137 IRON TRANSFER ACROSS THE LLAMA PLACENTA (LAMA GUANICOE GLAMA)

2006 ◽  
Vol 18 (2) ◽  
pp. 177
Author(s):  
M. A. Miglino ◽  
D. Iturrizaga ◽  
A. C. Morini ◽  
F. T. Verechia ◽  
J. R.o Kfoury Jr ◽  
...  

The placenta of the llama has been described as epitheliochorial in type, but recent studies have not shown extensively the fetal nutrition aspects in this animal. In epitheliochorial placentation there is development of structures called areolae, as well as inter-microvillous attachment of the trophoblast, with irregular contact, to the uterine epithelium. This attachment is interrupted and the transfer of substances between the mother and the fetus takes place across the areolar cavity. These areolae appeared as small rounded or dome-shaped elevated areas of the chorioallantoic membrane over the narrow uterine gland openings. In order to detail their mechanisms of iron transfer in the llama placenta, we collected the samples of nine uteri between 28 to 36 weeks of pregnancy in association with fetal membranes. These samples were fixed in 4% paraformaldehyde in PBS, processed, and stained for light microscopy (HE, picrosirius, and Masson's trichrome), histochemistry (Perls, acid phosphatase, and PAS reactions) and immunohistochemistry with rabbit anti pig uteroferrin antibody to confirm the iron transfer, because the uteroferrin is an iron transporter and a progesterone-induced hematopoietic growth factor. The trophoblast formed a columnar-type single layer that was comprised of cells of various sizes and shapes with basal nuclei, including the giant binucleate cells. The trophoblast formed chorionic projections which presented ramifications in number from 4 to 5. A great quantity of blood vessels were found in the materno-fetal interface, between the cells of uterine epithelium and around of the chorionic projections. A PAS-positive reaction was observed with diffuse cytoplasmic PAS staining at the apical region of the trophoblast at the materno-fetal interface as well as in the endometrial glands. Collagen fibers were observed in the mesenchyme and inside the chorionic projections. In the areolae we confirmed the positive reaction of the acid phosphatase enzyme that detects phagocytic activity. In the basal region of the uterine gland epithelium, which is columnar type, and in the gland lumina, this reaction demonstrated a strong positive stain. The Perls histochemical reaction that reveals ferric iron was positive in the areola, as well as in the uterine glands. The uteroferrin immunohistochemistry showed a strong stained in the areolae and in the epithelium and lumina of the uterine glands. Our findings suggest that the areola region and the endometrial glands play an important role in histiotrophic nutrition in llamas, and in fetal red blood cell formation by iron transfer from mother to the fetus. This work was supported by FAPESP, CNPq, CAPES, PRONEX, Brazil.

2006 ◽  
Vol 18 (2) ◽  
pp. 141 ◽  
Author(s):  
F. Pereira ◽  
F. Meirelles ◽  
F. Braga ◽  
J. Visintin ◽  
R. Rumpf ◽  
...  

