This is the first study where the systematic application of theories and techniques used in mammalian sperm cryopreservation have been applied to honey bee (Apis mellifera L.) semen as a means to improve postthaw viability of cryopreserved sperm. Six newly designed diluents, three cryoprotectants (dimethyl sulfoxide, DMA, glycerol), and five diluent:semen ratios (1:1, 3:1, 6:1, 9:1, and 12:1) were tested. In addition, the sperm freezing tolerance of three honey bee strains was evaluated. Specific protocols were designed to control semen freezing and thawing rates. Sperm motility was assessed visually, whereas sperm viability was assessed using SYBR-14 and propidium iodide fluorescent stains. Diluent treatments did not affect fresh (nonfrozen) sperm viability yet affected fresh sperm motility (P<0.05). Based on these assessments, two diluents were chosen and used in all successive cryopreservation experiments. Using the selected diluents, semen was collected at various diluent:semen ratios, along with one of the three cryoprotectants. Semen collected at high dilution ratios, using a hypotonic antioxidant diluent containing catalase, in combination with dimethyl sulfoxide, provided higher postthaw sperm viability than that of all other combinations tested (68.3+/-5.4%; P<0.05). Using this combination of dilution ratio, diluent, and cryoprotectant, there were no differences among honey bee strains for postthaw sperm viability (P=0.805). Nevertheless, these new semen dilution and freezing methods improved postthaw viability of sperm to levels that could theoretically sustain worker populations in colonies, thus providing potential for further optimization of cryopreservation techniques for the genetic preservation and improvement of honey bee genotypes.
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http://dx.doi.org/10.1016/j.theriogenology.2009.02.012 | DOI Listing |
Sci Rep
January 2025
Agroecology and Environment, Agroscope, Reckenholzstrasse 191, Zürich, 8046, Switzerland.
Solitary wild bees play a key role as pollinators of wild plants and crops, but they are increasingly at risk from anthropogenic global change, such as climate warming. However, how warmer temperature during overwintering affects reproductive success of those bees remains largely unknown. In a semi-field experiment we assessed individual life-long reproductive success of 144 females of the solitary bee species Osmia bicornis that had been wintered at three different temperatures.
View Article and Find Full Text PDFJ Agric Food Chem
January 2025
Plant Protection Research Institute, Key Laboratory of Green Prevention and Control on Fruits and Vegetables in South China Ministry of Agriculture and Rural Affairs, Guangdong Provincial Key Laboratory of High Technology for Plant Protection, Guangdong Academy of Agricultural Sciences, Guangzhou 510640, PR China.
Microplastics (MPs) and pesticides are identified as two environmental pollutants. In the present study, we showed evidence of toxic effects on honey bees from chronic oral exposure to food containing difenoconazole alone (Dif) and in a binary mixture with polystyrene (PS)-MPs (Dif + PS). We observed a disrupted gut microbial community structure in bees after difenoconazole exposure, and the gut microbiota structure richness increased at the phylum and genus levels in Dif + PS group.
View Article and Find Full Text PDFActa Otolaryngol
January 2025
Department of Otolaryngology, Haydarpasa Research and Training Hospital, İstanbul, Türkiye.
Background: Caffeic acid phenethyl ester (CAPE), an active component of honey bee propolis, has been demonstrated in animal models and studies to have anti-inflammatory, antioxidant, immunomodulatory, neuroprotective, and cytoprotective properties.
Objective: We investigated the efficacy of CAPE, which we believe may be therapeutically useful in facial nerve restoration due to its neuroprotective and antioxidant properties.
Material And Methods: 20 Sprague Dawley rats were divided randomly into 4 primary and 2 secondary groups and assigned as control, methylprednisolone, CAPE, CAPE+methylprednisolone groups and the sham and the trauma groups.
Front Microbiol
January 2025
Cellular and Organismic Networks, Faculty of Biology, Ludwig-Maximilians-Universität Munich, Planegg-Martinsried, Germany.
Introduction: The global decline in biodiversity and insect populations highlights the urgent need to conserve ecosystem functions, such as plant pollination by solitary bees. Human activities, particularly agricultural intensification, pose significant threats to these essential services. Changes in land use alter resource and nest site availability, pesticide exposure and other factors impacting the richness, diversity, and health of solitary bee species.
View Article and Find Full Text PDFEcology
January 2025
Department of Biological Sciences, Brock University, St. Catharines, Ontario, Canada.
Optimal nest site selection is crucial in animals whose offspring are completely dependent on the shelter of a nest. Parental decisions influencing nest thermal conditions are particularly important because temperature strongly influences juvenile activity, metabolism, growth, developmental rate, survival, and adult body size. In small ectotherms such as bees, maternal decisions to nest in sun-exposed or shady sites can lead to marked differences in thermal microenvironments inside nests.
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