The honeybee as a model insect for developmental genetics

Abstract

Honeybees are an important component of modern agricultural systems, and a fascinating and scientifically engrossing insect. Honeybees are not commonly used as model systems for understanding development in insects despite their importance in agriculture. Honeybee embryogenesis, while being superficially similar to Drosophila, is molecularly very different, especially in axis formation and sex determination. In later development, much of honeybee biology is modified by caste development, an as yet poorly understood, but excellent, system to study developmental plasticity. In adult stages, developmental plasticity of the ovaries, related to reproductive constraint exhibits another aspect of plasticity. Here they review the tools, current knowledge and opportunities in honeybee developmental biology, and provide an updated embryonic staging scheme to support future studies.

The ovary and its genes—developmental processes underlying the establishment and function of a highly divergent reproductive system in the female castes of the honey bee, Apis mellifera

“…In fact, for thorough information, one must go back to studies done in the early twentieth century (Nelson 1915;Schnetter 1935), followed later by detailed descriptions of embryonic stages (DuPraw 1967;Sander 1986, 1988). Fortunately, this has somewhat changed once the fully sequenced honey bee genome became available, making possible in-depth comparisons with Drosophila embryonic development (Cridge et al 2017). Embryonic development has since came under scrutiny primarily with respect to axial patterning, segmentation and Hox genes (Walldorf et al 2000;Dearden et al 2006;Wilson et al 2010), as well as microRNAs regulating such patterning genes (Freitas et al 2017).…”

“…While the prospective germ cells in Drosophila become clearly distinguishable at this stage at the posterior pole of the blastoderm embryo, dependent on pole plasm factors (Mahowald 1962), no evidence was found for such pole plasm determinants in the honey bee (Nelson 1915;DuPraw 1967), even though most of the genes encoding pole cell components involved in Drosophila germ cell determination have homologs in the honey bee genome (Dearden et al 2006). Hence, the mode of germline specification is thought to be quite distinct from that of Drosophila and in fact guided by epigenetic factors (Dearden 2006;Cridge et al 2017). The next developmental step then is the migration towards and arrival and integration of the primordial germline cells in the somatic (mesodermal) gonad.…”

Development of a film-assisted honeybee egg collection system (FECS)

“…The FECS can be also employed in honeybee developmental biology. In honeybees, the location and timing of germ cell development are still unclear, as are the exact mitotic cycles of embryos (Dearden 2006;Pires et al 2016;Cridge et al 2017). As the transparent nature of the film enables real-time observation of egg laying from the backside of the comb box, researchers can easily record or mark eggs, thereby allowing collection of a large quantity of eggs with known ages.…”

Honey bee as an alternative model invertebrate organism

“…W przypadku pszczół miodnych nie bez znaczenia pozostaje również fakt, że rozwój larw następuje poza ciałem matki, co pozwala na obserwację i wykonywanie analiz organizmu pszczelego na każdym etapie jego rozwoju (94). Uważa się więc, że badania nad plastycznością fenotypową u owadów będą doskonałą bazą dla łatwiejszego zrozumienia mechanizmów epigenetycznych ludzi (29). Szczególnie istotne jest wykorzystanie pszczół miodnych jako narzędzia w rozwoju diagnostyki chorób o podłożu zaburzeń epigenomu.…”