X- and Y-chromosome specific variants of the amelogenin gene allow sex determination in sheep (Ovis aries) and European red deer (Cervus elaphus)

Abstract

Background: Simple and precise methods for sex determination in animals are a pre-requisite for a number of applications in animal production and forensics. However, some of the existing methods depend only on the detection of Y-chromosome specific sequences. Therefore, the abscence of a signal does not necessarily mean that the sample is of female origin, because experimental errors can also lead to negative results. Thus, the detection of Y- and X-chromosome specific sequences is advantageous.

Results: A novel method for sex identification in mammals (sheep, Ovis aries and European red deer, Cervus elaphus) is described, using a polymerase chain reaction (PCR) and sequencing of a part of the amelogenin gene. A partial sequence of the amelogenin gene of sheep and red deer was obtained, which exists on both X and Y chromosomes with a deletion region on the Y chromosome. With a specific pair of primers a DNA fragment of different length between the male and female mammal was amplified.

Conclusion: PCR amplification using the amelogenin gene primers is useful in sex identification of samples from sheep and red deer and can be applied to DNA analysis of micro samples with small amounts of DNA such as hair roots as well as bones or embryo biopsies.

Figure 1

DNA sequence comparison of the X and Y amelogenin gene fragments of sheep and European red deer. (.) ins/del

Figure 2

Detail of an ethidiume bromide stained agarose gel showing amplicons of the amelogenin gene fragments of sheep and European red deer. Lane 1–2 samples from male red deer, lane 3–4 samples from male sheep, lane 5 sample from female sheep and lane 6–7 samples from female red deer. The star 1 indicates the AMELX band, the star 2 indicates a non specific band in male sheep and male red deer and the star 3 indicates the AMELY band.