Characterization of Saprolegnia isolates from Persian sturgeon ( Acipencer persicus) eggs based on physiological and molecular data

• Published in: Journal de mycologie médicale 2010-03, Vol.20 (1), p.1-7
• Main Authors: Ghiasi, M., Khosravi, A.R., Soltani, M., Binaii, M., Shokri, H., Tootian, Z., Rostamibashman, M., Ebrahimzademousavi, H.
• Format: Article
• Language: English
• Subjects: Acipencer persicus; Acipenser; Apicenter persicus; Biological and medical sciences; Esturgeon; Fundamental and applied biological sciences. Psychology; Infectious diseases; Medical sciences; Microbiology; Miscellaneous; Mycology; Mycoses; RAPD-PCR; Saprolegnia; Sturgeon; Teleostei; Zoospore; Zoospores; Œuf
• ISSN: 1156-5233; 1773-0449
• DOI: 10.1016/j.mycmed.2009.11.005

To investigate the physiological characteristics and genetic variations of Saprolegnia species isolated from Persian sturgeon ( Acipencer persicus) eggs. One hundred and fifty fish eggs covered with fungal hyphae were collected from propagation center of sturgeon and teleost fish Shahid Rajaii in Mazandaran province between March and May 2007. The samples were cultured into the specific media and the colony hyphal radial growth rates were determined at 18 °C and 12 °C. Random amplification of polymorphic DNA polymerase chain reaction (RAPD-PCR) was applied for genetic variations of the isolates. All samples were positive for Saprolegnia species. Most fungal isolates grew well at 18 °C but no isolates grew at 12 °C. Repeated zoospore emergence was found in isolates of Saprolegnia species, which were genetically linked to reference S. parasitica. This phenomenon was not seen in isolates that genetically liked to reference S. diclina. The RAPD analysis among Saprolegnia isolates was counteracted from 385 amplified products in 21 separable positions and indicated that the fungal isolates were composed of four genetically distant groups. We found different physiological characteristics and genetic variations of Saprolegnia isolates from Acipencer persicus eggs. Although repeated zoospore emergence was clearly not specific for pathogenic Saprolegnia species, it was present in certain groups of isolates defined by genotype and can be useful in distinguishing subgroups of pathogenic Saprolegnia species. Évaluer les caractéristiques physiologiques et les variations génétiques des espèces de Saprolegnia isolées d’œufs d’esturgeon ( Apicenter persicus). Entre les mois de mars et de mai 2007, les œufs de 150 poissons présentant des amas d’hyphes ont été récoltés au centre d’élevage de l’esturgeon et des téléostéens de Shahid Rajaii situé dans la province de Mazandaran. Les échantillons sont ensemencés sur des milieux spécifiques et après incubation à 12 °C et 18 °C, le taux de mycélium est évalué sur la base de la croissance radiale. L’ADN génomique des Saprolegnia est ensuite extrait et amplifié par PCR (RAPD-PCR) pour la détermination des variations génétiques des isolats. Tous les échantillons présentent des Saprolegnia en culture. La majorité de ces isolats montrent une croissance à 18 °C, en revanche, elle n’est pas observée à 12 °C pour certains d’entre eux. L’apparition répétée de zoospores est présente au sein des espèces de Saprolegnia qui sont génétiquement