Old World camels in a modern world – a balancing act between conservation and genetic improvement

Abstract

Old World camels have served humans in cross-continental caravans, transporting people and goods, connecting different cultures and providing milk, meat, wool and draught since their domestication around 3000-6000 years ago. In a world of modern transport and fast connectivity, these beasts of burden seem to be out-dated. However, a growing demand for sustainable milk and meat production, especially in countries affected by climate change and increasing desertification, brings dromedaries (Camelus dromedarius) and Bactrian camels (Camelus bactrianus) back onstage and into the focus of animal breeders and scientists. In this review on the molecular genetics of these economically important species we give an overview about the evolutionary history, domestication and dispersal of Old World camels, whereas highlighting the need for conservation of wild two-humped camels (Camelus ferus) as an evolutionarily unique and highly endangered species. We provide cutting-edge information on the current molecular resources and on-going sequencing projects. We cannot emphasise enough the importance of balancing the need for improving camel production traits with maintaining the genetic diversity in two domestic species with specific physiological adaptation to a desert environment.

Genome-Wide Diversity, Population Structure and Demographic History of Dromedaries in the Central Desert of Iran

“…The trend of Ne shows a bottleneck around 2000-6000 years ago in Iranian central desert dromedary camels. This is consistent with a decline in Ne in Old World camels around 4000-5000 years ago and might be related to the domestication scenarios of dromedary and Bactrian camels [2].…”

“…Camelini (one-and two-humped camels) and Lamini (New World camels) are two tribes of the Camelidae family [1]. Camelids influence human endurance and thriving in the peripheral agro-natural zones of (semi-) deserts [2]. Today, camels have gained significance as sustainable livestock species with certain important properties (e.g., immunogenic and milk composition) [3].…”

Scanning electron microscopy of Onchocerca fasciata (Filarioidea: Onchocercidae) adults, microfilariae and eggs with notes on histopathological findings in camels

“…In this study nucleotides sequences of 12S rRNA and cox1 genes of the microfilariae revealed a high similarity with O. fasciata from Bactrian camels in China (Gen-Bank: JQ316672). Based on the hypothesis of Onchocerca species evolution, Africa has been suggested as the origin of O. fasciata [37]; however, divergence and domestication of Bactrian camels took place earlier in history than one-humped dromedaries [45]. Hence Bactrian camels could have acquired the infection from dromedaries through the historical network of trade caravan routes (e.g.…”

Dromedary (Camelus dromedarius) and Bactrian camel (Camelus bactrianus) crossbreeding husbandry practices in Turkey and Kazakhstan: An in-depth review

“…Rigorous pedigree recording, combined with permanent camel identification, are therefore better tools to clearly identify individual hybrids and the exact genetic contributions of dromedary and Bactrian camel to their genetic make-up. The increasing availability of advanced techniques for genetic and parentage testing will allow a better understanding of the genetics of dromedary, Bactrian camel, and their hybrids, possibly permitting the detection of valuable genetic traits related to increased productivity or adaptability (Burger et al 2019). Explanatory notes: Hump area-8, Bactrian humps; 7, two well-developed humps closer than in the Bactrian but separate at their base; 6, two well-developed humps with their bases touching each other; 5, one large hump with two symmetric small humps at the apex; 4, one large hump with two asymmetric small humps at the apex, the rear hump bigger than the front one; 3, one large hump with two visible mounds at the apex; 2, one large hump with a clear depression several centimetres deep on the front top margin; 1, dromedary hump.…”