Sanaz Ramezanpour - Academia.edu (original) (raw)
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Papers by Sanaz Ramezanpour
General and Comparative Endocrinology, 2013
In the present study, we surveyed developmental changes in the transcription of growth hormone (g... more In the present study, we surveyed developmental changes in the transcription of growth hormone (gh), insulin-like growth factor-I (igf-I), ghrelin (ghrl) and vascular endothelial growth factor (vegf) genes in the largest freshwater fish, European sturgeon (Beluga, Huso huso) and compared the same parameters to that of its phylogenically close moderate-sized species, Persian sturgeon (Acipenser persicus). The transcripts of gh, igf-I, ghrl and vegf were detected at all developmental time-points of Persian sturgeon and Beluga from embryos to juvenile fish. Changes in normalized gh, igf-I, ghrl and vegf transcription by using the geometric average of genes encoding ribosomal protein L6 (RPL6) and elongation factor (EF1A) over the time of development of Persian sturgeon and Beluga were statistically significant (P < 0.05). Our results showed that the mRNA expression levels of both igf-I and ghrl were low during early larval development and then increased significantly to the late larval time-points when larvae started exogenous feeding. In both Beluga and Persian sturgeon, after a low mRNA expression during the embryonic stage, the transcript levels of vegf displayed an increasing trend during yolk-sac fry, consistent with organogenesis. The vegf level remained constantly high in the time of exogenous feeding. The highest detection of gh transcripts coincided with the end of the embryonic stage (hatching time) in Persian sturgeon and 3 dayspost-hatching (dph) in Beluga. In Persian sturgeon, the gh transcript started to decrease to the rest of the developmental time-points, whereas in Beluga gh transcript had a marked second increase from the time of exogenous feeding (20-dph). This Beluga specific increase in gh transcription may be associated with the marked growth rate and extraordinary size of this fish species.
Comparative Clinical Pathology, 2011
The functions of ghrelin, a novel weightregulatory peptide, have not been intensively investigate... more The functions of ghrelin, a novel weightregulatory peptide, have not been intensively investigated in primitive fish. This experiment was conducted to determine whether ghrelin has a specific effect on growth hormone (GH), prolactin and cortisol levels in Persian sturgeon (Acipenser persicus). Juvenile Persian sturgeons with a mean body weight of 320±30 g were given a single injection of ghrelin at three doses of 0.1, 1 and 10 ng/g body weight. Control animals were injected with vehicle (sterile saline) only. Blood samples were collected at 0, 2, 4, 8, 24, 48 and 72 h after injection. The level of plasma hormones were determined by ELISA kit. As expected, ghrelin injection significantly elevated plasma GH (P< 0.05), whereas prolactin levels did not significantly change after injection (P>0.05). Plasma cortisol levels decreased in fish injected with high doses of ghrelin (P<0.05). Ghrelin at 10 ng/g body weight had the most influence on GH release, and 1 ng/g ghrelin injection caused the lowest level of cortisol. These results show for the first time that ghrelin induces some plasma hormonal changes in sturgeon fish, as lower vertebrates, but more investigations are needed in this area.
In order to study genetic diversity in rice genotypes In Iran, the variation in 38 rice cultivars... more In order to study genetic diversity in rice genotypes In Iran, the variation in 38 rice cultivars were evaluated using 14 SSR markers. The experimental design was a randomized complete block at the research station located in the city in 1392 was Azadshahr. Plant samples at tillering genotypes were collected in the early morning. DNA was extracted from plant samples denaturation was carried out on polyacrylamide gels. Large genetic distances between cultivars showed high genetic diversity among the genotypes of rice. Principal component analysis of variance was 62%. The highest polymorphic information content RM262 (81/0) and lowest at RM241 (33/0) were recorded and the average PIC, 51/0 respectively. 33/0 Shannon's index of microsatellite markers used in this study, markers RM142 RM255, RM341, RM262, had high discriminatory power. The highest number of positive markers in height (11), respectively. Genotypes and cluster analysis methods into three classes, respectively. In gene...
