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Zhang X, Lan T, Jiang H, Ye K, Dai Z. Bacterial community driven nitrogen cycling in coastal sediments of intertidal transition zone. THE SCIENCE OF THE TOTAL ENVIRONMENT 2024; 908:168299. [PMID: 37926266 DOI: 10.1016/j.scitotenv.2023.168299] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/01/2023] [Revised: 10/14/2023] [Accepted: 11/01/2023] [Indexed: 11/07/2023]
Abstract
Microorganisms inhabiting in coastal sediments significantly affect the nitrogen cycling in coastal waters and ecosystems. However, the bacterial community that related to the key active nitrogen transformation processes in intertidal transition zone are still not understood. Across a long flat intertidal zone at depths from 0 to 3 m in Daya Bay, China, the bacterial communities in sediments and their driven nitrogen cycling potential were evaluated with environmental factors and 16S rRNA sequencing. The results showed that the intertidal zone is a divide for environmental factors as pH, salinity and C/N ratio, instead of an average shift from freshwater to salt water. At the same time, the environmental factors influenced the abundance of bacterial community related to nitrogen cycling. Across the intertidal zone, the dominant nitrogen transformation processes were different. At the high tide and middle tide sites, the primary nitrogen cycling process was nitrification that worked with Nitrosomonadaceae, Nitrospiraceae, 0319-6A21, and wb1-A12. At the low tide sites, nitrogen fixation was the dominant function conducted by Bradyrhizobiaceae. The reduction of nitrate was carried out with the help of Xanthomonadales but relatively weak in all sampling sites especially for low tide sites. This was mostly because the richness and evenness of bacterial community were the lowest at the low tide sites. Meanwhile, the pH, Cl-, salinity, NH4+, NO3- and C/N ratio were the important factors that shaped the composition of local bacterial community. Further, the nonmetric multidimensional scaling results indicated that there were significant statistical differences in the composition of bacterial community among samples at different layers. The dominant nitrogen cycling processes in coastal sediments at different tide levels were revealed in this study, which offered an extended concept of nitrogen transformation along the groundwater discharge path in the intertidal transition zone. The distributions and compositions of bacterial communities and predicted functions provided a new insight for coastal environment and ecosystem management.
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Affiliation(s)
- Xiaoying Zhang
- Institute of Intelligent Simulation and Early Warning for Subsurface Environment, Jilin University, Changchun 130026, China; College of Construction Engineering, Jilin University, Changchun 130026, China
| | - Tianshan Lan
- Institute of Intelligent Simulation and Early Warning for Subsurface Environment, Jilin University, Changchun 130026, China.
| | - Hongchen Jiang
- State Key Laboratory of Biogeology and Environmental Geology, China University of Geosciences, Wuhan 430074, China
| | - Kexin Ye
- Institute of Intelligent Simulation and Early Warning for Subsurface Environment, Jilin University, Changchun 130026, China
| | - Zhenxue Dai
- Institute of Intelligent Simulation and Early Warning for Subsurface Environment, Jilin University, Changchun 130026, China; College of Construction Engineering, Jilin University, Changchun 130026, China.
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Fine JD, Foster LJ, McAfee A. Indirect exposure to insect growth disruptors affects honey bee (Apis mellifera) reproductive behaviors and ovarian protein expression. PLoS One 2023; 18:e0292176. [PMID: 37782633 PMCID: PMC10545116 DOI: 10.1371/journal.pone.0292176] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/25/2022] [Accepted: 09/14/2023] [Indexed: 10/04/2023] Open
Abstract
Pesticide exposure and queen loss are considered to be major causes of honey bee colony mortality, yet little is known regarding the effects of regularly encountered agrochemicals on honey bee reproduction. Here, we present the results of a two-generational study using specialized cages to expose queens to commonly used insect growth disrupting pesticides (IGDs) via their retinue of worker bees. Under IGD exposure, we tracked queen performance and worker responses to queens, then the performance of the exposed queens' offspring was assessed to identify patterns that may contribute to the long-term health and stability of a social insect colony. The positive control, novaluron, resulted in deformed larvae hatching from eggs laid by exposed queens, and methoxyfenozide, diflubenzuron, and novaluron caused a slight decrease in daily egg laying rates, but this was not reflected in the total egg production over the course of the experiment. Curiously, eggs laid by queens exposed to pyriproxyfen exhibited increased hatching rates, and those larvae developed into worker progeny with increased responsiveness to their queens. Additionally, pyriproxyfen and novaluron exposure affected the queen ovarian protein expression, with the overwhelming majority of differentially expressed proteins coming from the pyriproxyfen exposure. We discuss these results and the potential implications for honey bee reproduction and colony health.
