scholarly journals NCAM polypeptides in heart development: association with Z discs of forms that contain the muscle-specific domain.

1995 ◽  
Vol 128 (1) ◽  
pp. 209-221 ◽  
Author(s):  
M K Byeon ◽  
Y Sugi ◽  
R R Markwald ◽  
S Hoffman

Previous studies of neural cell adhesion molecule (NCAM) cDNAs have revealed an alternatively spliced set of small exons (12A, 12B, 12C, and 12D) that encode a region in the extracellular portion of the molecule known as the muscle-specific domain (MSD). The entire MSD region can be expressed in skeletal muscle, heart, and skin; only exons 12A and 12D have been found in brain. These studies did not reveal which NCAM polypeptides contain the MSD region or the immunohistochemical distribution of these NCAM molecules. To address these questions, we prepared antibodies against the oligopeptides encoded by exons 12A and 12B and by exons 12C and 12D, and we used these antibodies to study the forms of NCAM containing the MSD region expressed during embryonic chicken heart development. These antibodies recognize certain forms of NCAM found in the heart, but they do not recognize brain NCAM. In the heart, each of the splice variants of NCAM (large cytoplasmic domain, small cytoplasmic domain, and small surface domain) that differ in their mode of attachment to the plasma membrane or in the size of their cytoplasmic domain is expressed in a form that contains and in a form that lacks the MSD region. No microheterogeneity is observed in the size of NCAM molecules containing the MSD region, even at the level of cyanogen bromide fragments, suggesting that exons 12A-D are expressed as a single unit. Depending on the site and the stage of development, the percent of NCAM molecules containing the MSD region can vary from nearly 0 to 100%. In general, this percentage increases during development. In immunohistochemical studies of hearts from stage 18 embryos, forms of NCAM containing the MSD region colocalized with Z discs. No other adhesion molecules were found in this distribution at this early stage of development. Studies on isolated cells in vitro demonstrate that the colocalization with Z discs of NCAM molecules containing the MSD region does not depend on cell-cell contact, and they raise the possibility that this form of NCAM is involved in cell-extracellular matrix interactions. The association of NCAM molecules containing the MSD region with Z discs suggests that this form of NCAM is involved in early myofibrillogenesis.

2020 ◽  
Author(s):  
Vera A van der Weijden ◽  
Meret Schmidhauser ◽  
Mayuko Kurome ◽  
Johannes Knubben ◽  
Veronika L Flöter ◽  
...  

Abstract Background: The transcriptional changes around the time of embryonic genome activation in pre-implantation embryos indicate that this process is highly dynamic. In vitro produced porcine blastocysts are known to be less competent than in vivo developed blastocysts. To understand the conditions that compromise developmental competence of in vitro embryos, it is crucial to evaluate the transcriptional profile of porcine embryos during pre-implantation stages. In this study, we investigated the transcriptome dynamics in in vivo developed and in vitro produced 4-cell embryos, morulae and hatched blastocysts.Results: In vivo developed and in vitro produced embryos displayed largely similar transcriptome profiles during development. Enriched canonical pathways from the 4-cell to the morula transition that were shared between in vivo developed and in vitro produced embryos included oxidative phosphorylation, tRNA charging, and EIF2 signaling. The shared canonical pathways from the morula to the hatched blastocyst transition were 14-3-3-mediated signaling, signaling of Rho family GTPases, and NRF2-mediated oxidative stress response. The in vivo developed and in vitro produced hatched blastocysts were compared to identify molecular signaling pathways indicative of lower developmental competence of in vitro produced hatched blastocysts. A higher metabolic rate and expression of the arginine transporter SLC7A1 were found in in vitro produced hatched blastocysts.Conclusions: Our findings suggest that embryos with compromised developmental potential are arrested at an early stage of development, while embryos developing to the hatched blastocyst stage display largely similar transcriptome profiles, irrespective of the embryo source. The hatched blastocysts derived from the in vitro fertilization-pipeline showed an enrichment in molecular signaling pathways associated with lower developmental competence, compared to the in vivo developed embryos.


