Locomotory Behavior of a BI6 Melanoma Variant Line Selected for Increased Invasiveness

1980 ◽  
pp. 163-169 ◽  
Author(s):  
I.R. Hart
PLoS ONE ◽  
2015 ◽  
Vol 10 (12) ◽  
pp. e0145870 ◽  
Author(s):  
Kyle Moy ◽  
Weiyu Li ◽  
Huu Phuoc Tran ◽  
Valerie Simonis ◽  
Evan Story ◽  
...  

1984 ◽  
Vol 62 (8) ◽  
pp. 1513-1520 ◽  
Author(s):  
Yves Bouchard ◽  
Conrad Cloutier

The parasitoid Aphidius nigripes spent more time searching on potato plants previously infested with aphids than on fresh plants, suggesting the presence of searching stimulants on infested plants. Water extracts of aphid honeydew applied to the surface of foliage or to filter paper discs increased searching time and affected the locomotory behavior of parasitoids. When crossing a honeydew-treated area on filter paper, female parasitoids exhibited arrestment, antennal examination, abdominal protraction, reduced walking speed, and increased turning. Upon losing contact with honeydew-contaminated substrate, parasitoids often exhibited a klinotactic response which drove them back to the treated area. The time spent by individual parasitoids within a honeydew-treated area on filter paper decreased with successive visits, but the initial response level was restored when the insect was prevented from contacting honeydew for 1 h. The retention response exhibited by parasitoids contacting a honeydew-treated area increased with honeydew concentration, but levelled off at high concentrations. Naive parasitoids were more responsive to the retention effect of honeydew than experienced individuals.


eLife ◽  
2017 ◽  
Vol 6 ◽  
Author(s):  
Hayao Ohno ◽  
Morikatsu Yoshida ◽  
Takahiro Sato ◽  
Johji Kato ◽  
Mikiya Miyazato ◽  
...  

Peptide signaling controls many processes involving coordinated actions of multiple organs, such as hormone-mediated appetite regulation. However, the extent to which the mode of action of peptide signaling is conserved in different animals is largely unknown, because many peptides and receptors remain orphan and many undiscovered peptides still exist. Here, we identify two novel Caenorhabditis elegans neuropeptides, LURY-1-1 and LURY-1-2, as endogenous ligands for the neuropeptide receptor-22 (NPR-22). Both peptides derive from the same precursor that is orthologous to invertebrate luqin/arginine-tyrosine-NH2 (RYamide) proneuropeptides. LURY-1 peptides are secreted from two classes of pharyngeal neurons and control food-related processes: feeding, lifespan, egg-laying, and locomotory behavior. We propose that LURY-1 peptides transmit food signals to NPR-22 expressed in feeding pacemaker neurons and a serotonergic neuron. Our results identified a critical role for luqin-like RYamides in feeding-related processes and suggested that peptide-mediated negative feedback is important for satiety regulation in C. elegans.


1998 ◽  
Vol 66 (9) ◽  
pp. 4080-4086 ◽  
Author(s):  
Maria M. Mota ◽  
K. Neil Brown ◽  
Anthony A. Holder ◽  
William Jarra

ABSTRACT CBA/Ca mice infected with 5 × 104 Plasmodium chabaudi chabaudi AS-parasitized erythrocytes experience acute but self-limiting infections of relatively short duration. Parasitemia peaks (∼40% infected erythrocytes) on day 10 or 11 and is then partially resolved over the ensuing 5 to 6 days, a period referred to as crisis. How humoral and cellular immune mechanisms contribute to parasite killing and/or clearance during crisis is controversial. Humoral immunity might be parasite variant, line, or species specific, while cellular immune responses would be relatively less specific. For P. c. chabaudi AS, parasite clearance is largely species and line specific during this time, which suggests a primary role for antibody activity. Accordingly, acute-phase plasma (APP; taken fromP. c. chabaudi AS-infected mice at day 11 or 12 postinfection) was examined for the presence of parasite-specific antibody activity by enzyme-linked immunosorbent assay. Antibody binding to the surface of intact, live parasitized erythrocytes, particularly those containing mature (trophozoite and schizont) parasites, was demonstrated by immunofluorescence in APP and the immunoglobulin G (IgG)-containing fraction thereof. Unfractionated APP (from P. c. chabaudi AS-infected mice), as well as its IgG fraction, specifically mediated the opsonization and internalization of P. c. chabaudi AS-parasitized erythrocytes by macrophages in vitro. APP from another parasite line (P. c. chabaudi CB) did not mediate the same effect against P. c. chabaudi AS-parasitized erythrocytes. These results, which may represent one mechanism of parasite removal during crisis, are discussed in relation to the parasite variant, line, and species specificity of parasite clearance during this time.


2016 ◽  
Vol 26 (24) ◽  
pp. 3336-3342 ◽  
Author(s):  
Antonin J.J. Crumière ◽  
M. Emilia Santos ◽  
Marie Sémon ◽  
David Armisén ◽  
Felipe F.F. Moreira ◽  
...  

1983 ◽  
Vol 157 (1) ◽  
pp. 371-376 ◽  
Author(s):  
M Fogel ◽  
P Altevogt ◽  
V Schirrmacher

A plastic adherent variant line (ESb-M) of a highly invasive and metastatic murine T cell lymphoma (ESb) was found to have lost its metastatic potential while still being tumorigenic in normal syngeneic hosts. The variant retained most of its ESb-derived antigenic and biochemical characteristics but differed at binding sites for certain lectins with specificity for terminal N-acetylgalactosamine residues. Whereas such sites were masked by sialic acid on metastatic ESb cells, they became unmasked on the adherent variant line. Metastatic revertants of ESb-M cells did not express the respective lectin receptor sites because these were again masked by sialic acid. It is suggested that the masking of specific lectin receptors sites on the tumor cell surface is of crucial importance for metastatis. If freely exposed, these sites may change adherence characteristics of the cells possibly not only in vitro (to plastic) but also in vivo.


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