Abstract
Phenotypic plasticity is a hallmark of the caste systems of social insects, expressed in their life history and morphological traits. These are best studied in bees. In their co-evolution with angiosperm plants, the females of corbiculate bees have acquired a specialized structure on their hind legs for collecting pollen. In the highly eusocial bees (Apini and Meliponini), this structure is however only present in workers and absent in queens. By means of histological sections and cell proliferation analysis we followed the developmental dynamics of the hind legs of queens and workers in the fourth and fifth larval instars. In parallel, we generated subtractive cDNA libraries for hind leg discs of queen and worker larvae by means of a Representational Difference Analysis (RDA). From the total of 135 unique sequences we selected 19 for RT-qPCR analysis, where six of these were confirmed as differing significantly in their expression between the two castes in the larval spinning stage. The development of complex structures such as the bees’ hind legs, requires diverse patterning mechanisms and signaling modules, as indicated by the set of differentially expressed genes related with cell adhesion and signaling pathways.
Highlights
Within the framework of a relatively fixed body plan, winged insects have become the most species-rich group in terrestrial ecosystems, especially so the holometalous orders, which have made their appearance about 350 mya (Misof et al, 2014)
This study investigated the localization pattern for two homeobox proteins, the honey bee Ultrabithorax (Ubx) and Abdominal A (AbdA) homologs, in the developing hind legs of honey bee pupae, showing Ubx-free spots in the tibia epidermis of worker pupae where the characteristic corbicula bristles are expected to be formed (Bomtorin et al, 2012)
As to further our understanding of the processes underlying the complex structural difference in the hind legs of queens and workers, we addressed this question through a histological analysis on the development of their hind legs throughout the critical stages of postembryonic development
Summary
Within the framework of a relatively fixed body plan, winged insects have become the most species-rich group in terrestrial ecosystems, especially so the holometalous orders, which have made their appearance about 350 mya (Misof et al, 2014). While most of the hymenopteran species and families have a carnivorous or parasitic life style, bees have switched to a plant-based diet, in pollen and nectar. This switch, which is thought to have occurred in the early-to-mid Cretaceous (Michener, 2007), represents a major lifestyle novelty within this group, and prompted a very strong co-evolutionary relationship with angiosperm plants. Are bees the major pollinators of angiosperm plants and, by doing so, guarantee the biodiversity of most terrestrial ecosystems, they nowadays provide multibillion dollar ecosystem services to agriculture worldwide. Most of the high value crops (fruits, nuts, legumes) are strongly dependent on pollina-
Sign-in/Register to view highlights & summary Sign-in/Register to access full text options 
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a callDisclaimer: All third-party content on this website/platform is and will remain the property of their respective owners and is provided on "as is" basis without any warranties, express or implied. Use of third-party content does not indicate any affiliation, sponsorship with or endorsement by them. Any references to third-party content is to identify the corresponding services and shall be considered fair use under The CopyrightLaw.
