scholarly journals FOXL2 antagonises the male developmental pathway in embryonic chicken gonads

2019 ◽  
Vol 243 (3) ◽  
pp. 211-228 ◽  
Author(s):  
Andrew T Major ◽  
Katie L Ayers ◽  
Justin Chue ◽  
Kelly N Roeszler ◽  
Craig A Smith
Keyword(s):  
Egg Laying ◽  
Female Gonad ◽  
Main Role ◽  
Developmental Pathway ◽  
In Ovo ◽  
Cortical Cells ◽  
Aromatase Expression ◽  
Oestrogen Receptor Alpha ◽  
Embryonic Chicken ◽  
And Function

FOXL2 is a conserved transcription factor with a central role in ovarian development and function. Studies in humans and mice indicate that the main role of FOXL2 is in the postnatal ovary, namely folliculogenesis. To shed light on the function and evolution of FOXL2 in the female gonad, we examined its role in embryonic avian gonads, using in ovo overexpression and knockdown. FOXL2 mRNA and protein are expressed female specifically in the embryonic chicken gonad, just prior to the onset of sexual differentiation. FOXL2 is expressed in the medullary cord cells, in the same cell type as aromatase (CYP19A1). In addition, later in development, expression also becomes localised in a subset of cortical cells, distinct from those expressing oestrogen receptor alpha. Misexpression of FOXL2 in the male chicken embryonic gonad suppresses the testis developmental pathway, abolishing local expression of the male pathway genes SOX9, DMRT1 and AMH and repressing Sertoli cell development. Conversely, knockdown of FOXL2 expression allows ectopic activation of SOX9 in female gonads. However, misexpression of FOXL2 alone was insufficient to activate aromatase expression in male gonads, while FOXL2 knockdown did not affect aromatase expression in females. These results indicate that FOXL2 plays an important role in embryonic differentiation of the avian ovary via antagonism of SOX9, but may be dispensable for aromatase activation at embryonic stages. The data suggest that FOXL2 has different roles in different species, more central for embryonic ovarian differentiation in egg-laying vertebrates.

scholarly journals Design and verification of additional filtration for the application of ecological transmission and hydraulic fluids in tractorc

2013 ◽  
Vol 61 (5) ◽  
pp. 1305-1311 ◽  
Author(s):  
Pavel Máchal ◽  
Radoslav Majdan ◽  
Zdenko Tkáč ◽  
Bohuslav Stančík ◽  
Rudolf Abrahám ◽  
...  
Keyword(s):  
Chemical Elements ◽  
Main Role ◽  
Additive Concentration ◽  
Test Operation ◽  
Time Period ◽  
Medium Level ◽  
Agricultural Tractors ◽  
High Level ◽  
And Function

This contribution presents the design and function verification of additional filtration. It is intended for the common transmission and hydraulic oil filling of tractors. The main role of this filtration concept is to ensure a high level of oil cleanness as a condition for the application of ecologic fluids in tractors. The next one is to decrease the wear of lubricated tractor components, the degradation of oil and eventually to extend the interval of oil change. The designed additional filtering is characterized by ease installation through the use of quick couplings and hoses to the external hydraulic circuit. Therefore, the filtration is suitable for various tractor types. Filter element has been designed with the filter ability 1micron and the ability to separate to 0.5 dm3 of water from oil. Function of additional filtration was verified during the 150 engine hours of tractor operation. During this time period the oil contamination was evaluated on the basis of chemical elements content such as Fe, Cu, Si, Al, Ni, Mo and Cr. The additive concentration was evaluated on the basis of chemical elements content such as Ca, P and Zn. During the test operation of tractor the concentration decrease of chemical elements reached the values 25.53 % (Fe), 23.53 % (Si), 25 % (Al) and 5.5 % (Cu). The decrease of additive concentration reached only medium level (6.6 %). Therefore, the designed additional filtration doesn’t remove additives from oil. Based on the evaluation of the content of chemical elements (that representing contamination and additives), we can say that the designed filtering method is suitable for use in agricultural tractors.

scholarly journals Podocytes—The Most Vulnerable Renal Cells in Preeclampsia

2020 ◽  
Vol 21 (14) ◽  
pp. 5051
Author(s):  
Ewa Kwiatkowska ◽  
Katarzyna Stefańska ◽  
Maciej Zieliński ◽  
Justyna Sakowska ◽  
Martyna Jankowiak ◽  
...  
Keyword(s):  
Current Knowledge ◽  
Damage Mechanism ◽  
Endothelial Damage ◽  
Main Role ◽  
Long Time ◽  
National Cohort ◽  
History Of ◽  
Stage Renal Disease ◽  
End Stage ◽  
And Function

