Female reproduction bears no survival cost in captivity for gray mouse lemurs

The survival cost of reproduction has been revealed in many free‐ranging vertebrates. However, recent studies on captive populations failed to detect this cost. Theoretically, this lack of survival/reproduction trade‐off is expected when resources are not limiting, but these studies may have failed to detect the cost, as they may not have fully accounted for potential confounding effects, in particular interindividual heterogeneity. Here, we investigated the effects of current and past reproductive effort on later survival in captive females of a small primate, the gray mouse lemur. Survival analyses showed no cost of reproduction in females; and the pattern was even in the opposite direction: the higher the reproductive effort, the higher the chances of survival until the next reproductive event. These conclusions hold even while accounting for interindividual heterogeneity. In agreement with aforementioned studies on captive vertebrates, these results remind us that reproduction is expected to be traded against body maintenance and the survival prospect only when resources are so limiting that they induce an allocation trade‐off. Thus, the cost of reproduction has a major extrinsic component driven by environmental conditions.     

SOX2-Dependent Transcription in Clock Neurons Promotes the Robustness of the Central Circadian Pacemaker

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Brain-State-Dependent Modulation of Neuronal Firing and Membrane Potential Dynamics in the Somatosensory Thalamus during Natural Sleep

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Trio Haploinsufficiency Causes Neurodevelopmental Disease-Associated Deficits

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X-ray sterilization of biopharmaceutical manufacturing equipment—Extractables profile of a film material and copolyester Tritan™ compared to gamma irradiation

The biopharmaceutical industry gains enormous flexibility in production processes by using sterilized preassembled single-use devices. Gamma irradiation is an established sterilization technology that may be restricted in the future by the availability of ⁶⁰Co as irradiation source and irradiation capacities. X-ray technology is considered an alternative type of radiation for sterilizing SU equipment. In the context of extractables and leachables—one concern connected with the use of single-use process equipment—the effect of X-ray irradiation on the extractables profile of the materials needs to be compared to established gamma irradiation to qualify this alternative technology. An approach is presented to obtain robust and comprehensive extractables data for materials used in SU devices after sterilization either using X-ray or gamma irradiation. A careful selection of the test items and the test design allows a one-to-one comparison of data obtained from a combination of orthogonal analytical techniques. The extractables of a modern SU film material and the copolyester Tritan™ are evaluated. The data presented allow a risk evaluation on the safety of this new sterilization modality for biopharmaceutical applications. It is demonstrated that the extractables profile of a polymer is not affected by the type of irradiation used for sterilization.     

Differing conformational pathways before and after chemistry for insertion of dATP versus dCTP opposite 8-oxoG in DNA polymerase beta

To elucidate how human DNA polymerase β (pol β) discriminates dATP from dCTP when processing 8-oxoguanine (8-oxoG), we analyze a series of dynamics simulations before and after the chemical step with dATP and dCTP opposite an 8-oxoG template started from partially open complexes of pol β. Analyses reveal that the thumb closing of pol β before chemistry is hampered when the incorrect nucleotide dATP is bound opposite 8-oxoG; the unfavorable interaction between active-site residue Tyr²⁷¹ and dATP that causes an anti to syn change in the 8-oxoG (syn):dATP complex explains this slow motion, in contrast to the 8-oxoG (anti):dCTP system. Such differences in conformational pathways before chemistry for mismatched versus matched complexes help explain the preference for correct insertion across 8-oxoG by pol β. Together with reference studies with a nonlesioned G template, we propose that 8-oxoG leads to lower efficiency in pol β's incorporation of dCTP compared with G by affecting the requisite active-site geometry for the chemical reaction before chemistry. Furthermore, because the active site is far from ready for the chemical reaction after partial closing or even full thumb closing, we suggest that pol β is tightly controlled not only by the chemical step but also by a closely related requirement for subtle active-site rearrangements after thumb movement but before chemistry.     

Hydrophilic carotenoids: surface properties and aggregation of an astaxanthin-lysine conjugate, a rigid, long-chain, highly unsaturated and highly water-soluble tetracationic bolaamphiphile

The surface and aggregation properties of a synthetic, highly water-soluble carotenoid, the tetracationic astaxanthin-lysine conjugate (Asly), have been examined through measurements of surface tension, optical absorption and dynamic light scattering. The following parameters were determined: critical aggregation concentration c(M), surface concentration Gamma, molecular area a(m), free energy of adsorption and aggregation (DeltaG(ad) degrees and DeltaG(M) degrees , respectively), and the aggregate size r(H). The compound forms true monomolecular solutions in water below c(M); aggregates emerge only at rather high concentrations (> or =2.18 mM).     

Caenorhabditis elegans mutants resistant to attachment of Yersinia biofilms

The detailed composition and structure of the Caenorhabditis elegans surface are unknown. Previous genetic studies used antibody or lectin binding to identify srf genes that play roles in surface determination. Infection by Microbacterium nematophilum identified bus (bacterially unswollen) genes that also affect surface characteristics. We report that biofilms produced by Yersinia pestis and Y. pseudotuberculosis, which bind the C. elegans surface predominantly on the head, can be used to identify additional surface-determining genes. A screen for C. elegans mutants with a biofilm absent on the head (Bah) phenotype identified three novel genes: bah-1, bah-2, and bah-3. The bah-1 and bah-2 mutants have slightly fragile cuticles but are neither Srf nor Bus, suggesting that they are specific for surface components involved in biofilm attachment. A bah-3 mutant has normal cuticle integrity, but shows a stage-specific Srf phenotype. The screen produced alleles of five known surface genes: srf-2, srf-3, bus-4, bus-12, and bus-17. For the X-linked bus-17, a paternal effect was observed in biofilm assays.