جستجوی مقالات مرتبط با کلیدواژه « تخمک » در نشریات گروه « زیست شناسی »

In this research, the embryological characteristics of Anthemis haussknechtii were investigated. This study aimed to characterize the reproductive features of A. haussknechtii to find unique embryological characteristics. Light and fluorescence microscopes were used to examine different developmental stages. According to the results, the anther was tetrasporangiate and its wall development followed the dicotyledonous type. Young anther walls were composed of the epidermis, endothecium, middle layer, and tapetum from the outside to the inside. The tapetum layer was secretory. Tetrads of microspores were tetrahedral and tetragonal. Pollen grains were two-celled, triporate, and echinate when they shed. The ovule was of anatropous, unitegmic, and tenuinucellate type. Endothelium was composed of one row of cells. The micropylar megaspore developed into an eight-nucleate embryo sac with the pattern of Polygonum type. The tapetum type, mature pollen grain, and embryonic sac were different from the studied species of Anthemis. These results revealed valuable developmental features that could be used to differentiate this species from other members of the Asteraceae family.

Freezing is a long-term egg storage method that plays an important role in assisted reproductive methods. The aim of the present study is to investigate the effect of freezing solutions and docetaxel on the expression changes of autophagy genes such as Atg5 and Beclin-1 in mouse MII oocytes after glass freezing by cryotop method. To achieve this goal, mouse MII oocytes were collected and frozen in two different concentrations of 15% ethylene glycol, 15% dimethyl sulfoxide and 0.5 M sucrose in group A (VS1) and 7.5% ethylene glycol, glycerol. 7.5% and 0.5 M sucrose were frozen in group B (VS2) and some groups were affected by docetaxel before freezing. After thawing, the eggs were fertilized.The percentage of survival and fertilization of frozen and thawed oocytes was evaluated and the expression changes of genes (Atg5 and Beclin-1) were investigated by RT-PCR method. The results showed that there are significant differences between the percentage of survival and the percentage of fertilization in the freezing groups compared to the control group (P<0.05). The percentage of survival and fertilization in the VS1 group decreased compared to the VS2 group. Also, the percentage of survival and conception of the groups pre-incubated with Docetaxel was higher than the non-incubated groups. This study showed that vitrification with cryotop changes the transcript levels of autophagy genes in frozen-thawed MII oocytes, and pre-incubation of oocytes with docetaxel before vitrification can decrease the transcript levels of Atg5 and Beclin-1 in the experimental groups and above Increase the percentage of survival and the percentage of formation of two-celled embryos.

Optimizing cell culture conditions to improve oocyte growth and maturation in vitro culture conditions has been the focus of many researchers today, but the quality improvement mechanism is not fully understood. Apoptosis or programmed cell death is a process to remove old and damaged cells from tissues and plays a major role in the life of follicles and immature oocytes. Most of the defective reproductive cells as well as extra cells are removed from the ovaries through apoptosis. One of the ways to reduce oxidative stress in the laboratory culture of oocyte maturation is the use of antioxidants. Statins are drugs for the treatment of high cholesterol for which antioxidant and anti-apoptotic properties have been reported. Atorvastatin in high doses has side effects for the heart and kidneys, but in low concentrations, it has antioxidant and anti-inflammatory effects for cells, and no side effects have been reported for it.In this study, we investigated the effect of low-dose atorvastatin on the rate of apoptosis in mouse oocytes. 

24 h after PMSG (Pregnant Mare Serum Gonadotropin) inhection, 200 oocytes were obtained from adult female Wistar rats at the age of 4-5 weeks, were from were divided into 2 groups of 100 including the control group (MEM:Minimum Essential Medium culture+ Growth factor) and the atorvastatin group (MEM culture medium + 2 mg/kg atorvastatin+Growth factor) and cultured in the incubator(35 oC,CO2 %). After 24 hours of oocyte culture, Matured oocytes that met the standards of a healthy mature oocyte(oocytes that were in the first meiosis and had the first and mature polar body) were isolated the amount of apoptosis in each group was checked using tunnel staining and fluorescent microscope, the data were analyzed by variance analysis.

After 24 hours of oocyte culture, the amount of apoptosis in the group receiving atorvastatin in the culture medium and the control group was investigated. The rate of apoptosis in the atorvastatin group and the control group was 24% and 22%, respectively, In the atorvastatin group, apoptosis increased by 2% compared to the control group butt the difference between the two groups was not statistically significant (p =0.11).

