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A light and electron microscopy study of the yak placentome
Affiliations- Academic of Veterinary Medicine, Gansu Agricultural University, Lanzhou, China
- Technology and Research Centre of Gansu Province for Embryonic Engineering of Bovine and Sheep and Goat, Lanzhou, China
- College of Life Science and Resources and Environment, Yichun University, Yichun, China
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Abstract
Background and Materials and methods: In order to clarify and reveal the morphological characteristics of yak placentomes, placentomes obtained from 151 to 180 days of pregnant yaks were observed using light microscopy and scanning and transmission electron microscopy.
Results: The results indicated that sessile, dome-shaped yak placentomes seemed to have a relatively complex villous-crypt architecture pattern. There was a straight maternal plate beneath the placentome. Plentiful uterine glands and a dense cellular layer were present in the endometrium lamina propria close to the maternal plate. Trophoblast giant cells appeared to have similar ultrastructure features to these in other ruminants, including abundant mitochondria, an extensive array of rough endoplasmic reticulum, advanced Golgi complex and many specific secretory granules. Trophoblast giant cells could also secrete neutral and acid glycoconjugates. Furthermore, numerous glycoconjugates were distributed in the connective zones between mononuclear trophoblast cells and crypt epithelial cells as well as in maternal connective tissues. Mononucleate trophoblast cells, which had abundant microvilli that interdigitated with the corresponding microvilli arising from the crypt epithelial cells, had numerous mitochondria and vesicles, but there were no glycoconjugates.
Conclusions: The morphological structures of yak placentomes were similar to those of other bovid genera; however, certain differences were observed. These findings might provide morphological evidence for evolutionary relationships between different bovid genera.
Abstract
Background and Materials and methods: In order to clarify and reveal the morphological characteristics of yak placentomes, placentomes obtained from 151 to 180 days of pregnant yaks were observed using light microscopy and scanning and transmission electron microscopy.
Results: The results indicated that sessile, dome-shaped yak placentomes seemed to have a relatively complex villous-crypt architecture pattern. There was a straight maternal plate beneath the placentome. Plentiful uterine glands and a dense cellular layer were present in the endometrium lamina propria close to the maternal plate. Trophoblast giant cells appeared to have similar ultrastructure features to these in other ruminants, including abundant mitochondria, an extensive array of rough endoplasmic reticulum, advanced Golgi complex and many specific secretory granules. Trophoblast giant cells could also secrete neutral and acid glycoconjugates. Furthermore, numerous glycoconjugates were distributed in the connective zones between mononuclear trophoblast cells and crypt epithelial cells as well as in maternal connective tissues. Mononucleate trophoblast cells, which had abundant microvilli that interdigitated with the corresponding microvilli arising from the crypt epithelial cells, had numerous mitochondria and vesicles, but there were no glycoconjugates.
Conclusions: The morphological structures of yak placentomes were similar to those of other bovid genera; however, certain differences were observed. These findings might provide morphological evidence for evolutionary relationships between different bovid genera.
Keywords
yak, placentome, microstructure, ultrastructure, histochemistry
About this articleTitle
A light and electron microscopy study of the yak placentome
Journal
Issue
Article type
Original article
Pages
818-826
Published online
2019-03-13
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992
Article views/downloads
852
DOI
Pubmed
Bibliographic record
Folia Morphol 2019;78(4):818-826.
Keywords
yak
placentome
microstructure
ultrastructure
histochemistry
Authors
T. Xu
B. Liu
Y. Cui
J. He
J. Fan
S. Yu
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