LAUSR

Abstract Male fertility is one aspect of animal reproduction that was targeted by many biotechnology studies aiming to improve reproductive efficiency and, hence, productive capacity in different species. The current investigation aimed to determine expression of hypothetical fertility-related molecular markers in male camels. At the peak of rutting period (February), thirty ejaculates were collected from three adult dromedary bulls, Camelus dromedarius, whose reproductive history were verified over the past 10 years. Each raw ejaculate was subjected to sperm physical and morphological assessment immediately after collection. Furthermore, blood samples were obtained from each male at the peak of rutting (February) as well as out of breeding season (August) to identify potential fertility-related molecular markers by fluorescently-labeled differential display PCR (FDD). The results revealed that semen physical characteristics of each camel were in consistence with its reproductive history. Accordingly, the males were categorized into 3 fertility grades; i.e. high, medium and low prolific. Concurrently, the results of FDD successfully delineated this variation in fertility. Visualized chromatograms of differentially displayed fragments evinced detection of 24 seasonally-expressed mRNA molecules; of which 5 were expressed off the breeding season (down-regulated), and 19 molecules were expressed at the peak of rutting period (up-regulated). Furthermore, the expression of the later fragments varied concomitantly along with sperm physical characteristics as well with each male’s prolific index. These results represent the first step in utilizing modern molecular genetics techniques to identify fertility-related molecular markers in adult dromedary bulls, or even further to predict potential fertility of pre-pubertal males.