In this study, 78 sheep fetuses were used for the evaluation of anatomic and histologic aspects of lens with three methods (H&E, Verhoeff's and P.A.S. staining). The results showed that the lens vesicle was formed completely by 30th day and lost its contact with the superficial ectoderm. In 40th day of fetal period, the epithelium of the posterior wall of the lens gradually started to disappear due to its development and formation of forward facing elastic fibers limiting the internal space of the vesicle. By 150th day, the density and thickness of these fibers were increasing. In addition, at this day, the capsule of the posterior surface of the lens started to form. In 50th day of fetal period the internal space of vesicle was filled with elastic fibers and the epithelium of the anterior surface became simple cuboidal. At that day, the capsule of the anterior surface of the lens gradually was formed and in 60-day fetus, it became complete. By 150th day, its thickness was increased a little. After 80th day, the convexity of the posterior part would become more than the convexity of the anterior part because of the increased growth of lens fibers.

In this study, 36 samples of sheep fetal at different and modal ages have been used.Sample after preparation and determination of age immediately fixed and anatomic and histological studies were done. In Histological studies in addition to conventional H& E staining, two staining that include Masson trichrome and verhuff staining was used. The yield results revealed that cornea is distinct in the second month of embryonic period and in the next ages spends the stages of growth. From the beginning in cornea formed in horizontal ellipse type so the internal curve of is larger than external curve. The growth process from the point of longitudinal diameter, transverse diameter and corneas height from the border of sclera is ascending with the raising of age. Upper and lower eyelids was impacted in the early and late time of the second month and separated from together again in the third month of embryonic period. Third eyelid approximately appears in 120 days of age in the internal angle of the eye. Histology of external epithelial tissue growth observed from simple cubic to six layers stratified cubic form. Matrix has been strengthened from point of cells (fibroblast) and a filaments (collagen) with the rising of age. Increases in the elastic filaments are appreciable at the end of embryonic stages.Desmit membrane appears as limiting membrane in the early time of the second month of embryonic period in the beneath of internal epithelial tissue and also growth with rising of age. Desmit membrane has any elastic filaments. No Bowman layer or the external limiting membrane was seen in this animal. Tricrummasson staining confirms collagen filaments and verhuff staining confirm elastic filaments growth with rising of age.

The aim of this study was to investigate the differentiation of nephron and other structures of metanephric kidney in goat fetuses. The study was descriptive which was conducted in 2013 at the Islamic Azad University of Tabriz. The approximate age of the embryos was determined based on the formula presented by Gal et al (1994) in order to estimate the age of the goat fetus. Taking into account the age of the fetus, they were divided into 4 groups of 25 fetuses in each. The first, second, third, and fourth groups were on 38-60, 61-90, 91-120, and 121-150 days of pregnancy, respectively. The kidneys of the fetus were isolated following autopsy of the baby's abdominal cavity in order to examine the metanephros tissue differentiation. Isolated samples were placed in 10% buffered formalin solution. They were examined under the optical microscope after the preparing of tissue sections. Data analysis among the groups was conducted using ANOVA and Tukey's multiple comparison tests as well as SPSS 10 software. According to the results there was a significant difference between the four groups since 30-days old until birth in terms of the mean length (p <0.05). Also, there was a significant difference in the mean fetal weight. A significant difference was also observed in the mean of the quantitative parameter such as length, width, thickness and weight of the right and left metanephric kidneys of goat embryos among groups in different ages (p<0.05), but the difference was not significant between the right and left kidneys. The glomerular emergence and growth pattern from the nephrogenic vesicular stage to final glomerule is similar to the human embryo. A glomerule should run its evolution and the process was made from the surface to the metanephric level.

The purpose of this study is to determine the differentiation time of cerebellum tissue during fetal life. This study is a descriptive observation of 100 fetuses of pregnant sheep uterus that were chosen randomly. After fixation, morphological measurement and preparing histological sections, the samples were stained by H&E and were examined under a light microscope. According to microscopic observations of 40th day of gestation, cerebellum tissue had not yet differentiated. Therefore, at this stage, the appearance of cerebellum was like an overlying mass of neuroepithelial cells in metencephalon area of neural tube. At the 50th day of gestation, the initial form of the cerebellum was separable due to the placement of migrating cells in layers and creating initial wrinkle under the pia mater. At the 70th day, great number of wrinkles could be seen on long strips in a way that primary wrinkle was underneath the secondary wrinkle. At the 80th day of gestation, Purkinje cells were observed between granular and molecular layers. At the 90th day of gestation, cerebellum tissue had primary, secondary, and tertiary wrinkles. At the 120th day, the whole tissue structure of cerebellum, in the last month of pregnancy, was seen as a mature form in a way that in the last three months there were no significant changes. This can be concluded that the differentiation of cerebellum tissue from the mass of migrating cells of neural tube starts after the sixth week and the whole cerebellum tissue structure appears in fetal life and a month before birth.

