The present study evaluated: (1) in vivo follicular development in canine ovarian tissue after slow freezing and xenotransplantation; and (2) the use of erythropoietin (EPO) as an angiogenic factor to optimise the transplantation procedure. Frozen-thawed ovarian tissue from five bitches was grafted into severe combined immunodeficient (SCID) mice (n=47) treated with or without EPO (500 IU kg(-1), once daily for 3 days) (Groups A and B, respectively) and analysed after 0, 1, 8 or 16 weeks. Follicle grade, follicle density, follicle morphology and stromal cells density were assessed by histological analysis, whereas vascularisation of the graft was quantified by immunohistochemistry with anti-α-smooth muscle actin antibody. Despite a massive loss of follicles after grafting, secondary follicle density was higher at 8 and 16 weeks than at 1 week regardless of EPO treatment. EPO significantly improved early follicle morphology and stromal cell density after 8 weeks and blood vessel density at 16 weeks after transplantation (P<0.05). Intact secondary follicles with more than three granulosa cells layers were observed 16 weeks after transplantation. The results suggest that canine ovarian tissue can be successfully preserved by our slow-freezing protocol because the tissue showed follicular growth after xenotransplantation. EPO treatment did not lessen the massive loss of follicles after transplantation.

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M. uberis is an emerging skin pathogen in dairy animals. Its genome underwent massive reduction and gene decay, leading to a minimal set of genes required for an obligatory intracellular lifestyle, which highly resembles the evolution of the leprosy agents M. leprae and M. lepromatosis. The genomic similarity between M. uberis and the leprosy bacilli can help in identifying key virulence factors of these closely related species or in identifying genes responsible for the distinct differences between thelitis or scrotitis and leprosy with respect to clinical manifestations. Specific DNA markers can now be developed for quick detection of this pathogen.