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131.
132.
Claudio Iribarren Viviana Hermosilla Violeta Morin Marcia Puchi 《Journal of cellular biochemistry》2013,114(8):1779-1788
In amphibians, sperm histone transition post‐fertilization during male pronucleus formation is commanded by histone chaperone Nucleoplasmin (NPM). Here, we report the first studies to analyze the participation of a Nucleoplasmin‐like protein on male chromatin remodeling in sea urchins. In this report, we present the molecular characterization of a nucleoplasmin‐like protein that is present in non fertilized eggs and early zygotes in sea urchin specie Tetrapygus niger. This protein, named MP62 can interact with sperm histones in vitro. By male chromatin decondensation assays and immunodepletion experiments in vitro, we have demonstrated that this protein is responsible for sperm nucleosome disorganization. Furthermore, as amphibian nucleoplasmin MP62 is phosphorylated in vivo immediately post‐fertilization and this phosphorylation is dependent on CDK‐cyclin activities found after fertilization. As we shown, olomoucine and roscovitine inhibits male nucleosome decondensation, sperm histone replacement in vitro and MP62 phosphorylation in vivo. This is the first report of a nucleoplasmin‐like activity in sea urchins participating during male pronucleus formation post‐fecundation. J. Cell. Biochem. 114: 1779–1788, 2013. © 2013 Wiley Periodicals, Inc. 相似文献
133.
134.
Santeri Kiviluoto Tomas Luyten Lars Schneider Dmitrij Lisak Diego Rojas-Rivera Kirsten Welkenhuyzen Ludwig Missaen Humbert De Smedt Jan B. Parys Claudio Hetz Axel Methner Geert Bultynck 《Cell calcium》2013
Bax Inhibitor-1 (BI-1) is an evolutionarily conserved six-transmembrane domain endoplasmic reticulum (ER)-localized protein that protects against ER stress-induced apoptotic cell death. This function is closely connected to its ability to lower steady-state ER Ca2+ levels. Recently, we elucidated BI-1's Ca2+-channel pore in the C-terminal part of the protein and identified the critical amino acids of its pore. Based on these insights, a Ca2+-channel pore-dead mutant BI-1 (BI-1D213R) was developed. We determined whether BI-1 behaves as a bona fide H+/Ca2+ antiporter or as an ER Ca2+-leak channel by investigating the effect of pH on unidirectional Ca2+-efflux rates. At pH 6.8, wild-type BI-1 expression in BI-1−/− cells increased the ER Ca2+-leak rate, correlating with its localization in the ER compartment. In contrast, BI-1D231R expression in BI-1−/−, despite its ER localization, did not increase the ER Ca2+-leak rate. However, at pH < 6.8, the BI-1-mediated ER Ca2+ leak was blocked. Finally, a peptide representing the Ca2+-channel pore of BI-1 promoting Ca2+ flux from the ER was used. Lowering the pH from 6.8 to 6.0 completely abolished the ability of the BI-1 peptide to mediate Ca2+ flux from the ER. We propose that this pH dependence is due to two aspartic acid residues critical for the function of the Ca2+-channel pore and located in the ER membrane-dipping domain, which facilitates the protonation of these residues. 相似文献
135.
Claudia Menzel Andrew Fowler Claudio Tennie Josep Call 《International journal of primatology》2013,34(3):533-553
Researchers have described apparently self-medicative behaviors for a variety of nonhuman species including birds and primates. Wild chimpanzees, bonobos, and gorillas have been observed to swallow rough leaves without chewing, a behavior proposed to be self-medicative and to aid control of intestinal parasites. Researchers have hypothesized that the presence of hairs on the leaf surface elicits the behavior. We investigated the acquisition and the underlying mechanisms of leaf swallowing. We provided 42 captive great apes (24 chimpanzees, six bonobos, six gorillas, and six orangutans) with both rough-surfaced and hairless plants. None of the subjects had previously been observed to engage in leaf swallowing behavior and were therefore assumed naïve. Two chimpanzees and one bonobo swallowed rough-surfaced leaves spontaneously without chewing them. In a social setup six more chimpanzees acquired the behavior. None of the gorillas or orangutans showed leaf swallowing. Because this behavior occurred in naïve individuals, we conclude that it is part of the behavioral repertoire of chimpanzees and bonobos. Social learning is thus not strictly required for the acquisition of leaf swallowing, but it may still facilitate its expression. The fact that apes always chewed leaves of hairless control plants before swallowing, i.e., normal feeding behavior, indicates that the surface structure of leaves is indeed a determinant for initiating leaf swallowing in apes where it occurs. 相似文献
136.
137.
