scholarly journals Characterization of Melanocytes in Wool-bearing Skin of Merino Sheep

1985 ◽  
Vol 38 (3) ◽  
pp. 245 ◽  
Author(s):  
JW Forrest ◽  
MR Fleet ◽  
GE Rogers

The distribution and character of melanocytes in the wool-bearing skin of Merino sheep of known genotypes were examined by light and electron microscopy. In black Merino sheep (ww, homozygous recessive), melanocytes were localized within three regions of the skin: epidermal-dermal border, outer root sheath and follicle bulb. Melanocytes within these regions were found to be actively producing melanin, had numerous dendritic extensions and were able to transfer melanin to adjacent keratinocytes. In a black Merino sheep whose fibres were white due to an experimentally induced copper deficiency the melanocytes were amelanotic. In contrast, for both WW (homozygous dominant) and Ww (heterozygous) white Merino sheep melanocytes were observed only at the epidermal-dermal border of the epidermis. The melanocytes appeared also to differ in character containing less melanin, appearing less dendritic in shape and having a reduced ability to transfer melanin to adjacent keratinocytes. The gene for white fleece (W), therefore, appears able to regulate pigmentation in Merino sheep, at least in part, by controlling the location and activity of melanocytes within the wool-bearing skin.

Animals ◽  
2021 ◽  
Vol 11 (10) ◽  
pp. 2798
Author(s):  
Yanyu He ◽  
Xiu Liu ◽  
Jie De ◽  
Saihong Kang ◽  
John S. Munday

This experiment compared secondary hair follicles (SFs) in Tibetan cashmere goats from two different steppes that were at different altitudes and had different temperatures. Twenty-four 2-year-old goats were studied. Twelve goats were from Rikaze in Tibet which is at an altitude of above 5000 m with an average temperature of 0 °C. The other 12 studied goats were from Huan County of Gansu Province which is around 2000 m above sea level with an average temperature of 9.2 °C. The structural features of SFs were assessed using light microscopy and transmission electron microscopy. The presence of HIF-1a, HIF-2a, HIF-3a, HSP27, and HOXC13 proteins was studied using immunohistochemistry and immunofluorescence. Light and electron microscopy revealed that the SFs of the Tibetan cashmere goats that lived in the Rikaze Steppe were in the proanagen stage in May. However, the SFs of the goats from the lower warmer Huan County were in the anagen stage at the same time. Immunohistochemistry revealed intense immunostaining for HIF-1a protein in the inner root sheath (IRS) and hair shaft (HS); immunostaining against HIF-2a in the outer root sheath (ORS) and IRS; HIF-3a protein immunostaining in the ORS; HSP27 immunostaining in the ORS, IRS, and HS; and HOXC13 immunostaining in the ORS and HS. HIF-1a protein expression in the IRS and HS was higher than the expression in the ORS (p < 0.05) while the expression of HIF-2a protein was higher in the ORS and IRS than the HS (p < 0.05). The expression of HIF-3a protein was higher in the ORS than in the IRS (p < 0.05). Expression of HOXC13 protein was higher in the ORS than in the IRS and HS (p < 0.05). Immunostaining of HIF-1a, HIF-2a, and HSP27 protein was significantly higher in SFs from cashmere goats from Rikaze than in goats from Huan (p < 0.05). In contrast, HOX13 protein immunostaining was significantly higher in cashmere goats from Huan than from Rikaze (p < 0.05). Significant differences were observed in the SFs of cashmere goats from two locations that differ in altitude and temperature. This suggests the differences in the secondary hair follicles could be due to the hypoxia and lower temperatures experienced by the goats in Rikaze. These results are useful in understanding how altitude and temperature influence SF development. Hair produced by the SFs are used for down fiber. Therefore, understanding of the factors that influence SF development will allow the production and harvest of these valuable fibers to be maximized.


