1
|
Martins JR, Silva IC, Mazzoni TS, de Barrios GH, Freitas FCDP, Barchuk AR. Minibrain plays a role in the adult brain development of honeybee (Apis mellifera) workers. INSECT MOLECULAR BIOLOGY 2024. [PMID: 39167296 DOI: 10.1111/imb.12955] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/01/2024] [Accepted: 08/04/2024] [Indexed: 08/23/2024]
Abstract
The brain of adult honeybee (Apis mellifera) workers is larger than that of queens, facilitating behavioural differentiation between the castes. This brain diphenism develops during the pharate-adult stage and is driven by a caste-specific gene expression cascade in response to unique hormonal milieus. Previous molecular screening identified minibrain (mnb; DYRK1A) as a potential regulator in this process. Here, we used RNAi approach to reduce mnb transcript levels and test its role on brain diphenism development in honeybees. White-eyed unpigmented cuticle worker pupae were injected with dsRNA for mnb (Mnb-i) or gfp, and their phenotypes were assessed two and 8 days later using classic histological and transcriptomic analyses. After 2 days of the injections, Mnb-i bees showed 98% of downregulation of mnb transcripts. After 8 days, the brain of Mnb-i bees showed reduction in total volume and in the volume of the mushroom bodies (MB), antennal, and optic lobes. Additionally, signs of apoptosis were observed in the Kenyon cells region of the MB, and the cohesion of the brain tissues was affected. Our transcriptomic analyses revealed that 226 genes were affected by the knockdown of mnb transcripts, most of which allowing axonal fasciculation. These results suggest the evolutionary conserved mnb gene has been co-opted for promoting hormone-mediated developmental brain morphological plasticity generating caste diphenism in honeybees.
Collapse
Affiliation(s)
- Juliana Ramos Martins
- Departamento de Biologia Celular e do Desenvolvimento, Instituto de Ciências Biomédicas, Universidade Federal de Alfenas, UNIFAL-MG, Alfenas, Minas Gerais, Brazil
| | - Izabella Cristina Silva
- Departamento de Genética e Evolução, Centro de Ciências Biológicas e da Saúde, Universidade Federal de São Carlos, UFScar, São Carlos, São Paulo, Brazil
| | - Talita Sarah Mazzoni
- Departamento de Biologia Celular e do Desenvolvimento, Instituto de Ciências Biomédicas, Universidade Federal de Alfenas, UNIFAL-MG, Alfenas, Minas Gerais, Brazil
| | - Gabriela Helena de Barrios
- Departamento de Biologia Celular e do Desenvolvimento, Instituto de Ciências Biomédicas, Universidade Federal de Alfenas, UNIFAL-MG, Alfenas, Minas Gerais, Brazil
| | - Flávia Cristina de Paula Freitas
- Departamento de Genética e Evolução, Centro de Ciências Biológicas e da Saúde, Universidade Federal de São Carlos, UFScar, São Carlos, São Paulo, Brazil
| | - Angel Roberto Barchuk
- Departamento de Biologia Celular e do Desenvolvimento, Instituto de Ciências Biomédicas, Universidade Federal de Alfenas, UNIFAL-MG, Alfenas, Minas Gerais, Brazil
| |
Collapse
|
2
|
Kittelmann M, McGregor AP. Looking across the gap: Understanding the evolution of eyes and vision among insects. Bioessays 2024; 46:e2300240. [PMID: 38593308 DOI: 10.1002/bies.202300240] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/15/2023] [Revised: 02/29/2024] [Accepted: 03/05/2024] [Indexed: 04/11/2024]
Abstract
The compound eyes of insects exhibit stunning variation in size, structure, and function, which has allowed these animals to use their vision to adapt to a huge range of different environments and lifestyles, and evolve complex behaviors. Much of our knowledge of eye development has been learned from Drosophila, while visual adaptations and behaviors are often more striking and better understood from studies of other insects. However, recent studies in Drosophila and other insects, including bees, beetles, and butterflies, have begun to address this gap by revealing the genetic and developmental bases of differences in eye morphology and key new aspects of compound eye structure and function. Furthermore, technical advances have facilitated the generation of high-resolution connectomic data from different insect species that enhances our understanding of visual information processing, and the impact of changes in these processes on the evolution of vision and behavior. Here, we review these recent breakthroughs and propose that future integrated research from the development to function of visual systems within and among insect species represents a great opportunity to understand the remarkable diversification of insect eyes and vision.
