The fine structure of the lens and photoreceptors of Nereis virens

Dorsett, D. A.; Hyde, Régine

doi:10.1007/bf00325039

Cited by 32 publications

(5 citation statements)

References 10 publications

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“…Juveniles are found in the sediments higher on the shore which act as a nursery (Miron 1988). Larvae are recruited to the higher levels as the tide rises, and settle onto the sediment through a negative phototactic response (Dorsett and Hyde 1968), through physico-chemical selection of sediments, and in response to hydrostatic pressure and salinity changes (Evans 1971). Larvae are recruited to the higher levels as the tide rises, and settle onto the sediment through a negative phototactic response (Dorsett and Hyde 1968), through physico-chemical selection of sediments, and in response to hydrostatic pressure and salinity changes (Evans 1971).…”

Section: Discussionmentioning

confidence: 99%

Distributions and population structures of two intertidal estuarine polychaetes in the lower St. Lawrence Estuary, with special reference to environmental factors

Miron

Desrosiers

1990

Mar. Biol.

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An intensive study of the spatial distribution of Nereis virens (Sars) and Nephtys caeca (Fabricius) was conducted during the spring and autumn of 1986 in the lower St. Lawrence estuary. Statistical analysis showed that spatial variations in density, individual body weight and sexual maturity, particularly in the case of Nereis virens, are correlated with the intertidal level, with certain sediment characteristics, and with the thickness of the colonizable sediment layer. The density of N. virens increases in an offshore-onshore direction, whereas that of Nephtys caeca decreases in the same direction. For both species, mean body weight increases downshore from the upper intertidal level. Other specific relationships exist in relation to sediment characteristics. Sexually mature Nereis virens are found only at the lower intertidal level; sexual maturity in Nephtys caeca was not studied. There were no changes in spatial distribution patterns between spring and autumn. The spatial distribution of Nereis virens parallels depth contours and may reflect its ability to inhabit environments which become more physically unstable in an offshore-onshore direction. This spatial distribution is consistent with a model whereby larvae are recruited in the upper intertidal zone and juveniles migrate downshore.

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Section: Discussionmentioning

confidence: 99%

Distributions and population structures of two intertidal estuarine polychaetes in the lower St. Lawrence Estuary, with special reference to environmental factors

Miron

Desrosiers

1990

Mar. Biol.

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“…References are specified as follows: 01 this study, 02 Purschke unpubl. observations, 03 Arendt et al (2002, 2004, 04 Bartolomaeus (1987), 05 Bartolomaeus (1992), 06 Bartolomaeus (1993), 07 Bassot and Nicolas (1977), 08 Bocquet and Dhainaut-Courtois (1973), 09 Bocquet (1977), 10 Brandenburger and Eakin (1981), 11 Dorsett and Hyde (1968), 12 Eakin and Brandenburger (1985), 13 Eakin (1972), 14 Eakin et al (1977), 15 Ermak andEakin (1976), 16 Fischer and Bröckelmann (1966), 17 Hermans and Cloney (1966), 18 Hermans and Eakin (1974), 19 Holborow andLaverack (1972), 20 Lacalli (1988), 21 Marsden and Hsieh (1987), 22 Pietsch and Westheide (1985), 23 Purschke (1992), 24 Purschke (2005), 25 …”

Section: Distinguishing Larval Eyes and Adult Eyesmentioning

confidence: 90%

Ultrastructure of pigmented adult eyes in errant polychaetes (Annelida): implications for annelid evolution

Suschenko

Purschke

2008

Zoomorphology

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The evolution of photoreceptor cells and eyes in Metazoa is far from being resolved, although recent developmental and structural studies have provided strong evidence for a common origin of photoreceptor cells and existence of sister cell types already in early metazoans. These sister cell types are ciliary and rhabdomeric photoreceptor cells, depending on which part of each cell is involved in photoreception proper. However, a crucial point in eye evolution is how the enormous structural diversity of photoreceptor cells and visual systems developed, given the general molecular conservation of the photoreceptor cells. One example of this diversity can be observed in Annelida. Within the polychaetes the errant forms, taxon Aciculata, constitute the only group possessing true multicellular eyes in the adult stage. Thus far these organs have been investigated only in taxa of Phyllodocida, a subgroup of Aciculata. Data on Eunicida and Amphinomida as well as certain phyllodocidan taxa had been lacking. The ultrastructure of these adult eyes was investigated in various species of errant polychaetes, belonging to Amphinomidae, Eunicidae and Hesionidae, to elucidate whether they provide any phylogenetic clues regarding either the evolution of visual systems in Annelida or lophotrochozoan phylogeny in general. These eyes are composed of numerous supportive pigment cells and rhabdomeric photoreceptor cells and sometimes additional cell types. As a rule the pigment and rhabdomeric cell types form a continuous epithelium in which the two types intermingle. Presence of granules with shading pigment in sensory cells is a common feature but is apparently restricted to a taxon comprising Phyllodocida and Eunicida s. str. Very likely a lens-like structure does not belong to the ground pattern of annelid eyes, despite its presence in Phyllodocida. These lens-like structures are formed by secretions or cellular processes of the pigment cells. In many species the eye cup communicates with the exterior via a small cuticularized canal. This canal is interpreted as a rudiment due to the mode of formation in the epidermis. With respect to current phylogenetic hypotheses, these multicellular eyes have either been developed in the stem species of a taxon Aciculata nested within the polychaetes or have been evolved in the stem lineage of Annelida. Similarities to gastropod eyes are interpreted as convergent and not as indication of common origin. Except for the photoreceptor cells proper, the structure of the adult eyes in polychaetes most likely does not help to resolve lophotrochozoan phylogeny.

