Abstract:The objective of this study was to characterize the morphometry and ultrastructure of porcine preantral and antral follicles, especially the lipid component evolution. Ovarian tissue was processed for light microscopy. Ovarian tissue and dissected antral follicles (< 2, 2-4, and 4-6 mm) were also processed for transmission electron microscopy using routine methods and using an osmium-imidazole method for lipid detection. Primordial follicles (34 ± 5 μm in diameter, mean ± SD) had one layer of flattened-cuboida… Show more
“…When we compared our findings with the results of other species we observed that the mean follicular diameter was higher in primordial follicles, unilaminar and multilaminar primary follicles (45.13 μm, 70.35 μm and 127.60 μm) than diameters obtained in other species as in pre-pubertal gilts (33.8 μm, 40.4 μm and 84.5 μm) [13] and young women (< 13 years) (39 μm and 44.1 μm) [17]; the mean follicular diameter of older queens was higher in primordial and unilaminar primary follicles (43.24 μm and 68.11 μm, respectively) compared to post-pubertal female buffaloes (7 -10 years) (35 μm and 41.8 μm, respectively) [10]; the mean oocyte diameter in young animals was higher in primordial, unilaminar and multilaminar primary follicles (40.55 μm, 47.97 μm and 62.35 μm, respectively) when comparing with pre-pubertal gilts (26 μm, 27.3 μm and 39.1 μm) [13] and women (< 13 years) with values for primordial and unilaminar primary follicles (34.3 μm and 41 μm, respectively) [17].…”
Background: In humans and bitchs the age is another factor that may affect the size of ovarian structures, verifying alterations in the quality of the pool and size of follicular structures, which can compromise the use of these structures for in vitro maturation. There are no reports correlating the morphometric characteristics of the follicles and ovarian apoptosis at different ages in cats. The aim of this study was to evaluate the histomorphometric parameters of follicular growth and the relationship with the occurrence of apoptosis in ovarian tissue of young, adult and senile queens. Materials, Methods & Results: Eighteen domestic queens, multiparous, of different breeds and age groups were used in this study and divided into three groups according to their ages: five months to one year -young; (7.8 ± 1.0 months); one to six years -adults (2.8 ± 0.5 years); and more than six years -senile (8.0 ± 0.9 years). Vaginal cytology was performed in order to characterize the estrous phase associated with plasma concentrations of progesterone. The morphology and percentage of the vaginal epithelium cells were evaluated and queens were classified into estrous and non-estrus and plasma concentrations of progesterone were determined. Ovarian samples were collected after ovariohysterectomy to routine histological processin and all follicles were counted and categorized into two groups, non-atresic and atresic. The mean follicular and oocyte diameters were calculated between the measurement of the largest diameter and perpendicular diameter. The relationship between follicle and oocyte were determined using the measurements of diameter, area and perimeter. The apoptotic cells were detected and cells were considered positive when TUNEL reaction was detected. The morphometric index of 1039 follicles were evaluated. Primordial follicles in young animals showed larger diameter, follicular area and perimeter than the structures of adult queens, as well as the unilaminar primary follicles of the same group were larger compared with senile animals (P < 0.05). Comparing adult and younger queens, the first showed a significant decrease of oocyte diameter in primary and unilaminar primary follicles, as well as oocyte area and perimeter (P < 0.05). The values for follicular diameter, oocyte area and perimeter for multilaminar primary, secondary and pre-ovulatory structures did not present statistical differences between the groups (P > 0.05). For the pre-ovulatory follicles there was no positive correlation between the oocyte growths regarding the follicles (P > 0.05). Only in senile animals positive markers for apoptosis were identified in nuclei of primordial follicles. No significant differences concerning the number of follicles and Tunel positive cells were observed between groups (P > 0.05). Discussion: Considering the importance of this study for greater knowledge in the basic aspects for reproductive biotechnologies, we verified that secondary follicles showed the largest diameters and younger animals the largest val...
“…When we compared our findings with the results of other species we observed that the mean follicular diameter was higher in primordial follicles, unilaminar and multilaminar primary follicles (45.13 μm, 70.35 μm and 127.60 μm) than diameters obtained in other species as in pre-pubertal gilts (33.8 μm, 40.4 μm and 84.5 μm) [13] and young women (< 13 years) (39 μm and 44.1 μm) [17]; the mean follicular diameter of older queens was higher in primordial and unilaminar primary follicles (43.24 μm and 68.11 μm, respectively) compared to post-pubertal female buffaloes (7 -10 years) (35 μm and 41.8 μm, respectively) [10]; the mean oocyte diameter in young animals was higher in primordial, unilaminar and multilaminar primary follicles (40.55 μm, 47.97 μm and 62.35 μm, respectively) when comparing with pre-pubertal gilts (26 μm, 27.3 μm and 39.1 μm) [13] and women (< 13 years) with values for primordial and unilaminar primary follicles (34.3 μm and 41 μm, respectively) [17].…”