Preeclampsia (PE) is a disorder that affects 3–5% of normal pregnancies. It was believed for a long time that the kidney, similarly to all vessels in the whole system, only sustained endothelial damage. The current knowledge gives rise to a presumption that the main role in the development of proteinuria is played by damage to the podocytes and their slit diaphragm. The podocyte damage mechanism in preeclampsia is connected to free VEGF and nitric oxide (NO) deficiency, and an increased concentration of endothelin-1 and oxidative stress. From national cohort studies, we know that women who had preeclampsia in at least one pregnancy carried five times the risk of developing end-stage renal disease (ESRD) when compared to women with physiological pregnancies. The focal segmental glomerulosclerosis (FSGS) is the dominant histopathological lesion in women with a history of PE. The kidney’s podocytes are not subject to replacement or proliferation. Podocyte depletion exceeding 20% resulted in FSGS, which is a reason for the later development of ESRD. In this review, we present the mechanism of kidney (especially podocytes) injury in preeclampsia. We try to explain how this damage affects further changes in the morphology and function of the kidneys after pregnancy.

Seasonal reproductive anatomy and sperm storage in pleurocerid gastropods (Cerithioidea: Pleuroceridae)

2014 ◽  
Vol 92 (12) ◽  
pp. 989-995 ◽  
Author(s):  
Nathan V. Whelan ◽  
Ellen E. Strong
Keyword(s):  
Seasonal Variation ◽  
Life Histories ◽  
Gross Anatomy ◽  
Egg Laying ◽  
Conservation Strategies ◽  
Freshwater Species ◽  
Form And Function ◽  
Reproductive Anatomy ◽  
And Function ◽  
And Behavior

Life histories, including anatomy and behavior, are a critically understudied component of gastropod biology, especially for imperiled freshwater species of Pleuroceridae. This aspect of their biology provides important insights into understanding how evolution has shaped optimal reproductive success and is critical for informing management and conservation strategies. One particularly understudied facet is seasonal variation in reproductive form and function. For example, some have hypothesized that females store sperm over winter or longer, but no study has explored seasonal variation in accessory reproductive anatomy. We examined the gross anatomy and fine structure of female accessory reproductive structures (pallial oviduct, ovipositor) of four species in two genera (round rocksnail, Leptoxis ampla (Anthony, 1855); smooth hornsnail, Pleurocera prasinata (Conrad, 1834); skirted hornsnail, Pleurocera pyrenella (Conrad, 1834); silty hornsnail, Pleurocera canaliculata (Say, 1821)). Histological analyses show that despite lacking a seminal receptacle, females of these species are capable of storing orientated sperm in their spermatophore bursa. Additionally, we found that they undergo conspicuous seasonal atrophy of the pallial oviduct outside the reproductive season, and there is no evidence that they overwinter sperm. The reallocation of resources primarily to somatic functions outside of the egg-laying season is likely an adaptation that increases survival chances during winter months.

scholarly journals Anatomical and histological changes in the oviducts of Japanese quail, Coturnix japonica, after embryonic exposure to ethynyloestradiol

Reproduction ◽  
2001 ◽  
pp. 155-165 ◽  
Author(s):  
C Berg ◽  
L Holm ◽  
I Brandt ◽  
B Brunstrom
Keyword(s):  
Japanese Quail ◽  
Egg Laying ◽  
Coturnix Japonica ◽  
In Ovo ◽  
Histological Changes ◽  
Bird Populations ◽  
Embryonic Exposure ◽  
Exogenous Oestrogen ◽  
Tubular Gland ◽  
Sexually Mature

Oestrogen is needed for normal oviductal development in female birds, but excessive early exposure to oestrogen can cause oviductal abnormalities and impair egg-laying ability. In this study, the anatomical and histological effects of in ovo exposure to the synthetic oestrogen ethynyloestradiol on the oviducts of immature and adult female Japanese quail, Coturnix japonica, were investigated. A series of abnormalities was observed after injection of ethynyloestradiol (2 or 20 ng g(-1) egg) into the yolk on day 3 of incubation. Ethynyloestradiol induced precocious differentiation of the luminal epithelium and tubular glands in immature chicks. Right-side oviduct retention occurred at all the ages studied, whereas certain other effects were not evident until sexual maturity. The left oviduct was reduced in size and tubular gland density in the uterus (shell gland) was reduced in sexually mature birds that had been treated with ethynyloestradiol. The utero-vaginal junction was longer than in control birds and had a higher tubular gland density. The epithelial cells in the magnum were taller in birds treated with ethynyloestradiol. Embryonic exposure to the environmental contaminant ethynyloestradiol may cause persisting structural malformations in oviducts of quails, which can impair fertility. As oviductal malformations are indicative of embryonic exposure to exogenous oestrogen, they are potentially useful as biomarkers of xenooestrogen exposure in wild bird populations.