1976 ◽  
Vol 22 (3) ◽  
pp. 575-583
Author(s):  
K.E. Johnson

Circus movements, which involve the circumferential rotation of a hyaline cytoplasmic protrusion, occur in cells obtained by EDTA dissociation of gastrula-stage Xenopus laevis embryos. Only a few dissociated blastula-stage cells show circus movements, more early gastrula-stage cells show them, and nearly all late gastrula-stage cells show them. Circus movements cease in cells prior to mitosis and begin again in daughter cells after mitosis is completed. In early gastrulae, only 17% of prospective endodermal cells show circus movements while 79% of prospective mesodern, archenteric roof, and posterior neural ectoderm do so. Isolated cells as well as groups of cells in vitro are often propelled by circus movements. There is an obvious antagonism between cell contact and circus movements. The morphogenetic significance of circus movements and blebbing locomotion is discussed.


Lankesteriana ◽  
2015 ◽  
Vol 15 (1) ◽  
Author(s):  
Jesús Bernardo Cruz-Higareda ◽  
Bárbara Susana Luna-Rosales ◽  
Amadeo Barba-Álvarez

We developed a new and novel seed baiting technique sowing mature seeds of the epiphyitic orchid Rhynchostele cervantesii under natural conditions, We introduced a sponge in each package that may serve as a reservoir for water retention to benefit germination; In three of 22 packets we found protocorms in an early stage of development, six of wich were of sufficient size to warrant fungal isolations; Nine strains were isolated in pure culture and were inoculated on seeds and protocorms under in vitro conditions. 


2000 ◽  
Vol 113 (22) ◽  
pp. 4121-4135 ◽  
Author(s):  
U. Kaufmann ◽  
C. Zuppinger ◽  
Z. Waibler ◽  
M. Rudiger ◽  
C. Urbich ◽  
...  

The cytoplasmic domain of the transmembrane protein M-cadherin is involved in anchoring cytoskeletal elements to the plasma membrane at cell-cell contact sites. Several members of the armadillo repeat protein family mediate this linkage. We show here that ARVCF, a member of the p120 (ctn) subfamily, is a ligand for the cytoplasmic domain of M-cadherin, and characterize the regions involved in this interaction in detail. Complex formation in an in vivo environment was demonstrated in (1) yeast two-hybrid screens, using a cDNA library from differentiating skeletal muscle and part of the cytoplasmic M-cadherin tail as a bait, and (2) mammalian cells, using a novel experimental system, the MOM recruitment assay. Immunoprecipitation and in vitro binding assays confirmed this interaction. Ectopically expressed EGFP-ARVCF-C11, an N-terminal truncated fragment, targets to junctional structures in epithelial MCF7 cells and cardiomyocytes, where it colocalizes with the respective cadherins, beta-catenin and p120 (ctn). Hence, the N terminus of ARVCF is not required for junctional localization. In contrast, deletion of the four N-terminal armadillo repeats abolishes this ability in cardiomyocytes. Detailed mutational analysis revealed the armadillo repeat region of ARVCF as sufficient and necessary for interaction with the 55 membrane-proximal amino acids of the M-cadherin tail.


2003 ◽  
Vol 177 (2) ◽  
pp. 249-259 ◽  
Author(s):  
JJ Gagliardino ◽  
H Del Zotto ◽  
L Massa ◽  
LE Flores ◽  
MI Borelli

The aim of this work was to study the possible relationship between pancreatic duodenal homeobox-1 (Pdx-1) and islet neogenesis-associated protein (INGAP) during induced islet neogenesis. Pregnant hamsters were fed with (S) and without (C) sucrose, and glycemia, insulin secretion in vitro, and pancreas immunomorphometric parameters were measured in their 7-day-old offspring. S offspring had significantly lower glycemic levels than C animals. Insulin release in response to increasing glucose concentrations in the incubation medium (2-16 mM glucose) did not increase in pancreata from either C or S offspring. However, pancreata from S offspring released more insulin than those from C animals. In S offspring, beta-cell mass, beta-cell replication rate and islet neogenesis increased significantly, with a simultaneous decrease in beta-cell apoptotic rate. INGAP- and Pdx-1-positive cell mass also increased in the islets and among acinar and duct cells. We found two subpopulations of Pdx-1 cells: INGAP-positive and INGAP-negative. Pdx-1/INGAP-positive cells did not stain with insulin, glucagon, somatostatin, pancreatic polypeptide, or neurogenin 3 antibodies. The increment of Pdx-1/INGAP-positive cells represented the major contribution to the Pdx-1 cell mass increase. Such increments varied among pancreas subsectors: ductal>insular>extrainsular. Our results suggested that INGAP participates in the regulation of islet neogenesis, and Pdx-1/INGAP-positive cells represent a new stem cell subpopulation at an early stage of development, highly activateable in neogenesis.


