Download Effects of cadmium, estrogen, androgen, PAH and their

Exjobbsredovisningar 16 januari 2014
Degree projects presentations
Biblioteket 1 våningen (Zoologen)
10.30-10.40
Max Lindmark (15 hp Biologi)
Bifångster i det svenska sillfisket på västkusten
10.45-11.10
Anna von Wirth (30 hp Marin ekologi)
Burutveckling för havskräftsfiske, Nephrops norwegicus - en
undersökning av burars fångstegenskaper i laboratorium
och fält
13.00-13.20
Fredrik Larsson (15 hp Zoologi)
To be announced
13.20-13.40
Jesper Paulson (15 hp Zoologi)
To be announced
13.40-14.00
Fika
14.00-
Bertille Debris (Master 60 hp Zoophysiology)
The effect of ghrelin on the gene expression of appetite
regulatory neuropeptides and leptin, and on plasma levels
of growth regulatory hormones in rainbow trout
(Oncorhynchus mykiss)
Opponent: Catharina Olsson
15.00-
Andrea Mariossi (Master 60 hp Zoophysiology)
Effects of cadmium, estrogen, androgen, PAH and their
mixture in the three-spined stickleback, Gasterosteus
aculeatus
Opponent: Michael Axelsson
Abstracts (Master presentations)
The effect of ghrelin on the gene expression of appetite regulatory
neuropeptides and leptin, and on plasma levels of growth regulatory hormones
in rainbow trout (Oncorhynchus mykiss)
Bertille Debris
Institutionen för Biologi & Miljövetenskap, GU (Handledare: Lisa Jönsson Bergman)
For survival, organisms need to maintain their energy balance. The energy is obtained by food intake,
which is regulated by physiological mechanisms where various appetite regulatory hormones play
important roles. The hypothalamus is the main organ for appetite control, and here a number of
neuropeptides modulate appetite. Neuropeptide Y (NPY) is involved in the stimulation of appetite
whereas the CRH pathway, including signals such as propiomelanocortins (POMCs), cocaine and
amphetamine-regulated transcript (CART), corticotropin releasing hormone (CRH) and cholescystokinin
(CCK) are involved in its inhibition. Ghrelin, a peptide hormone produced in the stomach, is known for
its orexigenic effects in most species. But in rainbow trout (Oncorhynchus mykiss), ghrelin acts as an
anorexigenic factor. Ghrelin is also believed to be involved in other mechanisms such as growth through
the stimulation of growth hormone (GH) secretion, along with appetite and metabolism.
In the present work, the effect of ghrelin on central neuropeptides gene expression (NPY, POMC,
CART, CRH and CCK) was measured, as well as the interaction of ghrelin with other factors involved in
appetite regulation (leptin expression in liver) and growth (plasma GH and IGF-I levels). Juvenile
rainbow trout were implanted with ghrelin or control pellets for 2 or 10 days. Gene expression was
analyzed with qPCR and plasma hormone levels were measured with species specific RIAs. There was
no significant effect of ghrelin on gene expression but trends towards increased expression of
anorexigenic signals (CCK and CRH). Plasma GH and IGF-I level were not influenced by ghrelin
treatment, nor was the leptin expression. Overall, these findings confirm the anorexigenic role of
ghrelin in rainbow trout.
Effects of cadmium, estrogen, androgen, PAH and their mixture in the threespined stickleback, Gasterosteus aculeatus
Andrea Mariossi
Institutionen för Biologi & Miljövetenskap, GU (Handledare: Joachim Sturve)
There are great numbers of compounds that end up in the marine environment and the resulting
chemical cocktails is potentially responsible for adverse environmental impacts. This study evaluates
the effects of three different types of pollutants: cadmium, benzo(a)pyrene and bisphenol A in threespined stickleback (Gasterosteus aculeatus). Brackish-acclimated fishes were exposed for 5 day in a
semi-static exposure to the single compounds (low dose and high dose) and to a mixture of them at
three different concentrations. Biological responses were explored both through analyses of the
hepatic genes expression, metallothionein (heavy metal), cyp1A (PAH) vitellogenin (estrogen), nrf2
(regulator of an array of antioxidant response element) using real-time PCR and oxidative stress
parameters (catalase (CAT), glutathione peroxidase (GPx), glutathione reductase (GR) and glutathione
S-transferase (GST). In addition, 7-ethoxyresorufin-O-deethylase (EROD) was measured both in gill and
liver. MT induction in females and Vtg induction in males were both detectable at low doses of Cd and
BPA, respectively. BαP exposure did not induce cyp1A expression in the liver of female stickleback. All
three chemical induce the expression of nrf2 gene. Furthermore, in female stickleback a strong dosedependent induction of EROD in gills and liver, as well as CAT and GPx was observed in Cd and BαP
exposure. Gene expression in the mixture was showed weaker in comparison to the responses in the
single exposures, similar patterns was observed in the enzymatic activities. In conclusion, when multiple
compounds are present together, responsiveness of these biomarkers set is changed; further studies
are needed to understand the cascade of effects that are happening.