Dove reproduction and retinoid (vitamin A) dynamics in adult females and their eggs following exposure to 3,3′,4,4′-tetrachlorobiphenyl

1989 ◽  
Vol 67 (4) ◽  
pp. 908-913 ◽  
Author(s):  
P. A. Spear ◽  
D. H. Bourbonnais ◽  
D. B. Peakall ◽  
T. W. Moon
Keyword(s):  
Corn Oil ◽  
Retinyl Palmitate ◽  
Egg Laying ◽  
Exposed Group ◽  
Control Group ◽  
Serum Retinol ◽  
Embryo Viability ◽  
In Ovo ◽  
Compensatory Response ◽  
Streptopelia Risoria

One week before mating, ring doves (Streptopelia risoria) received an intraperitoneal injection of vitamin-stripped corn oil containing 0 or 40 μg/g 3,3′,4,4′-tetrachlorobiphenyl. Of numerous reproductive parameters investigated, egg laying was retarded (p < 0.001) and 43% of the embryos died primarily between days 4 and 7 of incubation in the exposed group. Exposed females laying viable eggs had higher (p < 0.01) serum retinol at the time of mating than exposed females producing eggs that failed to develop to hatching. Serum retinol concentrations were greater (p < 0.05) in exposed males than in control males. A method was developed to extract and quantify five naturally occurring retinoids in egg yolks. When the experiment was repeated, yolk retinol and retinyl palmitate decreased (p < 0.05) between days 3 and 8 of development in the eggs of the exposed group regardless of embryo viability. No change in yolk retinoids occurred in the control group. At day 3 of incubation, the ratio of retinol: retinyl palmitate in yolks was greater (p < 0.01) in the viable eggs of the exposed group than in either the controls or the nonviable eggs of the exposed group. Despite the reproductive effects, the repeated dose of biphenyl did not elicit liver porphyrin accumulation or alter internal organ weights. Liver retinol concentrations were lower in males (p < 0.001) and females (p < 0.05) exposed to the toxicant than in controls; liver retinyl palmitate was unchanged. These changes in retinoid dynamics during oogenesis and in ovo may be a compensatory response to the toxicant.

scholarly journals The management and protection of soil cover: an ecosystem approach

2010 ◽  
Vol 53 (1) ◽  
pp. 25-34
Author(s):  
Raimo Kõlli ◽  
Arno Kanal
Keyword(s):  
Land Use ◽  
Soil Degradation ◽  
Soil Cover ◽  
Soil Management ◽  
Ecosystem Approach ◽  
Sustainable Land Use ◽  
Main Role ◽  
Plant Soil ◽  
Environmental Status ◽  
And Function

The management and protection of soil cover: an ecosystem approach There is need for increased societal awareness of the importance of soil management for varying specific uses and for protection of the environment. The main purpose of the study was to analyze the role of soils in the formation and function of ecosystems, to elucidate the properties and mechanisms which play the main role in plant-soil mutual relationships, and to generalize the pedoecological principles of soil management and protection in conditions of Estonia. The treatment is a departure from the pedocentric viewpoint and is based on an ecosystem approach. The relationships between soil and plant covers are tested quantitatively on the basis of the ecosystems' phytoproductivity and fluxes of organic carbon, and qualitatively on the ground of humus forms and site types. On the basis of personal research and data available in literature, the constraints limiting soil cover functioning, the soil degradation features which occurred in actual time and the measures and activities for prevention of soil degradation are analyzed. Problems connected with biodiversity and soil environment protection ability as they relate to soil cover management and protection are discussed. For sustainable land use and to avoid deterioration of soil properties, the experience of local farmers, scientific research and monitoring of degradation features are needed. The soil cover is protected (or sustainable land use is attained) in circumstances when soil fertility and functioning is maintained adequately for the soil types' characteristics. Soil cover should be considered as a medium through which it is possible to improve the environmental status of the area.