2011 ◽  
Vol 135 (4) ◽  
pp. 503-510
Author(s):  
Darcy A Kerr ◽  
Vincent A Memoli ◽  
Sara S Cathey ◽  
Brent T Harris

Abstract We report findings from an autopsy of a 45-year-old woman with the rare lysosomal storage disease mucolipidosis type III α/β. Her disease manifested most notably as multiple bone and cartilage problems with tracheal and bronchial malacia. Principal autopsy findings included gross abnormalities in bone and cartilage with corresponding microscopic cytoplasmic lysosomal granules. These cytoplasmic granules were also seen in histologic preparations of the brain, myocardium, heart valves, and fibroblasts of the liver and skin by light and electron microscopy. By electron microscopy there were scattered, diffuse vesicular cytoplasmic granules in neurons and glia and an increase in lysosomal structures with fine electron lucent granularity in the above tissue types. Our findings help elaborate current understanding of this disease and differentiate it from the mucopolysaccharidoses and related disorders. To our knowledge, this is the first report to document pathologic findings in a patient with mucolipidosis type III α/β by autopsy.


1998 ◽  
Vol 4 (S2) ◽  
pp. 1024-1025
Author(s):  
Frederick R. Maxfield ◽  
Richik N. Ghosh ◽  
William G. Mallet ◽  
Thwe Thwe Soe ◽  
Philip L. Leopold ◽  
...  

We have used light and electron microscopy to analyze endocytic trafficking pathways. In one set of studies, we have used fluorescently labeled antibodies to trace an endocytic pathway from the cell surface to the trans- Golgi network (TGN). Cells were transfected with a construct consisting of the transmembrane and cytoplasmic domains of TGN38 and the extracellular domain of Tac. TGN38 is predominantly in the TGN, but a small fraction is found on the cell surface. We used FITC-labeled anti-Tac monoclonal IgG to analyze the pathway from the surface to the TGN. We compared the distribution of internalized Tac-TGN38 to internalized transferrin. We found that most Tac-TGN38 enters the same early endosomes as transferrin. Furthermore, most Tac-TGN38 returns to the cell surface from the endocytic recycling compartment (ERC) at the same rate as transferrin. However, on each pass through the cell approximately 18% of Tac-TGN is retained, and this Tac-TGN38 is delivered to the TGN.


1994 ◽  
Vol 127 (1) ◽  
pp. 76-93 ◽  
Author(s):  
Mary Bartlett Bunge ◽  
Vicky R. Holets ◽  
Margaret L. Bates ◽  
Theresa S. Clarke ◽  
Brant D. Watson

1994 ◽  
Vol 40 (1) ◽  
pp. 35-44 ◽  
Author(s):  
Srabani Banerjee ◽  
Judy Little ◽  
Maria Chan ◽  
Brian T. Luck ◽  
Colette Breuil ◽  
...  

A sensitive immunological tool has been developed to detect the sapstaining fungus Ophiostoma piceae 3871, which plagues the wood industry. Monoclonal antibodies (1F3(1), 4G3(14), 4G2(4), and 2B6(24)) produced against cell wall protein extracts of this fungus were specific. Specificity was estimated by enzyme linked immunosorbent assay, western blotting, and light and electron microscopy using the immunogold technique. Electron microscopy revealed gold particles localized on the outer surface of the cell wall. When screened against 24 biological control fungi the antibodies showed pratically no cross-reactivity (< 4%). When tested against 19 other staining fungi, the antibodies recognized three strains of Ophiostoma piceae, 1F3(1) recognized Phialophora botulispora, and the antibodies showed less than 5% reactivity with the other fungi. Chemical and enzymatic modification of the antigen revealed that the epitopes recognized by the monoclonal antibodies were glycospecific. Although the antibodies were produced against the cell wall protein extracts of the fungus grown in liquid culture, they also recognized the fungus growing in wood and therefore can be employed to investigate wood colonization by this fungus.Key words: Ophiostoma piceae, monoclonal antibodies, glycoprotein.


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