Search results for " Structures"
showing 10 items of 4162 documents
Robust Automated Assessment of Human Blastocyst Quality using Deep Learning
2018
AbstractMorphology assessment has become the standard method for evaluation of embryo quality and selecting human blastocysts for transfer inin vitro fertilization(IVF). This process is highly subjective for some embryos and thus prone to human bias. As a result, morphological assessment results may vary extensively between embryologists and in some cases may fail to accurately predict embryo implantation and live birth potential. Here we postulated that an artificial intelligence (AI) approach trained on thousands of embryos can reliably predict embryo quality without human intervention.To test this hypothesis, we implemented an AI approach based on deep neural networks (DNNs). Our approac…
Intraspecific variation in mating behaviour does not cause sexual isolation between Drosophila virilis strains
2005
There is increasing evidence that mate recognition systems vary within species. We studied the courtship rituals of five Drosophila virilis strains to investigate this intraspecific variation. Males that actively and persistently courted the female without paying much attention to the female's behaviour were the most successful at copulating. Intraspecific variation in mating rituals was high, but not as high as at the species level and it was not high enough to cause sexual isolation between the strains. The differences in courtship interactions of the strains reflected their geographical origin. Males from one of the strains did not produce audible song during their courtship, but still m…
Osmotic and cryoprotective effects of a mixture of DMSO and ethylene glycol on rabbit morulae.
1993
Abstract Comparisons were made of the osmotic and cryoprotective effects on rabbit embryos preserved by vitrification with 2 solutions and by conventional freezing. Embryos obtained from rabbits killed 70 to 72 h after mating were used in the study (n = 948). Initially, toxicity of the 3 cryoprotectants was studied in fresh (unfrozen) embryos (n = 135). Subsequently, embryos placed in ethylene glycol (EG, 40% v/v; n = 88) and ethylene glycol with dimethyl sulfoxide (EG+DMSO, 20% v/v each, respectively; n = 344) were loaded into straws and plunged directly into liquid nitrogen. Embryos placed in 1.5 M DMSO and 20% heat inactivated rabbit serum were subjected to conventional freezing in a pro…
Extremely low frequency electromagnetic fields (ELF-EMFs) induce in vitro angiogenesis process in human endothelial cells.
2008
Effects of extremely low frequency (ELF) electromagnetic fields (EMFs) on activation of angiogenesis were analysed using cultured umbilical human vein endothelial cells (HUVECs). The cultures were exposed to a sinusoidal EMF to intensity of 1 mT, 50 Hz for up to 12 h. EMFs increased the degree of endothelial cell proliferation and tubule formation, coupled by an acceleration in the process of wound healing. Since this process is physiologically accompanied by a large modification in the structural organization of actin and focal adhesions, we analyzed the rearrangement of some cytoskeleton elements demonstrating a major reorganization of the fibres and of the focal adhesion complexes after …
Spatially restricted expression of PlOtp, a Paracentrotus lividus Orthopedia-related homeobox gene, is correlated with oral ectodermal patterning and…
1999
ABSTRACT Several homeobox genes are expressed in the sea urchin embryo but their roles in development have yet to be elucidated. Of particular interest are homologues of homeobox genes that in mouse and Drosophila are involved in patterning the developing central nervous system (CNS). Here, we report the cloning of an orthopedia (Otp)-related gene from Paracentrotus lividus, PlOtp. Otp is a single copy zygotic gene that presents a unique and highly restricted expression pattern. Transcripts were first detected at the mid-gastrula stage in two pairs of oral ectoderm cells located in a ventrolateral position, overlying primary mesenchyme cell (PMC) clusters. Increases in both transcript abund…
Bruton tyrosine kinase-like protein, BtkSD, is present in the marine sponge Suberites domuncula.
2003
Sponges, the simplest and most ancient phylum of Metazoa, encode in their genome complex and highly sophisticated proteins that evolved together with multicellularity and are found only in metazoan animals. We report here the finding of a Bruton tyrosine kinase (BTK)-like protein in the marine sponge Suberites domuncula (Demospongiae). The nucleotide sequence of one sponge cDNA predicts a 700-aa-long protein, which contains all of the characteristic domains for the Tec family of protein tyrosine kinases (PTKs). The highest homology (38% identity, 55% overall similarity) was found with human BTK and TEC PTKs. Sponge PTK was therefore named BtkSD. Human BTK is involved in the maturation of B …
A galectin links the aggregation factor to cells in the sponge (Geodia cydonium) system.
1996
The cDNA for the full-length lectin from the marine sponge Geodia cydonium was cloned. Analysis of the deduced aa sequence revealed that this lectin belongs to the group of galectins. The full-length galectin, which was obtained also in a recombinant form, has an M(r) of 20,877; in the processed form it is a 15 kDa polypeptide. The enriched aggregation factor from G.cydonium also was determined to contain, besides minimal amounts of the galectin, a 140 kDa polypeptide which is involved in cell-cell adhesion. Monoclonal antibodies have been raised against this protein; Fab' fragments prepared from them abolished cell-cell reaggregation. Cell reaggregation experiments revealed that the aggreg…
Synthesis of heat-shock proteins in developing sea urchins.
1981
Heating sea urchin embryos at 31°C greatly reduces the synthesis of the bulk proteins, whereas it highly stimulates the synthesis of some new proteins, the main ones being two closely migrating proteins of about 70,000 daltons. The production of heat-shock proteins is obtained only if the embryos are heated after hatching. Stages which produce heat-shock proteins survive heating, whereas earlier stages, not producing heat-shock proteins, do not survive. Heat-shock proteins are not produced in the presence of actinomycin D.
Clustering transmembrane-agrin induces filopodia-like processes on axons and dendrites
2005
The transmembrane form of agrin (TM-agrin) is primarily expressed in the CNS, particularly on neurites. To analyze its function, we clustered TM-agrin on neurons using anti-agrin antibodies. On axons from the chick CNS and PNS as well as on axons and dendrites from mouse hippocampal neurons anti-agrin antibodies induced the dose- and time-dependent formation of numerous filopodia-like processes. The processes appeared within minutes after antibody addition and contained a complex cytoskeleton. Formation of processes required calcium, could be inhibited by cytochalasine D, but was not influenced by staurosporine, heparin or pervanadate. Time-lapse video microscopy revealed that the processes…
Optimum and Maximum Host Sizes at Parasitism for the Endoparasitoid <I>Hyposoter didymator</I> (Hymenoptera: Ichneumonidae) Differ Greatl…
2007
Host size is considered a reliable indicator of host quality and an important determinant of parasitoid fitness. Koinobiont parasitoids attack hosts that continue feeding and growing during parasitism. In contrast with hemolymph-feeding koinobionts, tissue-feeding koinobionts face not only a minimum host size for successful development but also a maximum host size, because consumption of the entire host is often necessary for successful egression. Here we study interactions between a generalist tissue-feeding larval endoparasitoid, Hyposoter didymator Thunberg (Hymenoptera: Ichneumonidae) and two of its natural hosts, Spodoptera exigua Hübner and Chrysodeixis chalcites Esper (Lepidoptera: N…