somes in sheep (26.14%) was significantly lower than on the orthologous acrocentrics in cattle (27.6%) and goats (28.2%), and their distribution along the SC arms differed significant-ly. The reduced recombination rate in metacentrics is prob-ably caused by interference acting across the centromere. © 2015 S. Karger AG, Basel In all organisms which reproduce sexually, homolo-gous chromosome synapsis and recombination play a crucial role in the correct segregation of chromosomes into gametes, as well as in creating genetic diversity for natural selection. The physical link between homologous chromosomes, mediated by crossing over, serves as a bond which helps paired chromosomes to align properly in the meiotic metaphase plate and segregate correctly to the opposite sides of the dividing cell, thus providing bal-anced gametes [Hassold et al., 2000; Cohen et al., 2006; Coop and Przeworski, 2007]. In mammalian males, dis-ruption of chromosome pairing and inability to execute crossing over is usually connected with a complete failure to produce viable gametes [Sciurano et al., 2012]. Regardless of the importance of recombination, our knowledge of the mechanism which determines the num-ber and position of crossover (CO) foci along chromo-