Ultrastructural modifications in the venom glands of workers of Apis mellifera L. (Hymenoptera: Apidae) promoted by topical application of juvenile hormone

Abstract

Neotropical Entomology 35(2): 469-476 (2006) Modificações Ultra-Estruturais nas Glândulas de Veneno de Operárias de Apis mellifera L. (Hymenoptera:Apidae) Promovidas pela Aplicação Tópica de Hormônio Juvenil RESUMO -O presente estudo analisou, através de estudos ultra-estruturais a influência do tratamento com hormônio juvenil sobre as glândulas de veneno de operárias de Apis mellifera L. Para tanto, operárias recém-emergidas receberam aplicação tópica de 1µl de hormônio juvenil, na concentração de 2 µg/µl, sendo usado o hexano como veículo. Foram feitos dois controles, um que não recebeu nenhum tipo de tratamento (grupo C1) e o outro que recebeu aplicação tópica de 1 µl de hexano (grupo C2). O aspecto das células glandulares, em operárias recém-emergidas, mostra que estas não estão ainda secretando ativamente. Observa-se que alterações celulares ocorrem de acordo com a idade da operária e da região glandular considerada no controle C1. Assim, a fase de secreção mais ativa da glândula ocorre entre a emergência e os 14 dias de idade; aos 25 dias as células já perderam sua característica secretora, sendo a região distal a primeira a sofrer degeneração. Os tratamentos com hormônio juvenil e com hexano alteram a cronologia do ciclo glandular, antecipando o início da secreção e da degeneração da glândula. PALAVRAS-CHAVE: Ciclo secretor, degeneração glandular, hexano, abelhaABSTRACT -The present study analyzed, the influence of the treatment with juvenile hormone on the ultrastructure of Apis mellifera L. workers' venom glands. Newly emerged workers received topical application of 1 µl of juvenile hormone diluted in hexane, in the concentration of 2 µg/µl. Two controls were used; one control received no treatment (group C1) and other received topical application of 1 µl of hexane (group C2). The aspect of the glandular cells, in not treated newly emerged workers, showed that they are not yet secreting actively. Cellular modifications happened according to the worker age and to the glandular area considered. The most active phase of the gland happened from the emergence to the 14th day. At the 25th day the cells had already lost their secretory characteristic, being the distal area the first to suffer degeneration. The treatment with juvenile hormone and hexane altered the temporal sequence of the glandular cycle, forwarding the secretory cycle and degeneration of the venom gland.

Alterations induced by the juvenile hormone in glandular cells of the Apis mellifera venom gland: Applications on newly emerged workers (Hymenoptera, Apidae)

“…This staining technique showed that the RNA, certainly composing the rough endoplasmic reticulum of these cells, was preferentially located at the apical portion of the cells and was packed into bundles, thus resulting in a heterogeneous staining of the cytoplasm. The heterogeneous staining by toluidine blue corresponds to the ultrastructural observations of the glandular cells evidencing that the cisterns of the rough endoplasmic reticulum pack into bundles (Roat et al, 2006). At this age, the glandular cells present large and spherical nuclei with numerous nucleoli and loose chromatin, thus suggesting an intense synthesis of rRNA.…”

“…Therefore, an alteration of the glandular product could occur in this compartment, which corresponds to the secretory pole of the cell, possibly through the reabsorption of water. This possibility was sustained by the presence of pynocytosis vesicles at the end of the microvilli that form around the canaliculi (Roat et al, 2006). The fact that the mercury bromophenol blue staining procedure marks the collecting canaliculi could be due to the secretion they contain but not to the canaliculi themselves, given that the cuticular intima is not stained by this dye.…”

MALDI Imaging Analysis of Neuropeptides in Africanized Honeybee (Apis mellifera) Brain: Effect of Aggressiveness

“…Newborn workers do not sting, and according to the temporal polyethism the workers will begin to use their sting by the age of 14 days to defend themselves against predators. 62 To investigate the correlation between the proteopeptidomic findings in the honeybee brain with the aggressive behavior of worker bees, a bioassay was set up based on the observation of a series of aggressiveness-related behaviors of the honeybee workers (flying around, attraction, target inspection with antenna, bites with the mandibulae, abdomen vibration, protrusion of sting, and target stinging) under the effect of 1 ng of AmAST A (69−76) or AmTRP (88−96) (Figure 7). It was not expected that 7 day old worker honeybees would present any of the aggressive behaviors described above; however, when the young bees received each neuropeptide, via hemocele application, the neurohormones possibly reached the brain carried by the circulatory system, and within a period of 5 min the young honeybee workers presented a complete series of aggressive behaviors, including some stinging on the target.…”

“…Honeybee worker venom glands produce venom in a single secretory cycle beginning at the end of pupation and reaching the maximum between the 16th and 20th days of the worker’s adult life. Newborn workers do not sting, and according to the temporal polyethism the workers will begin to use their sting by the age of 14 days to defend themselves against predators …”

Effect of the Honeybee Hybrid and Geographic Region on the Honey Bee Venom Production

“…It is synthesized by the venom glands associated with the sting apparatus of worker and queens, stored in the venom reservoir and injected through the sting apparatus during the stinging process. Its production increases during the first two weeks of the adult worker's life and reaches a maximum when the worker bee becomes involved in hive defense and foraging (Roat et al, 2006). Also, at Egypt Khodairy and Omar (2003) determined the relationship between bee venom produced by electrical impulses and certain characters of honey bee colonies (i.e.…”