Comparison of qualitative and quantitative evaluation of porcine primordial and primary follicles

TORRES, P.; GABRIEL, P.; FRATTO, C.; BOVIEZ, JD.; CISALE, H.; LOMBARDO, DM.; FISCHMAN, ML.

Buenos Aires

Jornada; III Jornadas Internacionales del Instituto de Investigación y Tecnología en Reproducción Animal – INITRA; 2012

Instituto de Investigación y Tecnología en Reproducción Animal - INITRA. Facultad de Ciencias Veterinarias. UBA

Digital image analysis provides information about preantral follicles morphology that cannot be obtained by optic qualitative evaluation. This method allows measurement of the nuclear (AN) and cytoplasmic area (AC), the oocyte size and circularity and the AN/AC relation. Our objective was to compare the qualitative histological assessment of primordial and primary porcine follicles with data obtained from quantitative evaluation by digital image analysis. Samples were taken from ovaries of slaughtered animals (n=10) and oocytes from primordial and primary follicles were evaluated (n=54 and n=32 respectively). Ovary cortex sheets were stained with hematoxylin and eosin and examined using an upright microscope (x400). Oocytes were classified in abnormal (A): cytoplasm and/or nucleus were damaged; or normal (N): both structures intact. Nucleus and cytoplasm were also classified as N or A. For this purpose, the degree of nuclear pyknosis, the integrity of the nuclear membrane and the degree of cytoplasmic vacuolization and/or eosinophilia were taken into account. The quantitative analysis was performed on digital photographs of the same follicles, using Qwin Plus®. The following parameters were measured: AC; AN; total area (AT=AC+AN), AN/AC relation, oocyte circularity (RO) and nuclear circularity (RN). Oocyte classification as N or A was compared with AN/AC relation, AT and RO. Nuclear classification as N or A was compared with AN and RN. Finally cytoplasm classification as N or A was compared with AC and RO. Data was analyzed using the median test, given the non-normal distribution of the variables. Significant differences (p <0,05) were found in AN/AC relation between N y A, both in primordial (A Me: 0,39; N Me: 0,59) and primary (A Me: 0,45; N Me: 0,61) follicles. Results show that in A oocytes, AC is proportionally bigger than AN, compared with N, in both primordial and primary follicles. AN/AC relation would be a useful quantitative parameter as an indicator of N/A in preantral porcine follicles.