| 1. |
- Arnason, T., et al.
(author)
-
Long-term rearing of Arctic charr Salvelinus alpinus under different salinity regimes at constant temperature
- 2014
-
In: Journal of Fish Biology. - : Wiley. - 0022-1112. ; 85:4, s. 1145-1162
-
Journal article (peer-reviewed)abstract
- Arctic charr Salvelinus alpinus of the Holar strain (mean+/- s. e. body mass= 152.1+/-3.1g) were reared at four different salinity regimes at a constant temperature of 7.4 degrees C. Two groups were given a three-month acclimation in salinity 18 before the salinity was increased to either 25 or 29 (groups called A25 and A29), and two groups were reared in salinities 25 or 29 over the full experimental period of 409 days (groups called F25 and F29). In the first 3months, the A25 and A29 groups had the highest growth rates. By October 2011, there were no significant differences (two-way nested ANOVA, P> 0.05) in the mean body masses among A25, F25 and F29 (c. 1450 g), whereas A29 had a lower mean mass (1282 g). The growth in the last period from October 2011 to January 2012 was reduced by sexual maturation in the highest salinity regimes (A29 and F29), whereas fish in groups A25 and F25 showed high growth throughout the study. Males in all salinity groups had higher growth rates than females for the most part of the study, but the divergence between the sexes was most pronounced in the highest salinity regimes. All salinity groups showed distinct changes in Na+, K+-ATPase activity, with high activity in spring and summer, and lower activity in the autumn. Plasma sodium (Na+) levels were stable indicating that none of the experimental groups had problems in maintaining hydromineral balance during the study. While plasma leptin levels were not affected by salinity regimes, it was noted that these levels were 13-30% higher in fish with empty guts compared with those having food in their gut at the time of sampling. This suggests a link between leptin levels and food intake, indicating that this hormone may play a role in food intake and energy allocation in fishes.
|
|
| 2. |
- Wade, C. M., et al.
(author)
-
Genome Sequence, Comparative Analysis, and Population Genetics of the Domestic Horse
- 2009
-
In: Science. - : American Association for the Advancement of Science (AAAS). - 0036-8075 .- 1095-9203. ; 326:5954, s. 865-867
-
Journal article (peer-reviewed)abstract
- We report a high-quality draft sequence of the genome of the horse ( Equus caballus). The genome is relatively repetitive but has little segmental duplication. Chromosomes appear to have undergone few historical rearrangements: 53% of equine chromosomes show conserved synteny to a single human chromosome. Equine chromosome 11 is shown to have an evolutionary new centromere devoid of centromeric satellite DNA, suggesting that centromeric function may arise before satellite repeat accumulation. Linkage disequilibrium, showing the influences of early domestication of large herds of female horses, is intermediate in length between dog and human, and there is long-range haplotype sharing among breeds.
|
|
| 3. |
- Gunnarsson, S., et al.
(author)
-
Effects of short-day treatment on long-term growth performance and maturation of farmed Arctic charr Salvelinus alpinus reared in brackish water
- 2014
-
In: Journal of Fish Biology. - : Wiley. - 0022-1112. ; 85:4, s. 1211-1226
-
Journal article (peer-reviewed)abstract
- The effects of a 6 week short-day photoperiod followed by continuous light, applied during the juvenile phase of Arctic charr Salvelinus alpinus in fresh water on smoltification and on the long-term growth andmaturity following transfer to brackish water (BW) (constant salinity of either 17 and 27 or increasing salinity in steps from 17 to 27) were investigated. Prior to salinity transfer, the juveniles were either reared at continuous light (C group) or reared for 6 weeks on a short day (8L: 16D, S group) followed by continuous light (24L: 0D). Increased salinity had negative effect on growth, with female fish reared at 17 salinity weighing 19 and 27% more than the salinity-step group (17-27) and the 27 salinity group, respectively. The stepwise acclimation to salinity had limited advantage in terms of growth rate. Short photoperiod for 6 weeks (November to January) followed by continuous light improved growth, but not seawater (SW) tolerance. Gill Na+, K+-ATPase activity and plasma Na+ levels changed with time, indicating some variation in osmoregulatory capacity during the experimental period. Overall, there appear to be interactive effects on maturation from applying short-day photoperiod followed by rearing at higher salinities. Plasma leptin varied with time and may be linked to stress caused by the observed variations in osmoregulatory ability. It is concluded that changes in growth rates observed in this study are mainly related to rearing salinity with higher growth rates at lower salinities. Short-day photoperiod has some growth-inducing effects but did not improve SW tolerance. Farmers of S. alpinus using BW for land-based rearing should keep salinity at moderate and stable levels according to these results to obtain best growth.
|
|
| 4. |
- Imsland, A.K, et al.
(author)
-
Temperature and salinity effects on plasma insulin-like growth factor-1 concentrations and growth in juvenile turbot (Scophthalmus maximus).
