Project description:The Formosan subterranean termite (Coptotermes formosanus) and the Asian subterranean termite (Coptotermes gestroi) are the most destructive termite pests in the world. Both species have spread to various regions worldwide with overlapping distributions in a few areas in which pre- and post-zygotic barriers against hybridization between the two species have been lifted. Although initial colony growth rates of hybrid colonies are similar to those of the parental species, colony growth appears to slow down in the hybrids after several years. Observations suggest that workers in hybrid colonies are slower to molt than those of the parental species, suggesting a disruption in this process. To understand the comprehensive gene expression profiles during the molting cycle of workers, differential gene expression profiles based on RNA-seq analysis were recorded for four mating combinations (2 conspecific workers and 2 heterospecific workers) at three different molting periods (pre-, post- and inter-molt). Many differentially expressed genes were identified between heterospecific and conspecific matings at each molting stage as well as within termite species among molting periods. We successfully identified molting-related genes by characterizing gene expression profiles of the parental species during the molting cycle conducting a time course analysis of transcriptome data. We then compared expression levels of these molting-related genes in the hybrids to identify genes that were over or under expressed compared to the parental species. Genes related to the molting cycle, muscle contraction, response to stress, and ecdysone metabolism were found to be under-expressed in hybrids relative to their parents. These differences will help elucidate the stability and fitness of hybrids between these two Coptotermes species. Moreover, identification of molting related genes in subterranean termites highlights the molecular pathways involved in the molting process in termites.
Project description:Examination of aging in social insects. Differential gene expression between old and young individuals of four castes of the termite Macrotermes bellicosus. Minor workers, major workers, kings, queens. Collected in January 2015 in Ivory Coast.
Project description:The genus Macrolepiota (Agaricales, Basidiomycota) is easy to recognize at the genus level because of big, fleshy basidiocarps with squamules covering the pileus; a single or double annulus; and big, thick-walled basidiospores with a germ pore. However, morphological identification is often unreliable in Macrolepiota due to similar morphological features among species. Due to the uncertainty of previous morphological identification in the genus Macrolepiota, it is necessary to re-examine Korean Macrolepiota using molecular data. We re-examined 34 Macrolepiota specimens collected from 2012 to 2018 in Korea using a reverse taxonomic approach, whereby species identification was first done based on the internal transcribed spacer (ITS) region analysis, followed by morphological confirmation. We identified the presence of four species: M. detersa, M. mastoidea, M. procera, and M. umbonata sp. nov. Two species (M. detersa and M. mastoidea) were previously unrecorded from Korea and M. umbonata is a new species. Detailed descriptions of all four species and taxonomic key are provided in this study. Macrolepiota procera and M. umbonata are distributed through the country, but M. detersa and M. mastoidea are distributed only in limited areas. According to our results, the combination of ITS locus and morphology proved to be a robust approach to evaluate the taxonomic status of Macrolepiota species in Korea. Additional surveys are needed to verify the species diversity and clarify their geographic distribution.
Project description:Temperature preference behavior in Drosophila depends on the level of PKA signaling in the mushroom bodies. To identify new components downstream to PKA, we carried out a genome-wide screen for genes regulated by PKA signaling in the mushroom bodies. Using the Gal4-UAS system, we increased or decreased PKA activity in the mushroom bodies by expressing dominant-negative (UAS-PKADN) or constitutively active PKA (UAS-PKACA), respectively. Expression of PKA transgenes was targeted to the mushroom bodies using the mushroom body-specific MB247-Gal4 driver. PKA expression was induced for 12-16 hours in three-day-old adults by inactivating the temperature-sensitive Gal80 at the restrictive temperature. We then analyzed gene-expression profiles to identify the genes showing altered expression levels in response to the high or low PKA activity.