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“The locomotor activity rhythm of the supralittoral sandhoppers, Talitrus saltator and Talorchestia deshayesii, was investigated over four seasons to reveal the impact of environmental variation on these sympatric species collected from Bizerte beach (37 degrees 19′N-9 degrees 51′E). For each

season, thirty adult individuals were collected by hand and transferred to individual actographs equipped with an infrared recording system, where they were subjected to two consecutive experimental light/dark regimens (natural light/dark cycle (LD) and continuous darkness (DD)) in a controlled environment cabinet at 18 degrees C +/- 0.5 degrees C. Periodogram analysis of the resulting actograms indicates a predominantly circadian rhythm with a period close to 24 h, with a less predictable semi-diurnal component of about 12 h in both T. saltator and T. deshayesii. A seasonal comparison of the various Selleckchem C59 rhythm characteristics showed that the greater mortality was observed in winter (36.6%) and in spring (70%), respectively, among the population of T. saltator and T. deshayesii; whereas, in summer, this rate PKC412 mouse was equal to zero

whatever the species. Moreover, irrespective of the season and the photoperiodic regimen, circadian rhythmicity was more important than the semi-diurnal one for all seasons and both under natural Light/Dark (nLD) cycle and free-running conditions. In addition, the stability of the circadian rhythm was better defined in spring, whatever the photoperiodic regimen imposed and the species. Similarities and differences observed between T. saltator and T. deshayesii over four seasons reflect an ecological plasticity of their biological clock adapted to different changing environmental conditions.”
“Formation of the placenta is a crucial step in mammalian pregnancy. Apart from

its function in ensuring an optimal supply of nutrients and oxygen to the fetus, the placenta is also the interface at which allo-recognition of invading trophoblast cells by the maternal immune system can potentially occur. We summarise here the “state of the art” on how variability of immune system genes that code for major histocompatibility complex (MHC) molecules and natural killer receptors AP26113 purchase (NKR) may impact on human placentation. MHC and NKR are the most polymorphic human genes. Our recent reports point out that specific combinations of fetal MHC and maternal NKR genes in humans correlate with the risk of pre-eclampsia, recurrent miscarriage (RM) and fetal growth restriction (FGR). Research in this field is still at an early stage and future studies in mouse and humans will be needed before the results can be translated to clinical applications. We discuss our recent work, as well as the opportunities offered by mouse genetics, to understand the cellular and molecular mechanisms underlying immune interactions at the maternal-fetal interface. (C) 2011 Elsevier Ltd. All rights reserved.