scholarly journals Changes in the structure and pigmentation of the eyes of honeybee (Apis mellifera L.) queens with the "limão" mutation

2000 ◽  
Vol 23 (1) ◽  
pp. 93-96 ◽  
Author(s):  
José Chaud-Netto ◽  
Carminda da Cruz-Landim
Keyword(s):  
Apis Mellifera ◽  
Morphological Changes ◽  
Compound Eyes ◽  
Ultrastructural Organization ◽  
Multivesicular Bodies ◽  
Electron Dense Material ◽  
Eye Color ◽  
Receptor Cells ◽  
Pigment Granules ◽  
Retinular Cells

This study describes the ultrastructural differences between the compound eyes of ch li/ch li and Ch/ch li honeybee queens. Heterozygous "limão" bees had an almost normal ultrastructural organization of the ommatidia, but there were some alterations, including small vacuoles in the crystalline cones and a loss of pigment by primary pigmentary cells. In homozygous bees many ommatidia had very deformed crystalline cones and there were some bipartite rhabdoma. There was a reduction in the amount of pigment in the primary and secondary pigmentary cells and receptor cells (retinulae) of mutant eyes. However, the eyes of both heterozygous and homozygous queens had the same type of pigment granules. Certain membrane-limited structures containing pigment granules and electron-dense material appeared to be of lysosomal nature. Since these structures occurred in the retinular cells of mutant eyes, they were considered to be multivesicular bodies responsible for the reduction in rhabdom volume in the presence of light, as a type of adaptation to brightness. The reduction of pigment in the pigmentary and retinular cells and the morphological changes seen in the rhabdom of the ommatidia may originate visual deficiencies, which could explain the behavioral modifications reported for Apis mellifera queens with mutant eye color.

Differentiation Processes of the Ocellar Retina of the Honeybee (Apis Mellifera L.)

1990 ◽  
Vol 48 (3) ◽  
pp. 430-431
Author(s):  
Maria Anna Pabst
Keyword(s):  
Apis Mellifera ◽  
Distal Part ◽  
Cell Layer ◽  
Single Layer ◽  
Photoreceptor Cells ◽  
Distal Segment ◽  
Compound Eyes ◽  
Thin Sections ◽  
Ultrastructural Studies ◽  
Adult Worker

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).

scholarly journals Longevity of africanized worker honey bees (Apis mellifera) carrying eye color mutant alleles

2003 ◽  
Vol 60 (2) ◽  
pp. 277-281 ◽  
Author(s):  
Rosana de Almeida ◽  
Ademilson Espencer Egea Soares
Keyword(s):  
Apis Mellifera ◽  
Honey Bees ◽  
Statistical Difference ◽  
Close Association ◽  
Control Group ◽  
Brown Pigment ◽  
Eye Color ◽  
Color Mutant ◽  
Extended Lifespan ◽  
Eye Pigmentation

The dark coloration of insects eyes is attributed to the accumulation of the brown pigment insectorubin, a mixture of ommochromes, xanthommatin and several ommins, biosynthesized from tryptophan. When any of the events in the synthesis chain is interrupted, formation and accumulation of pigments other than insectorubin occurs, and a new eye color will appear. The aim of the present work is to evaluate the longevity of worker honey bees Apis mellifera, homozygous and heterozygous for the mutant alleles cream (cr), snow-laranja (s la) and brick (bk). Eye pigmentation and average longetivity of bees are very closely related. Mutant bees carrying lighter eye pigmentation are unable to return to the hive; there is, therefore, a close association between the eye pigmentation and honey bees lifespan. Experiments ran in confinement cages confirm the orientation problems of mutant honey bees, which kept in a limited space, were able to return to the hive and had an extended lifespan in comparison to that observed in the nature, and did not present statistical difference (P>0.05) relative to the control group. Confinement to restricted areas improves honey bees orientation abilities and facilitates return to the hive.

