Twelve weeks after repeated spontaneous mating between a Bentheimer Landschaf ram and a West African dwarf doe was observed, the doe aborted a dead fetus. The aim of this study was to verify the parentage and the species of the supposed parents and the hybrid status of the fetus, using cytogenetic and molecular genetic methods. For this purpose, karyotypes were prepared using fresh blood samples from the ram and the doe, and genomic DNA was extracted from blood of the suspected parents and tissue of the aborted fetus. Fragments of the nuclear DNA-encoded interleukin-2 gene and the mitochondrial DNA-encoded 16S ribosomal RNA were sequenced and 19 microsatellites were genotyped in all 3 animals. The karyotypes and DNA sequences of the ram and the doe corresponded to domestic sheep and goat, respectively. The interleukin-2 sequence of the fetus was heterozygous at all positions where sheep and goat have different nucleotides. None of the 19 microsatellites excluded the ram and the dwarf doe as parents of the fetus. Taken together, we can conclude that the ram and the dwarf doe were from the species Ovis aries and Capra hircus, respectively, and that they were most likely the parents of the aborted fetus, which itself proved to be a hybrid of these 2 species.

Keywords:
Dwarf goat, Interleukin-2, Karyotype, Microsatellite, mtDNA, Parentage, Sheep, Sheep-goat hybrid
1.
Barch MJ: The ACT Cytogenetics Laboratory Manual 2 (Raven Press, New York 1991).
2.
Cortes-Gutierrez EI, Davila-Rodriguez MI, Lopez-Fernandez C, Fernandez JL, Gosalvez J: Alkali-labile sites in sperm cells from Sus and Ovis species. Int J Androl 31:354–363 (2008).
3.
Gyllensten U, Wharton D, Wilson AC: Maternal inheritance of mitochondrial DNA during backcrossing of two species of mice. J Hered 76:321–324 (1985).
4.
Henegariu O, Heerema NA, Lowe Wright L, Bray-Ward P, Ward DC, Vance GH: Improvements in cytogenetic slide preparation: controlled chromosome spreading, chemical aging and gradual denaturing. Cytometry 43:101–109 (2001).
5.
Hiendleder S, Mainz K, Plante Y, Lewalski H: Analysis of mitochondrial DNA indicates that domestic sheep are derived from two different ancestral maternal sources: no evidence for contributions from urial and argali sheep. J Hered 89:113–120 (1998).
6.
Jamieson A, Taylor SC: Comparisons of three probability formulae for parentage exclusion. Anim Genet 28:397–400 (1997).
7.
Kelk DA, Gartley CJ, Buckrell BC, King WA: The interbreeding of sheep and goats. Can Vet J 38:235–237 (1997).
8.
Letshwenyo M, Kedikilwe K: Goat-sheep hybrid born under natural conditions in Botswana. Vet Rec 146:732–734 (2000).
9.
Lühken G: Molecular Characterization of the Interleukin-2 Gene in Sheep, Goat and Cattle Species as Well as Mapping and Functional Analysis of DNA Variants of the Interleukin-2 Gene in Ovis aries (VVB Laufersweiler Verlag, Giessen 2007).
10.
Lühken G, Weimann C, Kraus M, Goldammer T, Womack JE, Erhardt G: Genetic and physical mapping of the ovine interleukin-2 gene (IL2). Anim Genet 33:245–247 (2002).
11.
McGovern PT: The effect of maternal immunity on the survival of goat × sheep hybrid embryos. J Reprod Fertil 34:215–220 (1973).
12.
Nadler CF, Hoffmann RS, Woolf A: G-band patterns, chromosomal homologies, and evolutionary relationships among wild sheep, goats, and aoudads (Mammalia, Artiodactyla). Experientia 30:744–746 (1974).
13.
Nijman IJ, Hogendoorn MP, Gruys E, Luikart G, Ortugrul O, et al: Detection of sheep-goat interspecies hybridization by analysis of satellite DNA. Online J Vet Res 1:1–6 (2002).
14.
Peter C, Bruford M, Perez T, Dalamitra S, Hewitt G, Erhardt G: Genetic diversity and subdivision of 57 European and Middle-Eastern sheep breeds. Anim Genet 38:37–44 (2007).
15.
Stewart-Scott IA, Pearce PD, Dewes HF, Thompson JW: A case of a sheep-goat hybrid in New Zealand. N Z Vet J 38:7–9 (1990).
16.
Taberlet P, Valentini A, Rezaei HR, Naderi S, Pompanon F, et al: Are cattle, sheep, and goats endangered species? Mol Ecol 17:275–284 (2008).
17.
Tucker EM, Denis B, Kilgour L: Blood genetic marker studies of a sheep-goat hybrid and its back-cross offspring. Anim Genet 20:179–186 (1989).
18.
Warwick BL, Berry RO: Inter-generic and intra-specific embryo transfers in sheep and goats. J Hered 40:297–303 (1949).
© 2009 S. Karger AG, Basel
2009
Copyright / Drug Dosage / Disclaimer
Copyright: All rights reserved. No part of this publication may be translated into other languages, reproduced or utilized in any form or by any means, electronic or mechanical, including photocopying, recording, microcopying, or by any information storage and retrieval system, without permission in writing from the publisher.
Drug Dosage: The authors and the publisher have exerted every effort to ensure that drug selection and dosage set forth in this text are in accord with current recommendations and practice at the time of publication. However, in view of ongoing research, changes in government regulations, and the constant flow of information relating to drug therapy and drug reactions, the reader is urged to check the package insert for each drug for any changes in indications and dosage and for added warnings and precautions. This is particularly important when the recommended agent is a new and/or infrequently employed drug.
Disclaimer: The statements, opinions and data contained in this publication are solely those of the individual authors and contributors and not of the publishers and the editor(s). The appearance of advertisements or/and product references in the publication is not a warranty, endorsement, or approval of the products or services advertised or of their effectiveness, quality or safety. The publisher and the editor(s) disclaim responsibility for any injury to persons or property resulting from any ideas, methods, instructions or products referred to in the content or advertisements.
You do not currently have access to this content.