tailieunhanh - Báo cáo sinh học: "Mitochondrial D-loop sequence variation among Italian horse breeds"

Tuyển tập các báo cáo nghiên cứu về sinh học được đăng trên tạp chí sinh học thế giới đề tài: Mitochondrial D-loop sequence variation among Italian horse breeds | Genet. Sel. Evol. 36 2004 663-672 INRA EDP Sciences 2004 DOI gse 2004023 663 Original article Mitochondrial D-loop sequence variation among Italian horse breeds Maria Cristina Cozzia Maria Giuseppina STRILLACCIa Paolo VALlATla Barbara BlGHlGNOLla Mario CANCEDDAb Marta ZANOTTIa a Istituto di Zootecnica Facoltà di Medicina Veterinaria Università degli Studi di Milano Via Celoria 10 20133 Milano Italy b Dipartimento di Biologia Animale Facoltà di Medicina Veterinaria Università degli Studi di Sassari Via Vienna 2 07100 Sassari Italy Received 3 December 2003 accepted 17 June 2004 Abstract - The genetic variability of the mitochondrial D-loop DNA sequence in seven horse breeds bred in Italy Giara Haflinger Italian trotter Lipizzan Maremmano Thoroughbred and Sarcidano was analysed. Five unrelated horses were chosen in each breed and twenty-two haplotypes were identified. The sequences obtained were aligned and compared with a reference sequence and with 27 mtDNA D-loop sequences selected in the GenBank database representing Spanish Portuguese North African wild horses and an Equus asinus sequence as the outgroup. Kimura two-parameter distances were calculated and a cluster analysis using the Neighbourjoining method was performed to obtain phylogenetic trees among breeds bred in Italy and among Italian and foreign breeds. The cluster analysis indicates that all the breeds but Giara are divided in the two trees and no clear relationships were revealed between Italian populations and the other breeds. These results could be interpreted as showing the mixed origin of breeds bred in Italy and probably indicate the presence of many ancient maternal lineages with high diversity in mtDNA sequences. mitochondrial DNA D-loop biodiversity phylogeny Italian horse 1. INTRODUCTION Mitochondrial DNA mtDNA analysis has often been used in evolutionary studies. Feral and domestic equine cells contain a large number of maternally inherited mitochondria from 100 to 1000 1 23 . The .