Studies on the possible relationships of microbodies and multivesicular bodies to oxalate, endopolygalacturonase, and cellulase (Cx) production by Sclerotinia sclerotiorum

1972 ◽  
Vol 50 (8) ◽  
pp. 1743-1748 ◽  
Author(s):  
Douglas P. Maxwell ◽  
Paul H. Williams ◽  
Martha D. Maxwell
Keyword(s):  
Sclerotinia Sclerotiorum ◽  
Enzyme Production ◽  
Functional Role ◽  
Carbon Sources ◽  
Extracellular Enzyme ◽  
Ultrastructural Organization ◽  
Multivesicular Bodies ◽  
Membrane Bound ◽  
High Production

The possible functional role of vesicles and crystal-containing microbodies in the production of oxalate, endopolygalacturonase, or cellulase by Sclerotinia sclerotiorum was investigated. The presence of multivesicular bodies in hyphal tips was not correlated with secretion or production of oxalate or these extracellular hydrolases. More crystal-containing microbodies were present in hyphal tips grown on media which supported greater extracellular enzyme production. No correlation existed between numbers of crystal-containing microbodies in hyphal tips and production of oxalate. Numerous membrane-bound vesicles (0.09–0.18 µm diam) were associated with tips grown on a D-glucose–Na succinate medium which supported high production of oxalate. The general ultrastructural organization of these hyphal tips was similar to that reported for other ascomycetes. Differences in numbers and distributions of organelles were observed between hyphal tips and older hyphae as well as between hyphal tips grown on the different carbon sources.

Fine structure of ocelli of the larval black fly Simulium vittatum (Diptera: Simuliidae)

1987 ◽  
Vol 65 (1) ◽  
pp. 142-150 ◽  
Author(s):  
Joyce M. Nyhof ◽  
Susan B. McIver
Keyword(s):  
Fine Structure ◽  
Polarized Light ◽  
Cell Organelles ◽  
Golgi Bodies ◽  
Simulium Vittatum ◽  
Pigment Granules ◽  
Transmission Electron ◽  
Structural Differences ◽  
Numerous Cell ◽  
Retinular Cells

The fine structure of light- and dark-adapted ocelli of last instar larval Simulium vittatum Zetterstedt was described using scanning and transmission electron microscopy. Larvae have six ocelli arranged in groups of three on each side of the head. The larger two ocelli of each group are externally visible as two darkly pigmented eyespots. The third, smaller ocellus lacks pigmentation and, therefore, is not externally visible. Each ocellus has its long axis oriented dorso-ventrally, has 13 retinular cells, and lacks an expanded cuticular lens. Conspicuous rhabdoms occur in the three ocelli. The rhabdoms of the pigmented ocelli are centrally located and enveloped by pigment granules. The microvilli of the rhabdoms are oriented primarily in one plane, an indication of a possible sensitivity to polarized light. The rhabdom of the unpigmented ocellus is eccentrically located and its microvilli are not uniplanar. Each ocellus has numerous cell organelles, including mitochondria, ribosomes, endoplasmic reticulum, and Golgi bodies. Especially conspicuous are membranous figures, which are associated with the nuclei and vary in size and complexity from simple stacks to lamellar whorls. These latter organelles are probably involved in the turnover processes of the rhabdomeric membranes. In light- and dark-adapted ocelli the only structural differences were associated with the microvilli and multivesicular bodies. Differences in location of pigment granules and in size of rhabdomeres and membranous figures were not observed.

scholarly journals Defective Pigment Granule Biogenesis and Aberrant Behavior Caused by Mutations in the Drosophila AP-3β Adaptin Gene ruby

Genetics ◽  
2000 ◽  
Vol 155 (1) ◽  
pp. 213-223
Author(s):  
Doris Kretzschmar ◽  
Burkhard Poeck ◽  
Helmut Roth ◽  
Roman Ernst ◽  
Andreas Keller ◽  
...  
Keyword(s):  
Protein Trafficking ◽  
Coat Color ◽  
Retinal Pigment ◽  
Skin Pigmentation ◽  
Pigment Granule ◽  
Adaptor Protein ◽  
Photoreceptor Cells ◽  
Cell Types ◽  
Eye Color ◽  
Pigment Granules

Abstract Lysosomal protein trafficking is a fundamental process conserved from yeast to humans. This conservation extends to lysosome-like organelles such as mammalian melanosomes and insect eye pigment granules. Recently, eye and coat color mutations in mouse (mocha and pearl) and Drosophila (garnet and carmine) were shown to affect subunits of the heterotetrameric adaptor protein complex AP-3 involved in vesicle trafficking. Here we demonstrate that the Drosophila eye color mutant ruby is defective in the AP-3β subunit gene. ruby expression was found in retinal pigment and photoreceptor cells and in the developing central nervous system. ruby mutations lead to a decreased number and altered size of pigment granules in various cell types in and adjacent to the retina. Humans with lesions in the related AP-3βA gene suffer from Hermansky-Pudlak syndrome, which is caused by defects in a number of lysosome-related organelles. Hermansky-Pudlak patients have a reduced skin pigmentation and suffer from internal bleeding, pulmonary fibrosis, and visual system malfunction. The Drosophila AP-3β adaptin also appears to be involved in processes other than eye pigment granule biogenesis because all ruby allele combinations tested exhibited defective behavior in a visual fixation paradigm.

