Cell and Tissue Journal

Abstract Aim: Pheasant is a pleasant bird whose long and magnificent tail distinguishes it from other types of birds. The cerebellum is organized in the form of leaves that are located in a row in the rostrocaudal axis of the brain. Myelin is the twisting of the plasma membrane of the oligodendrocyte and Schwann cells around an axon, which insulates it and increases the speed of nerve current conduction. Due to the importance and fundamental role of the nervous system, many studies have been done on the nervous system of mammals and other birds, but no research has been done on the development of the pheasant's nervous system, therefore, this research is proposed.
Material and methods: In this study, sixty fertilized pheasant eggs were used. Healthy eggs were placed in the automatic incubator and head sampling was done on different days of the embryo from the 7th day and the one-day-old chick. The specimens were immediately fixed in 10% neutral buffered formalin solution for 24–48 hours and then submitted to the dehydration process by passing them through a series of ascending ethanol alcohol each for two hours (70, 80, 90 and 100%) and then specimens were cleared in xylene for one hour after that embedded in paraffin wax and then the blocks were sectioned by microtome at 5μm thickness. First, all tissue sections were stained with Hematoxylin and Eosin for histological structure, and then to identify myelin fibers and glial cells, sections were stained with special stain; Luxal Fast Blue Cresyl Etch Violet and Mallory's Phosphotungstic Acid-Hematoxylin dyes.
Results: In the cerebellum of a 7-day-old pheasant fetus, myelin fibers were seen in the form of very thin short strands among the primary nerve cells in an irregular and scattered manner. With increasing fetal age, the density, and probably the length of myelin fibers and the size of nerve cells increased also, the spatial arrangement of myelin fibers was seen in the form of regular thickness and almost from the 17-day embryo of the pheasant onwards, the regular arrangement of these fibers led to the recognition of the white and gray matter of the cerebellum.
In 19-day-old pheasant embryo onwards, the regular arrangement of these fibers caused a clear recognition of the white and gray matter of the cerebellum, which until now from this age, they were not distinguishable, but empty spaces between myelin fibers were observed.
Conclusion: The results showed that myelin and glial cells start to form in the pheasant cerebellum from the age of 7 and as the embryo ages, these cells become bigger and completely fill the space between the neurons. Also, myelin fibers were first observed in the form of very thin and scattered threads at the age of 7 embryos and As the embryo ages, these fibers become denser  and finally, in the white matter of the cerebellum of a day-old chick, they find a spatial arrangement in the form of very thick and regular bundles.

Abstract Aim: In this research morphological, cell culture, immunochemical and inductive properties of rat’s claw dermal cells were investigated. Material and Methods: First, the toes and fingers of rat were amputated at the point of the last joint and the amputated parts were processed for histological studies. Moreover, the dermal tissue located beneath the claw’s plate was dissected and cultured in vitro. Cultured cells at passage two or three were transferred on the slide and treated with α-smooth muscle actin (ASMA) antibody. Finally the cultured cells were stained with DiI and implanted into the vibrissae semi-follicles and ears. Results: The rat’s claw dermal cells in terms of morphological, cell culture and expression of ASMA demonstrated similarity with dermal papilla cells of hair follicles. These cells showed a bipolar spindle-shaped morphology having an extracellular matrix rich in glycosaminoglycans. Majority of the cells expressed ASMA in cytoplasm with a higher intensity in lamelopodia.  However, with respect to hair follicular dermal papilla cells, the claw dermal cells were not able to induce an ectopic epidermis to form the skin appendage.  Conclusion: The inductive capability which has been seen in hair follicle’s dermal papilla cells can not be generalized to dermal cells present in other skin appendages, including claw. Based on the results presented here, the inductive factors exist in hair follicle dermal papilla cells is not expressed in the claw dermal cells.

Abstract Aim: During embryonic development, both bird’s feather follicle and mammal’s hair follicle originate by a similar manner, the aim of this research was to access and compare histology, cell growth potential and inductive properties of papilla cells this organs for initiating dermal-epidermal interactions.
Material and Methods: Feather and hair follicles were provided from house pigeons and PVG rats, respectively. Some of the follicles were processed for histological examination whiles others were used to dissect out their dermal papilla. The dissected dermal papillae were cultured in vitro. The cultured cells were then implanted into papilla-depleted follicles. After 28 days the implanted follicles were histologically examined.
Results: Histological surveys revealed that despite some distinct differences, both follicles (feather and hair) share a similar histological structure. Hair’s dermal papilla cells showed a greater rate of growth as well as a higher and denser cell aggregation when compared to that of feather follicles. In contrast to hair papilla, the feather papilla cells were not able to grow a hair fiber in implanted follicles.
Conclusion: Despite similarities in embryonic development, histological structure and cell growth in vitro, it seems that the signals coming from cultured dermal cells of a mature bird are not able to be understood by hair follicle epidermal cells and can not initiate dermal-epidermal interactions

