PCNA EXPRESSION IN THE PINEAL GLAND OF FOETUS AND SEXUAL IMMATURE VISCACHAS (Lagostomus maximus maximus): AN IMMUNOHISTOCHEMICAL AND MORPHOMETRIC STUDY

MOHAMED F; BUSOLINI F; SOSA MIGUEL ANGEL

San Luis

Congreso; XXXV Reunión Anual de la Sociedad de Biología de Cuyo; 2019

Sociedad de Biología de Cuyo

The proliferating cell nuclear antigen (PCNA) is a non‐histone nuclear protein who plays a key role in the initiation of cell proliferation. Functions as cofactor of DNA polymerase‐delta and its use as marker of proliferating cells has been validated by several studies in different species. The pineal gland acts as a neuroendocrine interface, transforming ambient light changes into hormonal variations. Our experimental model, the viscacha (Lagostomus maximus maximus), is a hystricomorph rodent with a seasonal reproductive pattern synchronized by the environmental photoperiod and modulated by the pineal melatonin. In this study we performed an immunohistochemical and morphometrical study of PCNA expression in the pineal gland of foetus and sexual immature viscachas. Four pineal glands (n=4) per group were analysed. The foetal glands were collected from foetuses of late pregnant females classified on the basis of foetal weight and crown‐heel length. The sexual immature animals (2?3 kg) were classified according to body weight and light microscopy observations of testes. The glands were processed for light microscopy and the PCNA was immunohistochemically identified. The percentage of immunoreactive cells was determined using the formula (A/A + B) × 100, where A is the number of immunoreactive cells and B is the number of nuclei in immunonegative cells. Statistical differences were evaluated by means of the Mann?Whitney test. A value of Ρ