Identification of the Sex Pheromone of a Protected Species, the Spanish Moon Moth Graellsia isabellae

Sex attractant pheromones are highly sensitive and selective tools for detecting and monitoring populations of insects, yet there has been only one reported case of pheromones being used to monitor protected species. Here, we report the identification and synthesis of the sex pheromone of a protected European moth species, Graellsia isabellae (Lepidoptera: Saturniidae), as the single component, (4E,6E,11Z)-hexadecatrienal. In preliminary field trials, lures loaded with this compound attracted male moths from populations of this species at a number of widely separated field sites in France, Switzerland, and Spain, clearly demonstrating the utility of pheromones in sampling potentially endangered insect species

PCNA dependent cellular activities tolerate dramatic perturbations in PCNA client interactions

Proliferating cell nuclear antigen (PCNA) is an essential cofactor for DNA replication and repair, recruiting multiple proteins to their sites of action. We examined the effects of the PCNA(S228I) mutation that causes PCNA-associated DNA repair disorder (PARD). Cells from individuals affected by PARD are sensitive to the PCNA inhibitors T3 and T2AA, showing that the S228I mutation has consequences for undamaged cells. Analysis of the binding between PCNA and PCNA-interacting proteins (PIPs) shows that the S228I change dramatically impairs the majority of these interactions, including that of Cdt1, DNMT1, PolD3(p66) and PolD4(p12). In contrast p21 largely retains the ability to bind PCNA(S228I). This property is conferred by the p21 PIP box sequence itself, which is both necessary and sufficient for PCNA(S228I) binding. Ubiquitination of PCNA is unaffected by the S228I change, which indirectly alters the structure of the inter-domain connecting loop. Despite the dramatic in vitro effects of the PARD mutation on PIP-degron binding, there are only minor alterations to the stability of p21 and Cdt1 in cells from affected individuals. Overall our data suggests that reduced affinity of PCNA(S228I) for specific clients causes subtle cellular defects in undamaged cells which likely contribute to the etiology of PARD

Characterization of Human DNA Polymerase Delta and Its Subassemblies Reconstituted by Expression in the Multibac System

Mammalian DNA polymerase δ (Pol δ), a four-subunit enzyme, plays a crucial and versatile role in DNA replication and DNA repair processes. We have reconstituted human Pol δ complexes in insect cells infected with a single baculovirus into which one or more subunits were assembled. This system allowed for the efficient expression of the tetrameric Pol δ holoenzyme, the p125/p50 core dimer, the core+p68 trimer and the core+p12 trimer, as well as the p125 catalytic subunit. These were isolated in milligram amounts with reproducible purity and specific activities by a highly standardized protocol. We have systematically compared their activities in order to gain insights into the roles of the p12 and p68 subunits, as well as their responses to PCNA. The relative specific activities (apparent kcat) of the Pol δ holoenzyme, core+p68, core+p12 and p125/p50 core were 100, 109, 40, and 29. The corresponding apparent Kd's for PCNA were 7.1, 8.7, 9.3 and 73 nM. Our results support the hypothesis that Pol δ interacts with PCNA through multiple interactions, and that there may be a redundancy in binding interactions that may permit Pol δ to adopt flexible configurations with PCNA. The abilities of the Pol δ complexes to fully extend singly primed M13 DNA were examined. All the subassemblies except the core+p68 were defective in their abilities to completely extend the primer, showing that the p68 subunit has an important function in synthesis of long stretches of DNA in this assay. The core+p68 trimer could be reconstituted by addition of p12

From shales to slates: The magnetite and pyrrhotite temperature windows

International audienceDuring burial of clay-rich sediments, magnetic minerals, just as other minerals, are continuously produced, altered, and dissolved. In shales, from early burial to anchi-metamorphism (Tburial< 250°C), magnetite is the main magnetic mineral. In slates, it is known that the dual breakdown of magnetite and pyrite trigger the formation of pyrrhotite for burial temperature close to 300°C (greenschist metamorphic grade). We propose to bracket the range of temperature of magnetite and pyrite breakdown using in combination magnetic studies and burial temperature obtained by Raman spectroscopy. Samples are late Cretaceous slates (burial temperature 250°-600°C) from Pyrenees. The identification of magnetite and pyrrhotite is firmly constrained by the identification of Verwey ( 120 K) and Besnus ( 32K) magnetic transition. Burial temperatures are estimated within ±30°C. Results show: 1) Magnetite is dominant for Tburial<330°C, with evidence of fine pyrrhotite in the superparamagnetic to single domain states. Magnetization is pretty low (<10-4 Am2/kg). 2) An assemblage of magnetite and pyrrhotite is observed for the range 330°C< Tburial <360°C. 3) Pyrrhotite is the only ferrimagnetic mineral detected for the range 360°C< Tburial <600°C. Magnetization displays a wide range (10-4-10-1 Am2/kg) in the pyrrhotite windows. There is therefore a high contrasting magnitude of magnetization of shales vs. slates. In shales, the remanence carried by magnetite is essentially a chemical remanent magnetization imprinted during peak burial. In contrast, the remanence carried by pyrrhotite is essentially a thermo remanent magnetization blocked in during the uplift of metamorphic units

From shales to slates: The magnetite and pyrrhotite temperature windows

International audienceDuring burial of clay-rich sediments, magnetic minerals, just as other minerals, are continuously produced, altered, and dissolved. In shales, from early burial to anchi-metamorphism (Tburial< 250°C), magnetite is the main magnetic mineral. In slates, it is known that the dual breakdown of magnetite and pyrite trigger the formation of pyrrhotite for burial temperature close to 300°C (greenschist metamorphic grade). We propose to bracket the range of temperature of magnetite and pyrite breakdown using in combination magnetic studies and burial temperature obtained by Raman spectroscopy. Samples are late Cretaceous slates (burial temperature 250°-600°C) from Pyrenees. The identification of magnetite and pyrrhotite is firmly constrained by the identification of Verwey ( 120 K) and Besnus ( 32K) magnetic transition. Burial temperatures are estimated within ±30°C. Results show: 1) Magnetite is dominant for Tburial<330°C, with evidence of fine pyrrhotite in the superparamagnetic to single domain states. Magnetization is pretty low (<10-4 Am2/kg). 2) An assemblage of magnetite and pyrrhotite is observed for the range 330°C< Tburial <360°C. 3) Pyrrhotite is the only ferrimagnetic mineral detected for the range 360°C< Tburial <600°C. Magnetization displays a wide range (10-4-10-1 Am2/kg) in the pyrrhotite windows. There is therefore a high contrasting magnitude of magnetization of shales vs. slates. In shales, the remanence carried by magnetite is essentially a chemical remanent magnetization imprinted during peak burial. In contrast, the remanence carried by pyrrhotite is essentially a thermo remanent magnetization blocked in during the uplift of metamorphic units