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It has been known for many years that centromeres cluster at the spindle pole body in fission yeast. In this issue of Developmental Cell, Fernandez-Alvarez et al. (2016) reveal that the functional significance of clustering is to promote spindle assembly by modulating nuclear envelope integrity at the onset of mitosis.

Adolescent and young adult abuse of short-acting MOP-r agonists such as oxycodone is a pressing public health issue. Few preclinical studies have examined how adolescent exposure to oxycodone impacts its effects in the transition to adulthood. Objective: To determine in mice how chronic adolescent oxycodone self-administration (SA) affects subsequent oxycodone-induced conditioned place preference (CPP), locomotor activity, and antinociception once mice reach early adulthood. Methods: Adolescent C57BL/6J male mice (4 weeks old, n = 6-11) and adult mice (10 weeks old, n = 6 -10) were surgically implanted with indwelling jugular catheters. Mice then acquired oxycodone self administration (14 consecutive 2-hr daily sessions; 0.25 mg/kg/infusion) followed by a 14-day drug free (withdrawal) period in home cage. After the 14-day drug-free period, mice underwent a 10-day oxycodone CPP procedure (0, 1, 3, 10 mg/kg i.p.) or were tested for acute oxycodone-induced anti-nociception in the hot plate assay (335, 5, 7.5 mg/kg i.p.). Results: Mice that self-administered oxycodone during adolescence exhibited greater oxycodone-induced CPP (at the 3 mg/kg dose) than their yoked saline controls and mice that self-administered oxycodone during "adulthood. Oxycodone dose-dependently increased locomotor activity, but sensitization developed only to the 3 mg/kg in the mice that underwent oxycodone self-administration as adolescents. Mice that self-administered oxycodone as adolescents decreased in the anti-nociceptive effects of oxycodone in one dose (5 mg/kg), whereas animals that self-administered oxycodone as adults did not show this effect. Conclusion: Chronic adolescent oxycodone self-administration led to increased oxycodone-induced CPP (primarily 1 and 3 mg/kg, i.p.) and reduced antinociceptive effect of oxycodone (5 mg/kg, i.p.) in adulthood. (C) 2016 Elsevier Ltd. All rights reserved.

B-type cyclins promote mitotic entry and inhibit mitotic exit. In Saccharomyces cerevisiae, four B-type cyclins, Clb1-4, carry out essential mitotic roles, with substantial but incomplete overlap of function among them. Previous work in many organisms has indicated that B-type cyclin-dependent inhibition of mitotic exit imposes a requirement for mitotic destruction of B-type cyclins. For instance, precise genomic removal of the Clb2 destruction box (D box) prevents mitotic proteolysis of Clb2, and blocks mitotic exit. Here, we show that, despite significant functional overlap between Clb2 and Clb3, D-box-dependent Clb3 proteolysis is completely dispensable for mitotic exit. Removal of the Clb3 D box results in abundant Clb3 protein and associated kinase throughout the cell cycle, but mitotic exit occurs with close to normal timing. Clb3 degradation is required for pre-Start G(1) control in the succeeding cell cycle. Deleting the CLB3 D box essentially eliminates all time delay before cell cycle Start following division, even in very small newborn cells. CLB3Ddb cells show no cell cycle arrest response to mating pheromone, and CLB3Ddb completely bypasses the requirement for CLN G(1) cyclins, even in the absence of the early expressed B-type cyclins CLB5,6. Thus, regulated mitotic proteolysis of Clb3 is specifically required to make passage of Start in the succeeding cell cycle "memoryless"-dependent on conditions within that cycle, and independent of events such as B-type cyclin accumulation that occurred in the preceding cycle.

Purpose of reviewUtilization of cryopreserved instead of fresh donor oocytes has rapidly increased in recent years. Whether treatment outcomes are comparable has, however, remained controversial.Recent findingsMore than 24% of initiated oocyte donation cycles in the USA during 2013-2014 involved previously cryopreserved oocytes. The use of cryopreserved-donated oocytes may simplify logistics and lower costs per treatment cycle. Whether cryopreserved donor oocytes also lower costs per live birth is still undetermined as they result in lower live birth rates in comparison to fresh donor oocyte cycles. National data regarding the safety of donated oocytes, including miscarriage rates and neonatal health outcomes, are lacking.SummaryCurrently available data on cryopreserved-donated oocytes are incomplete and, therefore, still insufficient to claim equivalency between fresh and cryopreserved donor oocytes. Until sufficient data are available, patients should be advised about advantages and disadvantages of both methods of oocyte donation, and the use of cryopreserved oocytes should be considered only with caution and appropriate informed consent. Because banking of donated human oocytes facilities their commercial trade, it challenges basic ethical considerations, which have been the basis of oocyte donation since its inception.

