Quantitative sexing (Q-sexing) technique for animal sex-determination based on X chromosome-linked loci: Empirical evidence from the Siberian tiger

Alasaad S., Fickel J., Soriguer R.C., Sushitsky Yu.P., Chelomina G.

В журнале African Journal of Biotechnology

Год: 2013 Том: 12 Номер: 1 Страницы: 14-18

Here we report a mammal sexing procedure based on the detection of quantitative differences between females and males in the X-linked loci (quantitative sexing, Q-sexing). This novel technique was validated using samples from Siberian tigers (Panthera tigris altaica) whose sexes were known. The Q- sexing technique relies on the fact that amplifications proceeding exclusively from the two X chromosomes in a female mammal should reach the threshold cycle (CT) in a real-time quantitative real time polymerase chain reaction (qPCR) assay sooner than amplifications from the single male X chromosome. Nevertheless, given that the amplification efficiency may vary between samples, results have to be calibrated to a marker that does not vary in copy number between the sexes (for example, an autosomal-linked locus). For this purpose we used quantitative real time polymerase chain reaction (RT qPCR) assays to quantify the amount of three specific Siberian tiger microsatellite markers (X-/Y- and autosomal-linked loci) in individual samples in order to determine the sex of an animal. A difference of one CT between the X and the autosome-linked loci was detected in males, but no such difference was present in female samples. The Q-sexing technique unambiguously separates female from male Siberian tigers. The future of RT qPCR is bright as technology is becoming ever more rapid, cost- effective, easier to use and capable of processing higher throughputs. Thus, we expect that our novel technique for animal sexing will have a wide applicability, although further studies are still needed to adapt it to other animal species using specific primers.

DOI 10.5897/AJB12.1689

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