scholarly journals Megalin Is Predominantly Observed in Vesicular Structures in First and Third Trimester Cytotrophoblasts of the Human Placenta

2016 ◽  
Vol 64 (12) ◽  
pp. 769-784 ◽  
Author(s):  
Tina Storm ◽  
Erik I. Christensen ◽  
Julie Nelly Christensen ◽  
Tine Kjaergaard ◽  
Niels Uldbjerg ◽  
...  
Keyword(s):  
Human Placenta ◽  
Fetal Development ◽  
First Trimester ◽  
Main Role ◽  
Third Trimester ◽  
Term Placenta ◽  
Complex Functions ◽  
And Function ◽  
Uptake Of Nutrients ◽  
Immunohistochemical Analyses

The membrane receptor megalin is crucial for normal fetal development. Besides its expression in the developing fetus, megalin is also expressed in the human placenta. Similar to its established function in the kidney proximal tubules, placental megalin has been proposed to mediate uptake of vital nutrients. However, details of megalin expression, subcellular localization, and function in the human placenta remain to be established. By immunohistochemical analyses of first trimester and term human placenta, we showed that megalin is predominantly expressed in cytotrophoblasts, the highly proliferative cells in placenta. Only limited amounts of megalin could be detected in syncytiotrophoblasts and least in term placenta syncytiotrophoblasts. Immunocytochemical analyses furthermore showed that placental megalin associates with structures of the endolysosomal apparatus. Combined, our results clearly place placental megalin in the context of endocytosis and trafficking of ligands. However, due to the limited expression of megalin in syncytiotrophoblasts, especially in term placenta, it appears that the main role for placental megalin is not to mediate uptake of nutrients from the maternal bloodstream, as previously proposed. In contrast, our results point toward novel and complex functions for megalin in the cytotrophoblasts. Thus, we propose that the perception of placental megalin localization and function should be revised.

scholarly journals Hemicentin mediated type IV collagen assembly strengthens juxtaposed basement membrane linkage

2021 ◽  
Author(s):  
Claire A Gianakas ◽  
Daniel P Keeley ◽  
William Ramos-Lewis ◽  
Kieop Park ◽  
Ranjay Jayadev ◽  
...  
Keyword(s):  
Basement Membrane ◽  
Type Iv Collagen ◽  
Fluorescent Proteins ◽  
Structure And Function ◽  
Egg Laying ◽  
Matrix Proteins ◽  
Type Iv ◽  
Seam Cell ◽  
Specialized Form ◽  
And Function

Basement membrane (BM) matrices surround and separate most tissues. However, through poorly understood mechanisms, BMs of adjacent tissues can also stably link to support organ structure and function. Using endogenous knock-in fluorescent proteins, conditional RNAi, optogenetics, and quantitative live imaging, we identified matrix proteins mediating a BM linkage (B-LINK) between the uterine utse and epidermal seam cell BMs in Caenorhabditis elegans that supports the uterus during egg-laying. We found that hemicentin is secreted by the utse and promotes fibulin-1 assembly to jointly initiate the B-LINK. During egg-laying, however, both proteins decline in levels and are not required for B-LINK maintenance. Instead, we discovered that hemicentin also promotes type IV collagen assembly, which accumulates to high levels during egg-laying and sustains the B-LINK during the mechanically active egg-laying period. This work reveals mechanisms underlying BM-BM connection maturation and identifies a crucial function for hemicentin and fibulin-1 in initiating attachment and type IV collagen in strengthening this specialized form of tissue linkage.

scholarly journals Trombositopenia Berat pada Ibu Hamil dengan Sistemik Lupus Erythematosus yang Dilakukan Seksio Sesarea

2020 ◽  
Vol 3 (2) ◽  
pp. 102-110
Author(s):  
Mariza Fitriati ◽  
Ratih Kumala Fajar Apsari ◽  
Sri Rahardjo
Keyword(s):  
Systemic Lupus Erythematosus ◽  
Lupus Erythematosus ◽  
Bleeding Time ◽  
Total Intravenous Anesthesia ◽  
Main Role ◽  
Severe Thrombocytopenia ◽  
Clotting Time ◽  
Systemic Lupus ◽  
Intravenous Anesthesia ◽  
And Function