Hepatitis C virus (HCV) species tropism is incompletely understood. We have previously shown that at the level of entry, human CD81 and occludin (OCLN) comprise the minimal set of human factors needed for viral uptake into murine cells. As an alternative approach to genetic humanization, species barriers can be overcome by adapting HCV to use the murine orthologues of these entry factors. We previously generated a murine tropic HCV (mtHCV or Jc1/mCD81) strain harboring three mutations within the viral envelope proteins that allowed productive entry into mouse cell lines. In this study, we aimed to characterize the ability of mtHCV to enter and infect mouse hepatocytes in vivo and in vitro. Using a highly sensitive, Cre-activatable reporter, we demonstrate that mtHCV can enter mouse hepatocytes in vivo in the absence of any human cofactors. Viral entry still relied on expression of mouse CD81 and SCARB1 and was more efficient when mouse CD81 and OCLN were overexpressed. HCV entry could be significantly reduced in the presence of anti-HCV E2 specific antibodies, suggesting that uptake of mtHCV is dependent on viral glycoproteins. Despite mtHCV's ability to enter murine hepatocytes in vivo, we did not observe persistent infection, even in animals with severely blunted type I and III interferon signaling and impaired adaptive immune responses. Altogether, these results establish proof of concept that the barriers limiting HCV species tropism can be overcome by viral adaptation. However, additional viral adaptations will likely be needed to increase the robustness of a murine model system for hepatitis C. IMPORTANCE At least 150 million individuals are chronically infected with HCV and are at risk of developing serious liver disease. Despite the advent of effective antiviral therapy, the frequency of chronic carriers has only marginally decreased. A major roadblock in developing a vaccine that would prevent transmission is the scarcity of animal models that are susceptible to HCV infection. It is poorly understood why HCV infects only humans and chimpanzees. To develop an animal model for hepatitis C, previous efforts focused on modifying the host environment of mice, for example, to render them more susceptible to HCV infection. Here, we attempted a complementary approach in which a laboratory-derived HCV variant was tested for its ability to infect mice. We demonstrate that this engineered HCV strain can enter mouse liver cells but does not replicate efficiently. Thus, additional adaptations are likely needed to construct a robust animal model for HCV.

In poor prognosis patients undergoing in vitro fertilization, advance determinations of likely oocyte yields are especially important since oocyte numbers to large degree determine in vitro fertilization cycle outcomes. Based on baseline follicle stimulating hormone and anti-mullerian hormone levels at time of initial presentation, we here, therefore, determined at all ages the probabilities of obtaining 1-aeyen5 oocytes in a retrospective analysis of 1554 consecutive patients undergoing in vitro fertilization cycles at an academically affiliated private fertility center. At lowest levels (aecurrency sign2.5 mIU/mL), Follicle stimulating hormone at all ages was highly predictable for aeyen1 oocyte (88-96 %). Probabilities declined and diverged between ages with increasing follicle stimulating hormone, though narrowed again at high follicle stimulating hormone. Anti-Mullerian hormone demonstrated at higher levels (2.5-aeyen5 ng/ml) at all ages almost perfect probabilities (99-100 %). With declining anti-Mullerian hormone, age categories, however, increasingly diverged, though to lesser degree than follicle stimulating hormone. In poor prognosis patients, follicle stimulating hormone and anti-Mullerian hormone, thus, offer at different ages very specific probabilities for retrieval of 1-aeyen5 oocytes. Since oocyte numbers are associated with embryo numbers, and numbers of transferable embryos with live birth rates, here presented probability tables should facilitate improved prognostication of poor prognosis patients. Discrepancies in here reported probabilities between follicle stimulating hormone and anti-mullerian hormone also further define follicle stimulating hormone and anti-mullerian hormone in their respective abilities to represent functional ovarian reserve at different ages.

Acinar cells make up the majority of all cells in the pancreas, yet the source of new acinar cells during homeostasis remains unknown. Using multicolor lineage-tracing and organoid-formation assays, we identified the presence of a progenitor-like acinar cell subpopulation. These cells have long-term self-renewal capacity, albeit in a unipotent fashion. We further demonstrate that binuclear acinar cells are terminally differentiated acinar cells. Transcriptome analysis of single acinar cells revealed the existence of a minor population of cells expressing progenitor markers. Interestingly, a gain of the identified markers accompanied by a transient gain of proliferation was observed following chemically induced pancreatitis. Altogether, our study identifies a functionally and molecularly distinct acinar subpopulation and thus transforms our understanding of the acinar cell compartment as a pool of equipotent secretory cells.

Cell types more advanced in development than embryonic stem cells, such as EpiSCs, fail to contribute to chimeras when injected into pre-implantation-stage blastocysts, apparently because the injected cells undergo apoptosis. Here we show that transient promotion of cell survival through expression of the anti-apoptotic gene BCL2 enables EpiSCs and Sox17(+) endoderm progenitors to integrate into blastocysts and contribute to chimeric embryos. Upon injection into blastocyst, BCL2-expressing EpiSCs contributed to all bodily tissues in chimeric animals while Sox17(+) endoderm progenitors specifically contributed in a region-specific fashion to endodermal tissues. In addition, BCL2 expression enabled rat EpiSCs to contribute to mouse embryonic chimeras, thereby forming interspecies chimeras that could survive to adulthood. Our system therefore provides a method to overcome cellular compatibility issues that typically restrict chimera formation. Application of this type of approach could broaden the use of embryonic chimeras, including region-specific chimeras, for basic developmental biology research and regenerative medicine.

The design of cancer-targeting particles with precisely tuned physicochemical properties may enhance the delivery of therapeutics and access to pharmacological targets. However, a molecular-level understanding of the interactions driving the fate of nanomedicine in biological systems remains elusive. Here, we show that ultrasmall (<10 nm in diameter) poly (ethylene glycol)-coated silica nanoparticles, functionalized with melanoma-targeting peptides, can induce a form of programmed cell death known as ferroptosis in starved cancer cells and cancer-bearing mice. Tumour xenografts in mice intravenously injected with nanoparticles using a high-dose multiple injection scheme exhibit reduced growth or regression, in a manner that is reversed by the pharmacological inhibitor of ferroptosis, liproxstatin-1. These data demonstrate that ferroptosis can be targeted by ultrasmall silica nanoparticles and may have therapeutic potential.