Project description:In honey bees, Vitellogenin (Vg) is hypothesized to be a major factor affecting hormone signaling, food-related behavior, immunity, stress resistance and lifespan. Likewise microRNAs play important roles in posttranscriptional gene regulation and affect many biological processes thereby showing many parallels to Vg functions. The molecular basis of Vg and microRNA interactions is largely unknown. Here, we exploited the well-established RNA interference (RNAi) protocol for Vg knockdown to investigate its effects on microRNA population in honey bee forager’s brain and fat body tissue. To identify microRNAs that are differentially expressed between tissues in control and knockdown foragers, we used µParaflo® microfluidic oligonucleotide microRNA microarrays. Our results show 76 and 74 miRNAs were expressed in the brain of control and knockdown foragers whereas 66 and 69 miRNAs were expressed in the fat body of control and knockdown foragers respectively. Target prediction identified potential seed matches for differentially expressed subset of microRNAs affected by Vg knockdown. These candidate genes are involved in a broad range of biological processes including insulin signaling, juvenile hormone (JH) and ecdysteroid signaling previously shown to affect foraging behavior. Thus, here we demonstrate a causal link between Vg expression-variation and variation in the abundance of microRNAs in different tissues with possible consequences for regulation of foraging behavior.
Project description:In honey bees, Vitellogenin (Vg) is hypothesized to be a major factor affecting hormone signaling, food-related behavior, immunity, stress resistance and lifespan. Likewise microRNAs play important roles in posttranscriptional gene regulation and affect many biological processes thereby showing many parallels to Vg functions. The molecular basis of Vg and microRNA interactions is largely unknown. Here, we exploited the well-established RNA interference (RNAi) protocol for Vg knockdown to investigate its effects on microRNA population in honey bee forager’s brain and fat body tissue. To identify microRNAs that are differentially expressed between tissues in control and knockdown foragers, we used µParaflo® microfluidic oligonucleotide microRNA microarrays. Our results show 76 and 74 miRNAs were expressed in the brain of control and knockdown foragers whereas 66 and 69 miRNAs were expressed in the fat body of control and knockdown foragers respectively. Target prediction identified potential seed matches for differentially expressed subset of microRNAs affected by Vg knockdown. These candidate genes are involved in a broad range of biological processes including insulin signaling, juvenile hormone (JH) and ecdysteroid signaling previously shown to affect foraging behavior. Thus, here we demonstrate a causal link between Vg expression-variation and variation in the abundance of microRNAs in different tissues with possible consequences for regulation of foraging behavior.
Project description:The western honey bee (Apis mellifera) often encounters chemical stressors in the form of phytochemicals, or pesticide residues. The first line of defense against these agrochemicals is constitutively expressed detoxification enzymes such as cytochrome P450s.Honey bees with lower levels of constitutively expressed enzymes experience greater immediate stress, which can lead to death, sub-lethal effects, and precocious foraging, if nursing. Precocious foragers are young, less developed honey bees that are recruited into the foraging population, whereas normal-aged foragers are much older. These precocious foragers are less capable flyers, and are more likely to die during their flights, which can in turn further stress the colony due to reduced food stores. In our study, we hypothesize that chemical stress sensitivity is directly linked to the onset of precocious foraging. Additionally, we believe that precocious foragers are less suited for foraging due to their rushed development, and are likely more transcriptionally similar to nurses instead of older foragers. We measured the survival of honey bees taken from 26 different colonies when exposed to a chemical stressor over 48 hours. Honey bees from each of these colonies were also all added to the same colony, and we measured the age and number of foragers from each colony over a 2-week period. Lastly, we performed transcriptomics of young and old nurses and foragers. Our results suggest that chemical stress tolerance was linked to the honey bee’s origin colony. Moreover, we found no significant correlation of the honey bees’ chemical tolerance to the age at which they began foraging. Rather, we found that bees from more tolerant colonies exhibited lower volumes of foraging by two weeks. Furthermore, transcriptomic analysis showed that precocious foragers exhibited global gene expression patterns more closely aligned with nurses than with older foragers, reinforcing age as the primary determinant of gene expression profiles. Susceptible bees displayed distinct expression profiles compared to more tolerant ones across different life stages, with notable overlap in genes encoding cytochrome P450e and a vitellogenin receptor, highlighting their potential roles in stress response and behavioral maturation.
Project description:Single-nucleus and spatial transcriptome identify brain landscape of gene regulatory networks associated with behavioral maturation in honeybees
Project description:Single-nucleus and spatial transcriptome identify brain landscape of gene regulatory networks associated with behavioral maturation in honeybees
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.
Project description:Apis mellifera intermissa (Buttel-Reepen, 1906) is the native honeybee subspecies of Algeria. A.m.intermissa occurs in Tunisia, Algeria and Morocco, between the Atlas and the Mediterranean and Atlantic coasts (Ruttner, 1988), in an area of more than 2500 km long. Intermissa indicates the position through this bee races between tropical Africa and European breeds (Peyvel, 1994). The settlement area of the Tellian extends from Tunisia to Morocco. Ruttner et al (1978) describes the pure Tellian. It is a black hair of his coat poverty brings out the black color. It is a small size, there are some times light illumination on the tergites. This bee is very aggressive, nervous, sick to take part, as swarms huge fall and even produced many brood and can build up to one hundred queen cells (Le Conte, 2002). A.m.intermissa is prone to swarming, shows an aggressive behaviour and an abundant use of propolis (Ruttner 1988). This study is part of the project funded by the USAID Grant No. TA-MOU-08-M29-075.