Premium
Comparative chromosomal studies of E. caballus (ECA) and E. przewalskii (EPR) in a female F1 hybrid
Author(s) -
Ahrens E.,
Stranzinger G.
Publication year - 2005
Publication title -
journal of animal breeding and genetics
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.689
H-Index - 51
eISSN - 1439-0388
pISSN - 0931-2668
DOI - 10.1111/j.1439-0388.2005.00494.x
Subject(s) - biology , electron paramagnetic resonance , karyotype , meiosis , centromere , genetics , x chromosome , fluorescence in situ hybridization , microbiology and biotechnology , chromosome , gene , nuclear magnetic resonance , physics
Summary Previous research revealed that the karyotypes of Equus przewalskii (2n = 66) and Equus caballus (2n = 64) differ by one pair of metacentric chromosomes, present in ECA but not in EPR, and two pairs of acrocentric chromosomes found only in the EPR karyotype. The formation of a trivalent during meiosis in a male F1 hybrid and the homologies in G‐banding patterns suggest that ECA 5 corresponds to two acrocentric EPR chromosomes resulting from a Robertsonian fusion or fission event. Chromosomal investigations of a female interspecies F1 hybrid including banded karyograms and fluorescence in situ hybridization (FISH) studies focusing on the p and q arm of ECA 5 were conducted. Q‐ and G‐banding patterns of E. caballus , E. przewalskii and the hybrid revealed interspecies homology between all chromosome pairs except for ECA 5, EPR 23 and EPR 24, which were unique for that particular species. Furthermore, they indicated homology between ECA 5p and EPR 23 as well as between ECA 5q and EPR 24. FISH revealed hybridization of the BACs laminin beta 3 (LAM B3) and laminin gamma 2 (LAM C2) to ECA 5p and EPR 23. However, nuclear factor I (NFIA) and immunoglobulin lambda (IGL@), primarily assigned to ECA 5q, mapped to ECA 7 and EPR 6 respectively. Thus the karyotypes of E. caballus and E. przewalskii differ solely by one Robertsonian translocation (ECA 5 =EPR 23 + EPR 24).