Protein acetylation in archaea, bacteria, and eukaryotes

Proteins can be acetylated at the alpha-amino group of the N-terminal amino acid (methionine or the penultimate amino acid after methionine removal) or at the epsilon-amino group of internal lysines. In eukaryotes the majority of proteins are N-terminally acetylated, while this is extremely rare in bacteria. A variety of studies about N-terminal acetylation in archaea have been reported recently, and it was revealed that a considerable fraction of proteins is N-terminally acetylated in haloarchaea and Sulfolobus, while this does not seem to apply for methanogenic archaea. Many eukaryotic proteins are modified by differential internal acetylation, which is important for a variety of processes. Until very recently, only two bacterial proteins were known to be acetylation targets, but now 125 acetylation sites are known for E. coli. Knowledge about internal acetylation in archaea is extremely limited; only two target proteins are known, only one of which--Alba--was used to study differential acetylation. However, indications accumulate that the degree of internal acetylation of archaeal proteins might be underestimated, and differential acetylation has been shown to be essential for the viability of haloarchaea. Focused proteomic approaches are needed to get an overview of the extent of internal protein acetylation in archaea

Protokoll for vurdering av modningsgrad hos oppdrettstorsk

Den gjeldende protokollen for vurdering av modningsnivået hos oppdrettstorsk skisserer distinkte modenhetsstadier hos både hann- og hunntorsk (Gadus morhua). Denne protokollen hjelper til med å evaluere graden av modenhet hos torsk i oppdrettsanlegg. Hvert stadium involverer en makroskopisk vurdering, som inkluderer bilder av gonadene både inne og utenfor fisken, detaljerte bilder, en generell beskrivelse av gonadene og fiskemålinger. I tillegg inkluderer det en mikroskopisk vurdering, med histologiske bilder og beskrivelser. Protokollen gir også retningslinjer for riktig innsamling av gonadeprøver fra hann- og hunntorsk for videre histologiske analyser.Protokoll for vurdering av modningsgrad hos oppdrettstorskpublishedVersio

Behaviour of reindeer as an indicator of an adaptation to feeding

Abstract: We assessed behaviour of reindeer affected by nutritional deprivation and how they adapted to various feeding strategies. The activity pattern of 61 penned eight month old female reindeer calves was observed during 20 of a total of 42 experimental days in winter 1997. The dominant activities were lying, ruminating, intake of feed and water, and standing. Few recordings of agonistic behaviour or snow intake occured. Restricted feed intake, half the ad lib. ration of a lichen-based diet, affected the eating behaviour of the reindeer, and more animals were standing and fewer lying compared to reindeer fed ad lib. Lack of energy in the diet correlated with animals lying curled up (lying with the muzzle close to the hind legs). This behaviour could be a useful complement to other measurements and registrations when studying adaptations to various feeding regimens.Abstract in Swedish/Sammanfattning:Syftet med studien var att undersöka om, och i så fall hur renars beteende påverkades av otillräckligt näringsintag och vid anpassning till olika utfodringsstrategier. Aktivitetsmönstret hos 61 inhägnade åtta månader gamla honrenkalvar studerades under 20 av totalt 42 försöksdagar. De vanligaste beteendekategorierna genom hela försöket var ligga, idissla, intag av foder och vatten samt stå passivt. Endast ett fåtal observationer av aggressivt beteende och snöätande registrerades. En begränsad giva dvs. halva mängden av fodergivan vid fri tillgång av en lavbaserad diet påverkade djuren ätbeteende. Dessutom observerades fler djur stå passivt medan färre låg jämfört med kontrollgruppen. Under första fasen av utfodring efter restriktionsperioden låg fler djur låg ihoprullade (med mulen tätt intill bakbenet) jämfört med kontrollgruppen, vilket tolkades som ett tecken på energibrist. Beteendestudierna visade sig vara ett värdefullt komplement till övriga mätningar och provtagningar vid studier av renars anpassning till olika utfodringsregimer

Change in nutrient composition of Artemia grown for 3–4 days and effects of feeding on-grown Artemia on performance of Atlantic halibut (Hippoglossus hippoglossus, L.) larvae

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Large predators and their impact on reindeer husbandry

Several large predators (wolf, lynx, wolverine, brown bear and eagle) are present within the Fennoscandian reindeer herding area, where reindeer are often their main prey. After being more or less eradicated during the 1800s and early 1900s, predators were gradually protected leading to the recovery of all species. Growing populations of predators evidently lead to increased damage to reindeer and reindeer husbandry. In Fennoscandia, the annual loss of reindeer due to predation is probably around 50,000–100,000 animals. Herders get economic compensation for losses. In Finland and Norway, this is based on the number of predator-killed reindeer that are found, while in Sweden the compensation is based on the number of predators (wolf, lynx or wolverine) or area of the herding district (bear and golden eagle). According to national policy, reindeer husbandry should be taken into account in the management of large predators, but often population goals for the predator override the interests of reindeer husbandry. Although reindeer herders acknowledge that predators have a place in the ecosystem, there is frustration about reimbursement not compensating for actual losses, and that herders’ voices are not heard, and their knowledge not recognized, when it comes to predator management

