Transcriptional and genomic parallels between the monoxenous parasite Herpetomonas muscarum and Leishmania

Trypanosomatid parasites are causative agents of important human and animal diseases such as sleeping sickness and leishmaniasis. Most trypanosomatids are transmitted to their mammalian hosts by insects, often belonging to Diptera (or true flies). These are called dixenous trypanosomatids since they infect two different hosts, in contrast to those that infect just insects (monoxenous). However, it is still unclear whether dixenous and monoxenous trypanosomatids interact similarly with their insect host, as fly-monoxenous trypanosomatid interaction systems are rarely reported and under-studied–despite being common in nature. Here we present the genome of monoxenous trypanosomatid Herpetomonas muscarum and discuss its transcriptome during in vitro culture and during infection of its natural insect host Drosophila melanogaster. The H. muscarum genome is broadly syntenic with that of human parasite Leishmania major. We also found strong similarities between the H. muscarum transcriptome during fruit fly infection, and those of Leishmania during sand fly infections. Overall this suggests Drosophila-Herpetomonas is a suitable model for less accessible insect-trypanosomatid host-parasite systems such as sand fly-Leishmania

Sleep oscillations and aging

Human sleep can be broadly categorized as rapid eye movement (REM) and non-REM (NREM) sleep according to the electrophysiological features and oscillations that characterize these distinct states. The most dramatic changes that occur to sleep are observed over the course of the life span. With aging, the neural oscillations of sleep may provide insight into the physiological changes that accompany aging, may signal poor health and pathology, and explain functional changes in daytime performance, learning, and memory. This review will discuss the age-related changes that occur to the neural oscillations that characterize sleep states, such as sleep spindles, k-complexes, slow waves, and REM-related neural activity. The physiological processes that underlie these changes and the functional significance of the age-related changes in sleep are discussed