Collapse
Affiliation(s)
- Maike Kittelmann
- Department of Biological and Medical Sciences, Oxford Brookes University, Oxford, UK
| | | |
Collapse
|
3
|
Beer K, Härtel S, Helfrich-Förster C. The pigment-dispersing factor neuronal network systematically grows in developing honey bees. J Comp Neurol 2021; 530:1321-1340. [PMID: 34802154 DOI: 10.1002/cne.25278] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/13/2020] [Revised: 10/25/2021] [Accepted: 11/11/2021] [Indexed: 11/08/2022]
Abstract
The neuropeptide pigment-dispersing factor (PDF) plays a prominent role in the circadian clock of many insects including honey bees. In the honey bee brain, PDF is expressed in about 15 clock neurons per hemisphere that lie between the central brain and the optic lobes. As in other insects, the bee PDF neurons form wide arborizations in the brain, but certain differences are evident. For example, they arborize only sparsely in the accessory medulla (AME), which serves as important communication center of the circadian clock in cockroaches and flies. Furthermore, all bee PDF neurons cluster together, which makes it impossible to distinguish individual projections. Here, we investigated the developing bee PDF network and found that the first three PDF neurons arise in the third larval instar and form a dense network of varicose fibers at the base of the developing medulla that strongly resembles the AME of hemimetabolous insects. In addition, they send faint fibers toward the lateral superior protocerebrum. In last larval instar, PDF cells with larger somata appear and send fibers toward the distal medulla and the medial protocerebrum. In the dorsal part of the medulla serpentine layer, a small PDF knot evolves from which PDF fibers extend ventrally. This knot disappears during metamorphosis and the varicose arborizations in the putative AME become fainter. Instead, a new strongly stained PDF fiber hub appears in front of the lobula. Simultaneously, the number of PDF neurons increases and the PDF neuronal network in the brain gets continuously more complex.
Collapse
Affiliation(s)
- Katharina Beer
- Department of Neurobiology and Genetics, Biocenter, University of Würzburg, Würzburg, Germany
| | - Stephan Härtel
- Department of Animal Ecology and Tropical Biology, Biocenter, University of Würzburg, Würzburg, Germany
| | | |
Collapse
|
4
|
He XJ, Jiang WJ, Zhou M, Barron AB, Zeng ZJ. A comparison of honeybee (Apis mellifera) queen, worker and drone larvae by RNA-Seq. INSECT SCIENCE 2019; 26:499-509. [PMID: 29110379 DOI: 10.1111/1744-7917.12557] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/12/2017] [Revised: 09/08/2017] [Accepted: 09/28/2017] [Indexed: 06/07/2023]
Abstract
Honeybees (Apis mellifera) have haplodiploid sex determination: males develop from unfertilized eggs and females develop from fertilized ones. The differences in larval food also determine the development of females. Here we compared the total somatic gene expression profiles of 2-day and 4-day-old drone, queen and worker larvae by RNA-Seq. The results from a co-expression network analysis on all expressed genes showed that 2-day-old drone and worker larvae were closer in gene expression profiles than 2-day-old queen larvae. This indicated that for young larvae (2-day-old) environmental factors such as larval diet have a greater effect on gene expression profiles than ploidy or sex determination. Drones had the most distinct gene expression profiles at the 4-day larval stage, suggesting that haploidy, or sex dramatically affects the gene expression of honeybee larvae. Drone larvae showed fewer differences in gene expression profiles at the 2-day and 4-day time points than the worker and queen larval comparisons (598 against 1190 and 1181), suggesting a different pattern of gene expression regulation during the larval development of haploid males compared to diploid females. This study indicates that early in development the queen caste has the most distinct gene expression profile, perhaps reflecting the very rapid growth and morphological specialization of this caste compared to workers and drones. Later in development the haploid male drones have the most distinct gene expression profile, perhaps reflecting the influence of ploidy or sex determination on gene expression.