Abstract Aim: To investigate spermatogenesis in the Marsh frog living in Makhmalkooh, Khorramabad, and determine which type of spermatogenesis found in this species.
Material and Methods: 34 male frogs were collected from the study area during September to February. First, the specimens were identified by measuring biometric, meristic characters and according the present keys. Then, abdominal cavity was dissected and the gonads were out and processed to prepare for histological sections methods. The tissue sections were finally examined for histological features and three quantitative parameters.
Results: Microscopic observations showed that in this species the event of sperm releasing starts in March and continue to June, during which spermatogenic cysts are observed on the wall of seminiferous tubules. This event ceases during July to September when spermatogenesis enters to its resting phase. During the resting phase the cysts are not found in the seminiferous tubules. A regenerative phase was distinguished during September to March as the number of cell increased in germinal layer. Quantitative surveys also illustrated that during March to September, diameter of the tubules and their germinal layer initially increased and then declined while the lumen’s diameter showed an opposite flux when compared with two other parameters.
Conclusion: Based on the results presented here, it seems that in this species the spermatogenesis does not occur as continuous but it is carried out in the form of semi-continuous or potentially continuous.
 

Abstract Aim: The aim was to study the histology of somatic embryogenesis stages in Dorema ammoniacum D. using tissue cultures as an efficient method for propagation of the plants with restriction in cultivation. Material and methods: Various explants were cultured on MS (Murashige and Skoog ) medium containing  30 g l^-1 sucrose and 7 g l^-1 agar as well as supplemented with different concentrations of  auxin and cytokinin. After eight weeks, different stages of development of somatic embryos in embryogenic callus were evaluated using histological method. Results: Out of different explants, only zygotic embryo was able to induce embryogenic callus. Presence of NAA (α-Naphthaleneacetic acid) increased callus induction and somatic embryogenesis. The highest callus formation was observed in MS medium supplemented with 1 mg/L NAA and 0.5 mg/L BA (N6-Benzyladenine). Different stages of somatic embryos including: globular, heart-shaped, torpedo and cotyledonus stages were observed in the prepared sections of callus. Conclusion: Using zygotic embryo the in vitro somatic embryogenesis of Dorema ammoniacum D. was possible. In addition the histological examinations of embryogenic callus showed the existence of the different stages of embryonic development.  

Abstract Aim: Histological study of kidney nephrons of Epinephelus coioides Juveniles and Immunolocalization of Na⁺, K⁺- ATPase during osmoregulation and adaptation with hypo- and hyper-osmotic (10 and 60 ppt) conditions.
Material and Methods: H & E staining and IgG 5 and FITC as primary and secondary antibodies were used for kidney nephrons histological studies and Immunolocalization of Na⁺, K⁺- ATPase, respectively.
Results: Results of microscopic study indicated that kidney nephrons of juvenile grouper were consisted of Glomerulus, Neck segment, Proximal, Distal and Collecting tubules. Immunolocalization of control group showed that Na⁺, K⁺- ATPase was distributed in all part of nephron structure but glomeruli. In hypo- and hyper-osmotic environments similar to control condition the enzyme distributed into the epithelial cells of proximal, distal and convoluted tubules but was not presence in glomeruli.
Conclusion: The results of present study indicated that, the structure of kidney nephrons of E. coioides was similarto that of other euryhaline species and presence of Na⁺, K⁺- ATPase in basolaterl portion of cell membrane indicated its active role in osmotic and ionic regulation in kidney.    
 

Abstract Aim: The aim of this study was to evaluate the validity of bulge hypothesis on the limited proliferative potential of epidermal cells located at the basal end of hair follicle.
Material and methods: Fibers of rat vibrissa follicles were plucked once or repeatedly and then pattern of cell replication and sequence of regenerative events was examined by measuring length of growing fiber, histology of regenerating follicle and immunohistochemistry (BrdU uptake of epidermal cells).
Results: Data provided here demonstrated that after single or multiple depletions, a new epidermal matrix originated merely from the residual germinative epidermal cells of the follicle base and cells from the bulge region had no role in formation of this structure. The matrix is the source of a new fiber which grows at a equivalent rate to its native counterparts from unplucked follicles. The total length of hair produced from the plucked follicles was much longer when compared to the fiber produced in normal follicles.
Conclusion: Based on our results, replicative potential of epidermal cells located at the follicle base is not limited to a single cycle. We therefore consider it unlikely as cessation of growth phase of follicle is due to restricted proliferative potential of these cells.
 
 

Abstract Aim: As there is not any comprehensive studies on cartilage tissue in Persian sturgeons and this valuable species is native in south coast of the Caspian Sea, in this reserch light and electron microscopic study of cartilage tissue of dorsal fin were provided to use in other related studies. Material and Methods: The routine procedures of preparation of tissues were followed for light microscopic study. Paraffin blocks were cut with a thickness of 6 microns, stained with H&E. For transmission electron microscopic study the samples after primary and post-fixation, were dehydrated and embedded in resin. Then, ultrathin sections of 50 nm were stained with uranyl acetate. Results: Light microscopic results showed that cartilage tissue of dorsal fin is made of prichondrium, chondroblast and chondrocyte and a large number of mature cells have the same origin and common lacunae. In ultrastructural studies chondroblasts have more aggregation of inter cellular organelles than the chondrocytes. This finding was prominent in upper age but membrane of cartilage tissue was not smooth in all age. Conclusion: Light and transmission electron microscopic studies of cartilage tissue of dorsal fin in Persian sturgeons were similar to the other species but a little difference were seen to be reported.