Detection of bacteria in crayfish hemolymph by polymerase chain reaction

Iako su deseteronožni rakovi ključne vrste slatkovodnih ekosustava, brojni aspekti njihove biologije su slabo istraženi, uključujući bakterijske zajednice prirodno prisutne u hemolimfi. Cilj ovog rada bio je po prvi puta pokušati detektirati bakterije u hemolimfi zdravih jedinki uskoškarog raka Pontastacus leptodactylus (zavičajna vrsta) i signalnog raka Pacifastacus leniusculus (invazivna vrsta) lančanom reakcijom polimerazom (engl. polymerase chain reaction, PCR). Na nekoliko lokacija na rijeci Korani uhvaćene su 34 jedinke uskoškarog i 69 jedinki signalnog raka. Nakon izolacije ukupne DNA iz hemolimfe, provedena je amplifikacija gena koji kodira za bakterijsku 16S rRNA. Bakterije su detektirane u 45 % uzoraka hemolimfe uskoškarog raka te samo u 15,7 % uzoraka signalnog raka. Najveći broj pozitivnih uzoraka obje vrste bio je s lokacije Belajske Poljice.Although crayfish are keystone species of freshwater ecosystems, many aspects of their biology remain understudied, including analyses of bacterial communities naturally occurring in the hemolymph. The objective of this study was to detect, for the first time, bacteria in the hemolymph of healthy narrow-clawed crayfish Pontastacus leptodactylus (native species) and signal crayfish Pacifastacus leniusculus (invasive species) using polymerase chain reaction (PCR). Thirty-four individuals of narrow-clawed crayfish and 69 of the signal crayfish were captured at multiple sites in Korana River. After extraction of total DNA from hemolymph, amplification of the gene encoding bacterial 16S rRNA was performed. Bacteria were detected in 45% of the narrow- clawed crayfish hemolymph samples and in 15.7% of samples from signal crayfish. The largest number of positive samples of both species came from the site Belajske Poljice