Large predators and their impact on reindeer husbandry

Several large predators (wolf, lynx, wolverine, brown bear and eagle) are present within the Fennoscandian reindeer herding area, where reindeer are often their main prey. After being more or less eradicated during the 1800s and early 1900s, predators were gradually protected leading to the recovery of all species. Growing populations of predators evidently lead to increased damage to reindeer and reindeer husbandry. In Fennoscandia, the annual loss of reindeer due to predation is probably around 50,000–100,000 animals. Herders get economic compensation for losses. In Finland and Norway, this is based on the number of predator-killed reindeer that are found, while in Sweden the compensation is based on the number of predators (wolf, lynx or wolverine) or area of the herding district (bear and golden eagle). According to national policy, reindeer husbandry should be taken into account in the management of large predators, but often population goals for the predator override the interests of reindeer husbandry. Although reindeer herders acknowledge that predators have a place in the ecosystem, there is frustration about reimbursement not compensating for actual losses, and that herders’ voices are not heard, and their knowledge not recognized, when it comes to predator management

Effects of dietary arachidonic acid on the reproductive physiology of female Atlantic cod (Gadus morhua L.)

publishedVersio

Sex-biased miRNA expression in Atlantic halibut (Hippoglossus hippoglossus) brain and gonads

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Entry into puberty is reflected in changes in hormone production but not in testicular receptor expression in Atlantic salmon (Salmo salar)

Background Puberty in male Atlantic salmon in aquaculture can start as early as after the first winter in seawater, stunts growth and entails welfare problems due to the maturation-associated loss of osmoregulation capacity in seawater. A better understanding of the regulation of puberty is the basis for developing improved cultivation approaches that avoid these problems. Our aim here was to identify morphological and molecular markers signaling the initiation of, and potential involvement in, testis maturation. Methods In the first experiment, we monitored for the first time in large Atlantic salmon males several reproductive parameters during 17 months including the first reproductive cycle. Since testicular growth accelerated after the Winter solstice, we focused in the second experiment on the 5 months following the winter solstice, exposing fish from February 1 onwards to the natural photoperiod (NL) or to continuous additional light (LL). Results In the first experiment, testis weight, plasma androgens and pituitary gonadotropin transcript levels increased with the appearance of type B spermatogonia in the testis, but testicular transcript levels for gonadotropin or androgen receptors did not change while being clearly detectable. In the second experiment, all males kept under NL had been recruited into puberty until June. However, recruitment into puberty was blocked in ~ 40% of the males exposed to LL. The first morphological sign of recruitment was an increased proliferation activity of single spermatogonia and Sertoli cells. Irrespective of the photoperiod, this early sign of testis maturation was accompanied by elevated pituitary gnrhr4 and fshb and testicular igf3 transcript levels as well as increased plasma androgen levels. The transition into puberty occurred again with stable testicular gonadotropin and androgen receptor transcript levels.publishedVersio

Atlantic salmon male post-smolt maturation can be reduced by using a 3-hour scotophase when inducing smoltification

Photoperiod regulates the occurrence of unwanted male post-smolt maturation during the production of large (>100 g) Atlantic salmon (Salmo salar) smolts. However, the optimal daylength for triggering smoltification, but not male puberty, has yet to be established. We used either continuous light (24:0 light/dark) or long days (18:6 and 21:3) after a six week “winter” zeitgeber (12:12) to induce smoltification in fish of around 120 g reared at 16 °C. The fish were sampled 1, 2, 3, and 6 weeks after the initiation of the three different photoperiod treatments (n = 153 males in total with 9–18 males/photoperiod/time point). As expected, the smoltification indicator gill Na+/K+-ATPase (NKA) was significantly (p < 0.05) elevated and peaked 2 to 3 weeks after the initiation of the different photoperiods. Pubertal males were identified in all treatments via the combined use of relative testis size and histology, plasma 11-ketotestosterone, changes in body condition, and growth rate. The total incidence of puberty was significantly higher among males on continuous light at 33% (n = 16/49) compared to 10% (6/61) and 12% (5/43) in 21:3 and 18:6, respectively. The incidence of puberty increased over time in all photoperiods, with 62% (8/13), 19% (3/16), and 38% (3/8) of the males from 24:0, 21:3, and 18:6 pubertal at week 6, respectively. The mean weight of males that went on to initiate puberty was significantly higher (13%) at the beginning of the trial compared to those that remained immature (mean weight, 127 vs 112 g, respectively), but there was no initial difference in body condition. Puberty significantly reduced gill NKA by 35% compared to immature males at week six but had no effect at earlier time-points. Photoperiod had no effect on the female GSI, and they were all considered immature. In conclusion, the incidence of male puberty during smoltification is regulated by photoperiod and leads to an earlier decline in a key indicator of seawater readiness. As such, photoperiods with a short scotophase (21:3 or 18:6) following the winter zeitgeber in a square-wave (long-short-long day) smolt regime are recommended to limit the incidence of male puberty.publishedVersio