PCNA EXPRESSION IN THE PINEAL GLAND OF PREGNANT AND NON-PREGNANT VISCACHAS (Lagostomus maximus maximus): AN IMMUNOHISTOCHEMICAL AND MORPHOMETRIC STUDY

BUSSOLINI F; GALLOL LE; MOHAMED F; SOSA MA

Congreso; XXXIX Reunión Anual de la Sociedad de Biología de Cuyo; 2021

Sociedad de Biología de Cuyo

The proliferating cell nuclear antigen (PCNA) is a non-histone nuclear protein that appears to play a key role in coordinating the recruitmentof many proteins to sites of DNA replication and in some cases regulates their activities. PCNA acts as an auxiliary protein for DNApolymerase delta by enhancing its activity. It also works as an auxiliary factor for DNA polymerase epsilon. The pineal gland acts as aneuroendocrine interface, transforming ambient light changes into hormonal variations. Our experimental model, the viscacha, is ahystricomorph rodent with a seasonal reproductive pattern synchronized by the environmental photoperiod and modulated by the pinealmelatonin. Female viscachas usually have an oestrous period in early autumn, get pregnant during winter and offsprings are usually bornin spring. In this study we performed an immunohistochemical and morphometrical study of PCNA expression in the pineal gland ofpregnant and non-pregnant females. Four pineal glands (n=4) per group were analysed. The reproductive condition was assessed accordingto body weight and light microscope observations of ovaries. Additionally, the uterine horns were examined to evaluate the presence ofembryos and foetuses. The glands were processed for light microscopy and the PCNA was immunohistochemically identified. Thepercentage of immunoreactive cells was determined using the formula (A/A + B) × 100, where A is the number of immunoreactive cellsand B is the number of nuclei in immunonegative cells. Statistical differences were evaluated by means of Mann?Whitney test. A value ofΡ