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I Spies

Publications and source records attributed to I Spies.

5 recordsLinked to original sources
PubMed2003

A consolidated linkage map for rainbow trout (Oncorhynchus mykiss).

Androgenetic doubled haploid progeny produced from a cross between the Oregon State University and Arlee clonal rainbow trout (Oncorhynchus mykiss) lines, used for a previous published rainbow trout map, were used to update the map with the addition of more amplified fragment length polymorphic (AFLP) markers, microsatellites, type I and allozyme markers. We have added more than 900 markers, bringing the total number to 1359 genetic markers and the sex phenotype including 799 EcoRI AFLPs, 174 PstI AFLPs, 226 microsatellites, 72 VNTR, 38 SINE markers, 29 known genes, 12 minisatellites, five RAPDs, and four allozymes. Thirty major linkage groups were identified. Synteny of linkage groups in our map with the outcrossed microsatellite map has been established for all except one linkage group in this doubled haploid cross. Putative homeologous relationships among linkage groups, resulting from the autotetraploid nature of the salmonid genome, have been revealed based on the placement of duplicated microsatellites and type I loci.

Animals↗
PubMed1997

Immunolocation of mitochondria-rich cells in epidermis of the common toad, Bufo bufo L.

The mitochondria-rich cells (MRCs) in adult toad epidermis have an important osmoregulatory function, being specialized for chloride transport. Immunostaining with monoclonal antibodies against human keratins was used to compare the keratin expressed by MRCs with that of principal cells (PCs). By the indirect immunoperoxidase technique, keratin epitopes in vertical cryosections (4-6 microns) of toad skin were labelled and examined by light microscopy. MRCs were stained selectively by the antibodies 6B10 (anti-keratin 4) and RCK102 (anti-keratins 5 and 8). In contrast, MRCs were not detected by the oligospecific MoAb K 8.12 that recognized the intermediate PCs, but not the basal ones. The polyspecific antibody LP34 stained both the MRCs and the basal PCs, whereas the antibody RCK107 (anti-keratin 14) stained MRCs intensely and part of the basal PCs more weakly. These immunoreactions indicate that the MRCs and the intermediate PCs express amphibian equivalents to the human keratins 4/5 and 13/15, respectively. Notably, MRCs were detected in all epidermal layers except stratum corneum. Presumably, the MRCs originate in the basal layer and retain their expression of an amphibian equivalent to the human keratin pair 4/5 + 14 throughout epidermis.

Animals↗
PubMed1995

Tissue kinetics, ion transport, and recruitment of mitochondria-rich cells in the skin of the toad (Bufo bufo) in response to exposure to distilled water.

Mitochondria-rich cells (MRC) of the amphibian epidermis are responsible for active chloride uptake at low external salinity, and new MRCs are recruited in response to exposure to distilled (deionized) water. The time-course of this recruitment, the tissue kinetics and ion transport have been studied in toads (Bufo bufo) immediately before, and after 2,7, and 14 days exposure to distilled water. General epidermal structure was not affected. However, the numbers of MRCs per mm2 (DMRC) increased throughout the experiment as revealed by staining of epidermal sheets with AgNO3 (Ag) or methylene blue (MB). Part of the increased DMRC was accounted for by an increase in MRC subpopulation(s) that stained neither with Ag nor MB. The cell birth rate (Kb) decreased and cell loss by moulting (Kd) increased without any significant change in epidermal cell pool size, indicating a reduced apoptotic rate. The increase in DMRC was accompanied by a 3-fold increase in Cl- current (ICl). At day-2 there was a transient reduction in the ICl per MRC. H+ secretion was progressively reduced during prolonged exposure to distilled water. Thus, at day-2 MRCs appeared incompletely differentiated as indicated by decreased ICl and H+ flux per MRC, and by the increased proportion of MRCs unstained by Ag or MB. Full Cl- (but not H+) transport capacity, was restored at day-7. We conclude that increased DMRC following exposure to low external Cl-, rather than being due to an increased Kb, is the combined effect of a decreased apoptotic rate and an increased rate of differentiation, where 'morphological differentiation' precedes 'functional differentiation'.

Animals↗
PubMed1989

Epidermal tissue homeostasis: apoptosis and cell emigration as mechanisms of controlled cell deletion in the epidermis of the toad, Bufo bufo.

In normal, non-expanding toad epidermis more cells are produced than needed to replace cells lost by moulting. By implication, cell deletion additional to moulting must take place. This paper deals with the mechanisms by which the "surplus" of cells is deleted, taking advantage of the fact that the ratio between cell birth rate (Kb) and the rate of desquamation (Kd), which in normal toads is 2 to 3, can be manipulated. In toads deprived of the pars distalis of the pituitary gland it is decreased to 0.2 to 0.3, and in toads with hydrocortisone pellets implanted into the subcutaneous lymph space it is increased to 7 to 10. Thus, structures candidates for the morphological manifestation of the deletion process should occur rarely in toads in which the pars distalis has been removed and frequently in toads with hydrocortisone pellets implanted. Categorization and enumeration of such structures by light microscopy in the epidermis from operated, normal, and hormone-treated toads were performed. The incidence of structures referred to as "dark cells" and "omega-figures" were found to correlate relatively well with the Kb/Kd-ratio. A subsequent ultrastructural analysis - on a cell-by-cell basis - of "dark cells" showed these to reflect various stages of apoptosis. The duration of the apoptotic process was calculated to be approximately 7 h. Light- and electron microscopy of "omega-figures" combined with histochemical observations of PSA-lectin binding were interpreted as reflecting a release of cells from the basal epidermis and their final elimination within the dermis. It is concluded (i) that apoptosis is an important mechanism of controlled cell deletion, (ii) that emigration to, and elimination in, the dermis is a possible deletion mechanism, and (iii) that necrosis is unlikely to play a role in controlled cell deletion.

Animals↗