Changes of seminiferous epithelium in hybrids of mice carrying Robertsonian karyotype.

Different wild mouse populations have been found in Italy characterized by different Robertsonian karyotypes. Hybrids between carriers of karyotype have severe impairment of fertility due to different Robertsonian rearrangements, because of the difficulties of the meiotic chromosome pairing. Homozygous Robertsonian mice (Cittaducale, CD, Ancarano, ACR and Lipari Island, LIP) are able to release mature spermatozoa while in hybrid F1 mice (CD X ACR, ACR X LIP, and LIP X CD) the impairment of seminiferous epithelium cycle is evidenced by a germinal aplasia. In the hybrid mice the more predominant lesion is represented by a pathological arrangement of the basement membrane introflecting and splitting inside the seminiferous epithelium.