Gene expression following induction of regeneration in <Emphasis Type="Italic">Drosophila</Emphasis> wing imaginal discs. Expression profile of regenerating wing discs

Background  

Regeneration is the ability of an organism to rebuild a body part that has been damaged or amputated, and can be studied at the molecular level using model organisms. Drosophila imaginal discs, which are the larval primordia of adult cuticular structures, are capable of undergoing regenerative growth after transplantation and in vivo culture into the adult abdomen.     

Chemotaxonomic diagnostics: combining sucrose-water agar with TLC to discriminate <Emphasis Type="Italic">Fusarium graminearum</Emphasis> 3-acetyl-DON and 15-acetyl-DON chemotypes

Twelve randomly-selected isolates of Fusarium graminearum that produce 3-acetyl-deoxynivalenol (3-ADON) or 15-acetyl-deoxynivalenol (15-ADON) were screened by thin-layer chromatography (TLC) for their ability to produce ADON and zearalenone (ZEA) mycotoxins when grown on water agar containing different concentrations of sucrose. The results showed the ability of the F. graminearum 3-ADON chemotype population to produce DON and ZEA at a lower concentration range of sucrose (5-7%) compared with the 15-ADON chemotype (30-40%). The former distinction allows for sucrose-water agar to be employed as a rapid and simple differential medium, where two separate sucrose-gradient concentrations discriminate 3-ADON from 15-ADON populations. In the light of the shift in sugar concentrations occurring during the process of grain formation and maturation, the difference in mycotoxin production between the two populations is discussed with respect to predicting Fusarium head blight (FHB) epidemiology and accumulation of DON and ZEA.     

Developmental competence of heifer oocytes selected using the brilliant cresyl blue (BCB) test

The aim of this study was to evaluate the usefulness of the brilliant cresyl blue (BCB) test in the selection of more competent heifer oocytes for in vitro embryo production (IVEP). IVEP from selected BCB heifer oocytes was compared to IVEP from morphologically selected heifer (control group) and cow oocytes. BCB staining determines the activity of glucose-6-phosphate dehydrogenase (G6PD), an enzyme synthesized in growing oocytes but with less activity in grown oocytes. Six hundred and fifty seven heifer cumulus-oocyte complexes (COC) were classified morphologically as Grade 1-3 and exposed to 26 microM of BCB and classified as: blue (or grown) oocytes (BCB+) or unstained oocytes or growing oocytes (BCB-). Grade 1-3 heifer oocytes showed significantly different percentages of BCB+ oocytes (78.6, 66.2, and 51.1%, respectively; P<0.05). The diameter of BCB+ oocytes was significantly higher than BCB- oocytes (152.6+/-5.8 microm and 147+/-5.9 microm, respectively; P<0.001). The percentage of BCB+ oocytes reaching the blastocyst stage was significantly higher than those of BCB- and control heifer oocytes (12.3, 1.6, and 5.2%, respectively; P<0.05), but lower than those of cow oocytes (30.0%; P<0.05). In conclusion, heifer oocytes selected by the BCB test (BCB+) are larger and more competent for IVEP than control heifer oocytes. However, fewer heifer oocytes selected using the BCB test develop to blastocyst stage compared to cow oocytes.     

Minimal Features of Efficient Incorporation of the Hemagglutinin-Neuraminidase Protein into Sendai Virus Particles

Two transmembrane glycoproteins form spikes on the surface of Sendai virus, a member of the Respirovirus genus of the Paramyxovirinae subfamily of the Paramyxoviridae family: the hemagglutinin-neuraminidase (HN) and the fusion (F) proteins. HN, in contrast to F, is dispensable for viral particle production, as normal amounts of particles can be produced with highly reduced levels of HN. This HN reduction can result from mutation of an SYWST motif in its cytoplasmic tail to AFYKD. HN_AFYKD accumulates at the infected cell surface but does not get incorporated into particles. In this work, we derived experimental tools to rescue HN_AFYKD incorporation. We found that coexpression of a truncated HN harboring the wild-type cytoplasmic tail, the transmembrane domain, and at most 80 amino acids of the ectodomain was sufficient to complement defective HN_AFYKD incorporation into particles. This relied on formation of disulfide-bound heterodimers carried out by the two cysteines present in the HN 80-amino-acid (aa) ectodomain. Finally, the replacement of the measles virus H cytoplasmic and transmembrane domains with the corresponding HN domains promoted measles virus H incorporation in Sendai virus particles.     

Macrovipecetin,a C-type lectin from Macrovipera lebetina venom,inhibits proliferation migration and invasion of SK-MEL-28 human melanoma cells and enhances their sensitivity to cisplatin

Background

The resistance of melanoma cells to cisplatin restricts its clinical use. Therefore, the search for novel tumor inhibitors and effective combination treatments that sensitize tumor cells to this drug are still needed. We purified macrovipecetin, a novel heterodimeric C-type lectin, from Macrovipera lebetina snake venom and investigated its anti-tumoral effect on its own or combined with cisplatin, in human melanoma cells.