X-Autosome translocations, meiotic synapsis, chromosome evolution and speciation

Several theories have been proposed to explain the often-noted sterility of both reciprocal and Robertsonian X-autosome translocations in male mammals. However, there are a number of species in which all members of the species carry a Robertsonian X-autosome translocation. Meiosis in spermatocytes from these sterile vs. fertile animals is compared within the context of these theories. New technologies and insights into underlying mechanisms are summarized and suggestions presented for further studies.