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

Abstract

The strong dimorphism in ovary phenotype seen between honey bee queens and workers represents the anatomical fixation of reproductive division of labor. We review the developmental processes by which the divergent ovary phenotypes become established, mainly focusing on the massive programmed cell death (PCD) that destroys most of the ovariole primordia in the worker ovary during larval development. Ovary-specific transcriptome analyses revealed a set of differentially expressed genes associated with PCD, including two long noncoding RNAs. PCD also plays a major role regulating ovarian activity in adult honey bee workers, and a major effect candidate gene mediating this process is Anarchy , previously identified through classical genetics in a rebel worker strain. Finally, we ask how the strong ovary phenotype dimorphism in the genus Apis may have evolved, and we discuss this by contrasting honey bees with the equally eusocial stingless bees. Through a comparison of their mating systems (polyandry versus monandry), as well as comparative data on female and male gonad structure across several families of bees, we propose the hypothesis that the exceptional gonad structure in Apis queens and drones evolved via shared developmental pathways. Furthermore, we suggest that selection on massive sperm production in Apis drones may have been a driving force leading to this exaggerated gonad morphology. honeybee / gonad development / cell death / differential gene expression / meliponids Where does the spirit of the hive reside? At least to some extent it is in the ovaries of a crowd of bees working in a dark hive (Robert E.

Uncovering the Changing Gene Expression Profile of Honeybee (Apis mellifera) Worker Larvae Transplanted to Queen Cells

“…The food that the queen larvae and worker larvae receive differs significantly in terms of fat, sugar, and protein contents after the first 3 days ( Shuel and Dixon, 1960 ). Therefore, several studies have focused on genetic differences in queen and worker larvae caused by external factors after the age of 3 days ( Zhu et al, 2017 ; Hartfelder et al, 2018 ), ignoring the influence of the external environment on the development of larvae within the first 3 days. It was found that during queen breeding, the age of the transplanted worker larvae had a significant influence on the development of queen bees, affecting the quality of the queen.…”

Analysis of the Drosophila melanogaster anti‐ovarian response to honey bee queen mandibular pheromone

“…Finally, the ovary receives the signal, which suppresses oogenesis. Proposed mechanisms of suppression in the honey bee are the activation of the Notch pathway (Duncan et al, 2016) and activation of apoptosis (Ronai et al, 2016;Hartfelder et al 2017). Future work will entail further dissection of the olfactory receptors required for QMP reception and the mechanism of perception.…”

Brain microRNAs among social and solitary bees

“…The presence of this miRNA in the solitary bee genomes suggests that an evolutionary shift in expression pattern may have accompanied at least two independent origins of eusociality in bees. This miRNA coordinates Insulin and Notch signalling in D. melanogaster, both of which are important regulators of social dynamics in insects [50][51][52]. Interestingly, miR-305 is also upregulated in workerdestined compared with queen-destined honeybee larvae, and may thus play a role in caste differentiation [20].…”