Anatomical and histological characterization of the female reproductive organs of mouse deer (Tragulidae).

The Tragulidae may be a type that represents the earliest ruminant families to evolve. The female reproductive organs including ovary, oviduct, uterus and placenta were anatomically and histologically investigated. The structures of the ovary and oviduct were very similar to other ruminants. However, the gross structure of the placenta was diffuse and thus noticeably different from other ruminants which are polycotyledonary. Histologically, the placenta of Tragulidae appears to be epitheliochorial and therefore similar to other ruminants. Numerous trophoblastic binucleated cells which are characteristic of all other ruminants were observed. These results suggest that the placenta of Tragulidae is a transitional type between diffuse epitheliochorial and polycotyledonary synepitheliochorial categories.