Over-expression of p130/PRB2 in testis, sleen and thymus of transgenic mice.

P130/pRb2 is a tumor suppressor protein related to the retinoblastoma protein pRb. To better understand its physiological role, the gene of human p130/pRb was introduced in the murine genome obtaining two transgenic mice whose progeny has been studied and characterized independently. In both lineage of transgenic mice the expression of p130/pRb2 is enhanced in testis, spleen and thymus as compared with wild type control mice. The over-expression of p130/pRb2 in these tissues affects neither vitality or fertility of the transgenic animals but modifies blood levels of some hormones, as testosterone (enhanced in transgenic animals) and DHEAS (decreased in transgenic animals). These differences are already evident in very young animals (less than one month of age). Some alteration affecting male genital apparatus was observed in old transgenic mice (over 18 months of age) possibly due to the enhanced hormonal stimulation on target tissues. Studies are in progress to clarify the role of p130/pRb2 in thymus and spleen and the possible correlation between the over-expression in these tissues and the presence of abnormalities also observed in the lymphatic system.