X, Y and Mitchondrial DNA

-

It's all about the chromosomes (and mitochondria)

The 23 chromosomes of a human male. Courtesy: National Human Genome Research Institute

X, Y and Mitochondrial DNA are less well-known and not used by many genealogical researchers. Both Y and MtDNA tests are more expensive than the more common autosomal DNA tests. 

 X is always tested in an autosomal DNA test. However X results are less reported (FTDNA, 23andMe) or not reported at all (Ancestry, MyHeritage, LivingDNA), with the exception of Gedmatch.

 Rather than covering generations of your ancestry, each of these DNA types cover a smaller portion of your tree, which some see as a weakness. However, because of that restriction, the researcher gets a focused result, which can be powerful, if the test will help you answer your research question. 
Y DNA tests were first offered to the consumer in 2000 by only one company: FamilyTreeDNA. Ancestry also offered Y and mitochondrial tests between 2012 and 2014  but not since then. There are other companies now offering Y DNA tests, but none have the genealogy focus of FTDNA. FamilyTreeDNA was also the first to offer mitochondrial DNA tests. Both Y and mtDNA tests are more comprehensive and less expensive than they once were. And FTDNA's autosomal product called FamilyFinder exposes X matches in their chromosome browser, as does 23andMe.
In 2007, 23andMe became the first company to offer autosomal testing, and have since the beginning done some limited testing of the X, Y and mitochondrial DNA, even predicting haplogroups for Y and mt DNA. A haplogroup is a broad grouping of patrilineal or matrilineal DNA which indicate a common origin. 

 While one cannot search for X matches in 23andMe, X does show up in the chromosome browser if and only if there is a match on one of the 22 autosomes; the same is true for FTDNA. 

 If you and a relative match only on X, that will not show up in FTDNA or 23andMe. However, autosomal test data from any company uploaded to Gedmatch will show X matches and allow X analysis. However, a match only on X could reach back far into the past because of the nature of X chromosome recombination.
X chromosome to the left, tiny Y to the right.
Courtesy: National Human Genome Research Institute

We all have an X chromosome

Women have two! and men have one, which they get from their mother. Women have one from their mother, and one from their father's mother. If two men match on X, they both know that the match is on their mother's side of their family. It's a bit more nuanced for women.

 If X DNA analysis will answer one of your research questions, urge your most likely matches to upload to Gedmatch. 

Men get their Y from their fathers, who got it from their fathers

Why spend all that money to do a Y DNA test? In my case, it focused on what my Dad wanted to know -- his research question -- which was to learn more about his father's Cowans, who came from Selkirkshire Scotland to Upper Canada (now Ontario) in 1832. Scots parish records before the mid-1700s are rare, so Y DNA offers some help, and it was then the only DNA tool available. 

 One of my Dad's close matches had a very good tree back to Ireland, and we were able to surmise (but not yet prove) that both of our male lines came from a common ancestor in Stirling, Scotland around the time of the Plantation of Ireland in the early 1600s. 

Every human gets their mitochondrial DNA from their mother

Actual mitochondrial DNA is many time smaller than chromosomal DNA. By National Human Genome Research Institute - National Institutes of Health. National Human Genome Research Institute. “Talking Glossary of Genetic Terms.”Retrieved November 17, 2016, from https://www.genome.gov/glossary/index.cfm?id=129, Public Domain, https://commons.wikimedia.org/w/index.php?curid=53240683


I already had an autosomal test from 23andMe, so why would I want a mitochondrial test? Because my mother had died before I could test her. My dad had an autosomal test, so I knew that all the parts of my DNA that did not match him came from my mom. Mitochondrial DNA is special in that it follows the mother line and both men and women can test their maternal line. 

 I wanted to test DNA that was my mother's alone -- along with her entire mother line. I've always been interested in the maternal line, particularly since I read The Seven Daughters of Eve: The Science That Reveals Our Genetic Ancestry by Bryan Sykes years ago, before consumer testing was available. 

 So far, this mtDNA test has not led to any breakthroughs for me. Mitochondrial DNA is extremely stable, and even identical matches can be related through a common ancestor hundreds or even thousands of years in the past. That said, sometimes it is the only test which can support or disprove female parentage. 

We use DNA tests to answer our research questions

So how does one use these tests? For all DNA tests, be prepared to do a lot of research on your matches' trees. Most of them do not know how to do the research, and you do. This is as true for your X, Y and mtDNA matches as it is for auDNA matches.

 Make one of your trees your "home" tree for all of your DNA matches, and put everyone in one tree. "Build down" so that you can find descendants, and use the tools you have to make the matches and their line easy to find. 

 If you have an auDNA test with Ancestry, I suggest using that as your main genetic tree, although you should always have a backup on your own computer and perhaps in the cloud as well. Place all your matches into that tree, no matter where the match's test is or what type. Tag the match and keep notes about the size of match, their haplogroup, where they tested; whatever you know right there in the tree. 

 Not only does your tree enable you to find each of your matches, it is your best advertising to cousin/matches. So put trees everywhere, and refresh them sometimes. You may end up using other tools too, such as spreadsheets. I personally want to be able to see each of the people in a tree rather than just on a spreadsheet. 

If you have Legacy FamilyTree Seminars, I suggest the DNA Foundations series, which is 5 hours of video from Dr. Blaine Bettinger. This will give you an excellent background.

