Max Planck Society

About: Max Planck Society is a nonprofit organization based out in Munich, Germany. It is known for research contribution in the topics: Galaxy & Population. The organization has 148289 authors who have published 406224 publications receiving 19522268 citations. The organization is also known as: Max-Planck-Gesellschaft zur Förderung der Wissenschaften e. V. & MPG.

Molecular gas in the host galaxy of a quasar at redshift z = 6.42

Abstract: Observations of molecular hydrogen in quasar host galaxies at high redshifts provide fundamental constraints on galaxy evolution, because it is out of this molecular gas that stars form. Molecular hydrogen is traced by emission from the carbon monoxide molecule, CO; cold H2 itself is generally not observable. Carbon monoxide has been detected in about ten quasar host galaxies with redshifts z > 2; the record-holder is at z = 4.69 (refs 1–3). Here we report CO emission from the quasar SDSS J114816.64 + 525150.3 (refs 5, 6) at z = 6.42. At that redshift, the Universe was only 1/16 of its present age, and the era of cosmic reionization was just ending. The presence of about 2 × 1010 M⊙ of H2 in an object at this time demonstrates that molecular gas enriched with heavy elements can be generated rapidly in the youngest galaxies.

Relocation of Aurora B from centromeres to the central spindle at the metaphase to anaphase transition requires MKlp2

Abstract: Mitotic kinases of the Polo and Aurora families are key regulators of chromosome segregation and cytokinesis. Here, we have investigated the role of MKlp1 and MKlp2, two vertebrate mitotic kinesins essential for cytokinesis, in the spatial regulation of the Aurora B kinase. Previously, we have demonstrated that MKlp2 recruits Polo-like kinase 1 (Plk1) to the central spindle in anaphase. We now find that in MKlp2 but not MKlp1-depleted cells the Aurora B-INCENP complex remains at the centromeres and fails to relocate to the central spindle. MKlp2 exerts dual control over Aurora B localization, because it is a binding partner for Aurora B, and furthermore for the phosphatase Cdc14A. Cdc14A can dephosphorylate INCENP and may contribute to its relocation to the central spindle in anaphase. We propose that MKlp2 is involved in the localization of Plk1, Aurora B, and Cdc14A to the central spindle during anaphase, and that the integration of signaling by these proteins is necessary for proper cytokinesis.

Massive restructuring of neuronal circuits during functional reorganization of adult visual cortex

Abstract: The cerebral cortex has the ability to adapt to altered sensory inputs. In the visual cortex, a small lesion to the retina causes the deprived cortical region to become responsive to adjacent parts of the visual field. This extensive topographic remapping is assumed to be mediated by the rewiring of intracortical connections, but the dynamics of this reorganization process remain unknown. We used repeated intrinsic signal and two-photon imaging to monitor functional and structural alterations in adult mouse visual cortex over a period of months following a retinal lesion. The rate at which dendritic spines were lost and gained increased threefold after a small retinal lesion, leading to an almost complete replacement of spines in the deafferented cortex within 2 months. Because this massive remodeling of synaptic structures did not occur when all visual input was removed, it likely reflects the activity-dependent establishment of new cortical circuits that serve the recovery of visual responses.