Collapse
Affiliation(s)
- Xu-Jiang He
- Honeybee Research Institute, Jiangxi Agricultural University, Nanchang, China
| | - Wu-Jun Jiang
- Honeybee Research Institute, Jiangxi Agricultural University, Nanchang, China
| | - Mi Zhou
- Biomarker Technologies Co., Ltd., Beijing, China
| | - Andrew B Barron
- Department of Biological Sciences, Macquarie University, North Ryde, NSW, Australia
| | - Zhi-Jiang Zeng
- Honeybee Research Institute, Jiangxi Agricultural University, Nanchang, China
| |
Collapse
|
5
|
Lichtenstein L, Grübel K, Spaethe J. Opsin expression patterns coincide with photoreceptor development during pupal development in the honey bee, Apis mellifera. BMC DEVELOPMENTAL BIOLOGY 2018; 18:1. [PMID: 29382313 PMCID: PMC5791347 DOI: 10.1186/s12861-018-0162-8] [Citation(s) in RCA: 15] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 10/04/2017] [Accepted: 01/16/2018] [Indexed: 12/12/2022]
Abstract
Background The compound eyes of insects allow them to catch photons and convert the energy into electric signals. All compound eyes consist of numerous ommatidia, each comprising a fixed number of photoreceptors. Different ommatidial types are characterized by a specific set of photoreceptors differing in spectral sensitivity. In honey bees, males and females possess different ommatidial types forming distinct retinal mosaics. However, data are lacking on retinal ontogeny and the mechanisms by which the eyes are patterned. In this study, we investigated the intrinsic temporal and circadian expression patterns of the opsins that give rise to the ultraviolet, blue and green sensitive photoreceptors, as well as the morphological maturation of the retina during pupal development of honey bees. Results qPCR and histological labeling revealed that temporal opsin mRNA expression differs between sexes and correlates with rhabdom elongation during photoreceptor development. In the first half of the pupal stage, when the rhabdoms of the photoreceptors are still short, worker and (dorsal) drone retinae exhibit similar expression patterns with relatively high levels of UV (UVop) and only marginal levels of blue (BLop) and green (Lop1) opsin mRNA. In the second half of pupation, when photoreceptors and rhabdoms elongate, opsin expression in workers becomes dominated by Lop1 mRNA. In contrast, the dorsal drone eye shows high expression levels of UVop and BLop mRNA, whereas Lop1 mRNA level decreases. Interestingly, opsin expression levels increase up to 22-fold during early adult life. We also found evidence that opsin expression in adult bees is under the control of the endogenous clock. Conclusions Our data indicate that the formation of the sex-specific retinal composition of photoreceptors takes place during the second half of the pupal development, and that opsin mRNA expression levels continue to increase in young bees, which stands in contrast to Drosophila, where the highest expression levels are found during the late pupal stage and remain constant in adults. From an evolutionary perspective, we hypothesize that the delayed retinal maturation during the early adult phase is linked to the delayed transition from indoor to outdoor activities in bees, when vision becomes important.