The histiotrophic nutrition by the endometrial glands and the materno-fetal interface in the cloned cattle placenta were analyzed in order to investigate the iron transfer. Placentomes and intercaruncular region samples were recovered at term Caesarean delivery from 14 cloned cattle and 10 controls, fixed in 4% paraformaldehyde and 10% formaldehyde in PBS, processed and stained for light microscopy (hematoxylin-eosin, picrosirius, and Masson's trichrome), histochemistry [Perls, acid phosphatase and periodic acid Schiff (PAS) reactions], and immunohistochemistry (with rabbit anti-pig uteroferrin antibody because the uteroferrin is an iron transporter protein). In the controls we verified blood extravasations in the materno-fetal interface between the uterine and the trophoblast epithelium characterized by hemophagous areas with consequent erythrophagocytosis by the adjacent trophoblast. This content presented extravasated erythrocytes, plasm, cell debris, and cells in a probable apoptotic process. The Perls histochemical reactions that exposed the ferric iron in the placentomes were positive, as was the uteroferrin immunohistochemistry in the trophoblast cytoplasm and in other deep points in the placentomes. The histochemical reactions, demonstrating the acid phosphatase enzyme that detects the phagocytic activity, were positive in the mesenchyme and trophoblast, with a weak stain in an endometrial stroma. In the top of fetal villi, mainly in the binucleate cells, we visualized accumulations of PAS-positive secretions, indicating the presence of mucoid material. The uterine gland epithelium was columnar-type and in the gland lumina there were cell debris and PAS-positive mucoid secretions. We confirmed the reactivity of the uterine glands to the acid phosphatase enzyme and to the Perls reaction in the epithelium and in the gland lumina. The uteroferrin immunohistochemistry showed a strong stain in the cytoplasm of the endometrial glands cells and in the lumina. In the NT bovine placentae, the blood extravasations between uterine and trophoblast epithelium were aberrant. There was also the remodeling of the maternal connective tissue (endometrial stroma) in this area. We also demonstrated phagocytic uptake of uteroferrin by the trophoblast, although the histochemical and immunohistochemical reactions were weak in the trophoblast of the placentomes and in the endometrial glands of the intercaruncular region, when compared with the controls. The results obtained by the histochemistry and immunohistochemistry indicated that these sites of transfer substances from mother to fetus are very important in providing adequate nutrition to the fetus, key to a successful pregnancy in NT bovines. This work was funded by FAPESP, Brazil.


2020 ◽  
Author(s):  
Zer Vue ◽  
Richard R. Behringer

AbstractBackgroundThe uterus is the location where multiple events occur that are required for the start of new life in mammals. The adult uterus contains endometrial or uterine glands that are essential for female fertility. In the mouse, uterine glands are located in the lateral and anti-mesometrial regions of the uterine horn. Previous 3D-imaging of the adult uterus, its glands, and implanting embryos has been performed by multiple groups, using fluorescent microscopy. Adenogenesis, the formation of uterine glands, initiates after birth. Recently, we created a 3D-staging system of mouse uterine gland development at postnatal time points, using light sheet fluorescent microscopy. Here, using a similar approach, we examine the morphological changes in the epithelium of the perinatal mouse uterus.ResultsThe uterine epithelium exhibits mesometrial-antimesometrial (dorsoventral) patterning as early as three days after birth (P3), marked by the presence of the mesometrially-positioned developing uterine rail. Uterine gland buds are present beginning at P4. Novel morphological epithelial structures, including a ventral ridge and uterine segments were identified.ConclusionsThe perinatal mouse uterine luminal epithelium develops mesometrial-antimesometrial (dorsal-ventral) morphologies at 3-4 days post-partum. Between 5-6 days post-partum uterine epithelial folds form, defining alternating left-right segments.Bullet pointsMorphological patterning events in the perinatal uterine epithelium are not well described.Light sheet microscopy was used to generate volumetric reconstructions of the perinatal mouse uterine epithelium.At postnatal day 3 (P3), the uterine epithelium shows the first signs of dorsoventral pattern, with the presence of the forming mesometrially-positioned uterine rail.The first morphological indication of uterine adenogenesis begins at P4.Novel morphological structures were identified from volumetric reconstructions, including the presence of a ventral ridge (another sign of dorsoventral pattern) and uterine segmentation.


2005 ◽  
Vol 17 (2) ◽  
pp. 209
Author(s):  
F. Pereira ◽  
F. Braga ◽  
J.R. Kfoury Jr ◽  
L. Oliveira ◽  
P. Papa ◽  
...  

