Genetic Inactivation of European Sea Bass (Dicentrarchus labrax L.) Eggs Using UV-Irradiation: Observations and Perspectives

Abstract

Androgenesis is a form of uniparental reproduction leading to progenies inheriting only the paternal set of chromosomes. It has been achieved with variable success in a number of freshwater species and can be attained by artificial fertilization of genetically inactivated eggs following exposure to gamma (γ), X-ray or UV irradiation (haploid androgenesis) and by restoration of diploidy by suppression of mitosis using a pressure or thermal shock. The conditions for the genetic inactivation of the maternal genome in the European sea bass (Dicentrarchus labrax L.) were explored using different combinations of UV irradiation levels and durations. UV treatments significantly affected embryo survival and generated a wide range of developmental abnormalities. Despite the wide range of UV doses tested (from 7.2 to 720 mJ.cm−2), only one dose (60 mJ.cm−2.min−1 with 1 min irradiation) resulted in a small percentage (14%) of haploid larvae at hatching in the initial trials as verified by flow cytometry. Microsatellite marker analyses of three further batches of larvae produced by using this UV treatment showed a majority of larvae with variable levels of paternal and maternal contributions and only one larva displaying pure paternal inheritance. The results are discussed also in the context of an assessment of the UV-absorbance characteristics of egg extracts in this species that revealed the presence of gadusol, a compound structurally related to mycosporine-like amino acids (MAAs) with known UV-screening properties.

De novo synthesis of a sunscreen compound in vertebrates

“…This rare ovoviviparous fish lives in caves 100–500 meters deep and feeds at night, and its lack of gadusol production ability may be directly related to its limited exposure to UV light and/or oxidative stress. Other than the well-documented presence of gadusol in fish eggs, where it can serve to protect the roe from UV damage ( Arbeloa et al, 2010 ; Colleter et al, 2014 ), nothing is known of its role(s) in fish, reptiles, amphibians, and birds. Exploring its function in these organisms will increase our understanding of their physiology and ecology.…”

Photochemistry and photophysics of mycosporine-like amino acids and gadusols, nature’s ultraviolet screens

“…The antioxidant properties of the compounds are comparable to those of ascorbic acid and this issue seems to have attracted most interest some years ago [4,11,14,53,54]. However, the UV-screening properties of gadusol have recently received particular attention in reference to potential roles in marine organisms [55,56]. In vitro studies about photoinduced processes of these molecules in solution are limited to a few publications [54,57,58].…”

Androgenetic haploid Japanese pufferfish (Takifugu rubripes) induced by cold shock

“…UV irradiation was used in Nile tilapia ( Oreochromis niloticus ), loach ( Misgurnus anguillicaudatus ), common carp ( Cyprinus carpio ), tiger barb ( Puntius tetrazona ) and common tench ( Tinca Tinca L.) (Bongers, Zandieh‐Doulabi, Richter, & Komen, ; Kirankumar et al, ; Masaoka, Arai, & Suzuki, ; Myers et al, ; Nowosad, Kucharczyk, Liszewski, Targońska, & Kujawa, ). Also, the androgenetic sea fish European Sea Bass ( Dicentrarchus labrax L.) was acquired by using UV irradiation (Colléter et al, ). X‐ray irradiation and Co 60 source were also employed in zebrafish ( Danio rerio ) and goldfish ( Carassius auratus ) respectively (Corley‐Smith, Lim, & Brandhorst, ; Paschos, Natsis, Nathanailides, Kagalou, & Kolettas, ).…”