Organisation and ultrastructure of the regenerative crypts in the midgut of the adult worker honeybee (L. Apis mellifera)

In addition to the compound eyes, honeybees have three dorsal ocelli on the vertex of the head. Each ocellus has about 800 elongated photoreceptor cells. They are paired and the distal segment of each pair bears densely packed microvilli forming together a platelike fused rhabdom. Beneath a common cuticular lens a single layer of corneagenous cells is present.Ultrastructural studies were made of the retina of praepupae, different pupal stages and adult worker bees by thin sections and freeze-etch preparations. In praepupae the ocellar anlage consists of a conical group of epidermal cells that differentiate to photoreceptor cells, glial cells and corneagenous cells. Some photoreceptor cells are already paired and show disarrayed microvilli with circularly ordered filaments inside. In ocelli of 2-day-old pupae, when a retinogenous and a lentinogenous cell layer can be clearly distinguished, cell membranes of the distal part of two photoreceptor cells begin to interdigitate with each other and so start to form the definitive microvilli. At the beginning the microvilli often occupy the whole width of the developing rhabdom (Fig. 1).

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Transcriptional Control of Honey Bee (Apis mellifera) Major Royal Jelly Proteins by 20-Hydroxyecdysone

Insects ◽

10.3390/insects9030122 ◽

2018 ◽

Vol 9 (3) ◽

pp. 122 ◽

Cited By ~ 4

Author(s):

Paul Winkler ◽

Frank Sieg ◽

Anja Buttstedt

Keyword(s):

Gene Expression ◽

Apis Mellifera ◽

Juvenile Hormone ◽

Honey Bee ◽

Honey Bees ◽

Transcriptional Control ◽

Royal Jelly ◽

Adult Worker ◽

Gene Expression Dynamics

One of the first tasks of worker honey bees (Apis mellifera) during their lifetime is to feed the larval offspring. In brief, young workers (nurse bees) secrete a special food jelly that contains a large amount of unique major royal jelly proteins (MRJPs). The regulation of mrjp gene expression is not well understood, but the large upregulation in well-fed nurse bees suggests a tight repression until, or a massive induction upon, hatching of the adult worker bees. The lipoprotein vitellogenin, the synthesis of which is regulated by the two systemic hormones 20-hydroxyecdysone and juvenile hormone, is thought to be a precursor for the production of MRJPs. Thus, the regulation of mrjp expression by the said systemic hormones is likely. This study focusses on the role of 20-hydroxyecdysone by elucidating its effect on mrjp gene expression dynamics. Specifically, we tested whether 20-hydroxyecdysone displayed differential effects on various mrjps. We found that the expression of the mrjps (mrjp1–3) that were finally secreted in large amounts into the food jelly, in particular, were down regulated by 20-hydroxyecdysone treatment, with mrjp3 showing the highest repression value.

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Identification of Mesophylic Bacterial Flora in Deceased Worker Adults of Apis mellifera caucasia (Pollmann, 1889)

Sociobiology ◽

10.13102/sociobiology.v68i1.5905 ◽

2021 ◽

Vol 68 (1) ◽

pp. 5905

Author(s):

Elif Çil ◽

Ömer Ertürk ◽

Kamil Işik

Keyword(s):

Apis Mellifera ◽

Honey Bees ◽

Phylogenetic Trees ◽

Bacterial Flora ◽

New Members ◽

Important Species ◽

Adult Worker ◽

Study Results ◽

Molecular Phylogenetic ◽

Bacillus Genus

Apis mellifera, widely farmed around the world, is the most economically important species within the genus Apis. While the microbiota of live honey bees have been extensively examined, bacteria found in deceased honey bees (which might indicate infection or opportunistic pathogens) is in contrast poorly studied. Therefore, we decided to investigate the mesophilic bacterial flora of dead honey bees. So, in September 2013, dead adult worker honey bees were collected from 12 different cities, most of which were in the border provinces of Turkey. We identified bacterial isolates at the species level by using different morphological, biochemical, physical and molecular methods, in conjunction with molecular phylogenetic analysis. We constructed phylogenetic trees for isolated bacteria with the MEGA 6.0 program and neighbor-joining trees were reconstructed based on 16S rDNA gene sequences. The phylogenetic trees indicated that isolates DE003, DE007, DE011, DE001, DE019 and DE016, DE029 could be new members of the genera Erwinia, Acidovorax, Hydrogenophaga and Bacillus genus, respectively. In the bioassay study results, we observed that DE019 Hydrogenophaga sp. (64.7%) and DE004 Klebsiella grimontii (73.3%) had lethal effects on the honey bees. The other mortalities ranged from 10% to 25% (p>0.05), and according to a One-Way ANOVA analysis DE004 and DE019 significantly affect the A. mellifera caucasia in adult worker honey bees. This study is the first report of Hydrogenophaga as honey bee pathogen.

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