The transplacental transport of iron by uteroferrin (Uf), and the hemophagous areas in the water buffalo placenta were analyzed to clarify the mechanism of blood extravasation in the materno-fetal interface with consequent transfer of iron to the fetus through the trophoblastic erythrophagocytosis (Murai and Yamauchi 1986 Nippon Juigaki Zasshi 48, 75–88) and in the endometrial glands (Bazer et al. 1991 Exp. Hematol. 19 910–19 915). In the water buffalo placenta this mechanism remains unclear; uteroferrin is very important in this process because it is both an iron transporter and a progesterone-induced hematopoietic growth factor. Our objective was to characterize these hemophagous areas and the endometrium of the water buffalo, focusing in the materno-fetal transfer of iron. Small pieces of the placentomes and interplacentomal region of water buffaloes (Bubalus bubalis bubalis, n = 51) in all of the gestation periods were fixed in 4% paraformoldehyde, and 2.5% glutaraldehyde in PBS, processed, and stained for light and transmission electron microscopy to characterize the hemophagous areas and endometrial glands morphologically, histochemically (Perls, acid phosphatase reaction), and immunohistochemically with rabbit anti-pig uteroferrin antibody to confirm the iron transfer. The hemophagous areas were present in the placentome from 4–10-months-pregnant placentae. The Perls reaction for ferric iron staining was negative in the placentome and positive in the endometrial glands, and the acid phosphatase reaction to detect phagocytic activity was positive in the placentome as well as in the interplacentomal region. The uteroferrin immunohistochemical reaction was positive in the trophoblast, mainly in determined regions of the materno-fetal interface and in other points deep in the placentome, and the endometrial glands showed a strong reaction in the epithelium and in the lumina. The ultrastructure of the hemophagous areas revealed ingested erythrocytes inside the epithelial cells of trophoblasts, endocytic vesicles, and caveolae. The endometrial gland epithelium is of the columnar type with microvilli and basal nuclei. The results obtained mainly by histochemistry and immunohistochemistry indicated that the hemophagous areas and endometrial glands are very important sites for iron transfer in water buffalo, and are thus involved in the regulation of fetal hematopoiesis. This work was funded by FAPESP.


2021 ◽  
Vol 12 (1) ◽  
Author(s):  
Kazuki Motomura ◽  
Hidenori Takeuchi ◽  
Michitaka Notaguchi ◽  
Haruna Tsuchi ◽  
Atsushi Takeda ◽  
...  

AbstractDuring the double fertilization process, pollen tubes deliver two sperm cells to an ovule containing the female gametes. In the pollen tube, the vegetative nucleus and sperm cells move together to the apical region where the vegetative nucleus is thought to play a crucial role in controlling the direction and growth of the pollen tube. Here, we report the generation of pollen tubes in Arabidopsis thaliana whose vegetative nucleus and sperm cells are isolated and sealed by callose plugs in the basal region due to apical transport defects induced by mutations in the WPP domain-interacting tail-anchored proteins (WITs) and sperm cell-specific expression of a dominant mutant of the CALLOSE SYNTHASE 3 protein. Through pollen-tube guidance assays, we show that the physiologically anuclear mutant pollen tubes maintain the ability to grow and enter ovules. Our findings provide insight into the sperm cell delivery mechanism and illustrate the independence of the tip-localized vegetative nucleus from directional growth control of the pollen tube.


2017 ◽  
Vol 114 (6) ◽  
pp. E1018-E1026 ◽  
Author(s):  
Andrew M. Kelleher ◽  
Wang Peng ◽  
James K. Pru ◽  
Cindy A. Pru ◽  
Francesco J. DeMayo ◽  
...  

Establishment of pregnancy is a critical event, and failure of embryo implantation and stromal decidualization in the uterus contribute to significant numbers of pregnancy losses in women. Glands of the uterus are essential for establishment of pregnancy in mice and likely in humans. Forkhead box a2 (FOXA2) is a transcription factor expressed specifically in the glands of the uterus and is a critical regulator of postnatal uterine gland differentiation in mice. In this study, we conditionally deleted FOXA2 in the adult mouse uterus using the lactotransferrin Cre (Ltf-Cre) model and in the neonatal mouse uterus using the progesterone receptor Cre (Pgr-Cre) model. The uteri of adult FOXA2-deleted mice were morphologically normal and contained glands, whereas the uteri of neonatal FOXA2-deleted mice were completely aglandular. Notably, adult FOXA2-deleted mice are completely infertile because of defects in blastocyst implantation and stromal cell decidualization. Leukemia inhibitory factor (LIF), a critical implantation factor of uterine gland origin, was not expressed during early pregnancy in adult FOXA2-deleted mice. Intriguingly, i.p. injections of LIF initiated blastocyst implantation in the uteri of both gland-containing and glandless adult FOXA2-deleted mice. Although pregnancy was rescued by LIF and was maintained to term in uterine gland-containing adult FOXA2-deleted mice, pregnancy failed by day 10 in neonatal FOXA2-deleted mice lacking uterine glands. These studies reveal a previously unrecognized role for FOXA2 in regulation of adult uterine function and fertility and provide original evidence that uterine glands and, by inference, their secretions play important roles in blastocyst implantation and stromal cell decidualization.