2001 ◽  
Vol 26 (2) ◽  
pp. 437-440
Author(s):  
W.H. McMillan ◽  
D.N. Wells ◽  
AJ. Peterson ◽  
M.J. Donnison

AbstractThe reported post transfer survival rate to term of cloned embryos derived from both undifferentiated blastomeres and differentiated foetal and adult cells is very low (typically less than 20%). Furthermore, it is acknowledged that there are many technical issues that remain to be resolved to improve the efficiency of nuclear transfer before the technique will find widespread, practical and cost-effective use in multiplying valuable livestock in agriculture. The purpose of this study was to compare early embryo morphology following embryo transfer of nuclear transfer blastocysts derived from somatic cells of an adult Friesian cow with that of standard in vitro-produced embryos. In the present study, 150 embryos were transferred in bulk (i.e., 15, 20 or 25 per recipient) to the ipsilateral uterine horn of 8 recipients using standard non-surgical embryo transfer procedures. Embryos were then recovered following necropsy on either Day 14 or Day 23 of pregnancy and developmental traits described. Embryo recovery and elongation rates were similar on Day 14 of pregnancy (Table 1), although cloned conceptuses were longer and narrower (P<0.05). Embryo recovery and viability rates by Day 23 were similar, although many of the developmental traits appeared more advanced in cloned conceptuses. (Table 1). Allantois development was different because of greater widths and the presence of ‘spurs’ that were not observed with in vitro-produced embryos. We conclude that apparently abnormal conceptus development occurs by about 3 weeks of pregnancy following nuclear transfer, but that embryo survival is not compromised at this early stage of development.


BMC Genomics ◽  
2021 ◽  
Vol 22 (1) ◽  
Author(s):  
Vera A. van der Weijden ◽  
Meret Schmidhauser ◽  
Mayuko Kurome ◽  
Johannes Knubben ◽  
Veronika L. Flöter ◽  
...  

Abstract Background The transcriptional changes around the time of embryonic genome activation in pre-implantation embryos indicate that this process is highly dynamic. In vitro produced porcine blastocysts are known to be less competent than in vivo developed blastocysts. To understand the conditions that compromise developmental competence of in vitro embryos, it is crucial to evaluate the transcriptional profile of porcine embryos during pre-implantation stages. In this study, we investigated the transcriptome dynamics in in vivo developed and in vitro produced 4-cell embryos, morulae and hatched blastocysts. Results In vivo developed and in vitro produced embryos displayed largely similar transcriptome profiles during development. Enriched canonical pathways from the 4-cell to the morula transition that were shared between in vivo developed and in vitro produced embryos included oxidative phosphorylation and EIF2 signaling. The shared canonical pathways from the morula to the hatched blastocyst transition were 14–3-3-mediated signaling, xenobiotic metabolism general signaling pathway, and NRF2-mediated oxidative stress response. The in vivo developed and in vitro produced hatched blastocysts further were compared to identify molecular signaling pathways indicative of lower developmental competence of in vitro produced hatched blastocysts. A higher metabolic rate and expression of the arginine transporter SLC7A1 were found in in vitro produced hatched blastocysts. Conclusions Our findings suggest that embryos with compromised developmental potential are arrested at an early stage of development, while embryos developing to the hatched blastocyst stage display largely similar transcriptome profiles, irrespective of the embryo source. The hatched blastocysts derived from the in vitro fertilization-pipeline showed an enrichment in molecular signaling pathways associated with lower developmental competence, compared to the in vivo developed embryos.


2020 ◽  
Author(s):  
Vera A van der Weijden ◽  
Meret Schmidhauser ◽  
Mayuko Kurome ◽  
Veronika L Flöter ◽  
Johannes Knubben ◽  
...  

