Results 161 to 170 of about 8,571 (229)
Journal of Morphology, 2021 AbstractHighly mineralized rigid‐shelled eggs characterize one lineage of gekkotans. In contrast, poorly mineralized flexible‐shelled eggs characterize basal lineages of gekkotans and all other squamates. Low oxygen permeability of rigid‐shelled eggs is associated with small eggs and hatchlings, and long incubation lengths compared to flexible‐shelled ...
Robin M. Andrews
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Morphogenesis of extraembryonic membranes and placentation in Mabuya mabouya (Squamata, Scincidae)
Journal of Morphology, 2003 AbstractTopological and histological analyses of Mabuya mabouya embryos at different developmental stages showed an extraembryonic membrane sequence as follows: a bilaminar omphalopleure and progressive mesodermal expansion around the whole yolk sac at gastrula stages; mesodermal split and formation of an exocoelom in the entire embryonic chamber at ...
Adriana Jerez +1 more
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Nature, 1975 RANDOM X inactivation makes the female mammal a natural mosaic for clones of cells having either the maternally derived X (Xm) or paternally derived one (Xp) which is genetically inactive1. There are, however, instances in which inactivation is obviously not random2–7.
Takagi, N, Sasaki, M
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Radioautographic studies of DNA synthesis in the developing extraembryonic membranes of the mouse
The Anatomical Record, 1967 AbstractTritiated thymidine was injected into pregnant BALB/c mice intravenously at 8, 10, 12, 14 and 16 days of pregnancy. Radioautographs were prepared in order to determine the extent of synthesis of DNA in the extraembryonic membranes at the above stages of gestation. The extent of synthesis of DNA was expressed as a radioactive index. The index is
Saccoman, F M, Morgan, C F, Wells, L J
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Paternal X chromosome expression in extraembryonic membranes of XO mice
Journal of Experimental Zoology, 1979 AbstractThe paternally derived allelic form of the X chromosome linked enzyme phosphoglycerate kinase (PGK‐1) is expressed in both the fetus and extraembryonic membranes of 9.5 day post coitum XO (XPO) mouse conceptuses. Previous studies on trophectoderm and primitive endoderm derived extraembryonic membranes in XX conceptuses suggest expression of ...
Frels, W I, Chapman, V M
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Embryology of the sheep. I. Extraembryonic membranes and the development of body form
Journal of Morphology, 1972 AbstractThe developmental anatomy of the sheep in the early prenatal period (14 to 34 days) was studied using embryos of known coital age, and embryos of known size with estimated coital age. Characteristics of the embryos were studied by gross observation under the dissecting microscope, and by means of serial sections.
M. M. Bryden +5 more
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Journal of Experimental Zoology Part A: Comparative Experimental Biology, 2003 AbstractAn understanding of the evolutionary morphology of extraembryonic membranes in reptiles requires information about oviparous as well as viviparous species. We are studying histology and ultrastructure of the extraembryonic membranes of snakes to clarify the evolutionary history of reptilian fetal membranes, including determination of basal ...
Amy R. Johnson +2 more
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