DNA or mtDNA being present. If any is found on a hair without the follicle it could be shed skin cells, or bacterial contamination (hygiene issues, perhap).

The biggest problem I see with DNA testing now to confirm or eliminate a PoI, especially Ross, is what to compare it to. If there are changes that could eliminate him as a suspect (brother’s DNA would be awesome), why wouldn’t he be happy to give a sample. Even with limited markers, someone could potentially be ruled out.If he is sick of hearing about it, give a sample and lets see what matches in the mt DNA (unless a marker is that 1 in a lot mutations). That, to me, adds more suspicion.

If other tests were genomic, there is the extreme possibility since you have a 50% chance of getting DNA from mom or pop at particular location,. The odds of even an incomplete profile have it all be different is low, but not impossible. Maybe they can exhume the dad, I think he was not cremated. But it would be easier if the surviving brother agreed. And then the brothers’s DNA would be best.

The biggest other issues in forensic DNA is chain of custody of samples. Riverside seems not forthcoming with their evidence. I do not know about the Stine case. The reason so much is backlogged is time of "approved" labs. I wish every rape kit or un-id’s tissues from murders could be id’s tomorrow a lot of future crime would be prevented.

I think a huge problem with the whole DNA senerio, as it relates to this case, is that it is almost assured that any evidence that could be used to extract a sample is highly cross contaminated.

I think a huge problem with the whole DNA senerio, as it relates to this case, is that it is almost assured that any evidence that could be used to extract a sample is highly cross contaminated.

Yes. It would have to be from, say, under a stamp. And even that would be possible to question.

That said, I doubt this will ever come down to running Z-DNA through a database in order to find a match, so the cross contamination problem doesn’t worry me that much. What could happen, at best, is something like the Ross scenario above:

– Develop a case against NN to the point where it becomes reasonable to compare his DNA to the Z sample.

– Get a sample. Either from NN’s relatives or, ideally, from NN himself in one form or another.

– The probative nature of the thing isn’t really the point, as NN will in all likelihood be deceased.

– If the comparison shows that the two samples are most likely from the same individual, well, that will be enough for most people.

I don’t think it’s realistic to hope for anything more than the above. But then again the above wouldn’t be bad – considering the more likely outcome, which is…well, nothing. Ripper territory, etc.

(this is a question of cell deterioration, i.e. what type of cells deteriorate more slowly/quickly – I’m sure marie can tell us more about that aspect).

Actually, thats a great question I would have to ask around about, but my inclination as a whole is to say its storage of the sample or item (like Stine’s shirt- get back to that in a sec) that would make the most difference. The one lab I worked in that had long term storage of tissue and cell samples stored them in tubes kept under liquid nitrogen. Also, there is solid matrix which I have used to, um, preserve potentially one of my cat’s DNA (no, I am not quite crazy and have no intention of cloning him- but he died from an interesting cancer and I had free samples of this matrix, which can be stored at room temperature, so what the heck. And I also saved fabric samples he liked to chew on of my clothes, and have them in a non-defrosting freezer).

But new techniques can get around some degradation. leaving us with contamination issues. But when I look at the photos where they are analyzing Stine’s shirt- they are not wearing gloves, have it spread out on a table surrounded by may people, no masks (a simple sneeze would spray the whole sample, contaminate, and increase degradation).

But I can give some examples from reality in a bit that might be worth following up on. First, we need the DNA mt or n markers that were run and what variant was present.The variants present in populations have been extensively studied and there are charts of how common that variant may be in a particular population (race, ethnicity, location (an isolated village or tribe may not have much variablility, etc). Percentages (or chance of having the variant) from these numbers is what is used. Elimination of a suspect can be 100%, however inclusion can only approach 100% since it is the "chance of having the variant", and there is always the possibility someone, somewhere in the wold may have the same profile. Now they try to get the chance to 1 in the billions, greater than the population of the earth.

And if anyone would like to read some of my publications as proof I generally now what I am talking about, feel free to PM me, we can FB friend, or I can send you links to a few publications. Marie is my middle name as I like some anonymity on public boards

Marie:
Thank you muchly for providing us with knowledgeable info re DNA, mtDNA, etc. It would appear, to my aging eyes that, despite degradation, sloppy handling, and so forth there’s a very good chance samples attributed to Zodiac could lead to his identification today–or at least point the finger of suspicion at an individual who could then be microscoped (so to speak). Am I right, or have I misread your posts?

Marie:
Thank you muchly for providing us with knowledgeable info re DNA, mtDNA, etc. It would appear, to my aging eyes that, despite degradation, sloppy handling, and so forth there’s a very good chance samples attributed to Zodiac could lead to his identification today–or at least point the finger of suspicion at an individual who could then be microscoped (so to speak). Am I right, or have I misread your posts?

IMHO, in the right hands, it could be done. Some cutting edge tricks (or techniques, perhaps would be a better term) should be used, but if a bit of DNA remains, its possible. The biggest problem will be getting someone related to compare it to, in the case of Ross Sullivan.

A cool example of a new technology (it doesn’t go into scientific details) is here http://www.illumina.com/areas-of-intere … 013227IBN2 with a one minute video that says about what I am saying. I have used this technology for a different reason and found some needles in the haystack.

I have also reached out to a new company/technology that developed from an upstart at a University where I worked, and had met the founder and CTO some 15 years ago, hoping he might remember me. I didn’t give details of the specific case, just asked if he thought is could be used for our kind of forensic/cold case with degraded DNA analysis. The company has worked with the CDC and found causes of outbreaks well before older techniques.

-marie

You’ve brought up another interesting point, Marie: the necessity of a relative’s DNA being used to provide identification. I’m no legal scholar, but it seems to me that said relative could not be compelled to provide a DNA sample. Right or wrong?