Project description:The exoskeleton gives to insects its shape, waterproofing and a range of other roles, besides serving as means of locomotion, the motor function being accomplished by the attachment of somatic muscles. Exoskeleton is renewed every time the insect molts under the control of ecdysteroid hormones. The last molt, which in the holometabolous transforms pupae in adults, involves biosynthesis of the definitive exoskeleton by the subjacent epidemis, followed by progressive differentiation. We used whole genome-based oligonucleotide microarray hybridization and RNA extracted from the honey bee thoracic dorsum, at three time-points of the pupal-to-adult molt, as a strategy to screen genes involved in exoskeleton formation. Gene ontology analysis separated the differentially expressed genes (DEGs) in distinct Biological Processes and Molecular Functions dependently on the time-point approached, thus revealing the functional categories required for adult exoskeleton formation. Approximately 546 of a list of 1253 unique DEGs were up-regulated in the thoracic dorsum during adult cuticle formation, including 23 among the 24 identified cuticle protein (CP) genes, and 29 muscle-related genes. Conserved sequence motifs allowed to include the CP genes in the CPR, Tweedle, Apidermin, CPF, CPLCP1 and Analogous-to-Peritrophins families. Two genes, which do not pertain to any known CP families, were abundantly expressed in the epidermis during adult cuticle formation as shown by in situ hybridization, thus strongly suggesting that they are genuine CP genes. The search for cis-regulatory motifs in the 5’untranslated region of the DEGs revealed potential binding sites for known transcript factors. Several of them were shared by CP genes and thoracic muscle genes, thus allowing to infer that they are co-regulated during differentiation of the thoracic exoskeleton. Together, these data add new information on molecular aspects of exoskeleton formation in the context of the ecdysteroid-coordinated pupal-to-adult molt.
Project description:The exoskeleton gives to insects its shape, waterproofing and a range of other roles, besides serving as means of locomotion, the motor function being accomplished by the attachment of somatic muscles. Exoskeleton is renewed every time the insect molts under the control of ecdysteroid hormones. The last molt, which in the holometabolous transforms pupae in adults, involves biosynthesis of the definitive exoskeleton by the subjacent epidemis, followed by progressive differentiation. We used whole genome-based oligonucleotide microarray hybridization and RNA extracted from the honey bee thoracic dorsum, at three time-points of the pupal-to-adult molt, as a strategy to screen genes involved in exoskeleton formation. Gene ontology analysis separated the differentially expressed genes (DEGs) in distinct Biological Processes and Molecular Functions dependently on the time-point approached, thus revealing the functional categories required for adult exoskeleton formation. Approximately 546 of a list of 1253 unique DEGs were up-regulated in the thoracic dorsum during adult cuticle formation, including 23 among the 24 identified cuticle protein (CP) genes, and 29 muscle-related genes. Conserved sequence motifs allowed to include the CP genes in the CPR, Tweedle, Apidermin, CPF, CPLCP1 and Analogous-to-Peritrophins families. Two genes, which do not pertain to any known CP families, were abundantly expressed in the epidermis during adult cuticle formation as shown by in situ hybridization, thus strongly suggesting that they are genuine CP genes. The search for cis-regulatory motifs in the 5M-bM-^@M-^Yuntranslated region of the DEGs revealed potential binding sites for known transcript factors. Several of them were shared by CP genes and thoracic muscle genes, thus allowing to infer that they are co-regulated during differentiation of the thoracic exoskeleton. Together, these data add new information on molecular aspects of exoskeleton formation in the context of the ecdysteroid-coordinated pupal-to-adult molt. The microarray experiments compared differential gene expression in the thoracic integuments of newly-ecdysed pupae (Pw phase), pupae-in-apolysis (Pp phase) and pharate-adults (Pbl phase) collected at the same time from a single honey bee colony. Two separate pools of 10 thoracic integuments each were prepared for each developmental phase (Pw, Pp and Pbl). Dye swaps were done for each comparison and two slides were used to evaluate the differential expression.
Project description:We analyzed the changes in the brain tissue of Apis mellifera ligustica at the molecular level by sequencing after using fluvalinate. We found that the differentially expressed miRNAs (DEM) may be involved in hippocampal cell apoptosis and damage to memory functions. This result may be related to behaviors observed after the administration of this medication, such as a lack of homing at night and behavioral disturbances. Overall, our results provide new information about the molecular mechanisms and pathways of fluvalinate action in the brain tissue of Apis mellifera ligustica.
Project description:Apis mellifera syriaca is the native honeybee subspecies of Jordan and much of the Middle East. It expresses behavioral adaptations to a regional climate with very high temperatures, nectar dearth in summer, attacks of the Oriental wasp Vespa orientalis and in most cases it is resistant to varroa mites. The Thorax control sample of A. m. syriaca in this experiment was originally collected and stored since 2001 from Wadi Ben Hammad a remote valley in the southern region of Jordan. Using morphometric and Mitochondrial DNA markers it was proved that bees from this area had show higher similarity than other samples collected from the Middle East as represented by reference samples collected in 1952 by Brother Adam. The samples L1-L5 are collected from the National Center for Agricultural Research and Extension breading apiary which was originally established for the conservation of Apis mellifera syriaca. Goal was to use the genetic information in the breeding for varroa resistant bees and to determine the successfulness of this conservation program. Project funded by USAID-MERC grant number: TA-MOU-09-M29-075.