Ultrasonographic characterization of implantations in a physiological e mbryonic death model: Lagostomus maximus (Mammalia, Rodentia,

FRANCISCO ACUÑA , GUADALUPE RANEA , CLAUDIO GUSTAVO BARBEITO , ENRIQUE LEO PORTIANSKY , MARÍA ANGÉLICA MIGLINO , MIRTA ALICIA FLAMINI

Simposio; LASDB2019 Simposio Latinoamericano de Biología de Desarrollo 2019; 2019

Latinoamerican Society Development Biology

The plain viscacha Lagostomus maximus constitutes a model of physiologicalembryonic death due to the differential survival of its implantations. Of 10 12imp lantations only 2 near the cervix will progress; the rest are reabsorbed by stillunknown causes. In this work, implantations (i) of females with early pregnancy(first third of gestation) were characterized by ultrasound. After anesthesia, thegravid uter ine horns (UH) of 3 females were analyzed with a linear transducer. Thepresence of 4i/UH was observed and identified as: i1, i2, i3 and i4 following thecraniocaudal axis of the organ. The size of these implants increased from i1 to i4.Implants i1 to i3 were solid, echogenic and lacking an embryo, fluid and placenta(gestational vesicles in resorption). In contrast, the presence of a solid, echogenicand discoid structure (placenta) was observed in i4. Besides, a cavity filled withanechoic fluid containi ng an embryo with developed cephalic and caudal poles,absence of limbs and viscera was observed. The vascular Doppler determined theviability of this embryo due to cardiac activity. These preliminary data will allow tocharacterize the embryonic developm ent of Lagostomus maximus and, in turn, toestablish the moment in which physiological and sectorized embryonic deathbegins. In addition, it will allow morphological and molecular studies to understandembryonic differential survival in mammals, with emph asis on species of interestfor veterinary medicine.