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Cytokinesis begins in anaphase with the formation of the central spindle. PRC1 is a microtubule associated protein that plays an essential role in central spindle formation by crosslinking antiparallel microtubules. We have identified PRC1 as a novel binding partner for p27 Kip1 (p27). p27 is a cyclin-CDK inhibitor that causes cell cycle arrest in G1. However, p27 has also been involved in the regulation of G2/M progression and cytokinesis, as well as of other cellular processes, including actin and microtubule cytoskeleton dynamics. We found that p27 interferes with the ability of PRC1 to bind to microtubules, without affecting PRC1 dimerization or its capacity to interact with other partners such as KIF4. In this way, p27 inhibited microtubule bundling by PRC1 in vitro and prevented the extensive microtubule bundling phenotype caused by PRC1 overexpression in cells in culture. Finally, co-expression of p27 or a p27 mutant that does not bind cyclin-CDKs inhibited multinucleation induced by PRC1 overexpression. Together, our results suggest that p27 may participate in the regulation of mitotic progression in a CDK-independent manner by modulating PRC1 activity., (Copyright © 2018 Elsevier B.V. All rights reserved.)

The nature and frequency of the major CFTR mutations in the North African population remain unclear, although a small number of CFTR mutation detection studies have been done in Algeria and Tunisia, showing largely European mutations such as F508del, G542X and N1303K, albeit at different frequencies, which presumably emerged via population admixture with Caucasians. Some unique mutations were identified in these populations. This is the first study that includes a genetic and clinical evaluation of CF patients living in Algeria. In order to offer an effective diagnostic service and to make accurate risk estimates, we decided to identify the CFTR mutations in 81 Algerian patients. We carried out D-HPLC, chemical-clamp denaturing gradient gel electrophoresis, multiplex amplification analysis of the CFTR gene and automated direct DNA sequencing. We identified 15 different mutations which account for 58.5% of the CF chromosomes. We used a quantitative PCR technique (quantitative multiplex PCR short fragment fluorescence analysis) to screen for deletion/duplication in the 27 exons of the gene. Taking advantage of the homogeneity of the sample, we report clinical features of homozygous CF patients. As CFTR mutations have been detected in males with infertility, 46 unrelated Algerian individuals with obstructive azoospermia were also investigated.

Event-related potentials (ERPs) were recorded (01, 02, Fcz, Cpz leads) from 32 normal children aged from 6 to 8 years during a categorisation task performed with 4 types of stimuli that allowed for a holistic and/or an analytic development to modify information processing according to the child's age. Whatever age, derivation or stimulus, the individual ERPs showed a large negative N2 wave (mean latency: 230 ms) made up of two widely overlapping components. In order to separate these components, an initial principal component analysis (PCA) was performed on the waveforms; this PCA provided a principal component that accounted for the amplitude difference between the first negative peak of the N2 wave (180 ms after stimulus onset) and the subsequent slope change. A second PCA was then carried out on the corresponding individual component scores; this second PCA provided two factors according to whether the stimuli were holistically or analytically processed. Regarding the pre- and post-vertex data (Fcz and Cpz), these two factors accounted for the same ERP effect for the 6-year-old children but opposite effects after the age of seven. We interpreted this change as reflecting the differentiation of specific - holistic and analytic - modes of processing from a non-specific mode after the establishment of the concrete operation period.