Karyotype analysis in white bream (Blicca bjoerkna transcaucasica) from north coast of Iran

Preparation of chromosome spreads and karyotype analysis in Blicca bjoerkna transcaucasica were carried out using 0.01% solution of colchicines and Phytohaemagglutinin (PHA) (20 µg g-1 body weight). The gill and kidney tissues were collected and let to stand in a hypotonic solution of 0.075 M KCl and then treated with a fixative (Carnoy's solution) in three steps. The chromosomes spreads were then stained with 5% Giemsa solution for 20 min and examined under a light microscope. Appropriate metaphase plates were photographed in order to prepare karyotype. The size of the chromosomes (short and long arms), relative length of chromosomes and centromere index were calculated. Chromosome spreads from gill tissue cultures which were colchicine treated with PHA, had a well defined size, shape and number of chromosomes for karyotype analysis. Based on the 76 metaphase plates studied, chromosome count in 59 metaphase plates was 2n=49.74±0.25. By arranging homologous chromosomes beside each other the chromosome formula was calculated as 6 pairs of Metacentric, 10 pairs of Sub-Metacentric and 9 pairs of Sub-Telocentric (2n=6M+10+Sm+9St) and the chromosome arm number (NF) was 100. The largest chromosome in this species was a pair of metacentric chromosomes. On the basis of the number and type of chromosomes, the karyotype obtained for this species conformed to the findings of other researchers, but the chromosome formula was different, which could be attributed to the existence of different populations for this species

Age, growth and mortality of the Persian sturgeon, Acipenser persicus, in the Iranian waters of the Caspian Sea

The age and growth of the Persian Sturgeon, Acipenser persicus, obtained from the Iranian coastal waters of the Caspian Sea, were studied through analysis of the pectoral fin ray section from 180 specimens, ranging in fork length (FL) from 66 to 203 cm. The specimens were obtained from commercial fisheries between October 2008 and June 2010. Interpretation of growth bands in the pectoral fin ray sections was carried out objectively using the direct reading of thin sections and image analysis. The maximum age recorded in this study for the spacimens of Persian Sturgeon was 39 years. The von Bertalanffy growth parameters estimated for females were greater than for males. The estimates of asymptotic length (L∞) and growth coefficient (K) of females were 173.07 cm and 0.1 year -1, respectively and for males 164.33 cm L∞ and 0.08 year -1 K respectively,. Total mortality coefficient (Z) for females and males was estimated to be 0.45 and 0.76 year -1, respectively. This study revealed differences in life history parameters of the Persian Sturgeon compared with those of previous studies, which may be associated with the current increased fishing pressure and degradation of environmental conditions

Effect of vitamin d3 on mitochondrial biogenesis in granulosa cells derived from polycystic ovary syndrome

Background: Polycystic ovary syndrome (PCOS) is an endocrine disorder diagnosed by anovulation hyperandro-genism. Hyperandrogenism increases apoptosis, which will eventually disturb follicular growth in PCOS patients. Since mitochondria regulate apoptosis, they might be affected by high incidence of follicular atresia. This may cause infertility. Since vitamin D3 has been shown to improve the PCOS symptoms, the aim of study was to investigate the effects vitamin D3 on mtDNA copy number, mitochondrial biogenesis, and membrane integrity of granulosa cells in a PCOS-induced mouse model. Materials and Methods: In this experimental study, the PCOS mouse model was induced by dehydroepiandrosterone (DHEA). Granulosa cells after identification by follicle-stimulating hormone receptor (FSHR) were cultured in three groups: 1. granulosa cells treated with vitamin D3 (100 nM for 24 hours), 2. granulosa cells without any treatments, 3. Non-PCOS granulosa cells (control group). Mitochondrial biogenesis gene (TFAM) expression was compared between different groups using real-time PCR. mtDNA copy number was also investigated by qPCR. The mitochon-drial structure was evaluated by transmission electron microscopy (TEM). Hormonal levels were measured by an enzymelinked immunosorbent assay (ELISA) kit. Results: The numbers of pre-antral and antral follicles increased in PCOS group in comparison with the non-PCOS group. Mitochondrial biogenesis genes were downregulated in granulosa cells of PCOS mice when compared to the non-PCOS granulosa cells. However, treatment with vitamin D3 increased mtDNA expression levels of these genes compared to PCOS granulosa cells with no treatments. Most of the mitochondria in the PCOS group were spherical with almost no cristae. Our results showed that in the PCOS group treated with vitamin D3, the mtDNA copy number increased significantly in comparison to PCOS granulosa cells with no treatments. Conclusion: According to this study, we can conclude, vitamin D3 improves mitochondrial biogenesis and membrane integrity, mtDNA copy number in granulosa cells of PCOS mice which might improve follicular development and subsequently oocyte quality. © 2020, Royan Institute (ACECR). All rights reserved

