No abstract

Telocytes ( TCs ), a novel type of interstitial cells, were identified in various animals. Since TCs have not observed in avian skin, hence, we carried out immunohistochemistrical and transmission electron microscopical studies in the skin of the silky fowl to investigate the TCs. TCs appear as CD34, c-Kit, and PDGFRα immunopositive. The elongated TCs with 2 long and thin telopodes ( Tps ) are located in the dermis. Generally, a TC possesses a fusiform, ovoid and polygonal cell body with 2 Tps (lengths = 5.27–21.85 μm), which are uneven in thickness including thick sections – podoms (diameters = 0.40–0.47 μm) and thin sections – podomers (diameters = 0.03–0.04 μm). TCs/Tps are observed frequently in close proximity to neighboring cell types/structures, such as adipocytes, collagen fibers, and capillaries. Under a magnified field, homocellular TCs/Tps contacts are observed through gap junctions (distances = 0.01–0.05 μm), whereas some of TCs/Tps have heterocellular close contacts by point contacts with surrounding cells, including stem cells and melanocytes. The multivisicular bodies, especially exosomes (diameters = 0.09–0.23 μm) releasing from TCs/Tps are observed in close proximity to TCs/Tps. Our results illustrated that the novel type of interstitial cells – TCs are present in the dermis of the silky fowl, and they have special structural relationships with surrounding cell types. The study provides histological evidence for TCs involvement in intercellular communication, skin regeneration, and pigmentogenesis in avian skin.

Background:The Chinese mitten crab (Eriocheir sinensis) is an economically important aquatic species in China. The artificial breeding crabs are also increasing in number day by day. However, knowledge about spermatozoal organization of the crab is still very limited.Aims and Objectives:In the present study, the spermatozoal ultrastructure of the E. sinensis is illustrated for improving artificial breeding technique.Materials and Methods:The spermatozoa are observed by light microscopy and transmission electron microscopy.Results:Spermatozoa are located in the lumen of seminiferous tubules. The spermatocytes and spermatids are observed in the wall of seminiferous tubules. The spermatophores are both present in the lumen of vas deferens and seminal vesicles. A mature spermatozoon consists of a central electron dense acrosome and a peripheral electron lucent nucleus within structures-organelles complex. The acrosome is divided into three zones, including inner acrosome zone, outer acrosome zone and zonal texture. The centre of acrosome is the perforatorium within parallel arranged perforatorial tubules along vertical axis. The highest electron dense operculum surrounds the head side of perforatorium.Conclusion:The ultrastructure of spermatozoa of E. sinensis is illustrated. In particular, the outermost part of the acrosome appears as concentric circles and is described as zonal texture.