Evidence for several roles of dynein in pigment transport in melanophores

Nilsson, Helén; Wallin, Margareta

doi:10.1002/(sici)1097-0169(1997)38:4<397::aid-cm9>3.0.co;2-0

Cited by 83 publications

(69 citation statements)

References 39 publications

(43 reference statements)

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“…By exploiting this property, biologists have used melanosomes as markers for in vivo organelle transport studies (1). Several groups (2)(3)(4) have shown that myosin V, cytoplasmic dynein, and kinesin-2 are the molecular motors in charge of melanosome transport in Xenopus melanophores. Among these molecular motors, heterotrimeric kinesin-2, which contains two different polypeptide chains with motor domains, Xklp3A and Xklp3B, has been shown to be responsible for the dispersion of melanosomes (3).…”

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confidence: 99%

Tracking melanosomes inside a cell to study molecular motors and their interaction

Kural

Serpinskaya

Chou

et al. 2007

Proc. Natl. Acad. Sci. U.S.A.

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Cells known as melanophores contain melanosomes, which are membrane organelles filled with melanin, a dark, nonfluorescent pigment. Melanophores aggregate or disperse their melanosomes when the host needs to change its color in response to the environment (e.g., camouflage or social interactions). Melanosome transport in cultured Xenopus melanophores is mediated by myosin V, heterotrimeric kinesin-2, and cytoplasmic dynein. Here, we describe a technique for tracking individual motors of each type, both individually and in their interaction, with high spatial (Ϸ2 nm) and temporal (Ϸ1 msec) localization accuracy. This method enabled us to observe (i) stepwise movement of kinesin-2 with an average step size of 8 nm; (ii) smoother melanosome transport (with fewer pauses), in the absence of intermediate filaments (IFs); and (iii) motors of actin filaments and microtubules working on the same cargo nearly simultaneously, indicating that a diffusive step is not needed between the two systems of transport. In concert with our previous report, our results also show that dynein-driven retrograde movement occurs in 8-nm steps. Furthermore, previous studies have shown that melanosomes carried by myosin V move 35 nm in a stepwise fashion in which the step rise-times can be as long as 80 msec. We observed 35-nm myosin V steps in melanophores containing no IFs. We find that myosin V steps occur faster in the absence of IFs, indicating that the IF network physically hinders organelle transport.bright-field imaging with one-nanometer accuracy (bFIONA) ͉ dynein ͉ kinesin-2 ͉ myosin V ͉ intermediate filaments M elanin-carrying melanosomes can be seen under brightfield illumination because the dark color of the melanosome creates a strong contrast between the organelle and the background. By exploiting this property, biologists have used melanosomes as markers for in vivo organelle transport studies (1). Several groups (2-4) have shown that myosin V, cytoplasmic dynein, and kinesin-2 are the molecular motors in charge of melanosome transport in Xenopus melanophores. Among these molecular motors, heterotrimeric kinesin-2, which contains two different polypeptide chains with motor domains, Xklp3A and Xklp3B, has been shown to be responsible for the dispersion of melanosomes (3). Unlike conventional kinesin subunits, kinesin-2 subunits cannot homodimerize due to repulsion between their charged residues in the stalk regions (5). [The reason that heterodimerization is favored over homodimerization is still unknown, although De Marco et al. (6,7) have shown that C-terminal coiled coils are crucial for the heterodimerization of the subunits.] In addition, there has been no investigation of the stepping mechanism for heterotrimeric kinesin: for example, the step size, effect of intermediate filaments (IFs), or interaction with other motors during a ''hand-off'' along microtubules or between microtubules and actin.Fluorescent particles have been used to study molecular motor-induced movement where sufficient contrast has enabled 1.5-nm reso...

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confidence: 99%

Tracking melanosomes inside a cell to study molecular motors and their interaction

Kural

Serpinskaya

Chou

et al. 2007

Proc. Natl. Acad. Sci. U.S.A.

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“…The skin explants were then fixed in ice-cold methanol for 6 minutes and rinsed in phosphate buffered saline for subsequent scoring of the amount of deformed versus spherical CMP´s on each explant. The results showed that microtubules, but not actin (not shown), maintain the spherical shape of the CPM (Nilsson and Wallin, 1997). Also here, the non-cell membrane permeable agent vanadate was added at different concentrations, now together with norepinephrine in the saponin containing lysis buffer.…”

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confidence: 87%

“…Skin explants in cultures have successfully been used for treatments with non-cell permeable agents to investigate intracellular mechanisms behind maintenance of the circular central pigment mass (CPM) and melanosome movements (Nilsson and Wallin 1997). The culture procedure makes the melanophores more exposed to the agents compared to the original biopsy, and the colour change reaction therefore occurs much faster.…”

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confidence: 99%

Skin Biopsies as Tools to Measure Fish Coloration and Colour Change

Svensson¹,

Nilsson-Sköld²

2011

Skin Biopsy - Perspectives

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“…The pigment cells respond to brightness, ultraviolet light, pressure, temperature, fish activity, pH, and chemicals via the neurohumoural and neurochemical systems producing melanophore-stimulating hormone, adrenocorticotrophic hormone, prolactin, somatolactin, melanin-concentrating hormone, melatonin, epinephrine and norepinephrine. 17,[19][20][21] In vertebrates, pigment cells develop from the neural crest of the embryo 22,23 . In the epidermis and dermis there are four pigment types: iridescent or blue, black, red, and yellow, which are made up of, respectively, blue and green pigment-containing iridocytes and guanophores, melanophores, erythrophores, and xanthophores.…”

Section: Pigments and Body Coloursmentioning

confidence: 99%

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Monvises¹,

Nuangsaeng²,

Sriwattanarothai³

et al. 2009

ScienceAsia

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ABSTRACT:The Siamese fighting fish, of which Betta splendens is representative, is gaining popularity as judged by increasing export values and demands for novel types worldwide, especially the ornamental ones. However, relatively little is known about the bettas scientifically. In this review we cover what is known about the desired morphology and pigments, genetics, aquaculture, diseases and feeds involved in breeding bettas. We also propose breeding the bettas for domestic enjoyment and export by exploiting current knowledge of gene technology and molecular developmental biology in addition to the use hitherto of only classical genetics. Other aspects of fish culture such as feeds, disease prevention and water quality should also be scientifically studied and improved upon. Because of dwindling and worsening habitats in Thailand, more studies on biodiversity and work towards species conservation of the wild types are needed.

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Evidence for several roles of dynein in pigment transport in melanophores

Cited by 83 publications

References 39 publications

Tracking melanosomes inside a cell to study molecular motors and their interaction

Tracking melanosomes inside a cell to study molecular motors and their interaction

Skin Biopsies as Tools to Measure Fish Coloration and Colour Change

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