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“…Characteristics of PRC microvilli in taxa other than arthropods are also of highly regular diameter and high packing density. This includes basally branching arthropods, such as onychophorans, as well as various lophotrochozoans, including annelids (Fischer and Br€ okelmann, 1966;Hermans and Cloney, 1966;Krasne and Lawrence, 1966;Dorsett and Hyde, 1968;R€ ohlich et al, 1970;Whittle and Golding, 1974;Bok et al, 2017), molluscs (Tonosaki, 1967;Boyle, 1969;Dilly, 1969;Hughes, 1970;Kataoka and Yamamoto, 1981;Howard and Martin, 1984;Blumer, 1994;(Salvini--Plawen, 2009), and platyhelminths (MacRae, 1966;Carpenter et al, 1974;Fournier and Combes, 1978;Lanfranchi et al, 1981;(Eakin and Brandenburger, 1981;Bedini and Lanfranchi, 1990;Sopott-Ehlers, 1991), and deuterostomes (Eakin and Kuda, 1971;Braun and Stach, 2017). PRCs of the Drosophila Bolwig organ are strikingly different from this picture, with MLPs spaced apart and of irregular length and diameter.…”

Section: Photoreceptor Membrane Stacking: Microvilli and Microvillar-mentioning

confidence: 99%

Serial electron microscopic reconstruction of the drosophila larval eye: Photoreceptors with a rudimentary rhabdomere of microvillar-like processes

Hartenstein

Yuan

Younossi-Hartenstein

et al. 2019

Developmental Biology

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Photoreceptor cells (PRCs) across the animal kingdom are characterized by a stacking of apical membranes to accommodate the high abundance of photopigment. In arthropods and many other invertebrate phyla PRC membrane stacks adopt the shape of densely packed microvilli that form a structure called rhabdomere. PRCs and surrounding accessory cells, including pigment cells and lens-forming cells, are grouped in stereotyped units, the ommatidia. In larvae of holometabolan insects, eyes (called stemmata) are reduced in terms of number and composition of ommatidia. The stemma of Drosophila (Bolwig organ) is reduced to a bilateral cluster of subepidermal PRCs, lacking all other cell types. In the present paper we have analyzed the development and fine structure of the Drosophila larval PRCs. Shortly after their appearance in the embryonic head ectoderm, PRC precursors delaminate and lose expression of apical markers of epithelial cells, including Crumbs and several centrosome-associated proteins. In the early first instar larva, PRCs show an expanded, irregularly shaped apical surface that is folded into multiple horizontal microvillar-like processes (MLPs). Apical PRC membranes and MLPs are covered with a layer of extracellular matrix. MLPs are predominantly aligned along an axis that extends ventro-anteriorly to dorso-posteriorly, but vary in length, diameter, and spacing. Individual MLPs present a "beaded" shape, with thick segments (0.2-0.3 μm diameter) alternating with thin segments (>0.1 μm). We show that loss of the glycoprotein Chaoptin, which is absolutely essential for rhabdomere formation in the adult PRCs, does not lead to severe abnormalities in larval PRCs.

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The fine structure of the lens and photoreceptors of Nereis virens

Cited by 32 publications

References 10 publications

Distributions and population structures of two intertidal estuarine polychaetes in the lower St. Lawrence Estuary, with special reference to environmental factors

Distributions and population structures of two intertidal estuarine polychaetes in the lower St. Lawrence Estuary, with special reference to environmental factors

Ultrastructure of pigmented adult eyes in errant polychaetes (Annelida): implications for annelid evolution

Serial electron microscopic reconstruction of the drosophila larval eye: Photoreceptors with a rudimentary rhabdomere of microvillar-like processes

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