Profiles

Lena Gustavsson

Lena Gustavsson

Forskare

View page in English
Arbetar vid Zoologiska institutionen
E-post lena.gustavsson@nrm.se
Besöksadress Frescativägen 40, Naturhistoriska riksmuseet
Postadress Zoologiska institutionen Box 50007, 104 05 Stockholm

Publikationer

I urval från Stockholms universitets publikationsdatabas
  • 2008. Erica Sjölin, Lena M. Gustavsson. Journal of morphology (1931. Print) 269 (1), 45-53

    The ultrastructure of the cuticle in four species of the marine Heterodrilus (H. paucifascis, H. pentcheffi, H. flexuosus, H. minisetosus) is investigated with transmission electron microscopy. The noncellular cuticle consists of several parts; closest to the epidermis is a thick zone of collagen fibers embedded in a matrix. The matrix continues outside the fiber zone, forming a layered epicuticle. The external surface of the epicuticle is covered by evenly distributed, membrane-bound bodies, termed epicuticular projections. The epicuticular projections have their longitudinal axis perpendicular to the surface of the cuticle and are attached to the surface by either the surrounding membrane itself or by short pedestals. Microvilli, extensions from the epidermal cells, penetrate and sometimes pass completely through the cuticle. There is interspecific variation in the morphology of the cuticle. The four studied species differ in the arrangement of the collagen fibers, from irregularly distributed fibril bundles to orthogonally arranged fiber layers, as well as in the number and density of layers in the epicuticle. One of the studied species, H. paucifascis, shows intraspecific variation, which is associated with sample locality. The Bahamian specimens of H. paucifascis have four layers in the epicuticle, club-shaped epicuticular projections, and collagen fibers forming a less defined orthogonal grid, while the Belizean specimens have three layers in the epicuticle, epicuticular projections with a bulging part at midlevel, and a distinct orthogonal grid. Based on these findings the variation in the morphology of the cuticle appears to be dependent on both phylogenetic constraints, and functional and environmental factors.

  • 2008. Erica Sjölin, Lena M. Gustavsson. Journal of morphology (1931. Print) 269 (1), 45-53

    The ultrastructure of the cuticle in four species of the marine Heterodrilus (H. paucifascis, H. pentcheffi, H. flexuosus, H. minisetosus) is investigated with transmission electron microscopy. The noncellular cuticle consists of several parts; closest to the epidermis is a thick zone of collagen fibers embedded in a matrix. The matrix continues outside the fiber zone, forming, a layered epicuticle. The external surface of the epicuticle is covered by evenly distributed, membrane-bound bodies, termed epicuticular projections. The epicuticular projections have their longitudinal axis perpendicular to the surface of the cuticle and are attached to the surface by either the surrounding membrane itself or by short pedestals. Microvilli, extensions from the epidermal cells, penetrate and sometimes pass completely through the cuticle. There is interspecific variation in the morphology of the cuticle. The four studied species differ in the arrangement of the collagen fibers, from irregularly distributed fibril bundles to orthogonally arranged fiber layers, as well as in the number and density of layers in the epicuticle. One of the studied species, H. paucifascis, shows intraspecific variation, which is associated with sample locality. The Bahamian specimens of H. paucifascis have four layers in the epicuticle, club-shaped epicuticular projections, and collagen fibers forming a less defined orthogonal grid, while the Belizean specimens have three layers in the epicuticle, epicuticular projections with a bulging part at midlevel, and a distinct orthogonal grid. Based on these findings the variation in the morphology of the cuticle appears to be dependent on both phylogenetic constraints, and functional and environmental factors.

  • 2008. Ida Envall, Christer Erséus, Lena Gustavsson. Journal of Morphology 269 (9), 1157-1167

    Various types of free-floating cells are found in the coelomic fluid of representatives of several annelid groups. The ultrastructure of these "coelomocytes," however, has been studied to a limited degree. In this study, we used a transmission electron microscope to investigate the coelomocytes in specimens of five species of Naidinae and three species of Rhyacodrilinae (all oligochaetous clitellates within the family Tubificidae). These were compared with each other and with previously described coelomocytes of representatives of other oligochaete taxa. Only one distinguishable coelomocyte type was found in the studied specimens: a round to oblong cell without pseudopodia or other appendages, primarily containing membrane-bound granules of varying electron density, a prominent network of rough endoplasmic reticulum, and free ribosomes. This type differs to a great extent from most of the previously described coelomocytes, but shows similarities to certain types found in members of Enchytraeidae and Megascolecidae. Although we noticed some variation, we did not find any ultrastructural characters in these cells obviously useful for phylogenetic studies within Tubificidae.

Visa alla publikationer av Lena Gustavsson vid Stockholms universitet

Senast uppdaterad: 27 september 2017

Bokmärk och dela Tipsa