A simple and reliable molecular method for sex identificationof the Brown-eared pheasant (Crossoptilon mantchuricum)from non-invasively collected samples

摘要

For sex identification of the Brown-eared pheasant (Crossoptilon mantchuricum), one of the critically endangered endemic birds in China, the morphological method of checking the astragalus, an extra tiny bone on the ankle only of male ones is inconvenient and even impossible for wild populations. In this paper, we investigated a simple reliable non-invasive method according to the difference of the sizes of sex-linked genes CHDI-W and CHDI-Z (Griffiths et al., 1996; Ellegren, 1996) to identify the gender of individuals in two captive populations of the Brown-eared pheasant. We extracted DNA from blood and feather samples and amplified the genes by PCR using two pairs of primers P2/P8 (Griffiths et al., 1998) and 2550F/2718R (Fridolfsson et al., 1999). The products amplified with P2/P8 failed to show the sex due to the low resolution of the agarose gel. PCR using the 2550F/2718R primer set amplified two products of different sizes for all known females and a single product for all known males when scored on the 2.0% agarose gel, which indicated that this primer set enabled sex identification. Both blood and feather samples gave identical results although the products amplified from the feather samples were fewer than the blood samples which were taken invasively and acted as control. This is the first time molecular methods was used for sex identifications of the Brown-eared pheasant and will assist their management by means of artificial propagation and allow the study of the ecology and conservation genetics of the Brown-eared pheasant.