- 2007
-
In: Aquaculture. - : Elsevier BV. - 0044-8486. ; 271:1-4, s. 546-552
-
Journal article (peer-reviewed)abstract
- The effects of temperature and salinity on plasma IGF-I levels and its interrelationship with growth, daily feed intake and feed conversion of juvenile turbot (initial mean weight 14 g) were investigated by rearing fish at 10, 14, 18 and 22 °C and 15, 25 and 33.5‰ for 3 months. The plasma IGF-I levels increased with increasing temperatures reaching a plateau around 18 °C. Further, both temperature and salinity had a significant effect on growth, daily feed intake and feed conversion efficiency in juvenile turbot. Growth, food consumption, and food conversion efficiency were highest at 18 °C and 15‰, and lowest at 10 °C and 33.5‰. Although there was a high variation between IGF-I values within all groups there was a positive relationship between IGF-I levels and specific growth rates and daily feed intake. The levels of IGF-I were almost three times higher for fish with higher growth rates than for those with lower growth. In addition, the results show evidence for an increased appetite in fish with high plasma IGF-I levels. Interestingly, there was no correlation between environmental salinity and IGF-I levels, although decreased salinity improves growth and feed conversion efficiency.
|
|
| 5. |
- Handeland, S. O., et al.
(author)
-
Long-term effects of photoperiod, temperature and their interaction on growth, gill Na+, K+-ATPase activity, seawater tolerance and plasma growth-hormone levels in Atlantic salmon Salmo salar
- 2013
-
In: Journal of Fish Biology. - : Wiley. - 0022-1112. ; 83:5, s. 1197-1209
-
Journal article (peer-reviewed)abstract
- This study was undertaken to examine the long-term effects of photoperiod, temperature and their interaction on growth, gill Na+,K+-ATPase (NKA) activity, seawater tolerance and plasma growth-hormone levels in Atlantic salmon Salmo salar pre-smolts and smolts. The fish (mean +/- s.e. initial body mass=159 +/- 04g) were reared on two photoperiods (continuous light, LL, and simulated natural photoperiod, LDN, 60 degrees 25 N) and two temperatures (83 and 127 degrees C) from June to May of the following year. Mean body mass was affected by photoperiod, temperature and their interactions. Both temperature groups on LL developed peak levels in gill NKA activity from October to November, 4-5months prior to the natural season for the parr-smolt transformation. Fish at 12 degrees C showed peak levels in NKA activity 4-6weeks before the fish at 8 degrees C. Fish in all four experimental groups showed maximum NKA activity within a similar size range (113-162g). The present findings further indicate that smoltification in S. salar is to some extent driven by size, and that S. salar will develop smolt characteristics, e.g. a marked increase in NKA activity, within a similar size range. Faster-growing S. salar will, thus, reach this size threshold at a relatively younger age. (C) 2013 The Fisheries Society of the British Isles
|
|
| 6. |
- Handeland, S. O., et al.
(author)
-
Physiology during smoltification in Atlantic salmon: effect of melatonin implants
- 2013
-
In: Fish Physiology and Biochemistry. - : Springer Science and Business Media LLC. - 0920-1742 .- 1573-5168. ; 39:5, s. 1079-1088
-
Journal article (peer-reviewed)abstract
- Melatonin implants were used to override natural melatonin rhythm in groups of juvenile Atlantic salmon, Salmo salar, raised at simulated natural photoperiod (SNP) and constant light (LL) from mid-March until end of August. The experiment contained also both sham control (with non-melatonin implants) and control (no implants). No differences were found in the experimental variables between these two control groups. Growth and food intake were negatively affected by melatonin implantation. Overall, higher GH levels were observed in the SNP melatonin-implanted group, whereas no differences in GH levels were seen between the SNP control, LL control, or the LL melatonin-implanted groups. Highest food intake was seen in the LL control group. No differences in food intake were recorded between the LL melatonin-implanted and SNP control groups. Gill Na+, K+, ATPase (NKA) activity was influenced by time as well as the interaction between photoperiod and time. No differences in gill NKA activity or plasma chloride levels following transfer to seawater were seen between the groups with melatonin implants and their controls. Based on the present results, it seems apparent that melatonin does play a role in regulating food intake and growth in Atlantic salmon smolts.
|
|
| 7. |
- Staiger, E. A., et al.
(author)
-
The evolutionary history of the DMRT3 'Gait keeper' haplotype
- 2017
-
In: Animal Genetics. - : WILEY. - 0268-9146 .- 1365-2052. ; 48:5, s. 551-559
-
Journal article (peer-reviewed)abstract
- A previous study revealed a strong association between the DMRT3:Ser301STOP mutation in horses and alternate gaits as well as performance in harness racing. Several follow-up studies have confirmed a high frequency of the mutation in gaited horse breeds and an effect on gait quality. The aim of this study was to determine when and where the mutation arose, to identify additional potential causal mutations and to determine the coalescence time for contemporary haplotypes carrying the stop mutation. We utilized sequences from 89 horses representing 26 breeds to identify 102 SNPs encompassing the DMRT3 gene that are in strong linkage disequilibrium with the stop mutation. These 102 SNPs were genotyped in an additional 382 horses representing 72 breeds, and we identified 14 unique haplotypes. The results provided conclusive evidence that DMRT3: Ser301STOP is causal, as no other sequence polymorphisms showed an equally strong association to locomotion traits. The low sequence diversity among mutant chromosomes demonstrated that they must have diverged from a common ancestral sequence within the last 10 000 years. Thus, the mutation occurred either just before domestication or more likely some time after domestication and then spread across the world as a result of selection on locomotion traits.
|
|