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Affiliation(s)
- Julia D. Fine
- Invasive Species and Pollinator Health Research Unit, USDA-ARS, Davis, CA, United States of America
| | - Leonard J. Foster
- Department of Biochemistry and Molecular Biology, Michael Smith Laboratories, University of British Columbia, Vancouver, BC, Canada
| | - Alison McAfee
- Department of Biochemistry and Molecular Biology, Michael Smith Laboratories, University of British Columbia, Vancouver, BC, Canada
- Department of Applied Ecology, North Carolina State University, Raleigh, NC, United States of America
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Langlands Z, du Rand EE, Yusuf AA, Pirk CWW. Functional response of the hypopharyngeal glands to a social parasitism challenge in Southern African honey bee subspecies. Parasitol Res 2022; 121:267-274. [PMID: 34988669 DOI: 10.1007/s00436-021-07391-6] [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: 05/10/2021] [Accepted: 11/19/2021] [Indexed: 11/30/2022]
Abstract
Hypopharyngeal gland (HPG) development in honey bee workers is primarily age-dependent and changes according to the tasks performed in the colony. HPG activity also depends on colony requirements and is flexible in relation to the need for feeding brood. Very little is known about HPG development in the honey bee subspecies found in Southern Africa. We examined HPG development in Apis mellifera scutellata and A. m. capensis, including A. m. scutellata colonies infested with an invasive parasitic clonal lineage of A. m. capensis known to manipulate food provisioning to the parasitic larvae by their A.m. scutellata hosts, under natural in-hive conditions in bees aged 0 to 14 days using light microscopy. We found marked differences in acini size (berry-like clusters of secretory cells) and the age at which maximum HPG development occurred between the subspecies and in the presence of the parasite. In A. m. scutellata workers, acini reached maximum size at 6 days. The acini of A. m. capensis workers were larger (up to double) than those of A. m. scutellata and reached maximum size at 8 days, while the HPG acini in A. m. scutellata workers infested with A. m. capensis clones reached development sizes similar to those of A. m. capensis at day 10 and were 1.5 times larger than those of uninfested A. m. scutellata. This provides foundational insights into a functional response affecting the development of the HPG most likely associated with brood pheromone composition and how this is altered in the presence of a social parasite.
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Affiliation(s)
- Zoë Langlands
- Social Insects Research Group, Department of Zoology and Entomology, University of Pretoria, Private Bag X20, Hatfield, Pretoria, 0028, South Africa
| | - Esther E du Rand
- Social Insects Research Group, Department of Zoology and Entomology, University of Pretoria, Private Bag X20, Hatfield, Pretoria, 0028, South Africa.
