Parasitology Research

, Volume 111, Issue 5, pp 2217–2221 | Cite as

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

  • Julia C. Hildebrandt
  • Albert Eisenbarth
  • Alfons Renz
  • Adrian Streit
Short Communication


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.


Blood Meal Ivermectin Gravid Female Territorial Male Female Worm 
These keywords were added by machine and not by the authors. This process is experimental and the keywords may be updated as the learning algorithm improves.



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.

Supplementary material

436_2012_2983_MOESM1_ESM.pdf (94 kb)
ESM 1 (PDF 94.2 kb)


  1. Determann A, Mehlhorn H, Ghaffar FA (1997) Electron microscope observations on Onchocerca ochengi and O. fasciata (Nematoda: Filarioidea). Parasitol Res 83(6):591–603PubMedCrossRefGoogle Scholar
  2. Eberhardt AG, Mayer WE, Streit A (2007) The free-living generation of the nematode Strongyloides papillosus undergoes sexual reproduction. Int J Parasitol 37:989–1000PubMedCrossRefGoogle Scholar
  3. Gross MR (1996) Alternative reproductive strategies and tactics: diversity within sexes. Trends Ecol Evol 11(2):92–98PubMedCrossRefGoogle Scholar
  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 PubMedCrossRefGoogle Scholar
  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):124–127PubMedCrossRefGoogle Scholar
  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 PubMedCrossRefGoogle Scholar
  7. Renz A, Enyong P, Wahl G (1994) Cattle, worms and zooprophylaxis. Parasite 1(1S):4–6Google Scholar
  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):31–37PubMedGoogle Scholar
  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 164Google Scholar
  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):423–440PubMedGoogle Scholar
  11. Wahl G, Achu-Kwi MD, Mbah D, Dawa O, Renz A (1994) Bovine onchocercosis in north Cameroon. Vet Parasitol 52(3–4):297–311PubMedCrossRefGoogle Scholar

Copyright information

© Springer-Verlag 2012

Authors and Affiliations

  • Julia C. Hildebrandt
    • 1
  • Albert Eisenbarth
    • 2
  • Alfons Renz
    • 2
  • Adrian Streit
    • 1
  1. 1.Department for Evolutionary BiologyMax Planck Institute for Developmental BiologyTübingenGermany
  2. 2.Institute of Evolution and Ecology, Department of Comparative ZoologyUniversity of TübingenTübingenGermany

Personalised recommendations