Claudio Sedivy Silvia Dorn Andreas Müller 《Biological journal of the Linnean Society. Linnean Society of London》2013,108(2):349-360
The construction of nests to rear offspring is restricted to vertebrates and few insect taxa, such as termites, wasps, and bees. Among bees, species of the family Megachilidae are characterized by a particularly high diversity in nest construction behaviour. Many megachilid bees nest in excavated burrows in the ground, others place their brood cells in a variety of above‐ground cavities or attach them to the surface of a substrate, and yet others have adopted a kleptoparasitic habit. Evolutionary transitions between the different nesting sites and between conventional nesting and kleptoparasitism in bees are poorly understood. In the present study, we traced the evolution of nesting site selection and kleptoparasitism in the Annosmia–Hoplitis group (Osmiini), which displays an exceptionally high diversity in nesting behaviour. We found that the evolution of nesting behaviour proceeded unidirectionally from nesting in excavated burrows in the ground to nesting in rock depressions and cavities, followed by the colonization of snail shells and insect borings in dead wood or hollow stems. Kleptoparasitism evolved once and the kleptoparasitic species have derived from the same lineage as their hosts. © 2012 The Linnean Society of London, Biological Journal of the Linnean Society, 2012, 108 , 349–360. 相似文献
138.
Fábio Takenori Higa Lucila Okuyama Fukasawa Maria Gisele Gon?alves Maristela Marques Salgado Ana Paula Silva de Lemos Lee H Harrison Priscilla Lima de Oliveira Carla Naufal da Silva Claudio Tavares Sacchi 《Memórias do Instituto Oswaldo Cruz》2013,108(2):246-247
We evaluated the use of a newly described sodC-based real-time-polymerase chain reaction (RT-PCR) assay for detecting Neisseria meningitidis in normally sterile sites, such as cerebrospinal fluid and serum. The sodC-based RT-PCR assay has an advantage over ctrA for detecting nongroupable N. meningitidis isolates, which are commonly present in asymptomatic pharyngeal carriage. However, in our study, sodC-based RT-PCR was 7.5% less sensitive than ctrA. Given the public health impact of possible false-negative results due to the use of the sodC target gene alone, sodC-based RT-PCR for the diagnosis of meningococcal meningitis should be used with caution. 相似文献
139.
Luiz Claudio Pereira Ribeiro Cassia Cristina Alves Gon?alves Carla Maria Sena Andrade Slater Silvia Maia Farias de Carvalho Marzia Puccioni-Sohler 《Memórias do Instituto Oswaldo Cruz》2013,108(6):730-734
Intrathecal synthesis of human T-lymphotropic virus type 1 (HTLV-1) antibodies
(Abs) represents conclusive evidence of a specific immune response in the
central nervous system of HTLV-1 associated myelopathy/tropical spastic
paraparesis (HAM/TSP) patients. Western blotting (WB) for HTLV Abs in serum is a
confirmatory test for HTLV-1 infection. The aim of this study was to standardise
the Western blot to demonstrate the intrathecal pattern of Abs against HTLV-1
proteins in HAM/TSP patients. Paired cerebrospinal fluid (CSF) and serum samples
were selected from 20 patients with definite HAM/TSP, 19 HTLV-1 seronegative
patients and two HTLV-1 patients without definite HAM/TSP. The presence of
reactive bands of greater intensity in the CSF compared to serum (or bands in
only the CSF) indicated the intrathecal synthesis of anti-HTLV-1 Abs. All
definite HAM/TSP patients presented with an intrathecal synthesis of anti-HTLV-1
Abs; these Abs were not detected in the control patients. The most frequent
intrathecal targets of anti-HTLV-1 Abs were GD21, rgp46-I and p24 and, to a
lesser extent, p19, p26, p28, p32, p36, p53 gp21 and gp46. The intrathecal
immune response against env (GD21 and rgp46-I) and
gag (p24) proteins represents the most important humoral
pattern in HAM/TSP. This response may be used as a diagnostic marker,
considering the frequent association of intrathecal anti-HTLV-1 Ab synthesis
with HAM/TSP and the pathogenesis of this neurological disease. 相似文献
140.
Many behavioural aspects of Anoplius infuscatus (Vander Linden) and Episyron sp. Schioedte were examined in detail, both on a qualitative and, when possible, on a quantitative level, during a long-term field study in Northern Italy. Both wasps dig unicellular nests on bare soil, which are filled with a single spider to feed the brood. The main differences regard the way to hunt their prey, that of burrowing, that of transporting and introducing the spider into the nest, the habit of amputating spider legs and the abdominal movements during nest closing. On the whole, starting from prey capture to nest closure, A. infuscatus is significantly slower than Episyron. The observed ethological differences are well fitted to the exploitation of the different preys consisting in wolf spiders (Lycosidae) and orb weaving spiders (Araneidae), respectively. Some flexibility in the observed behaviour is described. A critical re-examination of the literature shows that, even if most results agree with those of previous authors, two controversial points remain open regarding Episyron species: the position of the egg (on the prey or on the cell wall) and the way to grasp the spider during tranport and introdution into the nest. 相似文献