Morphometric analysis of the placenta in the New World mouse Necromys lasiurus (Rodentia, Cricetidae): a comparison of placental development in cricetids and murids

Abstract

BackgroundStereology is an established method to extrapolate three-dimensional quantities from two-dimensional images. It was applied to placentation in the mouse, but not yet for other rodents. Herein, we provide the first study on quantitative placental development in a sigmodontine rodent species with relatively similar gestational time. Placental structure was also compared to the mouse, in order to evaluate similarities and differences in developmental patterns at the end of gestation.MethodsFetal and placental tissues of Necromys lasiurus were collected and weighed at 3 different stages of gestation (early, mid and late gestation) for placental stereology. The total and relative volumes of placenta and of its main layers were investigated. Volume fractions of labyrinth components were quantified by the One Stop method in 31 placentae collected from different individuals, using the Mercator® software. Data generated at the end of gestation from N. lasiurus placentae were compared to those of Mus musculus domesticus obtained at the same stage.ResultsA significant increase in the total absolute volumes of the placenta and its main layers occurred from early to mid-gestation, followed by a reduction near term, with the labyrinth layer becoming the most prominent area. Moreover, at the end of gestation, the total volume of the mouse placenta was significantly increased compared to that of N. lasiurus although the proportions of the labyrinth layer and junctional zones were similar. Analysis of the volume fractions of the components in the labyrinth indicated a significant increase in fetal vessels and sinusoidal giant cells, a decrease in labyrinthine trophoblast whereas the proportion of maternal blood space remained stable in the course of gestation. On the other hand, in the mouse, volume fractions of fetal vessels and sinusoidal giant cells decreased whereas the volume fraction of labyrinthine trophoblast increased compared to N. lasiurus placenta.ConclusionsPlacental development differed between N. lasiurus and M. musculus domesticus. In particular, the low placental efficiency in N. lasiurus seemed to induce morphological optimization of fetomaternal exchanges. In conclusion, despite similar structural aspects of placentation in these species, the quantitative dynamics showed important differences.

Placental Evolution within the Supraordinal Clades of Eutheria with the Perspective of Alternative Animal Models for Human Placentation

“…Thus, several taxa including rare or wildlife species have been studied by means of histology and modern methods like immunohistochemistry or proper fine structural investigations by electron microscopy. Among 2 Advances in Biology them are nonmurine rodents native to South America and Africa [26][27][28][29][30][31][32][33][34][35][36][37][38][39][40], as was shown by Figure 2, bats [41][42][43], anteaters and armadillos [44,45], and some other taxa [46][47][48][49][50][51]. Also, there were several promising attempts to reinvestigate historical histological material from museum collections such as neotropical primates [52] or great apes [53][54][55][56] in order to answer open questions.…”

Multifunctional nanoparticles for real-time evaluation of toxicity during fetal development

“…A careful review of the literature found that studies of MRI-based measurement of gestation in the mouse are limited to ex vivo examples for the purpose of creating anatomical atlases of the developing mouse, and thus not useful for comparison. Instead, we identified a study which measured the growth of embryos and placentas in the new world mouse (Necromys lasiurus), using 3-dimensional stereology [ 50 ]. Our MRI indicated weights of MSN-exposed and control embryos follow the measurements reported therein, while placental measurements vary considerably.…”

Dinâmica da inversão do saco vitelino em preás (Galea spixii Wagler, 1831)

“…Os resultados obtidos no presente estudo permitiram afirmar que em preás ocorre um modelo de placentação vitelínica invertida, cuja inversão propriamente dita ocorre a partir do décimo quarto dia da gestação. Para trabalhos futuros, uma analise quantitativa através de técnicas inovadoras, como a estereologia, associada a analises estatísticas, como no trabalho realizado por Favaron et al (2013) em diferentes regiões da placenta de Necromys lasiurus (Cricetidae), poderá trazer dados numéricos sobre a dinâmica do desenvolvimento do saco vitelino, bem como do volume ocupado por essa membrana e suas diferentes porções (parietal e visceral) e dos diferentes tipos celulares constituintes ao longo da gestação, resultando em dados funcionais sobre a participação da placenta vitelina nos diferentes estágios gestacionais do preá.…”