The mechanism of physiological regeneration in the skin and intestinal epithelia of Saccoglossus mereschkowskii (Enteropneusta, Hemichordata)

Content Provider	Semantic Scholar
Author	Stolyarova, Marina Val’kovich, E. I.
Copyright Year	2016
Abstract	dylate buffer (pH 7.4) for 40–60 min at 4°С and then postfixed in 1–2% osmium tetroxide solution. Tonicity of the fixatives was adjusted to the seawater level (1000 mOsm for the Barents Sea) by adding sucrose or sodium chloride. Fixed small fragments of the proboscis and middle part of the trunk were dehydrated and embedded in Araldite. Semithin (1–2 μm) sections stained with toluidine blue were used as orientation cues within the specimens. Histological preparations were examined under a Leica DME light microscope; images were obtained with a Leica EC3 digital video camera (Leica, Germany). Thin sections (50–80 nm) for electron microscopy were cut using a LKB ultra-microtome III (Sweden) and transferred to support bare mesh grids or formvar-coated slot grids. Ultrathin sections were stained with uranyl acetate and lead citrate and examined using electron microscopes JEM-5G, JEM-7, and JEM-100B (Japan). In the skin epithelium of S. mereschkowskii, consisting of ciliated and glandular cells [3], mi-toses are rare events. Mitotic figures occur both in the superficial zone and at the level of the nucleus-containing cell bodies (Fig. 1a), as well as in the Among extant animals, the acorn worms (Hemichordata, Enteropneusta) are closest to the ancestors of chordates both in terms of structure [1] and molecular/biochemical features [2]. These traits make this group an important model for comparative morphology and physiology. Any information about the sources of physiological re-generation of epithelial tissues in acorn worms is currently lacking in the literature. The aim of the present work was to determine the morphological characteristics of mitotically dividing cells in the skin and intestinal epithelia of the Enteropneusta. The study was carried out on Saccoglossus mere-schkowskii (Hemichordata, Enteropneusta, Har-rimaniidae). The material was collected during summer in the littoral zone of the Barents Sea coast in the vicinity of Dal'nie Zelentsy village. For light microscopy, Bouin's and Carnoy's fixatives were used as well as formalin/acetic acid/ alcohol. Series of paraffin sections (5–7 μm) were stained with hematoxylin/eosin, iron hematoxy-lin, and Heidenhain's azan; the McManus' PAS-reaction was also performed. For electron microscopy, animals were fixed with 2.5% glutaraldehyde in phosphate or caco
Starting Page	84
Ending Page	86
Page Count	3
File Format	PDF HTM / HTML
DOI	10.1134/S0022093016010105
Alternate Webpage(s)	https://page-one.springer.com/pdf/preview/10.1134/S0022093016010105
Alternate Webpage(s)	https://doi.org/10.1134/S0022093016010105
Volume Number	52
Journal	Journal of Evolutionary Biochemistry and Physiology
Language	English
Access Restriction	Open
Content Type	Text
Resource Type	Article