Abstract Background The transcriptional changes around the time of embryonic genome activation in pre-implantation embryos indicate that this process is highly dynamic. In vitro produced porcine blastocysts are known to be less competent than in vivo developed blastocysts. To understand the conditions that compromise developmental competence of in vitro embryos, it is crucial to evaluate the transcriptional profile of porcine embryos during pre-implantation stages. In this study, we investigated the transcriptome dynamics in in vivo developed and in vitro produced 4-cell embryos, morulae and hatched blastocysts. Results In vivo developed and in vitro produced embryos displayed largely similar transcriptome profiles during development. Enriched canonical pathways from the 4-cell to the morula transition that were shared between in vivo developed and in vitro produced embryos included oxidative phosphorylation, tRNA charging, and EIF2 signaling. The shared canonical pathways from the morula to the hatched blastocyst transition were 14-3-3-mediated signaling, signaling of Rho family GTPases, and NRF2-mediated oxidative stress response. The in vivo developed and in vitro produced hatched blastocysts were compared to identify molecular signaling pathways indicative of lower developmental competence of in vitro produced hatched blastocysts. A higher metabolic rate and expression of the arginine transporter SLC7A1 were found in in vitro produced hatched blastocysts. Conclusions Our findings suggest that embryos with compromised developmental potential are arrested at an early stage of development, while embryos developing to the hatched blastocyst stage display largely similar transcriptome profiles, irrespective of embryo source. The hatched blastocysts derived from the in vitro fertilization-pipeline showed an enrichment in molecular signaling pathways associated with lower developmental competence, compared to the in vivo developed embryos.


Development ◽  
2002 ◽  
Vol 129 (17) ◽  
pp. 4045-4055 ◽  
Author(s):  
Georges Nemer ◽  
Mona Nemer

In vertebrates, heart development is a complex process requiring proper differentiation and interaction between myocardial and endocardial cells. Significant progress has been made in elucidating the molecular events underlying myocardial cell differentiation. In contrast, little is known about the development of the endocardial lineage that gives rise to cardiac valves and septa. We have used a novel in vitro model to identify the molecular hierarchy of endocardial differentiation and the role of transcription factor GATA5 in endocardial development. The results indicate that GATA5 is induced at an early stage of endothelial-endocardial differentiation prior to expression of such early endocardial markers as Tie2 and ErbB3. Inhibition of either GATA5 expression or NF-ATc activation, blocks terminal differentiation at a pre-endocardial stage and GATA5 and NF-ATc synergistically activate endocardial transcription. The data reveal that transcription factor GATA5 is required for differentiation of cardiogenic precursors into endothelial endocardial cells. This, in turn, suggests that the GATA5 pathway may be relevant to early stages of valvuloseptal development, defects of which account for the majority of human birth malformations.


2008 ◽  
Vol 294 (6) ◽  
pp. R1856-R1862 ◽  
Author(s):  
Linning Zhao ◽  
Eishin Yaoita ◽  
Masaaki Nameta ◽  
Ying Zhang ◽  
Lino Munoz Cuellar ◽  
...  

Tight junctions rarely exist in podocytes of the normal renal glomerulus, whereas they are the main intercellular junctions of podocytes in nephrosis and in the early stage of development. Claudins have been identified as tight junction-specific integral membrane proteins. Those of podocytes, however, remain to be elucidated. In the present study, we investigated the expression and localization of claudin-6 in the rat kidney, especially in podocytes. Western blot analysis and RT-PCR revealed that the neonatal kidney expressed much higher levels of claudin-6 than the adult kidney. Immunofluorescence microscopy showed intense claudin-6 staining in most of the tubules and glomeruli in neonates. The staining in tubules declined distinctly in adults, whereas staining in glomeruli was well preserved during development. Claudin-6 in glomeruli was distributed along the glomerular capillary wall and colocalized with zonula occludens-1. The staining became conspicuous after kidney perfusion with protamine sulfate (PS) to increase tight junctions in podocytes. Immunoelectron microscopy showed that immunogold particles for claudin-6 were accumulated at close cell-cell contact sites of podocytes in PS-perfused kidneys, whereas a very limited number of immunogold particles were detected, mainly on the basal cell membrane and occasionally at the slit diaphragm and close cell-cell contact sites in normal control kidneys. In puromycin aminonucleoside nephrosis, immunogold particles were also found mainly at cell-contact sites of podocytes. These findings indicate that claudin-6 is a transmembrane protein of tight junctions in podocytes during development and under pathological conditions.


Sign in / Sign up

Export Citation Format

Share Document