International Macaque Week

It’s international macaque week and as an ode to our furry relatives, I have decided to do a little piece on macaques as a group and some modern day conundrums involving primate species.

Macaques are a group of Old World monkeys that fall into the subfamily Cercopithecinae, consisting of 23 species worldwide [1]. Despite being a principally frugivorous taxonomic group, their diet may consist of seeds, leaves, flowers, tree bark, some invertebrates, and occasionally small vertebrates. Macaques are one of the most widespread members of the primate order, second only to humans, ranging across Asia to North Africa and Southern Europe. Macaques have an incredibly intricate social structure and hierarchy, with all social groups being arranged around dominant, matriarchal females [2]. Numerous macaque species are used in animal testing, kept as pets despite nearly all captive rhesus macaques being carriers of the herpes simian B virus [3], and are persecuted by humans. As such, many macaque species are classified as threatened.

I am now going to discuss an issue that has been itching at me since I first heard about it a couple of months ago – the recent cloning of crab-eating macaques [4].

Images of two crab-eating macaque infants (Macaca fascicularis) cloned using somatic cell nuclear transfer

Recently, similarly to Dolly the sheep 22 years ago, two crab-eating macaque infants were cloned using foetal fibroblasts (cells found in connective tissue) derived from an aborted female crab-eating macaque. Adjacent to the attempt at cloning with foetal fibroblasts, somatic cell nuclear transfer, whereby a viable embryo is created using a body cell and an egg cell, was attempted using adult monkey cumulus cells (cells that surround immature egg cells (oocytes)). However, whereas the former method  produced what the researchers describe as ‘healthy’ clones, the latter method was unable to do so, with infants dying hours after birth due to apparent respiratory failure.

The apparent reasoning behind this cloning is that these monkeys will be used for the investigation of human diseases, drug screening, and the development of other therapeutics. The researchers involved have stated that these clones will allow for the isolation of gene effects, with animals being genetically identical except for the particular genes that have been switched on/off/mutated.

You can read an article on the research here, and the full journal is available from here.

Now it’s time for my unsolicited opinion. I am by no means an expert in the field of genetics, and in no way do I claim to have a better understanding of the ethical issues encompassing these findings than those who conducted the research. However, it is my firm belief that creating life for such a purpose is incredibly cruel. Despite the fact that these creatures were created in a lab, they are tangible, living beings with their own minds and personalities. I have always had a problem with animal testing, especially when it is unwarranted and in the pursuit of vanity. In this case, I do not believe that the proposed testing would be conducted with such an end in mind. However, it is my opinion that purposely altering a living creature’s genetic code for insight into the mechanisms at play in certain diseases is appalling. If someone put forward the idea to conduct such research on humans, particularly human infants, the world would be in uproar. Some would claim you were playing God; others would call it torture.

I think it is so incredibly important that we all assess what price we are willing to pay for knowledge, and whether such an understanding of genetic diseases is worth the suffering that could potentially arise from such an undertaking. All life is precious. No one creature is more worthy of a comfortable existence than another. I sincerely hope that at some point in my life I will be blessed enough to see the end of animal testing, but I very much doubt it.

Sunda pig-tailed macaque on liana
Sunda pig-tailed macaque (Macaca nemestrina) on liana


[1] Primate Info Net. (2012). Primate Factsheets: Macaque (Macaca). [online] Available at: http://pin.primate.wisc.edu/factsheets/links/macaca [Accessed 3 May 2018].

[2] Fleagle, J. (1988). Primate adaptation & evolution. San Diego: Academic Press, p.123.

[3] Ostrowski, S. (1998). B-virus from Pet Macaque Monkeys: An Emerging Threat in the United States?. Emerging Infectious Diseases, 4(1), pp.117-121.

[4] Liu, Z., Cai, Y., Wang, Y., Nie, Y., Zhang, C., Xu, Y., Zhang, X., Lu, Y., Wang, Z., Poo, M. and Sun, Q. (2018). Cloning of Macaque Monkeys by Somatic Cell Nuclear Transfer. Cell, 172(4), pp.881-887.e7.



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