| | - Abdullahi A Yusuf
- Social Insects Research Group, Department of Zoology and Entomology, University of Pretoria, Private Bag X20, Hatfield, Pretoria, 0028, South Africa
| | - Christian W W Pirk
- Social Insects Research Group, Department of Zoology and Entomology, University of Pretoria, Private Bag X20, Hatfield, Pretoria, 0028, South Africa
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Arien Y, Dag A, Shafir S. Omega-6:3 Ratio More Than Absolute Lipid Level in Diet Affects Associative Learning in Honey Bees. Front Psychol 2018; 9:1001. [PMID: 29971031 PMCID: PMC6018467 DOI: 10.3389/fpsyg.2018.01001] [Citation(s) in RCA: 26] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/01/2018] [Accepted: 05/30/2018] [Indexed: 01/01/2023] Open
Abstract
Floral pollen is a major source of honey bee nutrition that provides them with micro- and macro-nutrients, including proteins, fatty acids, vitamins, and minerals. Different pollens vary in composition, including in the essential fatty acids, alpha-linolenic acid (omega-3) and linoleic acid (omega-6). Monocultures, prevalent in modern agriculture, may expose honey bee colonies to unbalanced omega-6:3 diets. The importance of omega-3 in the diet for adequate learning and cognitive function, with a focus on suitable omega-6:3 ratio, is well documented in mammals. We have recently shown, for the first time in invertebrates, the importance of omega-3 in diets for associative learning ability in honey bees. In the current work, we examine the effect of the absolute amount of omega-3 in diet compared to the omega-6:3 ratio on honey bee associative learning. We fed newly emerged bees for 1 week on different artificial diets, which had lipid concentration of 1, 2, 4, or 8%, with omega-6:3 ratios of 0.3, 1, or 5, respectively. We then tested the bees in a proboscis-extension response olfactory conditioning assay. We found that both omega-6:3 ratio and total lipid concentration affected learning. The most detrimental diet for learning was that with a high omega-6:3 ratio of 5, regardless of the absolute amount of omega-3 in the diet. Bees fed an omega-6:3 ratio of 1, with 4% total lipid concentration achieved the best performance. Our results with honey bees are consistent with those found in mammals. Best cognitive performance is achieved by a diet that is sufficiently rich in essential fatty acids, but as long as the omega-6:3 ratio is not high.
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Affiliation(s)
- Yael Arien
- B. Triwaks Bee Research Center, Department of Entomology, The Robert H. Smith Faculty of Agriculture, Food and Environment, The Hebrew University of Jerusalem, Rehovot, Israel
| | - Arnon Dag
- Gilat Research Center, Institute of Plant Sciences, Agricultural Research Organization, Negev, Israel
| | - Sharoni Shafir
- B. Triwaks Bee Research Center, Department of Entomology, The Robert H. Smith Faculty of Agriculture, Food and Environment, The Hebrew University of Jerusalem, Rehovot, Israel
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Mumoki FN, Pirk CWW, Yusuf AA, Crewe RM. Reproductive parasitism by worker honey bees suppressed by queens through regulation of worker mandibular secretions. Sci Rep 2018; 8:7701. [PMID: 29799016 PMCID: PMC5967312 DOI: 10.1038/s41598-018-26060-w] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/10/2018] [Accepted: 05/03/2018] [Indexed: 11/09/2022] Open
Abstract
Social cohesion in social insect colonies can be achieved through the use of chemical signals whose production is caste-specific and regulated by social contexts. In honey bees, queen mandibular gland pheromones (QMP) maintain reproductive dominance by inhibiting ovary activation and production of queen-like mandibular gland signals in workers. We investigated whether honey bee queens can control reproductively active workers of the intraspecific social parasite Apis mellifera capensis, parasitising A. m. scutellata host colonies. Our results show that the queen’s QMP suppresses ovarian activation and inhibits the production of QMP pheromone signals by the parasitic workers, achieved through differential expression of enzymes involved in the biosynthesis of these pheromones at two points in the biosynthetic pathway. This is the first report showing that honey bee queens can regulate reproduction in intraspecific social parasites and deepens our understanding of the molecular mechanisms involved in the regulation of worker reproduction in social insects.
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Affiliation(s)
- Fiona N Mumoki
- Social Insects Research Group, Department of Zoology and Entomology, University of Pretoria, Private Bag X20, Hatfield, 0028, Pretoria, South Africa.
| | - Christian W W Pirk
- Social Insects Research Group, Department of Zoology and Entomology, University of Pretoria, Private Bag X20, Hatfield, 0028, Pretoria, South Africa
| | - Abdullahi A Yusuf
- Social Insects Research Group, Department of Zoology and Entomology, University of Pretoria, Private Bag X20, Hatfield, 0028, Pretoria, South Africa
| | - Robin M Crewe
- Social Insects Research Group, Department of Zoology and Entomology, University of Pretoria, Private Bag X20, Hatfield, 0028, Pretoria, South Africa
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