| Autor: |
Giacchino M; Centro de Estudios Biomédicos, Biotecnológicos, Ambientales y Diagnóstico (CEBBAD), Universidad Maimónides, Hidalgo 775, C1405BCK, Buenos Aires, Argentina.; Consejo Nacional de Investigaciones Científicas y Técnicas (CONICET), Buenos Aires, Argentina., Inserra PIF; Centro de Estudios Biomédicos, Biotecnológicos, Ambientales y Diagnóstico (CEBBAD), Universidad Maimónides, Hidalgo 775, C1405BCK, Buenos Aires, Argentina.; Consejo Nacional de Investigaciones Científicas y Técnicas (CONICET), Buenos Aires, Argentina., Lange FD; Centro de Investigación y Desarrollo en Medicina Experimental (CIDME), Universidad Maimónides, Buenos Aires, Argentina., Gariboldi MC; Centro de Estudios Biomédicos, Biotecnológicos, Ambientales y Diagnóstico (CEBBAD), Universidad Maimónides, Hidalgo 775, C1405BCK, Buenos Aires, Argentina.; Consejo Nacional de Investigaciones Científicas y Técnicas (CONICET), Buenos Aires, Argentina., Ferraris SR; Centro de Investigación y Desarrollo en Medicina Experimental (CIDME), Universidad Maimónides, Buenos Aires, Argentina., Vitullo AD; Centro de Estudios Biomédicos, Biotecnológicos, Ambientales y Diagnóstico (CEBBAD), Universidad Maimónides, Hidalgo 775, C1405BCK, Buenos Aires, Argentina. vitullo.alfredo@maimonides.edu.; Consejo Nacional de Investigaciones Científicas y Técnicas (CONICET), Buenos Aires, Argentina. vitullo.alfredo@maimonides.edu. |
| Abstrakt: |
The South American hystricognathe Lagostomus maximus is a fossorial rodent whose females show unique reproductive characteristics. They have a 155-day long gestation, show massive polyovulation and a selective process of embryonic resorption in the first half of gestation. In order to explore and perform an in-situ characterization of the reproductive tract, we visualized internal structures through ultrasonography and video-endoscopy in pregnant and non-pregnant females. We describe the finding of protruding structures that lie on the yolk sac and their histological and ultrastructural characterization. The placenta was covered with whitish, small pearl-shaped structures. These structures were also seen on the extra-embryonic space, being the amnion and the umbilical cord free of them. Pearl-shaped structures were composed with loose connective tissue, lacked blood vessels, and showed collagen fibers organized in a spiral form. They were anchored by pedicles to the villous surface of the extraembryonic membrane. We discuss the biological and evolutionary meaning of the pearl-shaped structures that relate L. maximus to the African origin of the South American hystricognathe fauna. |
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