Sex-associated DNA markers from turbot

Abstract

The genomes of male and female turbot, Psetta maxima (Linnaeus, 1758), were screened for sex-specific sequences by comparative random amplified polymorphic DNA (RAPD) assays performed on pooled samples. As turbot females grow much faster than males, there is an increasing interest in differentiating between the sexes, and such markers would enable the sexing of individuals even at early stages of development. Four sex-associated DNA markers, with molecular sexing efficiencies ranging from 77 to 90%, were identified and further characterized. Two markers were identified from pooled female samples, one from pooled male samples (both sets collected from the wild), whereas a fourth marker was found in the female pool of farm-bred siblings. Parallel application of the three markers isolated from wild-caught individuals yielded a combined molecular sexing efficiency of 90% in males and 83.3% in females. While the three markers isolated from the wild should be useful to predict the sex in natural turbot populations, the fourth marker showed sex-association limited only to the family where it was isolated from. Nonetheless, it can be used for molecular sexing of brooders originating from the target family and potentially their offspring as well. The application of such molecular sex markers with limited scope is a potential strategy in aquaculture for those species for which no universal sex marker is available.

Nutritional value and flavor of turbot (Scophthalmus maximus) muscle as affected by cooking methods

“…[1] Turbot is a commercially important marine fish for aquaculture in northern China. [2][3][4] The harvest of flounder fish were 118,009 tons, it was the third maricultural fish in China in 2016. [5] Cooking is usually necessary to obtain palatable and pathogen-free foods.…”

A combined strategy involving Sanger and 454 pyrosequencing increases genomic resources to aid in the management of reproduction, disease control and genetic selection in the turbot (Scophthalmus maximus)

“…The induction of gynogenesis suggested a XX/XY system of sex determination [16], but later studies involving the analysis of progenies from sex-reversed parents revealed a ZW/ZZ system [17]. Linkage maps were developed [18-21] and led to the identification of the major sex-determining region [22] and facilitated the characterization and mapping of sex-associated markers [23,24], although the sex determining gene(s) is (are) still unknown.…”

Bulked segregant analysis of the pirarucu (Arapaima gigas) genome for identification of sex-specific molecular markers

“…Compared to other methods that have been used previously for identifying sequences present and absent from a genome, bulked segregant analysis with RAPD markers is a simple, low-cost approach, which has been used successfully in several recent studies aimed at identifying sex-specific markers in a number of species (Iturra et al, 1997;Lee and Donaldson, 2001;Gebler et al, 2007;Mariotti et al, 2009;Casas et al, 2011). Even in the current context where sequencing and resequencing of complete genomes are becoming widely accessible due to the greater capacity and reduced cost conferred by recent technological advances (Metzker, 2010), this methodology is still a proven approach with great potential to provide positive results in similar studies.…”

“…The identification of sex-specific molecular markers for development of diagnostic assays for sexing prepubescent fish has been accomplished in a number of species: rainbow trout, Oncorhynchus mykiss (Iturra et al, 1997); tilapia, Oreochromis niloticus (Lee and Donaldson, 2001); African catfish, Clarias gariepinus (Kovács et al, 2000); yellow catfish, Pelteobagrus fulvidraco (Wang et al, 2009); and turbot, Psetta maxima (Casas et al, 2011). A sex-specific molecular marker for A. gigas is needed to assist the development and application of innovative methods for rearing this species on a commercial scale.…”