According to the findings of this study, atorvastatin in low doses can have a pro-apoptotic effect and cause partial induction of apoptosis in mouse oocytes in a laboratory environment. Although this study was not conducted on other doses of atorvastatin, it is suggested that the effect of other doses of this drug on the rate of apoptosis induction should be investigated in order to make an evidence-based decision regarding its administration and use.

Juniperus species are resistant to frost and drought and have several medicinal and industrial uses. The genus has low regeneration that studies of structure and distribution of various species can helps to survey this reduction resons. J. seravshanica is distributed at different regions of Kerman province; young plants distribution is low and they are mostly seen in the crevices of mountains or rocks, but they have higher distribution in protected area of Gluchar. The leaves of young plants are arranged in whorls of 3, but during development both scaly and needle leaves are seen which the later with decussate arrangement, lignin epidermis and hypodermis and resin ducts are the main. The plant is diocious, but in some male plants, a few female cones are formed. Male cones are small, yellow, nonwoody without secretory structures and sclereids. Each cone has 8-14 scales and each scales has 3-5 pollen sacs. The pollen have mucilagenous intine. The female cones consist of attached 6-10 scales that are separated before pollination and become close again to form berries. The female cones develop into blue to brown with white coating. Many cones are dried during development, especially in the early stages. The development of the female cone takes about two years, and a set of one- and two-year-old cones are seen. The mature cone is fleshy which scleride cells form its main volume. It also has resin ducts that give it a pleasant smell. Each fruit has 2-6 seeds with hollow (empty) or immature embryos.

The present research aims to study pollen grain and ovule development in Ageratum houstonianum. It can be suitable pattern for several species of capitule inflorescence, The flowers and buds in different developmental stages were removed, fixed in FAA70, stored in 70% ethanol, embedded in paraffin and sectioned with a thickness of 5-7 μm by microtome. Staining was carried out with Eosine and Hematoxylin. Then slides were studied using light microscope and were photographed. Results indicated that in bisexual florets, consist of five stamens with free filaments and apart from each other. Anthers are tetrasporangiated and development of anther wall is of dicotyledonus type and composed of one-layered epidermis, an endothecium, one middle layer and tapetum. the tapetum was plasmodial. Microspore tetrads are tetrahedral. Pollen grains are three colpated with echinated sculpturing, at the shedding time. Ovule was anatropous, unitegumic and tenuinucellate. Cell division of megaspore mother cells is of both longitudinal and transverse type and resulted to form linear or massive tetrads.The embryo sac development is of the polygonum type. Results of this research showed the presence of formed crystals in anther, the layer endothecium wall anther, epidermal cells of ovary, ovule, style, stigma and petal that was species specific characteristic. secretory (papillate) epidermis on the adaxial surface of petals, On the outer surface of petal long, filamentous and one-celled trichoms were visible.

Due to its great medicinal value, the Moldavian dragonhead, belonging to Lamiaceae, is naturally distributed in Europe, Siberia, and Central Asia and planted in different Iranian provinces. This research studied the development of male/female reproductive organs. Flowers and buds in different stages of development were fixed and preserved in order to prepare microtome sections using appropriate solutions and embed them in paraffin. Hematoxylin-eosin was used to stain the slices. Based on the results, despite the relative simultaneity of the formation of stamen primordium and carpel, stamens develop faster than ovules. Nurses’ cells in secretory and plasmodium types are rectangular, spindle-shaped, and often mononuclear or more. The microspore’s tetrads had tetrahedral ornamentations, and mature pollen grains were hexacolpate with reticulate ornamentation of the exine. The ovules were anatropous, unitegmic, and tenuinucellate. The functional megaspore has a micropillar position, and the embryo sac development belongs to the Polygonum type.

Structure and developmental events of reproductive organs and seed in Onobrychis viciifolia Scop. (Fabaceae), were investigated for the first time using bright field microscopy with different staining techniques. The pedunculate ovary of this plant has long trichomas and one ovule. The mature ovule is anatropous, crassinucellar and bitegumic with zigzag micropyle. Meiosis of megasporocytes results in a T-shaped tetrad. In Onobrychis viciifolia embryo sac is the type of Polygonum. The polar nuclei are close to the egg apparatus and the fusion of them is very soon and before fertilization. The seed coat consists of cuticle, macrosclereid and osteosclereids that parenchyma layer with starch grain accumulation is under it. At the hill pole, the double palisade layer, tracheid bar and subhilar parenchyma are visible. Anther development starts when the flowers are very small. The anthers are tetrasporangiate and their wall development follows the dicotyledonous type and consists of four layers: epidermis, endothecium, one middle layer and uninucleate secretory tapetum. Microspore development is simultaneous in sporangia of an anther. Mature pollen grains are ellipsoidal and two-celled. Fibrous thickenings are developed in the endothecium when shed. The embryological characters studied in this plant have similarities and differences with other studied species of this genus and family. The study of these characters has led to the development of developmental science and increased information in the field of embryology of this plant and can be useful in the field of comparative studies

