{"status":"ok","message-type":"work","message-version":"1.0.0","message":{"indexed":{"date-parts":[[2026,6,30]],"date-time":"2026-06-30T18:47:55Z","timestamp":1782845275887,"version":"3.54.5"},"reference-count":19,"publisher":"Cambridge University Press (CUP)","issue":"2","license":[{"start":{"date-parts":[[2005,10,3]],"date-time":"2005-10-03T00:00:00Z","timestamp":1128297600000},"content-version":"unspecified","delay-in-days":0,"URL":"https:\/\/www.cambridge.org\/core\/terms"}],"content-domain":{"domain":[],"crossmark-restriction":false},"short-container-title":["Parasitology"],"published-print":{"date-parts":[[2006,2]]},"abstract":"<jats:p>Observations of low response of patients infected with <jats:italic>Onchocerca volvulus<\/jats:italic> to ivermectin suggest that the parasite may be under a selection process toward potential resistance. To limit the extension of this phenomenon, it is crucial to characterize the genes of <jats:italic>O. volvulus<\/jats:italic> that are involved. For this, <jats:italic>O. volvulus<\/jats:italic> adult worms collected before the introduction of ivermectin in an onchocerciasis endemic area of central Cameroon were genotyped for \u03b2-tubulin. To derive a baseline to investigate the selective pressure of ivermectin, we analysed (1) the frequency distribution of the \u03b2-tubulin alleles, and (2) the relationship between the different \u03b2-tubulin related genotypes and the fertility status of the female worms. The frequency of allele b of the \u03b2-tubulin gene was very low, as it was observed in West Africa. We observed a deficit of heterozygous female worms leading to Hardy Weinberg disequilibrium, which might be explained by a shorter life-span of these worms compared to the homozygous worms. Unexpectedly, our results also show that the heterozygous female worms were much less fertile than the homozygotes: more than two thirds of the homozygotes were fertile, whereas only 37% of the heterozygotes were fertile. These results will be further considered when analysing post-treatment data.<\/jats:p>","DOI":"10.1017\/s0031182005008899","type":"journal-article","created":{"date-parts":[[2005,10,3]],"date-time":"2005-10-03T09:34:21Z","timestamp":1128332061000},"page":"255-262","source":"Crossref","is-referenced-by-count":21,"title":["Genetic polymorphism of the \u03b2-tubulin gene of <i>Onchocerca volvulus<\/i> in ivermectin na\u00efve patients from Cameroon, and its relationship with fertility of the worms"],"prefix":"10.1017","volume":"132","author":[{"given":"C.","family":"BOURGUINAT","sequence":"first","affiliation":[],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"S. D. S.","family":"PION","sequence":"additional","affiliation":[],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"J.","family":"KAMGNO","sequence":"additional","affiliation":[],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"J.","family":"GARDON","sequence":"additional","affiliation":[],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"N.","family":"GARDON-WENDEL","sequence":"additional","affiliation":[],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"B. O. L.","family":"DUKE","sequence":"additional","affiliation":[],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"R. K.","family":"PRICHARD","sequence":"additional","affiliation":[],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"M.","family":"BOUSSINESQ","sequence":"additional","affiliation":[],"role":[{"vocabulary":"crossref","role":"author"}]}],"member":"56","published-online":{"date-parts":[[2005,10,3]]},"reference":[{"key":"S0031182005008899_ref003","unstructured":"Ardelli, B. F. and Prichard, R. K. (2005).Reduced genetic variation of an Onchocerca volvulus ABC transporter gene following treatment with ivermectin.Transactions of the Royal Society of Tropical Medicine and Hygiene (in the Press)."