Background: In humans and bitchs the age is another factor that may affect the size of ovarian structures, verifying alterations in the quality of the pool and size of follicular structures, which can compromise the use of these structures for in vitro maturation. There are no reports correlating the morphometric characteristics of the follicles and ovarian apoptosis at different ages in cats. The aim of this study was to evaluate the histomorphometric parameters of follicular growth and the relationship with the occurrence of apoptosis in ovarian tissue of young, adult and senile queens. Materials, Methods & Results: Eighteen domestic queens, multiparous, of different breeds and age groups were used in this study and divided into three groups according to their ages: five months to one year -young; (7.8 ± 1.0 months); one to six years -adults (2.8 ± 0.5 years); and more than six years -senile (8.0 ± 0.9 years). Vaginal cytology was performed in order to characterize the estrous phase associated with plasma concentrations of progesterone. The morphology and percentage of the vaginal epithelium cells were evaluated and queens were classified into estrous and non-estrus and plasma concentrations of progesterone were determined. Ovarian samples were collected after ovariohysterectomy to routine histological processin and all follicles were counted and categorized into two groups, non-atresic and atresic. The mean follicular and oocyte diameters were calculated between the measurement of the largest diameter and perpendicular diameter. The relationship between follicle and oocyte were determined using the measurements of diameter, area and perimeter. The apoptotic cells were detected and cells were considered positive when TUNEL reaction was detected. The morphometric index of 1039 follicles were evaluated. Primordial follicles in young animals showed larger diameter, follicular area and perimeter than the structures of adult queens, as well as the unilaminar primary follicles of the same group were larger compared with senile animals (P < 0.05). Comparing adult and younger queens, the first showed a significant decrease of oocyte diameter in primary and unilaminar primary follicles, as well as oocyte area and perimeter (P < 0.05). The values for follicular diameter, oocyte area and perimeter for multilaminar primary, secondary and pre-ovulatory structures did not present statistical differences between the groups (P > 0.05). For the pre-ovulatory follicles there was no positive correlation between the oocyte growths regarding the follicles (P > 0.05). Only in senile animals positive markers for apoptosis were identified in nuclei of primordial follicles. No significant differences concerning the number of follicles and Tunel positive cells were observed between groups (P > 0.05). Discussion: Considering the importance of this study for greater knowledge in the basic aspects for reproductive biotechnologies, we verified that secondary follicles showed the largest diameters and younger animals the largest val...
“…Furthermore, Isachenko et al (2003) identified two kinds of LD in porcine oocytes: homogenous, dark looking vesicles and 'gray' looking droplets with electron-lucent streaks. Silva et al (2011) suggested that dark LD may change to gray after lipid utilization. By measuring the fat gray value of porcine oocytes using a Nomarski microscope and ImageJ software, it was possible to distinguish different colour tones of fat areas reflecting alterations in lipid content.…”
Lipid droplets (LD) in porcine oocytes form a dark mass reaching almost all cytoplasm. Herein we investigated changes in fat areas, cytoplasmic tone and LD morphology duringin vitromaturation (IVM) of porcine oocytes cultured with 100 μMtrans-10,cis-12 conjugated linoleic acid (t10,c12 CLA) or 10 μM forskolin at different time periods. Four groups were constituted: control, excipient,t10,c12 CLA and forskolin, with drugs being supplemented during 44 to 48 h and the initial 22 to 24 h in Experiments 1 and 2, respectively. In Experiment 3, forskolin was supplemented for the first 2 h. Matured oocytes were inseminated with frozen-thawed boar semen and cleavage rate recorded. Before and during IVM, samples of oocytes were evaluated for LD, total and fat areas and fat gray value or for meiotic progression. Results showed that forskolin supplementation during 44 to 48 h or 22 to 24 h inhibits oocyte maturation (exp. 1: forskolin = 5.1 ± 8.0%, control = 72.6 ± 5.0%; exp. 2: forskolin = 24.3 ± 7.4%, control = 71.6 ± 5.6%) and cleavage (exp. 1: forskolin = 0.0 ± 0.0%, control = 55.4 ± 4.1%; exp. 2: forskolin = 8.3 ± 3.3%, control = 54.5 ± 3.0%). Forskolin also reduced oocyte and fat areas. In Experiment 3, forskolin negative effect on oocyte maturation and cleavage disappeared, although minor (P⩽ 0.03) LD and oocyte fat areas were identified at 22 to 24 h of IVM. Oocytes supplemented witht10,c12 CLA during 44 to 48 h presented a lighter (P⩽ 0.04) colour tone cytoplasm than those of control and forskolin. In conclusion,t10,c12 CLA and forskolin were capable of modifying the distribution and morphology of cytoplasmic LD during porcine oocyte maturation, thus reducing its lipid content in a time-dependent manner.
“…The nucleus is enclosed by a smooth envelope [51],[52]. Usually, the chromatin is found uncondensed and one or two nucleoli are observed (Figure 1C) [44],[49],[52],[53]. Figure 1 Transmission electron micrographs of primordial follicles.…”
Section: Introductionmentioning
confidence: 99%
“…In the ooplasm of buffaloes, a delimited region with a well-developed smooth endoplasmic reticulum is observed [45]. In yaks [52] and pigs [49], polyribosomes are seen on the surface of the rough endoplasmic reticulum and distributed throughout the ooplasm.…”
Section: Introductionmentioning
confidence: 99%
“…Especially in pigs, lipid droplets are abundant in the oocytes from the primordial stage onwards, and they appear as small dark round structures (Figure 1A) [49]. Lipid droplets are considered to be an energy source [60].…”
The ultrastructural analysis of oocytes and ovarian follicles has been used to evaluate the effects of assisted reproductive techniques, such as cryopreservation or in vitro oocyte maturation. It also benefits the understanding of such complex mechanisms that occur during folliculogenesis. From the beginning of primordial follicles growth until oocyte maturation in preovulatory follicles oocyte cytoplasmic organelles undergo dynamic alterations that reflect physiological changes and development. This review aims to make a retrospective survey of the relevant features of follicles and oocytes ultrastructure, highlighting the differences between mammalian species, specially the domestic ones.Electronic supplementary materialThe online version of this article (doi:10.1186/s13048-014-0102-6) contains supplementary material, which is available to authorized users.
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