Search

Roughly 90% of socially monogamous bird species exhibit some degree of extra-pair paternity (EPP), although the extent and the underlying mechanisms vary among species. We analyzed spatial and demographic patterns of EPP over a 6 year period (2005-2010) as part of a long-term population study of Canada Warblers (Cardellina canadensis (L., 1766)). We identified 12 microsatellite loci used to assess paternity for 185 nestlings from 61 nests. Extra-pair young (EPY) accounted for 41.6% of all nestlings and 57.4% of nests contained at least one EPY. Fewer than half of EPY were sired by males who shared territorial boundaries, and some males sired young in nests 1 km from their territory. The ageofsocial males did not differ from males who cuckolded them. The majority (83%) of EPY were sired by males in older age classes (2+ years old), while Key words: Canada Warbler, Cardellina canadensis, within-pair paternity, lifetime fitness. Un certain degre de paternite hors couple (PHC) caracterise environ 90 % des especes d'oiseaux monogames sur le plan social, bien que l'ampleur de ce phenomene et les mecanismes sous-jacents varient d'une espece a l'autre. Nous avons analyse les motifs spatiaux et demographiques de PHC pendant 6 ans (2005-2010) dans le cadre d'une etude de longue duree de populations de parulines du Canada (Cardellina canadensis (L., 1766)). Nous avons cerne 12 sites microsatellites utilises pour evaluer la paternite de 185 oiseaux niais issus de 61 nids. Les jeunes de paternite hors couple (JHC) representaient 41,6 % de tous les oiseaux niais et 57,4 % des nids contenaient au moins un JHC. Moins de la moitie des JHC etaient issus de males partageant des limites territoriales, et certains males avaient une progeniture dans des nids situes a 1 km de leur territoire. L'age des males sociaux n'etait pas different de celui des males qui les cocufiaient. La majorite (83 %) des JHC etaient issus de males de classes d'age plus vieilles (2 ans et plus), alors que Mots-cles : paruline du Canada, Cardellina canadensis, paternite au sein du couple, aptitude sur la duree de vie., Introduction Extra-pair paternity (EPP) is common among socially monogamous bird species with approximately 90% of socially monogamous species exhibiting some degree of EPP (Griffith et al. 2002), and this behavior [...]

Smokers and individuals exposed to second hand cigarette smoke (SHCS) have a higher risk of developing chronic sinus and bronchial infections. This suggests that cigarette smoke (CS) has adverse effects on immune defenses against pathogens. Epithelial cells are important in airway innate immunity and are the first line of defense against infection. Airway epithelial cells form a physical barrier, but also respond to the presence of microbes by secreting antimicrobials, cytokines and chemokines. These molecules can lyse infectious microorganisms and/or provide signals critical to the initiation of adaptive immune responses. We examined the effects of cigarette smoke on antimicrobial secretions of primary human nasal epithelial cells (PHNEC). Compared to non-CS exposed individuals, PHNEC from in-vivo cigarette smoke-exposed individuals secreted less CCL20, BD-1, and SLPI apically, less BD-1 and SLPI basolaterally, and more CCL20 basolaterally. Cigarette smoke extract (CSE) exposure in vitro decreased the apical secretion of CCL20 and beta defensin-1 by PHNEC from non-CS exposed individuals. Exposing PHNEC from non-CS exposed to cigarette smoke extract also significantly decreased the levels of many mRNA transcripts that are involved in immune signaling. Our results show that in-vivo or in vitro exposure to cigarette smoke alters the secretion of key antimicrobial peptides from PHNEC, but that in-vivo CS exposure is a much more important modifier of antimicrobial peptide secretion. Based on the gene expression data, it appears that cigarette smoke extract disrupts multiple immune signaling pathways in PHNEC. Our results provide mechanistic insight into how cigarette smoke exposure alters the innate immune response and increases an individual's susceptibility to pathogen infection. [ABSTRACT FROM AUTHOR]

Polyfluoro-alkyl substances (PFAS) are widely distributed environmental contaminants linked to human toxicity and developmental delays, especially low birthweight (LBW). In this study, Human Umbilical Vein Endothelial Cells (HUVECs) were exposed to the PFAS perfluorooctanesulfonic acid (PFOS). After 48-hours, their proliferation, and differential gene expression were assessed. A small, yet significant, reduction in proliferation was seen at 50 μg/mL and 75 μg/mL. RNA sequencing showed that estrogen response and notch signaling pathways were significantly altered. This study increases our understanding of how PFAS may interfere with endothelial cell (HUVECs) functions which may have larger effects on fetal growth, development, and birthweight., Competing Interests: The authors declare that there are no conflicts of interest present., (Copyright: © 2024 by the authors.)

Cigarette smoke (CS) exposure is known to increase infection rates, but the mechanisms are not well understood. These studies tested the hypothesis that CS exposure would impair antimicrobial activity of apical conditioned media from human airway (BEAS-2B) cultures by reducing induction and release of the antimicrobial peptide CCL20. BEAS-2B cultures were exposed to CS extract and assayed for temporal and physical characteristics of release as well as for antimicrobial activity. E. coli were exposed to Beas-2B-conditioned media (BCM) and subsequent bacterial colonies were enumerated. In time course studies TLR-agonist-induced CCL20 transcription and release were rapid, of short duration and release was consistently targeted to the apical/luminal compartment. Cells treated with CS extract had diminished release of CCL20 under both constitutive and toll-like receptor (TLR) agonist stimulating conditions. Exposure of the cells to CS significantly reduced the antimicrobial activity in BCM and neutralizing antibodies to CCL20 brought antibacterial activity back to baseline levels demonstrating that antimicrobial activity in this culture system was primarily attributable to CCL20. These studies add to the understanding of CCL20 as a mucosal antimicrobial and improve insight into a likely mechanism linking infection to CS exposure.