Testicular Germ Cell Differentiation and Proliferation in the South American Plains Vizcacha (Lagostomus maximus) During the Fetal Period

MUSCARSEL ISLA MARÍA LAURA; GONZALEZ CANDELA; FRAUNHOFFER NICOLÁS; LEOPARDO NOELIA; VITULLO ALFREDO DANIEL

La Serena, Chile

Congreso; XXI Reunión Anual Sociedad Chilena de Reproducción y Desarrollo; 2010

Sociedad Chilena de Reproducción y Desarrollo

Testicular Germ Cell Differentiation and Proliferation in the South American Plains Vizcacha (Lagostomus maximus) During the Fetal Period Muscarsel Isla ML, Gonzalez CR, Fraunhoffer NA, Leopardo NP, Vitullo AD.   Centro de Estudios Biomédicos, Biotecnológicos, Ambientales y Diagnóstico, CEBBAD, Universidad Maimónides,  Buenos Aires, Argentina.   Abstract Cell proliferation is an important process involved in the physiology of the testis. However, the ontogeny of germ cell proliferation in the developing testis has not been investigated in detail. The aim of the present study was to analyze the testicular morphometry and to establish the expression pattern by immunohistochemestry/ immunofluorescence of the proliferation cell nuclear antigen (PCNA) and germ cell markers (OCT-4 and VASA) in testis from early-, mid- and late-gestation embryos of Lagostomus maximus. The testicular morphometry revealed that seminiferous cords significantly increased in late-gestation testis (p<0.05) and was preceded by a significant proliferation of the interstitium at mid-gestation with respect to late-gestation embryos (p<0.05). Percent PCNA positive Leydig cells peaked at mid-gestation embryos in comparison to the other stages (early: 60.1±14.1, mid: 77.3±5.5 and late: 55.8±5.4, p<0.05). The percentage of PCNA positive germ cells was high throughout gestation (early: 79.1±2.8, mid: 88.2±1.7 and late: 87.1±5.3) with a significant increase (p<0.05) from mid- to late-gestation. Specific germ cell marker VASA, co-localized with PCNA throughout gestation. OCT-4 was also detectable in all stages analyzed (early: 35±8.1, mid: 45±11.2and late: 95±5.3, p<0.05), localized to the nucleus in germ cells, reaching a significantly higher value by the end of gestation. In conclusion, the present study shows that testicular germ cells in Lagostomus maximus exhibit a distinctive expression pattern of OCT-4 when compared to other mammals (mice, rat). It is suggested that the ontogeny of proliferation might contribute to the testicular morphometry and histology observed during the development of the fetal testis.