The Perspective of Creativity in the Process of Learning Mathematics

Mathematical creativity is often considered as a mysterious phenomenon. Most mathematicians seem to be not interested in analyzing their own thinking processes and do not describe how they work or conceive their theories. One of the goals of this paper, which is based on research findings from contemporary literature, presents some definitions and characteristics of mathematical creativity and also describes and analyzes mathematicians’ thinking processes during creating mathematics. For this purpose, a four-stage model is considered consisting of: preparation, incubation, illumination and verification. Referring to literature, it is evident that there is not a specific conventional definition of mathematical creativity. According to some of definitions, a creative act in mathematics could consist of: creating a new fruitful mathematical concept; discovering an unknown relation; and reorganizing the structure of a mathematical theory. The challenges in the identification and development of mathematical creativity are due to the large variety in definitions and characteristics of mathematical creativity. Understanding, intuition, insight and generalization are some of moving powers of mathematical creativity. Fallibility is one of the characteristics of creative mathematical activities which should be appreciated since this existing chance of fallibility could lead to major success achievements of human. Hence, considering all above mentioned, learning-teaching mathematics should be so that it provides environment that fosters ability to make connections among concepts and processes and also provides opportunities to generalize

Vitamin D3 regulates steroidogenesis in granulosa cells through AMP-activated protein kinase (AMPK) activation in a mouse model of polycystic ovary syndrome

Polycystic ovary syndrome (PCOS) is an endocrine and metabolic disorder in reproductive-aged women. Hormonal abnormality caused by steroidogenesis disturbances appears to be the main culprit of the clinical picture in PCOS. Vitamin D3 could regulate steroidogenesis in granulosa cells, but the mechanism of action of vitamin D3 on steroidogenesis remains unknown. AMP-activated protein kinase (AMPK) has a modulating role in steroid hormone production. We investigated the effect of vitamin D3 on steroidogenesis in cultured granulosa cells of dehydroepiandrosterone-induced PCOS mice and studied the involvement of AMPK signalling pathway in the current process. Immunoblotting assay showed that vitamin D3 could increase phosphorylation of AMPK alpha and acetyl-CoA carboxylase, main substrate of AMPK. Vitamin D3 and 5-aminoimidazole-4-carboxamide-1-β-D-riboside or Aicar (AMPK activator) not only reduced gene expression of steroidogenic enzymes (P450scc or Cyp11a1, StAR, Cyp19a1 and 3B-HSD), but also reduced production of progesterone and 17B-estradiol assessed by radioimmunoassay. Pretreatment with compound C (AMPK inhibitor) decreased APMK phosphorylation and eliminated the effects of vitamin D3 and Aicar on steroidogenic enzymes expression and estradiol and progesterone production. This study showed that vitamin D3 has the main role in regulating of steroidogenesis in granulosa cells of mouse polycystic ovary through activation of the AMPK signalling pathway. Significance of the Study: Polycystic ovarian syndrome (PCOS) is an endocrine disorder of women in reproductive age. This disorder is partly related to disruption in steroidogenesis pathway and dysregulation of estradiol and progesterone production in granulosa cells of polycystic ovaries. Previously, we have shown that vitamin D3 could modulate steroidogenesis pathway in PCOS granulosa cells. In this study, we investigate the molecular mechanism of vitamin D3 in regulation of steroidogenesis pathway. We have shown that vitamin D3 has a modulating role in steroidogenesis pathway of granulosa cells by regulation of AMP-activated protein kinase (AMPK) as an underlying molecular mechanism in mouse polycystic ovary. Copyright © 2018 John Wiley & Sons, Ltd