},{"key":"S0031182005008899_ref011","doi-asserted-by":"publisher","DOI":"10.1016\/S0140-6736(02)09456-4"},{"key":"S0031182005008899_ref019","doi-asserted-by":"crossref","unstructured":"Via, S. , Bouck, A. and Skillman, S. (2000).Reproductive isolation between divergent races of pea aphids on two hosts. II. Selection against migrants and hybrids in the parental environments.Evolution 54,1626\u20131637.","DOI":"10.1111\/j.0014-3820.2000.tb00707.x"},{"key":"S0031182005008899_ref010","doi-asserted-by":"publisher","DOI":"10.1016\/S0304-4017(02)00321-7"},{"key":"S0031182005008899_ref009","doi-asserted-by":"publisher","DOI":"10.1016\/j.molbiopara.2005.01.021"},{"key":"S0031182005008899_ref007","doi-asserted-by":"publisher","DOI":"10.1016\/S0924-4204(99)80024-9"},{"key":"S0031182005008899_ref001","doi-asserted-by":"publisher","DOI":"10.1016\/S0001-706X(02)00117-1"},{"key":"S0031182005008899_ref006","unstructured":"Blackhall, W. J. (1999) Genetic variation and multiple mechanisms of anthelmintic resistance in Haemonchus contortus. Ph.D. thesis, McGill University."},{"key":"S0031182005008899_ref013","unstructured":"Kl\u00e4ger, S. (1988).Investigations of enzymatically isolated male Onchocerca volvulus: qualitative and quantitative aspects of spermatogenesis.Tropical Medicine and Parasitology,39,441\u2013445."},{"key":"S0031182005008899_ref005","doi-asserted-by":"crossref","unstructured":"Awadzi, K. , Boakye, D. A. , Edwards, G. , Opoku, N. O. , Attah, S. K. , Osei-Atweneboana, M. Y. , Lazdins-Helds, J. K. , Ardrey, A. E. , Addy, E. T. , Quartey, B. T. , Ahmed, K. , Boatin, B. A. and Soumbey-Alley, E. W. (2004 b).An investigation of persistent microfilaridermia despite multiple treatments with ivermectin in two onchocerciasis endemic foci in Ghana.Annals of Tropical Medicine and Parasitology 98,231\u2013249.","DOI":"10.1179\/000349804225003253"},{"key":"S0031182005008899_ref016","unstructured":"Schulz-Key, H. , Albiez, E. J. and B\u00fcttner, D. W. (1977).Isolation of living adult Onchocerca volvulus from nodules.Tropenmedizin und Parasitologie 28,428\u2013430."},{"key":"S0031182005008899_ref012","doi-asserted-by":"crossref","unstructured":"Grant, W. (2000).What is the real target for ivermectin resistance selection in Onchocerca volvulus ?Parasitology today 16,501\u2013502.","DOI":"10.1016\/S0169-4758(00)01766-X"},{"key":"S0031182005008899_ref017","doi-asserted-by":"publisher","DOI":"10.1016\/0035-9203(84)90264-5"},{"key":"S0031182005008899_ref008","doi-asserted-by":"publisher","DOI":"10.1080\/00034983.2001.11813650"},{"key":"S0031182005008899_ref002","doi-asserted-by":"publisher","DOI":"10.1179\/000349804225003415"},{"key":"S0031182005008899_ref015","unstructured":"Schulz-Key, H. (1988).The collagenase technique: how to isolate and examine adult Onchocerca volvulus for the evaluation of drug effects.Tropenmedizin und Parasitologie 39,423\u2013440."},{"key":"S0031182005008899_ref004","doi-asserted-by":"crossref","unstructured":"Awadzi, K. , Attah, S. K. , Addy, E. T. , Opoku, N. O. , Quartey, B. T. , Lazdins-Helds, J. K. , Ahmed, K. , Boatin, B. A. , Boakye, D. A. and Edwards, G. (2004 a).Thirty-month follow-up of sub-optimal responders to multiple treatments with ivermectin, in two onchocerciasis-endemic foci in Ghana.Annals of Tropical Medicine and Parasitology 98,359\u2013370.","DOI":"10.1179\/000349804225003442"},{"key":"S0031182005008899_ref018","doi-asserted-by":"publisher","DOI":"10.1111\/j.1558-5646.1999.tb05381.x"},{"key":"S0031182005008899_ref014","unstructured":"Remme, J. , Ba, O. , Dadzie, K. Y. and Karam, M. (1986).A force-of-infection model for onchocerciasis and its applications in the epidemiological evaluation of the Onchocerciasis Control Programme in the Volta River basin area.Bulletin of the World Health Organization 64,667\u2013681."}],"container-title":["Parasitology"],"original-title":[],"language":"en","link":[{"URL":"https:\/\/www.cambridge.org\/core\/services\/aop-cambridge-core\/content\/view\/S0031182005008899","content-type":"unspecified","content-version":"vor","intended-application":"similarity-checking"}],"deposited":{"date-parts":[[2025,6,21]],"date-time":"2025-06-21T05:22:06Z","timestamp":1750483326000},"score":1,"resource":{"primary":{"URL":"https:\/\/www.cambridge.org\/core\/product\/identifier\/S0031182005008899\/type\/journal_article"}},"subtitle":[],"short-title":[],"issued":{"date-parts":[[2005,10,3]]},"references-count":19,"journal-issue":{"issue":"2","published-print":{"date-parts":[[2006,3]]}},"alternative-id":["S0031182005008899"],"URL":"https:\/\/doi.org\/10.1017\/s0031182005008899","relation":{},"ISSN":["0031-1820","1469-8161"],"issn-type":[{"value":"0031-1820","type":"print"},{"value":"1469-8161","type":"electronic"}],"subject":[],"published":{"date-parts":[[2005,10,3]]}}}