Search results for "botany"
showing 10 items of 4586 documents
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.
Nickel, lead, and cadmium induce differential cellular responses in sea urchin embryos by activating the synthesis of different HSP70s.
2004
Treatment with heavy metals, such as nickel, lead or cadmium, elicits different cellular stress responses according to the metal used and the length of treatment. In Paracentrotus lividus embryos the inducible forms of HSP70 (HSP70/72) are different in molecular mass from the constitutively expressed HSP75, and they can be used as markers of cellular stress. Even a short treatment with each metal induces the synthesis of HSP70/72 which remain stable for at least 20 h and differ little in their isoelectric points. Continuous treatment from fertilization with nickel or lead produces late irregular pluteus embryos, with peak HSP70/72 synthesis at blastula followed by the arrest of synthesis by…
Monoclonal antibodies recognizing larval- and pupal-specific cuticular proteins of Tenebrio molitor (Insecta, Coleoptera)
1993
To study the sequential expression of insect epidermal cells during metamorphosis, a library of monoclonal antibodies (MABs) was prepared against the water-soluble proteins from preecdysial pupal cuticle of Tenebrio molitor. Six selected MABs recognizing only larval and pupal cuticular proteins (CPs) in immunoblot analysis were classified into three types. Type 1 recognized a 21.5 and a 22 kDa polypeptide, type 2, a 26 kDa polypeptide, and type 3, three polypeptides of 18.5, 19.5 and 21.5 kDa. They did not immunoreact with any protein of fat bodies or haemolymph from pharate pupae, suggesting that the antigens originate from the epidermis. The stage-specificity was confirmed by electron mic…
Efficacy of clove oil and ethanol against Saprolegnia sp. and usability as antifungal agents during incubation of rainbow trout Oncorhynchus mykiss (…
2013
Inhibitory concentrations of clove oil and ethanol against growth of Saprolegnia sp. hyphae were screened by a modification of the hemp (Cannabis sativa L.) seed MicroPlate (HeMP) method and their usability as antifungal agents during incubation of rainbow trout Oncorhynchus mykiss eggs was tested. In vitro experiment showed that in continuous static exposure, clove oil at 100 mg L−1 significantly inhibited the growth of Saprolegnia, whereas in bath exposures, clove oil at 500 mg L−1 had no significant effect at any exposure time tested (15, 60 and 240 min), but clove oil at 10 000 mg L−1 significantly inhibited growth at all exposure times. Clove oil and ethanol treatments had no visible e…
Achievement of thermotolerance through hsps phosphorylation in sea urchin embryos.
1995
TPA treatment of sea urchin embryos is able to induce thermotolerance. Evidence is provided that TPA treatment induces phosphorylation of a constitutive stress protein of 38 KDa.
Cabut, a C2H2 zinc finger transcription factor, is required during Drosophila dorsal closure downstream of JNK signaling.
2005
AbstractDuring dorsal closure, the lateral epithelia on each side of the embryo migrate dorsally over the amnioserosa and fuse at the dorsal midline. Detailed genetic studies have revealed that many molecules are involved in this epithelial sheet movement, either with a signaling function or as structural or motor components of the process. Here, we report the characterization of cabut (cbt), a new Drosophila gene involved in dorsal closure. cbt is expressed in the yolk sac nuclei and in the lateral epidermis. The Cbt protein contains three C2H2-type zinc fingers and a serine-rich domain, suggesting that it functions as a transcription factor. cbt mutants die as embryos with dorsal closure …
In vitro rescue of zygotic embryos of sour orange, Citrus aurantium L., and their detection based on RFLP analysis
1998
Embryo development in vivo has been studied in four Citrus aurantium L. polyembryonic genotypes. Seeds were collected 65, 85, 105, 125 and 220 days after pollination (DAP). None of the immature seeds harvested 65 and 85 DAP contained visible embryos. A single embryo at a more advanced developmental stage was observed in the central position at the micropylar apex of the embryo sac in about 74% of seeds harvested at 105 DAP, while at 125 and 220 DAP the majority of seeds had two or more embryos at the same developmental stage crowded together. Restriction fragment length polymorphism (RFLP) analysis of low- and high-copy-number nuclear DNA was used to distinguish zygotic from nucellar seedli…
The influence of yeast glycosylated proteins on tannins aggregation in model solution
2004
<p style="text-align: justify;">The incidence of glycosylated yeast proteins on tannins aggregation in model solution was investigated using the spectrophotometric method (absorbance 700 nm). Glycosylated proteins released by two commercial <em>Saccharomyces cerevisiae</em> strains (RC212 and BM 45) during alcoholic fermentation in synthetic media, glycosylated proteins extracted by Peat’s method and industrial glycosylated proteins purified and separated by chromatography on Sepharose Concanavalin A were used to visualize effects on tannins aggregation. Results showed that tannins aggregation was limited by the glycosylated proteins according to their origin and their mod…
A study on the effect of the inhibition of polyadenylylation on the production of giant cytoplasmic RNA in sea urchin embryos.
1975
It is suggested that inhibition of RNA polyadenylylation in sea urchin mesenchyme blastulae causes a disturbance of the transport of all the size classes of newly synthesized RNA from the nucleus to the cytoplasm.
Biomineralizations: insights and prospects from crustaceans.
2011
19 pages; International audience; For growing, crustaceans have to molt cyclically because of the presence of a rigid exoskeleton. Most of the crustaceans harden their cuticle not only by sclerotization, like all the arthropods, but also by calcification. All the physiology of crustaceans, including the calcification process, is then linked to molting cycles. This means for these animals to find regularly a source of calcium ions quickly available just after ecdysis. The sources of calcium used are diverse, ranging from the environment where the animals live to endogenous calcium deposits cyclically elaborated by some of them. As a result, crustaceans are submitted to an important and energ…