Tumor reversion and embryo morphogenetic factors

Author(s):  
Sara Proietti ◽  
Alessandra Cucina ◽  
Andrea Pensotti ◽  
Andrea Fuso ◽  
Cinzia Marchese ◽  
...  
Author(s):  
J.L. Carrascosa ◽  
G. Abella ◽  
S. Marco ◽  
M. Muyal ◽  
J.M. Carazo

Chaperonins are a class of proteins characterized by their role as morphogenetic factors. They trantsiently interact with the structural components of certain biological aggregates (viruses, enzymes etc), promoting their correct folding, assembly and, eventually transport. The groEL factor from E. coli is a conspicuous member of the chaperonins, as it promotes the assembly and morphogenesis of bacterial oligomers and/viral structures.We have studied groEL-like factors from two different bacteria:E. coli and B.subtilis. These factors share common morphological features , showing two different views: one is 6-fold, while the other shows 7 morphological units. There is also a correlation between the presence of a dominant 6-fold view and the fact of both bacteria been grown at low temperature (32°C), while the 7-fold is the main view at higher temperatures (42°C). As the two-dimensional projections of groEL were difficult to interprete, we studied their three-dimensional reconstruction by the random conical tilt series method from negatively stained particles.


Development ◽  
1973 ◽  
Vol 29 (2) ◽  
pp. 267-281
Author(s):  
G. Teitelman

Removal of the polar lobe at the trefoil stage of the first cleavage division of Ilyanassa embryos causes abnormalities much later in development. To determine if the developmental differences between normal and delobed embryos were reflected in alterations in protein synthesis and at what stages of development these become evident, protein solutions were separated by disc electrophoresis on basic acrylamide gels. For the analysis of the newly synthesized proteins, two protein samples, one labelled with 14C and the other with 3H, were combined in the same electrophoretic column. Each was prepared from normal embryos or lobeless embryos at different stages of development. The distribution of the two groups of differentially labelled proteins was compared by a determination, for each fraction, of the ratio of the normalized 3H/14C counts for that particular fraction (R = 3H/14C). The plot of R versus fraction number was studied for various combinations of samples. During normal development the profile of labelled proteins remains unchanged until the onset of visible differentiation. At this stage, around day 4 of development, there are changes in biosynthesis revealed by a greater emphasis on the synthesis of slow moving proteins. The profile of labelled proteins of lobeless embryos remains unchanged up to the 5th day of development. This result is correlated with the absence, in the lobeless embryos, of many of the visible differentiations. Preliminary studies revealed that the spectrum of labelled proteins of the polar lobe is identical to the one present in lobeless embryos and in normal embryos in early stages of development. This suggests the possibility that the morphogenetic factors associated with the polar lobe are not among the newly synthesized proteins. A hypothesis is presented to account for the effects on morphogenesis and protein synthesis which are produced by removal of the polar lobe.


2011 ◽  
Vol 32 (1) ◽  
pp. 67-99 ◽  
Author(s):  
Piotr Zagórski

Shoreline dynamics of Calypsostranda (NW Wedel Jarlsberg Land, Svalbard) during the last century A 6 km long stretch of the coast of Calypsostranda between Skilvika and Joseph-bukta, situated on the western side of Recherchefjorden, was investigated. It is made of an accumulative marine terrace at a height of 2-8 m a.s.l. (terrace 1) and width of 40-180 m, divided by a cliffed section in the frontal moraines of Renardbreen. From the character and intensity of changes, the area was divided into 6 zones. The aim was to analyse the dynamics of changes within coastal zone from 1936 to 2007 and to characterise the influence of various morphogenetic factors (marine, fluvial, cryospheric). The important element of this study has been to determine sources and directions of sediment transport. The dynamics of changes of coastal zone in the Calypsostranda region was established from archival maps and precise GPS measurements for the periods: 1936-1960, 1960-1990, 1990-2000, 2000-2005, 2005-2006, 2006-2007. Comparing the extension of shoreline between 1936 and 2007 showed that there was more erosion than accumulation. Nearly 110 000 m2 of the area of terrace 1 decreased, whereas about 77 000 m2 appeared. The net balance for 1936-2007 was about -32 700 m2, on average over the whole length of the shoreline, it retreated by 5.7 m (0.08 m a-1). The cease of sediment delivery in the extramarginal sandur fans area of Renardbreen caused intensification of marine processes, that made the shoreline retreat by over 100 m. Continuing sediment delivery from the Scottelva catchment, with contribution of material from erosion of the north end of the shoreline studies, caused the aggradation of coastal zone by over 60 m near its mouth.


2018 ◽  
Vol 73 (1-2) ◽  
pp. 59-66 ◽  
Author(s):  
Yoko Nakamura ◽  
Christian Paetz ◽  
Wilhelm Boland

Abstract(9Z)-Methyl 4-dihydrotrisporate B and (9Z)-methyl trisporate B, pheromones of Zygomycetes fungi, have been synthesized using Stille cross-coupling from previously described cyclohexenone precursors. Conducting the coupling without protection groups allowed for a short and stereospecific synthesis route of the late trisporoids. Stability studies for both the compounds revealed (9Z)-methyl trisporate B to be very unstable against UV irradiation.