Collapse
Affiliation(s)
- Leonie Lichtenstein
- Department of Behavioral Physiology and Sociobiology, Biozentrum, University of Würzburg, Würzburg, Germany.
| | - Kornelia Grübel
- Department of Behavioral Physiology and Sociobiology, Biozentrum, University of Würzburg, Würzburg, Germany
| | - Johannes Spaethe
- Department of Behavioral Physiology and Sociobiology, Biozentrum, University of Würzburg, Würzburg, Germany
| |
Collapse
|
6
|
Lago DC, Humann FC, Barchuk AR, Abraham KJ, Hartfelder K. Differential gene expression underlying ovarian phenotype determination in honey bee, Apis mellifera L., caste development. INSECT BIOCHEMISTRY AND MOLECULAR BIOLOGY 2016; 79:1-12. [PMID: 27720811 DOI: 10.1016/j.ibmb.2016.10.001] [Citation(s) in RCA: 17] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/05/2016] [Revised: 09/26/2016] [Accepted: 10/03/2016] [Indexed: 06/06/2023]
Abstract
Adult honey bee queens and workers drastically differ in ovary size. This adult ovary phenotype difference becomes established during the final larval instar, when massive programmed cell death leads to the degeneration of 95-99% of the ovariole anlagen in workers. The higher juvenile hormone (JH) levels in queen larvae protect the ovaries against such degeneration. To gain insights into the molecular architecture underlying this divergence critical for adult caste fate and worker sterility, we performed a microarray analysis on fourth and early fifth instar queen and worker ovaries. For the fourth instar we found nine differentially expressed genes (DEGs) with log2FC > 1.0, but this number increased to 56 in early fifth-instar ovaries. We selected 15 DEGs for quantitative PCR (RT-qPCR) analysis. Nine differed significantly by the variables caste and/or development. Interestingly, genes with enzyme functions were higher expressed in workers, while those related to transcription and signaling had higher transcript levels in queens. For the RT-qPCR confirmed genes we analyzed their response to JH. This revealed a significant up-regulation for two genes, a short chain dehydrogenase reductase (sdr) and a heat shock protein 90 (hsp90). Five other genes, including hsp60 and hexamerin 70b (hex70b), were significantly down-regulated by JH. The sdr gene had previously come up as differentially expressed in other transcriptome analyses on honey bee larvae and heat shock proteins are frequently involved in insect hormone responses, this making them interesting candidates for further functional assays.
Collapse
Affiliation(s)
- Denyse Cavalcante Lago
- Departamento de Genética, Faculdade de Medicina de Ribeirão Preto, Universidade de São Paulo, Avenida Bandeirantes 3900, 14049-900 Ribeirão Preto, SP, Brazil.
| | - Fernanda Carvalho Humann
- Departamento de Biologia Celular e Molecular e Bioagentes Patogênicos, Faculdade de Medicina de Ribeirão Preto, Universidade de São Paulo, Avenida Bandeirantes 3900, 14049-900 Ribeirão Preto, SP, Brazil; Instituto Federal de Educação, Ciência e Tecnologia de São Paulo, Campus Matão, Rua Estéfano D'avassi, 625, 15991-502 Matão, SP, Brazil.
| | - Angel Roberto Barchuk
- Departamento de Biologia Celular e do Desenvolvimento, Instituto de Ciências Biomédicas, Universidade Federal de Alfenas, Rua Gabriel Monteiro da Silva 700, 37130-000 Alfenas, MG, Brazil.
| | - Kuruvilla Joseph Abraham
- Departamento de Puericultura e Pediatria Faculdade de Medicina de Ribeirão Preto, Universidade de São Paulo, Avenida Bandeirantes 3900, 14049-900 Ribeirão Preto, SP, Brazil; Universidade Estácio-Uniseb, Rua Abrahão Issa Halach 980, 14096-160 Ribeirão Preto, SP, Brazil.
| | - Klaus Hartfelder
- Departamento de Biologia Celular e Molecular e Bioagentes Patogênicos, Faculdade de Medicina de Ribeirão Preto, Universidade de São Paulo, Avenida Bandeirantes 3900, 14049-900 Ribeirão Preto, SP, Brazil.
| |
Collapse
|