Cieslak Jakub, Wodas Lukasz, Borowska Alicja, Cothran Ernest G, Khanshour Anas M, Mackowski Mariusz
Department of Horse Breeding, Poznan University of Life Sciences, Poznan, Poland.
Department of Veterinary Integrative Biosciences, College of Veterinary Medicine and Biomedical Science, Texas A&M University, College Station, TX, United States of America.
PeerJ. 2017 Aug 24;5:e3714. doi: 10.7717/peerj.3714. eCollection 2017.
The Polish Primitive Horse (PPH, Konik) is a Polish native horse breed managed through a conservation program mainly due to its characteristic phenotype of a primitive horse. One of the most important goals of PPH breeding strategy is the preservation and equal development of all existing maternal lines. However, until now there was no investigation into the real genetic diversity of 16 recognized PPH dam lines using mtDNA sequence variation. Herein, we describe the phylogenetic relationships between the PPH maternal lines based upon partial mtDNA D-loop sequencing of 173 individuals. Altogether, 19 mtDNA haplotypes were detected in the PPH population. Five haplotypes were putatively novel while the remaining 14 showed the 100% homology with sequences deposited in the GenBank database, represented by both modern and primitive horse breeds. Generally, comparisons found the haplotypes conformed to 10 different recognized mtDNA haplogroups (A, B, E, G, J, M, N, P, Q and R). A multi-breed analysis has indicated the phylogenetic similarity of PPH and other indigenous horse breeds derived from various geographical regions (e.g., Iberian Peninsula, Eastern Europe and Siberia) which may support the hypothesis that within the PPH breed numerous ancestral haplotypes (found all over the world) are still present. Only in the case of five maternal lines (Bona, Dzina I, Geneza, Popielica and Zaza) was the segregation of one specific mtDNA haplotype observed. The 11 remaining lines showed a higher degree of mtDNA haplotype variability (2-5 haplotypes segregating in each line). This study has revealed relatively high maternal genetic diversity in the small, indigenous PPH breed (19 haplotypes, overall HapD = 0.92). However, only some traditionally distinguished maternal lines can be treated as genetically pure. The rest show evidence of numerous mistakes recorded in the official PPH pedigrees. This study has proved the importance of maternal genetic diversity monitoring based upon the application of molecular mtDNA markers and can be useful for proper management of the PPH conservation program in the future.
波兰原始马（PPH，科尼克马）是一种原产于波兰的马种，主要通过一项保护计划进行管理，这主要是因为它具有原始马的典型表型。PPH育种策略的最重要目标之一是保存所有现有母系并使其均衡发展。然而，到目前为止，尚未使用线粒体DNA（mtDNA）序列变异对16个公认的PPH母系的实际遗传多样性进行调查。在此，我们基于对173个个体的部分mtDNA D环测序描述了PPH母系之间的系统发育关系。在PPH群体中总共检测到19种mtDNA单倍型。其中5种单倍型被推测为新发现的，其余14种与GenBank数据库中存档的序列具有100%的同源性，这些序列由现代马种和原始马种代表。总体而言，比较发现这些单倍型符合10种不同的公认mtDNA单倍群（A、B、E、G、J、M、N、P、Q和R）。一项多品种分析表明，PPH与源自不同地理区域（如伊比利亚半岛、东欧和西伯利亚）的其他本土马种在系统发育上具有相似性，这可能支持以下假设：在PPH品种中，许多祖先单倍型（在世界各地都有发现）仍然存在。仅在五个母系（博纳、季娜一世、热内扎、波皮埃利察和扎扎）的情况下观察到一种特定mtDNA单倍型的分离。其余11个母系显示出更高程度的mtDNA单倍型变异性（每个母系中有2 - 5种单倍型分离）。这项研究揭示了小型本土PPH品种中相对较高的母系遗传多样性（19种单倍型，总体单倍型多样性HapD = 0.92）。然而，只有一些传统上区分的母系可以被视为基因纯正。其余母系显示出官方PPH系谱中记录的许多错误证据。这项研究证明了基于分子mtDNA标记进行母系遗传多样性监测的重要性，并且在未来对PPH保护计划的妥善管理中可能会有所帮助。