1969 ◽  
Vol 11 (1) ◽  
pp. 118-124 ◽  
Author(s):  
J. A. Brumbaugh ◽  
J. W. Moore

The time of melanocyte differentiation in embryos and regenerating adult feathers was determined for three alleles at the E pigment locus in the fowl. Melanocytes were identified in dissociated embryonic skin tissue using the dopa reaction. In both embryos and female breast feathers, extended black (E) melanocytes differentiated early and produced eumelanin, while recessive wheaten (ey) melanocytes differentiated significantly later and synthesized pale phaeomelanin. Wild type (e+) melanocytes produced a more intense phaeomelanin and differentiated at an intermediate time. However, melanocytes in the male breast feathers of each genotype differentiated early and produced eumelanin. This suggests that the temporal variation in melanocyte differentiation is related directly to the type of melanin synthesized and only indirectly to genotype. It is suggested that the E allele present interacts with the morphogenetic factors of the growing feather to determine the type of melanin that will be synthesized. The time of observed melanin deposition then becomes a secondary effect of this 'decision', eumelanin being deposited early and phaeomelanins significantly later.


2021 ◽  
Vol 2021 ◽  
pp. 1-11
Author(s):  
Luca Fiorillo ◽  
Gabriele Cervino ◽  
Pablo Galindo-Moreno ◽  
Alan Scott Herford ◽  
Gianrico Spagnuolo ◽  
...  

The present investigation is aimed at systematically analyzing the recent literature about the innovative scaffold involved in the reconstructive surgeries by applying growth factors and tissue engineering. An extensive review of the contemporary literature was conducted according to the PRISMA guidelines by accessing the PubMed, Embase, and Scopus Elsevier databases. Authors performed the English language manuscript research published from 2003 to 2020. A total of 13 relevant studies were included in the present review. The present systematic review included only papers with significant results about correlation between scaffold, molecular features of growth factor, and reconstructive surgeries in oral maxillofacial district. The initial research with filters recorded about 1023 published papers. Beyond reading and considering of suitability, only 42 and then 36 full-text papers were recorded for the revision. All the researches recorded the possibility of using growth factors on rebuilding atrophic jaws. Different growth factors like morphogenetic factors, cytokines, and inflammatory ones and their application over different scaffold materials were recorded. Further investigations should be required in order to state scientific evidence about a clear advantage of applying tissue engineering for therapeutic purpose.


Development ◽  
1964 ◽  
Vol 12 (2) ◽  
pp. 183-195
Author(s):  
W. L. M. Geilenkirchen

Investigations on cellular reproduction have led to a highly resolved and integrated picture of the cell cycle in a morphological and physiological sense. The various preparations for division, doubling of components or syntheses, follow their own time course parallel to one another. It has become evident that the various factors involved in cell division are dissociable, for example chromosome doubling and reproduction of centrioles (Bucher & Mazia, 1960), DNA replication and protein synthesis (Zeuthen, 1961). The conditions for cell division in general are applicable to division of egg cells. However, in addition in egg cells there is a complicating system of morphogenetic factors acting, as must be postulated from the observation that in ‘mosaic’ eggs the fate of the blastomeres is fixed. In dividing eggs differences between daughter cells may be due to local differences established during oögenesis in the mother which are parcelled out during cleavages.


1971 ◽  
Vol 26 (2) ◽  
pp. 220-251 ◽  
Author(s):  
Don W. Fawcett ◽  
Winston A. Anderson ◽  
David M. Phillips

1991 ◽  
Vol 69 (11) ◽  
pp. 2811-2818 ◽  
Author(s):  
William R. Bates

The determination of cell fates in ascidian embryos is thought to be mediated primarily by factors localized in the cytoplasm. Morphogenetic factors were studied in ascidian eggs and early cleavage stage embryos by the partial deletion of blastomeres and by microinjection of sperm cells into anucleate, myoplasm-deficient egg fragments. In the first series of experiments, regions of blastomeres comprised of 20–30% of the volume of one blastomere were deleted from two- and four-celled embryos. Most of the embryos exhibited regulative capabilities, in that normal tadpole larvae developed from the operated embryos, irrespective of the deletion site. In a second series of experiments, the expression of endodermal alkaline phosphatase (AP) and muscle acetylcholinesterase (AchE) were tested in myoplasm-deficient egg fragments that were injected with sperm cells. After the unoperated controls had developed into tadpoles, myoplasm-deficient fragments injected with sperm cells were scored for their ability to express AP and AchE activity. Many of the myoplasm-deficient fragments that contained injected sperm cells expressed AP activity, whereas uninjected myoplasm-deficient fragments did not exhibit AP activity. When myoplasm-deficient fragments injected with sperm cells were tested for their ability to express AchE activity, none of the fragments expressed this muscle cell marker. Similar results were obtained using two species, Halocynthia roretzi and Styelaplicata. These results suggest that nuclear events are required for the expression of AP and that the myoplasmic region of the fertilized egg contains muscle cell determinants.


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