Laranja—an additional eye color gene in the snow series of Apis mellifera L.

1982 ◽  
Vol 73 (1) ◽  
pp. 80-80 ◽  
Author(s):  
Ademilson Espencer Egea Soares ◽  
José Chaud Netto
Keyword(s):  
Apis Mellifera ◽  
Eye Color ◽  
Color Gene

scholarly journals Localization of the Violet and Yellow Receptor Cells in the Crayfish Retinula

1973 ◽  
Vol 62 (4) ◽  
pp. 355-374 ◽  
Author(s):  
Eisuke Eguchi ◽  
Talbot H. Waterman ◽  
Jiro Akiyama
Keyword(s):  
Light Adaptation ◽  
Selective Adaptation ◽  
Compound Eyes ◽  
Intracellular Recordings ◽  
Intercellular Coupling ◽  
Retinular Cell ◽  
Particle Distributions ◽  
Wavelength Sensitivity ◽  
Retinal Distribution ◽  
Retinular Cells

Cellular identification of color receptors in crayfish compound eyes has been made by selective adaptation at 450 nm and 570 nm, wavelengths near the λmax's of the two retinular cell classes previously demonstrated. By utilizing earlier evidence, the concentration of lysosome-related bodies (LRB) was used to measure relative light adaptation and thus wavelength sensitivity in 665 retinular cells from six eyes. The observed particle distributions demonstrate the following. Both violet and yellow receptors occur ordinarily in each retinula. Of the seven regular retinular cells two (R3 and R4 using Eguchi's numbering [1965]) have mean sensitivities significantly greater to violet and less to yellow than the other five. The latter apparently comprise "pure" yellow receptors (R1 and R7) and mixed yellow and violet receptors (R2, R5, and R6). Explanations of such ambiguity requiring two visual pigments in single retinular cells or intercellular coupling of adjacent neuroreceptors are apparently precluded by previous evidence. Present data imply alternatively some positional variability in the violet pair's location in individual retinulas. Thus R3 and R4 are predominantly the violet receptors but in some retinulas R2 and R3 or R4 and R5 (or rarely some other cell pairs) may be. The retinal distribution of such variations has yet to be determined. In agreement with intracellular recordings the blue and yellow cells here identified belong to both the vertical and horizontal e-vector sensitive channels.

scholarly journals Scientific note on PCR inhibitors in the compound eyes of honey bees, Apis mellifera

Apidologie ◽  
2011 ◽  
Vol 42 (4) ◽  
pp. 457-460 ◽  
Author(s):  
Humberto Boncristiani ◽  
Jilian Li ◽  
Jay D. Evans ◽  
Jeff Pettis ◽  
Yanping Chen
Keyword(s):  
Apis Mellifera ◽  
Honey Bees ◽  
Compound Eyes ◽  
Pcr Inhibitors ◽  
Scientific Note

Possible role of the central retinular cells in the ommatidia of male black flies (Diptera: Simuliidae)

1987 ◽  
Vol 65 (12) ◽  
pp. 3186-3188 ◽  
Author(s):  
Susan B. McIver ◽  
Gail E. O'Grady
Keyword(s):  
Sensory Receptor ◽  
Compound Eyes ◽  
Black Flies ◽  
Dorsal Region ◽  
Blue Range ◽  
Retinular Cells ◽  
Dioptric Apparatus ◽  
Receptor Layer ◽  
Swarm Formation

In Cnephia dacotensis, a species that mates on rocks and plants without swarm formation, the eyes of the males are separate and undivided. Each ommatidium consists of two general regions: a distal dioptric apparatus and a sensory receptor layer with eight retinular cells. Six of these cells (R1–6) are located peripherally and two centrally; R7 occurs distally and R8 basally. In males of previously studied species in which females are detected as they fly above a male swarm, the compound eyes are holoptic and divided into distinct dorsal and ventral regions. Ommatidia in the dorsal region lack the R7 cell. If in black flies R7 is a blue receptor and R8 a uv receptor, then the absence of R7 means that swarm-forming males see the females against a background that provides a sharper contrast than a background of a uv to blue range. This would sharpen the visibility of the dark female against the background skylight, enabling the male to perceive her more swiftly.

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