1977 ◽  
Vol 25 (5) ◽  
pp. 319-328 ◽  
Author(s):  
E Dannen ◽  
M E Beard

Organelles with the morphologic characteristics of peroxisomes have been found in the cells of the kidney sac of two terrestrial pulmonate gastropods. Arion ater and Ariolimax columbianus. These peroxisomes appear in profile as circles or ellipses, 0.25 micron in diameter and 0.3-0.8 micron long; They have a finely granular matrix and a single-limiting membrane; the organelles are extensively associated with smooth endoplasmic reticulum. Some Ariolimax peroxisomes contained structures reminiscent of nucleoids while those of Arion did not. The peroxisomes of Arion ater show a strongly-positive staining reaction with the 3,3'-diaminobenzidine technique, which is inhibited in the presence of aminotriazole. Peroxisomes of Ariolimax columbianus did not show a positive reaction, despite a number of variations of the 3,3'-diaminobenzidine protocol. Speculations are made concerning the biochemical reasons for this cytochemical behavior. Peroxisomes in both tissues were negatively stained while lysosomes were positively stained in acid-phosphatase incubations.


2011 ◽  
Vol 33 (3) ◽  
pp. 765-773 ◽  
Author(s):  
Carla Rosana Eichelberger ◽  
Liana Johann ◽  
Fernanda Majolo ◽  
Noeli Juarez Ferla

Despite the importance of peach (Prunus persica (L.) Batsch) in Rio Grande do Sul, little is known about mites fluctuation population considered important to this crop. The objective of this study was to know the population diversity and fluctuation of mite species associated with Premier and Eldorado varieties in Roca Sales and Venâncio Aires counties, Rio Grande do Sul. The study was conducted from July 2008 to June 2009 when 15 plants were randomly chosen in each area. The plants were divided in quadrants and from each one a branch was chosen from which three leaves were removed: one collected in the apical region, another in the medium and the other in the basal region, totalizing 180 leaves/area. Five of the most abundant associated plants were collected monthly in enough amounts for the screening under the stereoscopic microscope during an hour. A total of 1,124 mites were found belonging to 14 families and 28 species. Tetranychus ludeni Zacher, 1913, Panonychus ulmi (Koch, 1836) and Mononychellus planki (McGregor, 1950) were the most abundant phytophagous mites, whereas Typhlodromalus aripo Deleon, 1967 and Phytoseiulus macropilis (Banks, 1904) the most common predatory mites. The period of one hour under stereoscopic microscope was enough to get a representative sample. In both places evaluated the ecologic indices were low, but little higherin Premier (H' 0.56; EqJ: 0.43) when compared to Eldorado (H' 0.53; EqJ 0.40). In Premier constant species were not observed and accessory only Brevipalpus phoenicis (Geijskes, 1939), T. ludeni and T. aripo. Higher abundance was observed in December and January and bigger amount in April. Already in Eldorado, T. ludeni and P. ulmi were constants. Greater abundance was observed in November and December, whereas grater richness in December and January. In both orchards were not found mites in buds. Tetranychus ludeni is the most abundant phytophagous mites with outbreak population in November, December and January and high predator diversity was observed on associated plants and on peach plants, indicating the existence of species mobility in peach orchard.


2002 ◽  
Vol 158 (2) ◽  
pp. 283-292 ◽  
Author(s):  
Michael C. Ashby ◽  
Madeleine Craske ◽  
Myoung Kyu Park ◽  
Oleg V. Gerasimenko ◽  
Robert D. Burgoyne ◽  
...  

