Editing Mitochondrial DNA (section)

=== Female inheritance ===
In [[sexual reproduction]], mitochondria are normally inherited exclusively from the mother; the mitochondria in mammalian sperm are usually destroyed by the egg cell after fertilization. Also, mitochondria are present solely in the midpiece, which is used for propelling the sperm cells, and sometimes the midpiece, along with the tail, is lost during fertilization. In 1999 it was reported that paternal sperm mitochondria (containing mtDNA) are marked with [[ubiquitin]] to select them for later destruction inside the [[embryo]].<ref>{{Cite journal |vauthors=Sutovsky P, Moreno RD, Ramalho-Santos J, Dominko T, Simerly C, Schatten G |date=November 1999 |title=Ubiquitin tag for sperm mitochondria |journal=Nature |volume=402 |issue=6760 |pages=371–372 |bibcode=1999Natur.402..371S |doi=10.1038/46466 |pmid=10586873 |s2cid=205054671}} Discussed in: {{cite journal |doi=10.2307/4012086 |jstor=4012086 |title=Mom's Eggs Execute Dad's Mitochondria |journal=Science News |volume=157 |issue=1 |page=5 |year=2000 | vauthors = Travis J |url=https://www.sciencenews.org/article/moms-eggs-execute-dads-mitochondria |archive-url=https://web.archive.org/web/20071219174548/http://www.sciencenews.org/articles/20000101/fob3.asp |archive-date=19 December 2007 |url-access=subscription }}</ref> Some ''[[in vitro]]'' fertilization techniques, particularly injecting a sperm into an [[oocyte]], may interfere with this.{{cn|date=November 2024}}

The fact that mitochondrial DNA is mostly maternally inherited enables [[Genetic genealogy|genealogical]] researchers to trace [[Matrilineality|maternal lineage]] far back in time. ([[Y chromosome|Y-chromosomal DNA]], paternally inherited, is used in an analogous way to determine the [[patrilineal]] history.) This is usually accomplished on [[human mitochondrial DNA]] by sequencing the [[hypervariable control region]]s (HVR1 or HVR2), and sometimes the complete molecule of the mitochondrial DNA, as a [[genealogical DNA test]].<ref>{{Cite web |date=2016 |title=Hiring a DNA Testing Company Genealogy |url=https://familysearch.org/wiki/en/Hiring_a_DNA_Testing_Company |url-status=live |archive-url=https://web.archive.org/web/20161003102034/https://familysearch.org/wiki/en/Hiring_a_DNA_Testing_Company |archive-date=3 October 2016 |access-date=2016-10-02 |website=Family Search |publisher=The Church of Jesus Christ of Latter-day Saints}}</ref> HVR1, for example, consists of about 440 base pairs. These 440 base pairs are compared to the same regions of other individuals (either specific people or subjects in a database) to determine maternal lineage. Most often, the comparison is made with the revised [[Cambridge Reference Sequence]]. Vilà ''et al.'' have published studies tracing the matrilineal descent of domestic dogs from wolves.<ref name="Vila">{{Cite journal |display-authors=6 |vauthors=Vilà C, Savolainen P, Maldonado JE, Amorim IR, Rice JE, Honeycutt RL, Crandall KA, Lundeberg J, Wayne RK |date=June 1997 |title=Multiple and ancient origins of the domestic dog |url=https://www.consevol.org/pdf/Vila_1997_Science_1.pdf |url-status=live |journal=Science |volume=276 |issue=5319 |pages=1687–1689 |doi=10.1126/science.276.5319.1687 |pmid=9180076 |archive-url=https://ghostarchive.org/archive/20221009/https://www.consevol.org/pdf/Vila_1997_Science_1.pdf |archive-date=2022-10-09}}</ref>
The concept of the [[Mitochondrial Eve]] is based on the same type of analysis, attempting to discover the origin of [[human]]ity by tracking the lineage back in time.{{cn|date=November 2024}}