SHORT COMMUNICATION A lost Sorraia maternal lineage found in the Lusitano horse breed C. Luı´s 1 , C. Bastos-Silveira 1 , J. Costa-Ferreira 2 , E.G. Cothran 3 & M.M. Oom 1 1 Universidade de Lisboa, Faculdade de Cie ˆ ncias, Departamento de Biologia Animal, Centro de Biologia Ambiental, Lisboa, Portugal 2 Servic ¸ o Nacional Coude ´ lico, Coudelaria de Alter, Alter do Chao, Portugal 3 Department of Veterinary Integrative Biosciences, College of Veterinary Medicine and Biomedical Sciences, Texas A&M University, College Station, TX, USA Introduction The Sorraia horse, one of the three Portuguese native horse breeds, was recovered by Ruy d’Andrade in 1937, from 12 founders: five males and seven females. This breed shares, along with the Przewalski, the extinct Tarpan, the Konik and the horses from the Norwegian fjords, characteristics considered prim- itive such as: yellow dun or mouse dun (grullo) col- our, black dorsal stripe, zebra stripes on legs, and sometimes shoulder stripes and darker rings or stripes on the foreheads (cobwebbing) (Andrade 1926; Lusis 1942; Strachurska 1999). The Sorraia also is believed to be the ancestor of the Lusitano and Andalusian breeds and thus an important ancestor of the entire World’s light saddle horses and also of the horses in the New World (Andrade 1926, 1937, 1945; Oom 1992; Oom & Cothran 1994). Therefore, addressing the phylogenetic relation- ships of the Sorraia with other horse breeds had an increased interest in the past few years, and has been attempted in several publications concerning horse relationships and domestication (Jansen et al. 2002; Cozzi et al. 2004; Lopes et al. 2005; Royo et al. 2005; Luı´s et al. 2006). In a work combining pedigree and mitochondrial DNA (mtDNA) information, Luı´s et al. (2002) dem- onstrated the existence of only two maternal line- ages still represented in the living Sorraia horses, corresponding to two haplotypes that differ by three nucleotides. Other authors, using a different set of samples, also found only these two maternal haplo- types (Jansen et al. 2002; Lopes et al. 2005) and in many publications it has been emphasized that the Sorraia haplotypes do not cluster with the mtDNA haplotypes more frequently found in Iberian horses Keywords D-loop; Lusitano horse; maternal lineage; mitochondrial DNA; Sorraia horse. Correspondence Maria do Mar Oom, Departamento de Biologia Animal, Centro de Biologia Ambiental, Faculdade de Cie ˆ ncias, Universidade de Lisboa, Edifı´cio C2- Piso 3, 1749-016 Lisboa, Portugal. Tel: +351 21 750 00 00, extn 24132; Fax: +351 21 750 00 28; E-mail: mmoom@fc.ul.pt Received: 13 February 2006 accepted: 12 June 2006 Summary A common female founder individual of the Portuguese horse breeds Sorraia and Lusitano was found while conducting research on the vari- ation of the Lusitano mitochondrial DNA lineages in relation to stud- book information. We obtained 416-bp control region sequences from 16 descendents of a female Sorraia founder (Pomba) still represented in the living population of the Lusitano, according to the most recent edi- tion of this breed’s studbook. The same haplotype was found for all ana- lysed samples and belongs to the haplogroup described by several authors as having predominantly Iberian, South American and North African haplotypes bringing new insights on the relationship between the Sorraia and the other Iberian breeds. This work illustrates how weak the boundary of breed establishment can be, especially at the same geo- graphical region. Using the same founders in different breeds is surely one of the explanations to frequently shared haplotypes among recent breeds, resulting in a lack of consistency between mtDNA sequences and breeds and/or geographical regions. J. Anim. Breed. Genet. ISSN 0931-2668 ª 2006 The Authors Journal compilation ª 2006 Blackwell Verlag, Berlin • J. Anim. Breed. Genet. 123 (2006) 399–402 399