14-3-3ε Is Required for Germ Cell Migration in Drosophila

Although 14-3-3 proteins participate in multiple biological processes, isoform-specific specialized functions, as well as functional redundancy are emerging with tissue and developmental stage-specificity. Accordingly, the two 14-3-3ε proteins in Drosophila exhibit functional specificity and redundancy. Homozygotes for loss of function alleles of D14-3-3ε contain significantly fewer germ line cells (pole cells) in their gonads, a phenotype not shared by mutants in the other 14-3-3 gene leo. We show that although D14-3-3ε is enriched within pole cells it is required in mesodermal somatic gonad precursor cells which guide pole cells in their migration through the mesoderm and coalesce with them to form the embryonic gonad. Loss of D14-3-3ε results in defective pole cell migration, reduced pole cell number. We present evidence that D14-3-3ε loss results in reduction or loss of the transcription factor Zfh-1, one of the main regulatory molecules of the pole cell migration, from the somatic gonad precursor cells

Positional Cues in the Drosophila Nerve Cord: Semaphorins Pattern the Dorso-Ventral Axis

Positional cues target sensory axons to appropriate volumes of the developing nervous system independently of their synaptic partners

Coe Genes Are Expressed in Differentiating Neurons in the Central Nervous System of Protostomes

Genes of the coe (collier/olfactory/early B-cell factor) family encode Helix-Loop-Helix transcription factors that are widely conserved in metazoans and involved in many developmental processes, neurogenesis in particular. Whereas their functions during vertebrate neural tube formation have been well documented, very little is known about their expression and role during central nervous system (CNS) development in protostomes. Here we characterized the CNS expression of coe genes in the insect Drosophila melanogaster and the polychaete annelid Platynereis dumerilii, which belong to different subgroups of protostomes and show strikingly different modes of development. In the Drosophila ventral nerve cord, we found that the Collier-expressing cells form a subpopulation of interneurons with diverse molecular identities and neurotransmitter phenotypes. We also demonstrate that collier is required for the proper differentiation of some interneurons belonging to the Eve-Lateral cluster. In Platynereis dumerilii, we cloned a single coe gene, Pdu-coe, and found that it is exclusively expressed in post mitotic neural cells. Using an original technique of in silico 3D registration, we show that Pdu-coe is co-expressed with many different neuronal markers and therefore that, like in Drosophila, its expression defines a heterogeneous population of neurons with diverse molecular identities. Our detailed characterization and comparison of coe gene expression in the CNS of two distantly-related protostomes suggest conserved roles of coe genes in neuronal differentiation in this clade. As similar roles have also been observed in vertebrates, this function was probably already established in the last common ancestor of all bilaterians

Posttraumatic Stress Disorder and the Risk of Respiratory Problems in World Trade Center Responders: Longitudinal Test of a Pathway

Objective: Posttraumatic stress disorder (PTSD) is associated with high medical morbidity, but the nature of this association remains unclear. Among responders to the World Trade Center (WTC) disaster, PTSD is highly comorbid with lower respiratory symptoms (LRS), which cannot be explained by exposure alone. We sought to examine this association longitudinally to establish the direction of the effects and evaluate potential pathways to comorbidity. Methods: 18,896 responders (8466 police and 10,430 nontraditional responders) participating in the WTC-Health Program were first evaluated between 2002 and 2010 and assessed again 2.5 years later. LRS were ascertained by medical staff, abnormal pulmonary function by spirometry, and probable WTC-related PTSD with a symptom inventory. Results: In both groups of responders, initial PTSD (standardized regression coefficient: beta = 0.20 and 0.23) and abnormal pulmonary function (beta = 0.12 and 0.12) predicted LRS 2.5 years later after controlling for initial LRS and covariates. At follow-up, LRS onset was 2.0 times more likely and remission 1.8 times less likely in responders with initial PTSD than in responders without. Moreover, PTSD mediated, in part, the association between WTC exposures and development of LRS (p \u3c .0001). Initial LRS and abnormal pulmonary function did not consistently predict PTSD onset. Conclusions: These analyses provide further evidence that PTSD is a risk factor for respiratory symptoms and are consistent with evidence implicating physiological dysregulation associated with PTSD in the development of medical conditions. If these effects are verified experimentally, treatment of PTSD may prove helpful in managing physical and mental health of disaster responders