Follicular development in the volcano mouse (Neotomodon alstoni alstoni, Rodentia: Muridae) from birth to maturity: A morphological approach

Abstract

Luis-Díaz, J., Cárdenaz-Vázquez, R., Villalpando-Fierro, I., Martínez-Torres, M. and Merchant, H. 2008. Follicular development in the volcano mouse ( Neotomodon alstoni alstoni , Rodentia: Muridae) from birth to maturity: a morphological approach. -Acta Zoologica (Stockholm) 89 : [185][186][187][188][189][190][191][192] The present study describes the morphology and ultrastructural features of postnatal follicular development in the volcano mouse ( Neotomodon alstoni alstoni ), an endemic Mexican rodent. By the first week of age, germ cells were organized in clusters within the ovigerous cords, and only 51.8% of them were associated with somatic cells. At the ultrastructural level, pairing chromosomes and cellular junctions between germ and pregranulosa cells, such as desmosomes, were observed. At this time, the zona pellucida could not be detected in the formed follicles. From 15 to 28 days postpartum, growing follicles were located at the medulla and inner cortex of the ovary, but most were atretic. The first preovulatory follicles were seen at 40 days. Likewise, corpora lutea were observed at this stage of development, which shows that the volcano mouse is a spontaneous ovulator. The follicular development of the volcano mouse shows strong similarities with that of the golden hamster, particularly during the first week. The morphological changes observed during postnatal follicular development of the volcano mouse follow the same general histological pattern as reported for other mammals, although the timing of these events is species-specific.

Histology, histochemistry and morphometry of the ovary of the adult plains viscacha (Lagostomus maximus) in different reproductive stages

“…Polyovular follicles were found in some of the L. maximus females analysed in this work. Unlike that described in the volcano mouse ( Neotomodon alstoni alstoni ) (Luis Díaz et al . 2008), polyovular follicles in L. maximus do not present a follicular antrum.…”