Publications by authors named "Martin Hasselmann"

A sustainable solution to the global threat of the mite is the selection of varroa-resistant honey bee () colonies. Both "mite non-reproduction" (MNR) and "varroa sensitive hygiene" (VSH) appear to be promising selection traits for achieving the goal of a resistant honey bee. MNR describes colonies that have a high number of non-reproductive mites (no offspring, no males, or delayed development of mite offspring).

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Anthropogenic activities like trade facilitate increasing rates of biological invasions. Asian long-horned beetle (ALB), which is naturally distributed in eastern Asia (China, Korean peninsula), was introduced via wood packing materials (WPM) used in trade to North America (1996) and Europe (2001). We used 7810 single nucleotide polymorphisms (SNPs) derived by a genotype-by-sequencing (GBS) approach to decipher the introduction patterns into Europe.

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Wild honeybees (Apis mellifera) are considered extinct in most parts of Europe. The likely causes of their decline include increased parasite burden, lack of high-quality nesting sites and associated depredation pressure, and food scarcity. In Germany, feral honeybees still colonize managed forests, but their survival rate is too low to maintain viable populations.

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The honey bee, Apis mellifera differs from all other social bees in its gonad phenotype and mating strategy. Honey bee queens and drones have tremendously enlarged gonads, and virgin queens mate with several males. In contrast, in all the other bees, the male and female gonads are small, and the females mate with only one or very few males, thus, suggesting an evolutionary and developmental link between gonad phenotype and mating strategy.

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Mitochondria and the energy metabolism are linked to both, the availability of Ca and P to provide the eukaryotic cell with energy. Both minerals are commonly used supplements in the feed of laying hens but little is known about the relationship between the feed content, energy metabolism and genetic background. In this study, we provide a large-scaled gene expression analysis of 31 mitochondrial and nuclear encoded genes in 80 laying hens in the context of dietary P and Ca concentrations.

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Article Synopsis
  • Cytoplasmic incompatibility (CI) is a reproductive issue seen in arthropods where infected males and uninfected females have low fertility due to maternally inherited symbionts.
  • A new CI symbiont was discovered in a strain of a certain bacterium that affects parasitoid wasps, allowing researchers to induce CI in uninfected insects by transferring the infected hemolymph.
  • Genome sequencing revealed that this symbiont lacks known CI genes from other studied organisms, indicating it evolved CI independently, but contains potential new CI-related genes linked to developmental processes.
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The gonads of honey bee, Apis mellifera, queens and drones are each composed of hundreds of serial units, the ovarioles and testioles, while the ovaries of the adult subfertile workers consist of only few ovarioles. We performed a comparative RNA-seq analysis on early fifth-instar (L5F1) larval gonads, which is a critical stage in gonad development of honey bee larvae. A total of 1834 genes were identified as differentially expressed (Padj < 0.

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The cellular energy metabolism is one of the most conserved processes, as it is present in all living organisms. Mitochondria are providing the eukaryotic cell with energy and thus their genome and gene expression has been of broad interest for a long time. Mitochondrial gene expression changes under different conditions and is regulated by genes encoded in the nucleus of the cell.

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Background: The black soldier fly (Hermetia illucens) is the most promising insect candidate for nutrient-recycling through bioconversion of organic waste into biomass, thereby improving sustainability of protein supplies for animal feed and facilitating transition to a circular economy. Contrary to conventional livestock, genetic resources of farmed insects remain poorly characterised. We present the first comprehensive population genetic characterisation of H.

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Analysis of plant pollen can provide valuable insights into the existing spectrum of microorganisms in the environment. When harvesting bee-collected pollen as a dietary supplement for human consumption, timely preservation of the freshly collected pollen is fundamental for product quality. Environmental microorganisms contained in freshly collected pollen can lead to spoilage by degradation of pollen components.

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Mitochondria are essential components of eukaryotes as they are involved in several organismic key processes such as energy production, apoptosis and cell growth. Despite their importance for the metabolism and physiology of all eukaryotic organisms, the impact of mitochondrial haplotype variation has only been studied for very few species. In this study we sequenced the mitochondrial genome of 180 individuals from two different strains of laying hens.

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The diversity and local differentiation of honey bees are subjects of broad general interest. In particular, the classification of Ethiopian honey bees has been a subject of debate for decades. Here, we conducted an integrated analysis based on classical morphometrics and a putative nuclear marker (denoted r7-) for elevational adaptation to classify and characterize these honey bees.

