Life history characteristics of a potential invasive Ponto-Caspian goby, Neogobius fluviatilis in natural lakes from its native range (Black Sea region of Turkey)

To fill the gap in and provide baseline knowledge for developing increased understandings of the factors driving the invasiveness of the Ponto-Caspian gobiid Neogobius fluviatilis, their life history traits (as somatic growth and reproduction) were studied in three natural freshwater lakes in its native range. These populations were characterised by slow somatic growth rates, being the slowest reported across all of their native and non-native ranges. Ages were recorded to seven years old. Across the three lakes, there was considerable variability in their sex ratios and reproductive traits (including length at maturity and fecundity at length and age), revealing considerable inter-population variability. These data thus suggest N. fluviatilis has considerable plasticity in the expression of their life history traits, with this plasticity argued as a key factor in facilitating their ability to establish and invade new waters following introductions

STRUCTURE, GROWTH AND MORPHOLOGY OF FISH POPULATIONS FROM GRAVEL-PIT VUKOVINA

Utvrđena je struktura ribljih populacija šljunčare Vukovina, te je istraženo deset morfometrijskih i četiri merističke osobine, kao i dužinsko-maseni odnosi. Neke merističke osobine kod klena (Leuciscus cephalus) i sunčanice (Lepomis gibbosus) prelazile su granice za ove vrste navedene u standardnom ključu za određivanje vrsta slatkovodnih riba. Dužinsko-maseni odnosi i faktor kondicije (CF) u svih istraživanih vrsta bili su znatno niži nego na drugim istraživanim lokacijama. To upućuje na izrazitu oligotrofnost i vrlo nisku ihtioproduciju šljunčare Vukovina.After the structure of fish populations from gravel-pit Vukovina was determined, those populations were checked for 10 morphometric and 4 meristic parameters, as well as for length-mass relationship. For chub (Leuciscus cephalus) and pumpkinseed (Lepomis gibbosus) some meristic characters expressed the values beyond those mentioned in the standard key for the freshwater fish species determination. When compared to other locations, length-mass relationship and condition factor (CF) were significantly lower for all checked populations. This indicates that gravel-pit Vukovina is extremely oligotrophic and has very poor fish production

KLJUČNI ČIMBENICI U UROĐENOM IMUNOLOŠKOM PREPOZNAVANJU VIRUSNE INFEKCIJE U SISAVACA I RIBA

Viral infection of mammalian cells activates an innate antiviral immune response characterized by production of interferon and subsequent enhanced transcription of interferon–stimulated genes important for antiviral defense. Cells recognize viral infection through various pathogen–associated molecular patterns, of which dsRNA seems to be the most important. In mammals, several gene products are important in recognition of dsRNA: RIG–I, TLR3, PKR and mda–5. Recent research proved that fish possess most of the key elements in recognition of viral infection which indicates that these mechanisms are very similar and evolutionary conserved in vertebrates.Virusna infekcija u stanicama sisavaca potiče urođeni odgovor karakteriziran proizvodnjom interferona i posljedičnom pojačanom transkripcijom interferonima stimuliranih gena, bitnih u obrani organizma od virusa. Stanice prepoznaju virusnu infekciju preko određenih molekularnih uzoraka povezanih s patogenima, od kojih je najvažnija dvolančana RNK. U organizmu sisavaca ključnu ulogu u prepoznavanju dvolančane RNK ima nekoliko gena: RIG–I, TLR3, PKR i mda–5. Dosadašnja su istra‘ivanja pokazala da ribe posjeduju većinu ključnih elemenata zaduženih za prepoznavanje virusne infekcije, što upućuje na veliku sličnost i evolucijsku očuvanost spomenutih mehanizama

Dietary Bile Salt Types Influence the Composition of Biliary Bile Acids and Gut Microbiota in Grass Carp

Lipid metabolism can influence host’s health. There is increasing evidence for interplay between two key regulating factors in lipid metabolism: bile acids (BAs) and gut microbiota. However, very little is known about how types of different diet-supplemented bile salts (BS) influence this interaction in vivo. We sought to explore these relationships using grass carp (Ctenopharyngodon idellus), which often suffers functional disorder of liver and gallbladder. We studied fluctuations of BAs in the gall and changes of microbial communities in the gut in response to seven different diets: five different BS, chelating BS agent, and control. The BS comprised two primary BS [sodium taurochololate (TCAS) and sodium taurochenodeoxycholate (TCDCAS)], sodium tauroursodeoxycholate (TUDCAS), and two secondary BS [sodium taurodeoxycholate (TDCAS) and sodium taurolithocholate (TLCAS)]. Supplementation of primary BS caused a more significant fluctuation of biliary BAs than secondary BS, and TCAS caused a more prominent increase than TCDCAS and TUDCAS. For the gut microbiota, primary BS tended to increase their diversity and induce community succession, secondary BS resulted in a higher firmicutes/bacteroidetes ratio, while TUDCAS had no significant effects. Changes of the gut microbiota triggered by different types of BS caused alteration in BAs biotransformation. Two-obesity-associated families, Lachnospiraceae and Ruminococcaceae were positively correlated with biliary cholic acid (CA), taurochenodeoxycholic acid (TCDCA), and deoxycholic acid (DCA). As both primary and secondary BS resulted in increased synthesis of toxic secondary Bas by the gut microbiota, future studies should pay closer attention to gut microbiota when considering BA treatment

Positive Selection Drives the Rapid Fixation of Dephosphorylation in IRF9

Abstract The arms race between humans and pathogens drives the evolution of the human genome. Here, based on the HPO (Human Phenotype Ontology) annotation, we focused on human genes related to recurrent infections of virus, (RVI), bacterial (RBI) and recurrent fungal infections (RFI) to understand positive selection on pathogen-responsive genes. Interestingly, cross-species positive selection analyses revealed that the proportion of unique genes under positive selection was higher for RVI (78.57%) than for RFI (57.14%) and RBI (58.68%). Based on results of the branch-site test, we further focused on the amino acid site Val129 of IRF9, which has a significant signal of positive selection based on multiple evidence. Interestingly, this novel and derived amino acid (V) has been rapidly fixed before the "out-of-Africa" event ~ 500,000 years ago from the ancestral state S, which is conserved among 88.5% of mammalian lineages. Phosphorylation analysis revealed that the conserved ancestral S may serve as the phosphorylation site of IRF9. Further analyses suggested that the rapid dephosphorylation of IRF9 via the change of S to V may have conferred potential molecular adaptations by boosting and extending the immune activity of IRF9. This study provides an interesting mode in which strong positive Darwinian selection drives the rapid fixation of a hominin specific amino acid leading to molecular adaptation for immune response.</jats:p