We have recently completed DNA testing within the Dugas Labreche family. The results for the male test came back Haplogroup J2, which is middle eastern/mediterranean. Since the Dugas Labreche family descends from Jean Ducas dit Labreche, we have done some extensive surname research and found that the Ducas name is jewish in origin and most people in Europe today with this surname are still Jewish. The surname appears on most jewish historical data including Jewish census lists in France, Cemetary records etc... Research is continuing and if you are interested, you can join the Yahoo discussion group AFDL, Association des Familles Dugas dit Labreche where we will continue to post new information. National Geographic has a genographic project section that explains these DNA studies very well at www.nationalgeographic.com/genographic
I would love to see a Dugas male descended from Abraham Dugas of Toulouse also take a DNA test to verify any possible relation. In looking at the Jewish Census lists of Toulouse there was a Gaus from Hungary living in Toulouse and the surname Duga is found in Catalonia starting at about 1590 and is quite common among eastern european Jewish people.
The whole region of Southwest France was a refuge for Spanish Jews who were escaping the inquisition and many settled there with some moving on to New France.