Introduction: In chick embryo, endodermal component of the liver becomes split into 2 diverticula in a short time. The anterior diverticulum lies to the left of the ductus venosus and the posterior one to its right side. As the liver primordium grows, it is invaded by the embryonic veins. Based on the different incubation time periods and evolutionary origin of avian species, various times for morphogenetic events of the liver are expected. The chukar partridge (Alectoris chukar) belongs to a common family with the chicken and shows 3 to 4 days longer embryonic period. This study was designed to describe normal histological and histochemical events of the liver HISTOGENESIS of the chukar partridge. It would be interesting to see how the time and sequence of developmental events of liver HISTOGENESIS are similar to those of the chick embryo.Methods: In this study, partridge (Alectoris chukar) embryos were studied from day 5 to 24 of incubation. In the course of the study, their liver 5-mm thick sagittal and transverse sections were prepared. Then, the sections were stained with hematoxylin-eosin (H&E) and Periodic Acid Schiff (PAS) methods and studied under the light microscope.Results: During the histogenetic study of the chukar partridge liver, we noted the structures and events such as the dark and light hepatocytes, mitotic divisions, sinusoids and kupffer cells, as well as the glycogen storage in the hepatocytes and their development, also changes due to the time of incubation period.Conclusion: Although the sequential events of the liver HISTOGENESIS of chukar partridge follow the general pattern of the other birds, some differences exist in the time of formation liver components compared to other studied species.

The aim of this study is determination pattern of development of testis structure in goat fetus. The samples in this study included the pregnant slaughtered goats in industrial slaughtered house in autumn season and unit of sampling was including 100 separated fetuses from uterus of pregnant mothers. The method of sampling was accidental .The age of collected fetuses were calculated according to Gall et al. (1994) as X=2.74 Y+30.15. After dissection of fetuses from different ages, the testis samples for histological study and performing histotechnique procedures were put in 10% buffered formalin and stained by methods of H&E, periodic shift acid and Masson, s trichrome and studied under light microscope . Data were analyzed by ANOVA and Tukey test and SPSS software. The results of microscopic studies, Showed that gonads in 35 days of pregnancy were as a mass connected to mesonephrosis. Primary sign of differentiation of testis in 35 days of pregnancy was observed that it was built of white membrane and in 42.5 days of pregnancy primary genital cords were formed. In 50 days of pregnantcy, we observed myoid cells that surround the genital cords and a few days after that leydig cells in internal space of testis observed. Genital cords until to birth surrounded with sertoli cells and gonocytes were in the center of cords so that it seems as solid tubule until birth. According to the results it was obtained that the time of differentiation of testis ruminants is different. The amount of biometry increased with growth of fetus gradually. So a significant difference between the age ol groups was observed (p<0.05).

Leiomyoma is a very rare intraocular tumor, which can occur in the iris, ciliary body and choroids. We report a case of choroidal leiomyoma in a 16-Years old women whose left eye was enucleated because of clinical suspicion for melanoma. Using conventional light microscopy tumor was interpreted as spindle cell tumor, most probably of neurogenic origin and after using immunohistochemical studies; smooth muscle origin of tumor was confirmed

The structure and HISTOGENESIS of the stigma of Datura stramonium was investigated by light and scanning electron microscopy to determine the developmental origin of the transmitting tissue and “wet stigma”. Four developmental stages were defined on the basis of bud length. Stage one, the HISTOGENESIS stage, was comprised of buds 2-15 mm in length. Stage two, signified by the growth and development of the stigma was comprised of buds 15-40 mm long. Stage three, with buds of 40-60 mm in length, represented a receptive and mature stigma. Stage four started with self pollination (occurs prior to anthesis) and ended with stigma senescence. A developing stigma showed a bilobed, papillated surface, covered with sticky secretion. The stigma consisted of two distinct zones; 1) Superficial zone; formed by papillae and 5-8 layers of secretory cells immediately beneath them. This zone was subjected to a gradual lysis in the ontogeny of the stigma. 2) Internal zone; formed by the transmitting tissue of the style. This zone remained intact throughout the development. Transmitting tissue and stigma both originated from the epidermis of the carpels. Similarities in structural organization of the stigma of Datura to those reported in Solanum tuberosum were considerable.

Introduction: This investigation was undertaken to examine chemical nature of glycoconjugate components on the surface of developing rat intestinal cells during gut HISTOGENESIS. Materials and Methods: Rat embryos at days 10-12 of gestation was fixed in B4G and processed for lectinhistochemistry. 5m paraffin sections were incubated with 10-15 µg/ml solution of HRP/lecti ns from arachis hypogaea (PNA) and dolichos biflorus (DBA), in 0.1 M PBS, pH 7.2. All sections were developed in substrate medium containing 0.03% DAB and 0.006% H2O2 in tris buffer pH 7.6. Results: Until day 15 of gestation none of two the tested lectin had any reaction with developing intestine. PNA had strong reaction with the submucosal layer of intestine at days 15 and 16. With the exeption and goblet cell the epithelial cells of intestine had strong reaction from day 17 to the time of birth. DBA reacted only with epithelial cells of large intestine two days before birth. Conclusion: The marked changes in the appearance and distribution of the intestinal glycoconjugates during gut morphogenesis support the concept that rapid changes occur in the structure of complex carbohydrates during embryonic and fetal development. The findings also suggest that GalNac and Gal.-GalNac.- containing glycoconjugate may be of functional importance in the regulation of the embryonic intestinal cells during the course of their development.