General and Comparative Endocrinology, 2013
In the present study, we surveyed developmental changes in the transcription of growth hormone (g... more In the present study, we surveyed developmental changes in the transcription of growth hormone (gh), insulin-like growth factor-I (igf-I), ghrelin (ghrl) and vascular endothelial growth factor (vegf) genes in the largest freshwater fish, European sturgeon (Beluga, Huso huso) and compared the same parameters to that of its phylogenically close moderate-sized species, Persian sturgeon (Acipenser persicus). The transcripts of gh, igf-I, ghrl and vegf were detected at all developmental time-points of Persian sturgeon and Beluga from embryos to juvenile fish. Changes in normalized gh, igf-I, ghrl and vegf transcription by using the geometric average of genes encoding ribosomal protein L6 (RPL6) and elongation factor (EF1A) over the time of development of Persian sturgeon and Beluga were statistically significant (P < 0.05). Our results showed that the mRNA expression levels of both igf-I and ghrl were low during early larval development and then increased significantly to the late larval time-points when larvae started exogenous feeding. In both Beluga and Persian sturgeon, after a low mRNA expression during the embryonic stage, the transcript levels of vegf displayed an increasing trend during yolk-sac fry, consistent with organogenesis. The vegf level remained constantly high in the time of exogenous feeding. The highest detection of gh transcripts coincided with the end of the embryonic stage (hatching time) in Persian sturgeon and 3 dayspost-hatching (dph) in Beluga. In Persian sturgeon, the gh transcript started to decrease to the rest of the developmental time-points, whereas in Beluga gh transcript had a marked second increase from the time of exogenous feeding (20-dph). This Beluga specific increase in gh transcription may be associated with the marked growth rate and extraordinary size of this fish species.
Comparative Clinical Pathology, 2011
The functions of ghrelin, a novel weightregulatory peptide, have not been intensively investigate... more The functions of ghrelin, a novel weightregulatory peptide, have not been intensively investigated in primitive fish. This experiment was conducted to determine whether ghrelin has a specific effect on growth hormone (GH), prolactin and cortisol levels in Persian sturgeon (Acipenser persicus). Juvenile Persian sturgeons with a mean body weight of 320±30 g were given a single injection of ghrelin at three doses of 0.1, 1 and 10 ng/g body weight. Control animals were injected with vehicle (sterile saline) only. Blood samples were collected at 0, 2, 4, 8, 24, 48 and 72 h after injection. The level of plasma hormones were determined by ELISA kit. As expected, ghrelin injection significantly elevated plasma GH (P< 0.05), whereas prolactin levels did not significantly change after injection (P>0.05). Plasma cortisol levels decreased in fish injected with high doses of ghrelin (P<0.05). Ghrelin at 10 ng/g body weight had the most influence on GH release, and 1 ng/g ghrelin injection caused the lowest level of cortisol. These results show for the first time that ghrelin induces some plasma hormonal changes in sturgeon fish, as lower vertebrates, but more investigations are needed in this area.
In order to study genetic diversity in rice genotypes In Iran, the variation in 38 rice cultivars... more In order to study genetic diversity in rice genotypes In Iran, the variation in 38 rice cultivars were evaluated using 14 SSR markers. The experimental design was a randomized complete block at the research station located in the city in 1392 was Azadshahr. Plant samples at tillering genotypes were collected in the early morning. DNA was extracted from plant samples denaturation was carried out on polyacrylamide gels. Large genetic distances between cultivars showed high genetic diversity among the genotypes of rice. Principal component analysis of variance was 62%. The highest polymorphic information content RM262 (81/0) and lowest at RM241 (33/0) were recorded and the average PIC, 51/0 respectively. 33/0 Shannon's index of microsatellite markers used in this study, markers RM142 RM255, RM341, RM262, had high discriminatory power. The highest number of positive markers in height (11), respectively. Genotypes and cluster analysis methods into three classes, respectively. In gene...