How to use X DNA to answer your research question

The Foundations series mentioned above covers X briefly, but Which Spot Does X Mark, Anyway? X-DNA Testing in Action by Debra Renard goes into detail. Be sure to download and read the syllabus before watching. Besides that video, which is excellent, I suggest this article by Debbie Parker Wayne from NGS Magazine and:

 Inheritance Fan Charts by Dr. Blaine Bettinger:

MS Word tables by Debbie Parker Wayne and Sue Griffith: 

Blogs & Wiki:

Y DNA: your paternal line

Y DNA is a huge subject. Basic to it is that there are two types of consumer test now. The most common test is STR (short tandem repeat) which shows up as a series of numbers which can be compared. More recent is the introduction of so called Big Y, which is an SNP (single nucleotide polymorphism) test, in a way akin to autosomal tests. I do not yet understand Big Y, but I won't give up! There is a series of links at https://brouwergenealogy.blogspot.com/p/genetic-genealogy.html which I plan to explore. Some links are dead, unfortunately.

 The most important thing to do with Y DNA is join a project or two. Join one for your surname, or includes your surname. Those project admins are your best resource and best source of advice. There are also haplogroup project groups which can be helpful, and some for localities. Do an internet search and another search at FamilyTreeDNA.

You may also choose to upload to MitoYDNA, which is a new project replacing the now-shuttered Ysearch and Mitosearch public databases, which allowed people who tested with other companies to have a place to share their Y and mtDNA data. Read more about it at https://www.yourdnaguide.com/ydgblog/2019/10/3/mitoydna-ydna-mtdna-free-website. There is even a Chrome plugin to make the process almost automatic. 

Mitochondrial DNA: your maternal line

Debbie Parker Wayne has a short article from NGS Magazine here. Then dig in with Roberta Estes: https://dna-explained.com/mitochondrial-dna/ and follow the entire series. Dr. Bettinger's Foundations in DNA series at Legacy also has an hour about mtDNA. 

Advertise!

For both Y and Mt DNA, remember to add your haplogroup to your Gedmatch profile. Sometimes a match can be sorted just by comparing a haplogroup! There are other places where you can create a profile, and folks sometimes forget that cousins will search for them, just as we do. You will have a profile at each company you tested with, or have a tree on. Ensure it entices your cousins to get in touch! You can add a custom fact even to FamilySearch Family Tree with the haplogroup of the tested person, and their Gedmatch kit number.

 If you use Groups.io, did you realize that you can change your profile per group? For any genealogy group, list your Gedmatch kit number, haplogroups and where you have tested. 

 Below is an image of my profile for our Genetic Genealogy/DNA group:

Comments

Post a Comment

Popular posts from this blog

What's the Question?

-
Image
We genealogists are often told by experienced researchers how important it is to begin with a research question. I resisted doing this for a long time, but now that I use a series of questions to guide my research, the search is more focused and actually finds more of the history of the family I'm investigating. I use a Google Doc as the  research proceeds, where I keep the question(s), the plan, timelines, checklist of resources to search, etc. all in one place. I've seen others use spreadsheets in the same way, perhaps splitting up things in tabs (Excel or Google Sheets). I prefer a document because I add source citations as I find them and I can begin writing up the case right there in the doc as the hypotheses are proven. Specific Questions in Previous Successes As beginners we often have no clue how much and what details we already know about a person, event or relationship, so it's hard to specify what we want to know. But when looking back at successful research, it
Read more

Looking for a Needle in a Haystack? GAME CHANGER at FamilySearch

-
Image
Generated with Bing ImageCreator (AI), March 13, 2024 Where is YOUR Needle, Your Missing Record? Genealogical Proof Standard When we use the GPS (Genealogical Proof Standard) as our guide, we all know that "exhaustive research" can be both tedious and exhausting. Is life long enough to search page by page through all the counties where all the members of a family might have lived, paid taxes, bought, leased or sold property, made a will or died intestate? It is possible that the new Full Text Search at FamilySearch will  eventually  allow us to do just that. It has been estimated that 75% or more of the records at FamilySearch were browsable but not searchable; the only indexes those found in the records themselves. Those records are certainly attainable by using those indexes and browsing to the record of interest, but the process is tedious, often frustrating, and slow. And once found, the record must be read and transcribed to be useful. This new Full Text Search tackles a
Read more

Shedding Your Genealogy "Stuff"

-
Image
AI: Bing Image Creator Generated Changing realities force many of us to consider the future of our genealogical collections. Whether a change in health, a new location or even just downsizing, it can be useful to evaluate what we have now, with an eye to the future. What we can pass along? Plan Ahead First: if you have online trees, create a plan to grant access to interested fellow researchers, even distant cousins. Depending on the website, you may need to add a codicil to your will, or just tell the site whom your successor will be.  Ancestry.com: there are two considerations: your DNA test and your tree(s). It is wise to share your DNA results with a cousin or other relative; no need to wait. Or you can  Assign a Manager .  For overall accounts and trees, there is  Ancestry® Family Plan Memberships .  FamilySearch help file:  How to Connect to a Family Member’s Tree .  B ecause it is a shared tree, a person cannot pass along their FamilySearch account. Ensure that your interested
Read more