Too often, non-experts and way too many genealogy experts use paternal and maternal when they should be using matrilineal and patrilineal. Half of your ancestors are maternal and half are paternal, but only a small fraction of those ancestors fail under patrilineal and matrilineal. At each level above you, only one female falls under the matrilineal lineage and one male under the patrilineal lineage. Go back enough generations to have 128 ancestors on one level and only one female and one male at that level are matrilineal and patrilineal, but 64 are paternal and 64 are maternal.
In my DNA presentations, I strive to always use patrilineal, paternal, matrilineal, and maternal in the appropriate places. It comes in handy because when you are dealing with Y-DNA or mtDNA haplogroups, there is only one female and one male at each level above you who can potentially provide the haplogroup. Also, you lose the haplogroup when it crosses from male to female for Y-DNA. For mtDNA, males inherit their mother’s mtDNA haplogroup, but don’t pass it on their children. My daughter has her mother’s mtDNA haplogroup, not mine. My sister’s two (2) daughters inherited my mother’s mtDNA haplogroup and passed it on their four (4) children. My sister’s grandson won’t pass on my mother’s mtDNA haplogroup, but the other three (3) are grand-daughters so they will if they have children.
For those who tested with 23andMe, it includes a basic to intermediate Y-DNA (for males although they often attach Y-DNA to females who had a male relative (brother, father, or other Y-DNA relative) test and males and females also receive a basic to intermediate mtDNA haplogroup. If my daughter ever tests at 23andMe, they would probably attach my basic Y-DNA haplogroup to her and show a rudimentary mtDNA haplogroup. If her husband and unborn son were to test, the son should have his own Y-DNA haplogroup that is probably close to my son-in-law’s Y-DNA and both would receive mtDNA haplogroup. For my grandson, it would match his mother’s mtDNA haplogroup or be very close. There can be minor haplogroup differences because 23andMe relies on SNPs to predict haplogroup when they should include STRs for improved accuracy. If you want improved Y-DNA or mtDNA haplogroup results, best to use FamilyTree DNA (FTDNA) or YSEQ.net as both companies offer a range of Y-DNA and mtDNA tests. The tests aren’t as cheap as an autosomal test, but can help narrow down matches in some cases. However, at the higher levels, the matches could be hundreds or thousands of years in the past. A lot depends on how many people have tested mtDNA or Y-DNA and how deeply they have tested.
With mtDNA, you can usually do a basic, intermediate, or full mtDNA test although FTDNA did away with their intermediate test a while back and only offer mtDNA Plus ($89) and mtFull Sequence ($199). YSEQ offers HVR1 ($25.00), HVR2 ($25.00) mtUpgrade ($115 which upgrades your HVR1 and HVR2 results if you have tested both to mtComplete), and mtComplete ($165.00). YSEQ’s mtDNA are cheaper, but you don’t get matching. However, if you are only wanting to verify siblings or other mtDNA matches as having the same mtDNA, this is a better deal than FTDNA. For those wanting matches who test with YSEQ, then you either have to add your results from a mtDNA test (HVR1, HVR2, or full mtDNA) and not simply your estimated haplogroup from 23andMe. FTDNA offers a full service http://www.mitosearch.org/ as a way to compare mtDNA results even if you didn’t test with them. Currently, the prevailing wisdom is testing mtDNA has limited benefits, but I think that’s a matter of so few people who have done complete mtDNA testing. Once full mtDNA or full DNA testing becomes the norm, I expect we will see increased value in mtDNA testing.
FTDNA also offers a similar service for Y-DNA testers at http://www.ysearch.org/. If you tested at another company, follow the instructions on how to add your Y-DNA results directly. For Y-DNA, the options are basically Y-12 to Y-111 at FTDNA, but you can order the Big-Y in addition which may give additional matches; you can also order SNP packs or individual SNPs. At YSEQ, there are a wide variety of options available. Another option for those who did Big-Y at FTDNA or Comprehensive Elite at Full Genomes (FGC). It’s $49 to upload your results to https://yfull.com/, but in my experience you may gain matches who only tested at FGC or another company who haven’t tested at FTDNA.