Springer Nature is making Coronavirus research free. View research | View latest news | Sign up for updates

Single worm genotyping demonstrates that Onchocerca ochengi females simultaneously produce progeny sired by different males

  • 192 Accesses

  • 9 Citations


Onchocerca ochengi is a filarial nematode parasite of African cattle and most closely related to Onchocerca volvulus, the causing agent of river blindness. O. ochengi females induce the formation of a nodule in the dermis of the host, in which they remain sedentary in very close association with the host’s tissue. Males, which do not adhere to the host’s tissue, are also found within the nodules at an average number of about one male per nodule. Young O. ochengi females tend to avoid the immediate proximity of existing nodules. Therefore, O. ochengi nodules are dispersed in the ventral inguinal skin at considerable distances from each other. It has been speculated that males avoid the risk of leaving a female once they have found one and remain in the nodule as territorial males rendering the reproductive strategy of O. ochengi essentially monogamous. We developed a protocol that allows reliable PCR amplification of single copy loci from different developmental stages of O. ochengi including embryos and microfilariae. From 32 O. ochengi nodules, we genotyped the female worms and the 67 adult male worms, found in these nodules, together with a fraction of the progeny from within the uteri of females. In 18 of 32 gravid females progeny derived from multiple males were found. In five nodules, the males isolated from the same nodule as the female were not sufficient to explain the genotypes of the entire progeny. We conclude that frequently O. ochengi females simultaneously produce progeny sired by different males and that most but not all males are still present in the nodule when their offspring is ready to hatch.

This is a preview of subscription content, log in to check access.


  1. Determann A, Mehlhorn H, Ghaffar FA (1997) Electron microscope observations on Onchocerca ochengi and O. fasciata (Nematoda: Filarioidea). Parasitol Res 83(6):591–603

  2. Eberhardt AG, Mayer WE, Streit A (2007) The free-living generation of the nematode Strongyloides papillosus undergoes sexual reproduction. Int J Parasitol 37:989–1000

  3. Gross MR (1996) Alternative reproductive strategies and tactics: diversity within sexes. Trends Ecol Evol 11(2):92–98

  4. Hoerauf A, Pfarr K, Mand S, Debrah AY, Specht S (2011) Filariasis in Africa—treatment challenges and prospects. Clin Microbiol Infect 17(7):977–985. doi:10.1111/j.1469-0691.2011.03586.x

  5. Nemetschke L, Eberhardt AG, Viney ME, Streit A (2010) A genetic map of the animal-parasitic nematode Strongyloides ratti. Mol Biochem Parasitol 169(2):124–127

  6. Post RJ, Crainey JL, Bivand A, Renz A (2009) Laser-assisted microdissection for the study of the ecology of parasites in their hosts. Mol Ecol Resour 9:480–486. doi:101111/j.1755-0998.2008.02437.x

  7. Renz A, Enyong P, Wahl G (1994) Cattle, worms and zooprophylaxis. Parasite 1(1S):4–6

  8. Renz A, Trees AJ, Achu-Kwi D, Edwards G, Wahl G (1995) Evaluation of suramin, ivermectin and CGP 20376 in a new macrofilaricidal drug screen, Onchocerca ochengi in African cattle. Trop Med Parasitol 46(1):31–37

  9. Renz A, Reiling S, Streit A, Achukwi MD (2010) Reproductive strategies and population biology of Onchocerca filariae. In: Mehlhorn H, Klimpel S, Palm HW (eds) Science in parasitology and protozoology solves problems. Duesseldorf University Press, Duesseldorf, p 164

  10. Schulz-Key H (1988) The collagenase technique: how to isolate and examine adult Onchocerca volvulus for the evaluation of drug effects. Trop Med Parasitol 39(Suppl 4):423–440

  11. Wahl G, Achu-Kwi MD, Mbah D, Dawa O, Renz A (1994) Bovine onchocercosis in north Cameroon. Vet Parasitol 52(3–4):297–311

Download references


We thank Melanie Mayer for critically reading the manuscript. This work was funded by the Max Planck Society and the Deutsche Forschungsgemeinschaft.

Conflict of interest

The authors declare that they have no conflict of interest.

Author information

Correspondence to Adrian Streit.

Electronic supplementary material

Below is the link to the electronic supplementary material.


(PDF 94.2 kb)

Rights and permissions

Reprints and Permissions

About this article

Cite this article

Hildebrandt, J.C., Eisenbarth, A., Renz, A. et al. Single worm genotyping demonstrates that Onchocerca ochengi females simultaneously produce progeny sired by different males. Parasitol Res 111, 2217–2221 (2012).

Download citation


  • Blood Meal
  • Ivermectin
  • Gravid Female
  • Territorial Male
  • Female Worm