The aim of the present study was to investigate the effect of docetaxel on the survival rate and in vitro fertilization of oocytes after vitrification by two cryopreservation solution.

For this NMRI mice (8-10 weeks old) were superovulated by injecting PMSG and HCG. Oocytes are surrounded by cumulus and corona cells and must be denuded by 0.1% hyaluronidase enzyme. The oocytes were then divided into 8 experimental groups including control, docetaxel, docetaxel + vitrification 1 solution; docetaxel + vitrification1; vitrification1; docetaxel + vitrification 2 solution; docetaxel + vitrification2; vitrification2. Mature oocytes were vitrified in ethylene glycol and dimethyl sulfoxide solutions at 15% concentration and 0.5 M sucrose in cryopreservation solution1 and ethylene glycol and glycerol at 7.5 concentration and 0.5 M sucrose in cryopreservation solution2. After thawing, their survival and fertilization rates were assessed up to the two-cell stage. Staining of the microtubules in the oocytes was performed with alpha-tubulin antibody.

The results showed a significant difference in survive and fertilization rates compared to the control group (P<0.05). The rate of survival and formation of 2-cell embryos in the first cryopreservation group decreased compared to the second cryopreservation group but the two groups were not statistically significant. The results showed that survival and fertilization rates in pre-incubated groups with docetaxel were higher than non-incubated groups.

Docetaxel could improve reproductive techniques by reducing the damage to the oocyte cytoskeleton.

As a stabilizing agent, docetaxel can potentially reduce the damage to the oocyte cytoskeleton during vitrification. The aim of the present study was to investigate the effect of docetaxel on the survival rate and in vitro fertilization of oocytes after vitrification. NMRI mice (8-10 weeks old) were superovulated by injecting PMSG and HCG. Oocytes are surrounded by cumulus and corona cells and must be denuded by 0.1% hyaluronidase enzyme. The oocytes were then divided into 5 experimental groups including control, docetaxel, docetaxel+vitrification solution; docetaxel+ vitrification and vitrification. Mature oocytes were vitrified in ethylene glycol and dimethyl sulfoxide solutions at 15% concentration and 0.5 M sucrose. After thawing, their survival and fertilization rates were assessed up to the two-cell stage. Staining of the microtubules in the oocytes was performed with alpha-tubulin antibody. The fertilization rate of each group showed a significant decrease compared to the control group (P=0.001). The rate of formation of 2-cell embryos in both vitrified groups (docetaxel+ vitrified and vitrified vitrified) was significantly lower than non-vitrified (control (P=0.001) and docetaxel ((P=0.004)). The results showed that survival and fertilization rates in pre-incubated groups with docetaxel were higher than non-incubated groups, so docetaxel could improve reproductive techniques by reducing the damage to the oocyte cytoskeleton.

Bunium persicum (Boiss.) B.Fedtsch is a family member of Apiaceae which fruits are considered as an important export in food and pharmaceutical industries. According to the significant role of the mentioned native plant and necessity of becoming familiar with the anatomical and developmental structures, some samples of this plant were collected in the current study. Moreover, the vegetative and generative parts were investigated using cell - histological methods include of the fixation with F.A.A fixator, preparation, embedding in paraffin, slices the samples, staining with Hematoxylin- Eosine utilizing stereomicroscope and optical microscopes.Preposition of results, the apical part of root is tuberiformis and leaves are polymorphic with anemocytique Stoma .The flower structure consists of 5 sepals, 5 petals, and 5 stamens, biloculate and inferior ovary. Furthermore, secretory canals were observed in all parts of the plant. The anther was tetra-sporangiate, the tapetum was of secretory type and also the shape of mature pollens was oval. The results of female reproductive organ showed the presence of anatropus ovule with one layered integuments and development of the embryo sac is of polygonum type.

