Abstract
Populations with small census sizes are at risk because of the loss of genetic variability and the increase of inbreeding and its harmful consequences. For situations with different numbers of males and females, several hierarchical designs have been proposed to control inbreeding through the fixation of individuals' contributions. An alternative method, based on the minimization of global coancestry, has been proposed to determine contributions as to yield of the lowest levels of inbreeding in the population. We use computer simulations to assess the relative efficiency of the different methods. The results show that minimizing the global coancestry leads to equal or lower levels of inbreeding in the short and medium term, although one of the hierarchical designs provides lower asymptotic inbreeding rates and, thus, less net inbreeding in the long term. We also investigate the performance of the alternative methods against departures from the ideal conditions, such as inbred or differentially related base individuals and random failures in the expected contributions. The method of minimization of global coancestry turns out to be more flexible and robust under these realistic situations.
Full Text
The Full Text of this article is available as a PDF (123.2 KB).
Selected References
These references are in PubMed. This may not be the complete list of references from this article.
- Caballero A. Developments in the prediction of effective population size. Heredity (Edinb) 1994 Dec;73(Pt 6):657–679. doi: 10.1038/hdy.1994.174. [DOI] [PubMed] [Google Scholar]
- Caballero A., Toro M. A. Interrelations between effective population size and other pedigree tools for the management of conserved populations. Genet Res. 2000 Jun;75(3):331–343. doi: 10.1017/s0016672399004449. [DOI] [PubMed] [Google Scholar]
- Hill W. G. A note on effective population size with overlapping generations. Genetics. 1979 May;92(1):317–322. doi: 10.1093/genetics/92.1.317. [DOI] [PMC free article] [PubMed] [Google Scholar]
- Sonesson A. K., Meuwissen T. H. Mating schemes for optimum contribution selection with constrained rates of inbreeding. Genet Sel Evol. 2000 May-Jun;32(3):231–248. doi: 10.1186/1297-9686-32-3-231. [DOI] [PMC free article] [PubMed] [Google Scholar]
- Sonesson A. K., Meuwissen T. H. Minimization of rate of inbreeding for small populations with overlapping generations. Genet Res. 2001 Jun;77(3):285–292. doi: 10.1017/s0016672301005079. [DOI] [PubMed] [Google Scholar]
- Sánchez Leopoldo, Bijma Piter, Woolliams John A. Minimizing inbreeding by managing genetic contributions across generations. Genetics. 2003 Aug;164(4):1589–1595. doi: 10.1093/genetics/164.4.1589. [DOI] [PMC free article] [PubMed] [Google Scholar]
- Wang J. More efficient breeding systems for controlling inbreeding and effective size in animal populations. Heredity (Edinb) 1997 Dec;79(Pt 6):591–599. doi: 10.1038/hdy.1997.204. [DOI] [PubMed] [Google Scholar]
- Wang J. Optimal marker-assisted selection to increase the effective size of small populations. Genetics. 2001 Feb;157(2):867–874. doi: 10.1093/genetics/157.2.867. [DOI] [PMC free article] [PubMed] [Google Scholar]
- Woolliams J. A., Bijma P. Predicting rates of inbreeding in populations undergoing selection. Genetics. 2000 Apr;154(4):1851–1864. doi: 10.1093/genetics/154.4.1851. [DOI] [PMC free article] [PubMed] [Google Scholar]