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The objective of this study was to compare 2 laying hen strains in 5 production periods regarding phytase activity, phytate (InsP) degradation, and myo-inositol (MI) release in the digestive tract and phosphorus (P) and calcium (Ca) utilization. One offspring of 10 nonrelated roosters per strain (Lohmann Brown-classic (LB) or Lohmann LSL-classic (LSL)) was placed in one of 20 metabolic units in a completely randomized block design in week 8, 14, 22, 28, and 58 of life. All hens were fed the same corn and soybean meal-based diet at one time, but the diet composition was adjusted to the requirements in the respective period.

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Laying hens require less phosphorus (P) but markedly more calcium (Ca) in their diet than broilers. These differences may cause more distinct interactions with phytate degradation and utilization of minerals in laying hens than those in broilers. The objective of the study was to characterize intestinal phytate degradation, ileal transcript copy numbers of transcellular Ca and P transporters, and mineral utilization by two laying hen strains fed with standard or reduced levels of dietary Ca and P at the laying peak.

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Article Synopsis
  • - Bumblebees are crucial for ecosystems and agriculture, with both social and solitary lifestyles, yet many species are declining due to factors like habitat loss and climate change.
  • - Researchers sequenced the genomes of 17 bumblebee species to understand genetic diversity and dynamics, uncovering variations that affect their ecology and behavior.
  • - The study highlights changes in genes related to foraging, immunity, and adaptations, showcasing how bumblebee genomes have evolved and emphasizing their ecological importance.
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When selection favours rare alleles over common ones (balancing selection in the form of negative frequency-dependent selection), a locus may maintain a large number of alleles, each at similar frequency. To better understand how allelic richness is generated and maintained at such loci, we assessed 201 sequences of the complementary sex determiner (csd) of the Asian honeybee (Apis cerana), sampled from across its range. Honeybees are haplodiploid; hemizygotes at csd develop as males and heterozygotes as females, while homozygosity is lethal.

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In general, honey bees (Apis mellifera L.) feed on honey produced from collected nectar. In the absence of nectar, during certain times of the year or in monocultural landscapes, honey bees forage on honeydew.

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Due to the combined effects of global warming and eutrophication, the frequency of deleterious cyanobacterial blooms in freshwater ecosystems has increased. In line with this, local adaptation of the aquatic keystone herbivore Daphnia to cyanobacteria has received major attention. Besides microcystins, the most frequent cyanobacterial secondary metabolites in such blooms are protease inhibitors (PIs).

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The Na ion-translocating NADH:quinone oxidoreductase (NQR) from is a membrane-bound respiratory enzyme which harbors flavins and Fe-S clusters as redox centers. The NQR is the main producer of the sodium motive force (SMF) and drives energy-dissipating processes such as flagellar rotation, substrate uptake, ATP synthesis, and cation-proton antiport. The NQR requires for its maturation, in addition to the six structural genes , a flavin attachment gene, , and the gene, presumably encoding a Fe delivery protein.

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Article Synopsis
  • * Over a thousand individual worker bees from disease-free apiaries were analyzed for eleven viruses, four parasites, and three bacteria, revealing that co-infections are common, with forager bees often carrying multiple viruses simultaneously.
  • * The findings suggest that low-level infections in honey bees are more prevalent than previously thought and indicate possible synergistic interactions among common pathogens, especially with black queen cell virus, highlighting the potential of this diagnostic approach in future research on nonmodel systems.
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Modern-day dairy cows express great variation in metabolic capacity to adapt to the onset of lactation. Although breeding programs increased the breeding value for longevity and robustness in the sires, a respective phenotype in female offspring has not been improving as predicted. Fundamental energy generating pathways such as mitochondrial fatty acid oxidation might have a crucial role for robustness and metabolic efficiency in dairy cows.

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Eusociality represents a major transition in evolution and is typified by cooperative brood care and reproductive division of labor between generations. In bees, this division of labor allows queens and workers to phenotypically specialize. Worker traits associated with helping are thought to be crucial to the fitness of a eusocial lineage, and recent studies of honey bees (genus Apis) have found that adaptively evolving genes often have worker-biased expression patterns.

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Understanding the genetic basis of adaption is a central task in biology. Populations of the honey bee Apis mellifera that inhabit the mountain forests of East Africa differ in behavior and morphology from those inhabiting the surrounding lowland savannahs, which likely reflects adaptation to these habitats. We performed whole genome sequencing on 39 samples of highland and lowland bees from two pairs of populations to determine their evolutionary affinities and identify the genetic basis of these putative adaptations.

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