The purpose of the study was to determine the exact developmental stages of reproductive organs and to compare the effects of aluminum oxide nanoparticles on different ovule development and pollen grains in bean plant as one of the main sources of food in the world. Bean plants were cultured in greenhouse conditions and treated with aluminum oxide nanoparticles in different concentrations (0.1, 0.01, 0.001 g/l). Flowers and buds were collected, in different sizes, and fixed in a FAA, dehydrated, embedded in paraffin and sliced with a rotary microtome. The staining was carried out using Hematoxylin-Eosin. Developmental stages of ovule and pollen grains were studied and compared in control plants and experimental plants. The results showed that in control plants, different developmental stages of ovule and pollen grains were followed as the prior reports. Ovule was anatropous, embryo sac is of polygonum type, tetrad arrangement is often linear and T-shaped some times. Anther was tetrasporangiate, tetrad arrangement was tetrahedral, tapetum was of secretory type at beginning, and plasmodial at the late developmental stages. Pollen grains were spherical to ovular shaped. Results showed that the treatments were not effective in the development of ovule, but cause to decrease bioavailability and increased thickness of the intine layer in pollen grains. Irregularities in tetrad microspores and structure of pollen grains are some effects of treatment by aluminum oxide nanoparticles.

Simaroubaceae is a monophyletic family in the order Sapindales with 22 genera and 109 species. Ailanthus altissima (Mill) Swingle, also known as the tree of heaven, is a highly invasive species, which systematically belongs to Simaroubaceae. Reproductive characteristics are essential for the deployment and maintenance of invasive species in new environments and examination of the reproductive system of these species is interesting. To date, no embryological investigations had been directed to A. altissima and our knowledge on the embryology of this species was very limited. A study was carried out on the embryology of A. altissima and the comparison of anther development in male and female flowers in order to gain insights into defining embryological features in this species. According to the results of histological analysis, male flowers have rudimentary gynoecia and anthers are tetrasporangiate. Cytokinesis in meiosis is simultaneous resulting in tetrahedral tetrads. Anther wall development follows the dicotyledonous type and the tapetum is secretory. Female flowers have staminodes and microspore mother cells are degraded too early before entering the course of meiosis. Ovules are anatropous, bitegmic, and crassinucellate. The development of the embryo sac follows the polygonum type. Embryos follow the Onagrad type. The endosperm development is nuclear type. A well-developed hypostase is present and a nucellar cap is formed. These observations will advance our understanding of embryology and embryo anatomy in A. altissima as an invasive species.

Asparagus officinalis L. belongs to the Asparagaceae family and it is monocotyledon. Its different species are used as anticancer, antifunji and anti inflammation. It is cultivated for medicinal, ornamentation, and food purposes. Target of this study focuses on the anatomical structure of the vegetative organs and the flower developmental stage of Asparagus officinalis L. that collected from Dezful City. To study the vegetative organs including root, stem, leaf, and generative organs, vegetative and generative samples collected in different stages of development and investigated by the conventional methods of cellular - histology and the optical microscope in biotechnology laboratory of the University of Science and Researches, in 1395. Observation of vegetative organ structures showed that roots Vascular Cambium include pericycle, vascular bundles (Xylem, phloem) and pith. Central cylinder of stem, is an atactostel, and Vascular Bundles are scattered irregularly and are the uni-strain type. The ovules of this plant are anatropous and its embryo sac is Polygonum type. The pollen of this plant is monosulcate and the ornamentation of its exine is poriferous. The results of this study showed that the anatomical structure of the vegetative organs and the developmental stages of pollen and pistil of this plant is similar to the anatomical and developmental structure of the monocotyledons.

In botanical and taxonomical science embryological studies are specially important. In this research, developmental stages of pollen grains and ovules were studied in Salvia verticillata L of Lamiaceae family.The flower and buds in different developmental stages were removed, fixed in FAA, stored in70% ethanol, embedded in paraffin and sliced with a microtome. Staining was done with Hematoxilin and Eosin. The prepared slides from different developmental stages were studied carefully using a light microscope. On the basis of this research results, ovule was anatropous, bitegumic and tenuinucellate. The development of the embryo sac followed the mono-sporic, polygonum type. After the meiosis, megaspore tetrads had linear arrangement. First, embryo sac was very small, so that its nuclei were compressed linearly but in maturation progress, embryo sac sustained longitude growth considerably. The anther was bisporangia. In S. verticillata, the tapetum was plasmodial and secretory with tetra- nucleate and bi-nucleate cells. In species microspore tetrads were observed with tetrahedral and tetragonal arrangement.