Trombositopenia adalah hal yang umum muncul pada kehamilan normal, disebut trombositopenia berat bila jumlah trombosit <50.000 /µL. Komplikasi kehamilan oleh penyakit Lupus Eritematosus Sistemik (Systemic Lupus Erythematosus = SLE) dapat menimbulkan trombositopenia berat patologis. Karena peran penting trombosit dalam pembekuan darah, dilain pihak proses persalinan akan menimbulkan perdarahan, maka dibutuhkan jumlah dan fungsi trombosit yang cukup. Trombositopenia-SLE berderajat berat perlu mendapat terapi untuk meningkatkan jumlah dan fungsi trombosit sebelum menjalani persalinan. Upaya peningkatan jumlah trombosit pada trombositopenia-SLE diawali dengan kortikosteroid sebagai terapi awal, dengan terapi alternatif lanjutan imunosupresif, splenektomi, plasmaferesis, trombopoetic, dan konsentrat trombosit. Pada kasus ini trombositopenia tidak dapat teratasi, sehingga pemeriksaan fungsional pembekuan darah bleeding time dan clotting time digunakan untuk membantu memperkirakan kemungkinan terjadi perdarahan berkelanjutan. Perhatian utama pada pemilihan tehnik anestesi kasus ini adalah kemungkinan terjadi perdarahan berkelanjutan, dalam hal ini dipilih yang dipertimbangkan berisiko terkecil yaitu total intravenous anesthesia (TIVA) dengan ketamin. Perawatan pasca operasi dilaksanakan juga dengan tetap mewaspadai kemungkinan terjadi perdarahan berkelanjutan.   Severe Trombositopenia in Pregnant Woman with Sistemic Lupus Erythematosus Ongoing Caesarean Section Abstract Thrombocytopenia is a common occurrence in normal pregnancy, will classified as severe thrombocytopenia if platelet count <50.000/ µL. Pregnancy complicated by Systemic Lupus Erythematosus (SLE) can lead to pathological severe thrombocytopenia. As thrombocytes has a main role in haemostasis, and delivery process will always caused bleeding, thrombocytes needed in proper amount and function. Severe SLE-Thrombocytopenia has to treat aiming higher total thrombocytes and function before delivery. Effort in raising thrombocytes count on SLE-thrombocytopenia patients recommended starting from corticosteroid as first line treatment, followed by any alternatif therapy if thrombocytes count did not responds to corticosteroid therapy, such as immunosuppresif drugs, splenectomy, plasmapharesis, thrombopoetic drugs, and trombocyte concentrate. In this case, severe thrombocytopenia couldn’t be resolved, so then the bleeding time and clotting time taken as tools to estimate blood’s ability to coagulate. The main consideration on choosing anesthesia’s plan in this case is possibility condition to held uncontrolled bleeding. Therefore, the procedure with the lowest risk for maternal and fetal, total intravenous anesthesia with ketamin, had chosen. Caring for post operative SLE-thrombocytopenia patient should never ignoring vigilance for sustainable bleeding.

scholarly journals Selective Binding of Lectins to Embryonic Chicken Vasculature

2003 ◽  
Vol 51 (5) ◽  
pp. 597-604 ◽  
Author(s):  
Shahla M. Jilani ◽  
Thomas J. Murphy ◽  
Shelley N.M. Thai ◽  
Anne Eichmann ◽  
Jackelyn A. Alva ◽  
...  
Keyword(s):  
Lens Culinaris ◽  
Developmental Stages ◽  
Chorioallantoic Membrane ◽  
Experimental System ◽  
In Ovo ◽  
Additional Advantage ◽  
Chicken Embryos ◽  
Lens Culinaris Agglutinin ◽  
Embryonic Chicken

Chicken embryos are an excellent model system for studies related to vascular morphogenesis. Development in ovo allows manipulations otherwise difficult in mammals, and the use of chicken-quail chimeras offers an additional advantage to this experimental system. Furthermore, the chicken chorioallantoic membrane has been extensively used for in vivo assays of angiogenesis. Surprisingly, few markers are available for a comprehensive visualization of the vasculature. Here we report the use of lectins for identification of embryonic chicken blood vessels. Nine lectins were evaluated using intravascular perfusion and directly on sections. Our results indicate that Lens culinaris agglutinin, concanavalin A, and wheat germ agglutinin can be used effectively for visualization of vessels of early chicken embryos (E2.5-E4). At later developmental stages, Lens culinaris agglutinin is a better choice because it displays equal affinity for the endothelia of arteries, veins, and capillaries. The findings presented here expand our understanding of lectin specificity in the endothelium of avian species and provide information as to the use of these reagents to obtain comprehensive labeling of the embryonic and chorioallantoic membrane vasculature.

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