Presentation on theme: "Y-chromosome DNA on this is passed down the paternal line with usually no change. Every few hundred years however there may be a change in one of the repeated."— Presentation transcript:
Y-chromosome DNA on this is passed down the paternal line with usually no change. Every few hundred years however there may be a change in one of the repeated sequences of DNA called “”Short tandem repeats” or “STRs”. We can analyse these STRs using techniques known as “PCR” and electrophoresis to produce a DNA “fingerprint”.
STRs Z Z Z Z Z Z Z Z Z The rows Z7, Z24 etc correspond to particular individuals. The columns 391, 390 etc correspond to the different number of STRs in 6 markers or parts of the Y- chromosome. The sequence of numbers etc. is known as a persons “haplotype”. We can enter this data into a database known as YHRD to look for matches with over other people tested in Europe.
HIT MISS 17 The numbers refer to the place. E.g. 17 = Croatia Here are a few examples….
Kevin Sampson267 matches/13003
Kevin Sampson267 matches/13003 So Kevin’s paternal ancestor “may” have come from this area
Chris Westhead, John Aindow, Roger Martlew, Alan Scarisbrick, Gordon Ashcroft, Tom Howard, John Rosbotham, Norman Penketh, Edward Webster, Ole Christiansen
Michael Fletcher166 matches/13003
Keith Rimmer89 matches/13003
Stanley Lunt339 matches/13003
John Risley 8 matches/13003
Michael Welch441 matches/13443
Tony Tottey166 matches/13003
Brian Totty166 matches/13003
STRs Z Z Z Z Z Z Z Z Z YHRD now allows “nearest neighbour” analysis”: during the course of 1000 years it is possible that there has been a single mutation of one of the Y-chromosome STRs along a man’s paternal ancestral line. e.g. for the man “Z7” the marker 391 could have originally been 9 or 11 repeats. Some mutations are rare and yield no matches.
Richard Harding’s Y-chromosome group One step mutation of one of his STR’s: Top matches for each mutation: West Norway (2ce) Oslo Puglia (followed by Central Norway) Vasterbotten, Sweden Uppsala Denmark No mutation, top matches: Ostgotland-Jonköping, Sweden and Gröningen, Friesland: ~8% of men have a match. Where the top matches for Richard’s Y-chromosome are to be found