Vitamin D3 regulates steroidogenesis in granulosa cells through AMP-activated protein kinase (AMPK) activation in a mouse model of polycystic ovary syndrome

Polycystic ovary syndrome (PCOS) is an endocrine and metabolic disorder in reproductive-aged women. Hormonal abnormality caused by steroidogenesis disturbances appears to be the main culprit of the clinical picture in PCOS. Vitamin D3 could regulate steroidogenesis in granulosa cells, but the mechanism of action of vitamin D3 on steroidogenesis remains unknown. AMP-activated protein kinase (AMPK) has a modulating role in steroid hormone production. We investigated the effect of vitamin D3 on steroidogenesis in cultured granulosa cells of dehydroepiandrosterone-induced PCOS mice and studied the involvement of AMPK signalling pathway in the current process. Immunoblotting assay showed that vitamin D3 could increase phosphorylation of AMPK alpha and acetyl-CoA carboxylase, main substrate of AMPK. Vitamin D3 and 5-aminoimidazole-4-carboxamide-1-β-D-riboside or Aicar (AMPK activator) not only reduced gene expression of steroidogenic enzymes (P450scc or Cyp11a1, StAR, Cyp19a1 and 3B-HSD), but also reduced production of progesterone and 17B-estradiol assessed by radioimmunoassay. Pretreatment with compound C (AMPK inhibitor) decreased APMK phosphorylation and eliminated the effects of vitamin D3 and Aicar on steroidogenic enzymes expression and estradiol and progesterone production. This study showed that vitamin D3 has the main role in regulating of steroidogenesis in granulosa cells of mouse polycystic ovary through activation of the AMPK signalling pathway. Significance of the Study: Polycystic ovarian syndrome (PCOS) is an endocrine disorder of women in reproductive age. This disorder is partly related to disruption in steroidogenesis pathway and dysregulation of estradiol and progesterone production in granulosa cells of polycystic ovaries. Previously, we have shown that vitamin D3 could modulate steroidogenesis pathway in PCOS granulosa cells. In this study, we investigate the molecular mechanism of vitamin D3 in regulation of steroidogenesis pathway. We have shown that vitamin D3 has a modulating role in steroidogenesis pathway of granulosa cells by regulation of AMP-activated protein kinase (AMPK) as an underlying molecular mechanism in mouse polycystic ovary. Copyright © 2018 John Wiley & Sons, Ltd

Assessment of PGC1α-FNDC5 axis in granulosa cells of PCOS mouse model

Background: Polycystic ovarian syndrome (PCOS) is a metabolic and endocrine disorder which is characterized by hyperandrogenism, anovulation or oligomenorrhea and polycystic ovarian morphology. It is believed that modulation in metabolism of granulosa cells of PCOS patients may lead to infertility. One of the metabolic modulators is FNDC5 and its cleaved form, irisin. The axis of PGC1α-FNDC5 pathway is one of the main factors affecting cellular energy balance the purpose of this study was to evaluate this pathway in granulosa cells derived from PCOS mice model in comparison with control group. Methods: In the present study, PCOS mouse model was developed by injection of dehydroepiandrosterone (DHEA) hormone in 20 mice for a period of 20 days. Also, 20 uninjected mice were used as the control. Meanwhile, a vehicle group consisted of mice which received daily subcutaneous sesame oil injection (n=20). Relative expressions of PGC1α and FNDC5 in granulosa cells were evaluated by RT-qPCR. Analysis of gene expressions was calculated by the ��CT method and the relative levels of mRNA were normalized to GAPDH transcript levels. Differences in genes expression among three groups were assessed using one-way ANOVA, Tukey's Post Hoc test. Results: Our results showed that expression of FNDC5 was significantly reduced in granulosa cells of DHEA-induced PCOS mice compared with control and vehicle groups (p<0.05), while there was no significant differences in PGC1α expression among different groups. Conclusion: Down regulation of FNDC5 transcript level may contribute in metabolic disturbance of granulosa cells derived from PCOS ovary apart from PGC1α levels which remained unchanged. © 2018 Avicenna Research Institute. All rights reserved