Falcaria vulgaris is a biennial herbaceous pastureland plant belongs to Apiaceae family, which has been recorded in Iranian traditional medicine. In this report developmental reproductive steps were studied. Flower buds at different developmental stages were collected and fixed in FAA then maintained in Ethanol (%70). After preparation and embedding samples in paraffin, the samples were sectioned by microtome and stained with Hematoxyline-Eosine respectively. Results showed that initiation patterns of flower and floral organ development is acropet. Stamen and gynoecium formation occurred with the time interval. Several schizogenical secretion channels exist in the ovary wall. The flower consists of five sepals, five isolated petals, five stamens and the inferior ovary with two carpels. The anthers are tetra sporangiate type and pollen grains are binuclear and have three colpates. Ovule is anatropous, unitegmic and tenuinucellate. Embryo sac is formed corresponding to the polygonum type.

Aim and Successful in vitro embryo production extremely depends on the components of culture media during in vitro maturation. With ingredients like Anitol, Fennel has properties similar to estrogen. The aim of this study was to investigate the effect of Fennel essence on nuclear maturation of bovine oocyte.
In order to in vitro maturation off oocytes, Cumulus-oocyte complexes (No. 772) from follicles 2–8 mm in diameter were aspirated and cultured in M199 maturation media containing 10% FBS, 10% bovine follicular fluid, 5 µg/ml FSH, 1 µg/ml oestradiol- 17β, 0.81mM sodium pyruvate and 50 µg/ml gentamicin sulfate. Maturation culture media supplemented with 0, 5, 10, 20, 30 and 50 mg/ml of Fennel essence and were cultured in a CO2 incubator containing 5% CO2 and 95% humidity in air at 38.5ºC for 24 h.
Results showed that the amount of maturation of oocytes under 5, 10, 20 and 30 mg/ml of Fennel essence were not significantly different based on expansion of cumulus cells and polar body extrusion in compared with control (P>0.05). However, 50 mg/ml of Fennel essence significantly decreased expansion of cumulus cells and polar body extrusion in compared to other groups (P From the results of current study we can conclude that, Fennel essence, based on cumulus expansion and polar body extrusion, unable to improve nuclear maturation of bovine oocytes. In order to investigate the effect of Fennel essence on nucleus and cytoplasmic maturation of bovine oocytes, it is suggested to use in vitro fertilization.

Despite of the increasing functional and molecular studies in the sunflower family (Asteraceae), the study of generative biology that consists of flowering developmental stages in necessary. In this research, Embryological characteristics including of ovule and pollen grains development of Echinops ilicifolius from Asteraceae family were studied. The flowers and buds in different developmental stages were removed, fixed in FAA70, stored in 70% ethanol, embedded in paraffin and sectioned with a thickness of 5-7 µm by microtome. Staining was carried out with Eosine and Hematoxylin. Then slides were studied using light microscope and were photographed. Results indicated that anthers were Tetra-Sporangiate and tapetum was of the periplasmodial type. Pollen tetrads were tetrahedral and tetragonal. In anther tissue interface particles were crystalline needles. Pollen grains were 2-celled at the time of Diffusion. Ovule was anatropous, unitegmic and tenuinucellate. Endothelium was uniseriate and connected with embryonic sac. Embryo sac development was of the Polygonum type Antipodal cells increased up to 6-8.

Cotton (Gossypium hirsutum L.) is an important crop in the world and increasing its fiber quality is very cr-ucial for textile industries. Spider silk is the strongest and most elastic fiber ever known in the nature. Cotton is one of the main crops in the world and increasing its fiber quality is very important for textile industries. In this regard, a synt-hetic construct has been designed to offer spider silk quality to cotton fibers by fiber-specific expression of Major am-pullate spidroin1 (MaSp1) gene under control of core sequence of GaRD22-like1 promoter. The synthetic construct was double digested by the EcoRI and NheI and sub-cloned in pCAMBIA1304 binary vector. E.coli DH5α was transformed using new plasmid namely pCSP. Ligation and intact backbone of plasmid was conformed using MaSp1 and hygrom-ycin re-sistance genes specific primers and finally with EcoRI/NheI double digestion. Agrobacterium tumefaciens LBA4404 was transformed with pCSP to transform cotton ovules of Varamin cultivar. The expression of MaSp1 in co-tton ovules and fibers showed that this synthetic sequence had been successfully expressed under control of GaRDL1 core promoter and this construct without codon optimization could be used for cotton transformation and its fiber qual-ity manipulation.