Ca2+-induced Ca2+ release (CICR) plays an important role in the generation of cytosolic Ca2+ signals in many cell types. However, it is inherently difficult to distinguish experimentally between the contributions of messenger-induced Ca2+ release and CICR. We have directly tested the CICR sensitivity of different regions of intact pancreatic acinar cells using local uncaging of caged Ca2+. In the apical region, local uncaging of Ca2+ was able to trigger a CICR wave, which propagated toward the base. CICR could not be triggered in the basal region, despite the known presence of ryanodine receptors. The triggering of CICR from the apical region was inhibited by a pharmacological block of ryanodine or inositol trisphosphate receptors, indicating that global signals require coordinated Ca2+ release. Subthreshold agonist stimulation increased the probability of triggering CICR by apical uncaging, and uncaging-induced CICR could activate long-lasting Ca2+ oscillations. However, with subthreshold stimulation, CICR could still not be initiated in the basal region. CICR is the major process responsible for global Ca2+ transients, and intracellular variations in sensitivity to CICR predetermine the activation pattern of Ca2+ waves.


2011 ◽  
Vol 38 (11) ◽  
pp. 910 ◽  
Author(s):  
Helen Bramley ◽  
Stephen D. Tyerman ◽  
David W. Turner ◽  
Neil C. Turner

In south-west Australia, winter grown crops such as wheat and lupin often experience transient waterlogging during periods of high rainfall. Wheat is believed to be more tolerant to waterlogging than lupins, but until now no direct comparisons have been made. The effects of waterlogging on root growth and anatomy were compared in wheat (Triticum aestivum L.), narrow-leafed lupin (Lupinus angustifolius L.) and yellow lupin (Lupinus luteus L.) using 1 m deep root observation chambers. Seven days of waterlogging stopped root growth in all species, except some nodal root development in wheat. Roots of both lupin species died back progressively from the tips while waterlogged. After draining the chambers, wheat root growth resumed in the apical region at a faster rate than well-drained plants, so that total root length was similar in waterlogged and well-drained plants at the end of the experiment. Root growth in yellow lupin resumed in the basal region, but was insufficient to compensate for root death during waterlogging. Narrow-leafed lupin roots did not recover; they continued to deteriorate. The survival and recovery of roots in response to waterlogging was related to anatomical features that influence internal oxygen deficiency and root hydraulic properties.


2007 ◽  
Vol 27 (6) ◽  
pp. 221-228 ◽  
Author(s):  
David M. Iturrizaga ◽  
Flavia T. Verechia ◽  
Tatiana C. Santos ◽  
Pedro P. Bombonato ◽  
Dulcinéa G. Teixeira ◽  
...  

Samples from 9 llamas (28 through 36 weeks of gestation) were collected and fixed in 4% buffered paraformaldehyde (light microscopy) and in 2.5% buffered glutaraldehyde (transmission and scanning electron microscopy). The material was processed in paraplast and slides (5mm) were stained with HE, PAS, Masson-Trichrome, acid phosphatase and Perl's. The uteroferrin was immunolocalized. The results show that llama placenta is chorioallantoic, diffuse, folded and epitheliochorial, and the fetus is covered with an epidermal membrane. The trophoblast cells have variable morphology: cubic, rounded and triangular cells, with cytoplasm containing PAS-positive granules. Binucleated cells with large cytoplasm and rounded nuclei, as well as giant trophoblastic cells with multiple nuclei were also observed. Numerous blood vessels were observed beneath the cells of the uterine epithelium and around the chorionic subdivided branches. Glandular activity was shown by PAS, Perl's, and acid phosphatase positive reactions in the cytoplasm and glandular lumen, and by immunolocalization of the uteroferrin in the glandular epithelium. The uterine glands open in spaces formed by the areoles, which are filled by PAS-positive material. The llama fetus was covered by the epidermal membrane, composed of stratified epithelium, with up to seven layers of mono-, bi- or trinucleated cells. The high level of maternal and fetal vascularization surfaces indicates an intense exchange of substances across both surfaces. The metabolic activity shown in the uterine glands suggests an adaptation of the gestation to the high altitudes of the natural habitat of this species.


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