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Paternity Assignments (paternity + assignment)
Selected AbstractsNovel polymorphic microsatellite markers for paternity analysis in the red-capped robin (Petroica goodenovii: Aves)MOLECULAR ECOLOGY RESOURCES, Issue 4 2003D. K. Dowling Abstract Seven microsatellite loci were isolated and characterized from the red-capped robin Petroica goodenovii, using nonradioactive polymerase chain reaction (PCR)-based techniques to screen an enriched genomic library. Five loci showed no evidence of null alleles and were variable [mean heterozygosity (HE) = 0.440, mean number of alleles = 8]. Cross-amplification using primers for microsatellites in Phylloscopus occipitalis and Emberiza schoeniclus yielded another two polymorphic loci. The combined set of five red-capped robin and two cross-amplified loci are suitable for paternity assignment (exclusion probability for seven unlinked loci = 0.9760). [source] Characterization of 22 microsatellites loci from the endangered Houbara bustard (Chlamydotis undulata undulata)MOLECULAR ECOLOGY RESOURCES, Issue 4 2002Faiza Chbel Abstract Here we present a new set of 22 microsatellite loci isolated from Chlamydotis undulata undulata, an endangered Houbara bustard found across North Africa. The number of alleles per locus ranged from one to nine, and heterozygosities ranged from 0.167 to 0.944. Total exclusionary probabilities using these loci for the first and the second parent were 0.992932 and 0.999915, respectively. Successful cross-amplification was observed in eight other Otididae species (12,22 of the 22 loci). These microsatellite markers are powerful tools for genetic identification, paternity assignment and population genetic studies. [source] Paternity validation and estimation of genotyping error rate for the BovineSNP50 BeadChipANIMAL GENETICS, Issue 5 2010J. I. Weller Summary Incorrect paternity assignment in cattle can have a major effect on rates of genetic gain. Of the 576 Israeli Holstein bulls genotyped by the BovineSNP50 BeadChip, there were 204 bulls for which the father was also genotyped. The results of 38 828 valid single nucleotide polymorphisms (SNPs) were used to validate paternity, determine the genotyping error rates and determine criteria enabling deletion of defective SNPs from further analysis. Based on the criterion of >2% conflicts between the genotype of the putative sire and son, paternity was rejected for seven bulls (3.5%). The remaining bulls had fewer conflicts by one or two orders of magnitude. Excluding these seven bulls, all other discrepancies between sire and son genotypes are assumed to be caused by genotyping mistakes. The frequency of discrepancies was >0.07 for nine SNPs, and >0.025 for 81 SNPs. The overall frequency of discrepancies was reduced from 0.00017 to 0.00010 after deletion of these 81 SNPs, and the total expected fraction of genotyping errors was estimated to be 0.05%. Paternity of bulls that are genotyped for genomic selection may be verified or traced against candidate sires at virtually no additional cost. [source] Nestling sex ratio of golden-winged warblers Vermivora chrysoptera in an introgressed populationJOURNAL OF AVIAN BIOLOGY, Issue 6 2008Kate J. Neville Sex ratio biases in avian species remain controversial, although several studies have documented apparent facultative adjustment of offspring sex ratios. While hybridizing pied and collared flycatchers have exhibited sex ratio skews that may be a response to sex-based costs associated with hybridization, this appears not to be true of a hybridized population of blue-winged Vermivora pinus and golden-winged V. chrysoptera warblers. We examined the primary sex ratio of nestlings in a population of hybrid and introgressed golden-winged warblers. The sex ratio of 298 nestlings from 81 nests in the population was approximately 50:50. We conducted paternity assignments and analyzed groups of nestlings with shared genetic parents ("genetic broods") and found no difference from the expected binomial distribution, and no statistically significant relationship between parental species phenotype and nestling sex ratio. We saw no evidence of preferential production of male or female nestlings, and female hybrids were found to mate and breed in the population. This suggests that heterogametic (female) hybrids are both viable and fertile, and thus that Haldane's Rule does not apply to this system. While populations of hybridizing golden-winged warblers should be monitored for evidence of costs of heterospecific pairings, it is unlikely that adjustment of sex ratios would be the form of compensation for sub-optimal mating conditions. Our results provide support for the emerging hypothesis that hybrids suffer no disadvantage relative to golden-winged and blue-winged warblers. [source] Do marker-based paternity assignments favour heterozygous and unrelated males?MOLECULAR ECOLOGY, Issue 9 2010JINLIANG WANG Abstract Genetic marker-based parentage analyses are widely applied to studies of natural populations in the fields of evolutionary biology, conservation biology and ecology. When the same markers used in a parentage analysis are used together with the inferred parentage in a downstream analysis, such as the analysis of mate choice in terms of heterozygosity or relatedness, a bias may be incurred because a subset of the genotypes are favoured in parentage assignments or non-exclusions. A previous simulation study shows that exclusion-based paternity analyses are biased in favour of heterozygous males, and males less related to the mothers than expected under random mating. In this study, I investigated the biases of genetic paternity analyses achieved by both exclusion- and likelihood-based methods, using both analytical and simulation approaches. It is concluded that while both exclusion- and likelihood-based methods can lead to biased paternity assignments or non-exclusions in favour of a subset of genotypes, the bias is not consistently towards heterozygous males or males apparently less related to mothers. Both the direction and extent of the bias depend heavily on the allele frequency distribution and the number of markers, the methods used for paternity assignments, and the estimators of relatedness. There exist important differences in the patterns of the biases between exclusion- and likelihood-based paternity analysis methods. It is concluded that the markers, except when they are highly informative to yield accurate paternity assignments or exclusions, should be split into two subsets which are used separately in the paternity and downstream analyses. [source] Genetic parentage assessment in the crayfish Orconectes placidus, a high-fecundity invertebrate with extended maternal brood careMOLECULAR ECOLOGY, Issue 10 2002D. Walker Abstract Microsatellite data have recently been introduced in the context of genetic maternity and paternity assignments in high-fecundity fish species with single-parent-tended broods. Here we extend such analyses to an aquatic invertebrate, the crayfish Orconectes placidus, in which gravid females carry large numbers of offspring. Genetic parentage analyses of more than 900 progeny from 15 wild crayfish broods revealed that gravid females were invariably the exclusive dams of the offspring they tended (i.e. there was no allomaternal care), and that most of the females had mated with multiple (usually two) males who contributed sometimes highly skewed numbers of offspring to a brood. Within any multiply sired brood, the unhatched eggs (or the hatched juveniles) from different fathers were randomly distributed across the mother's brood space. All of these genetic findings are discussed in the light of observations on the mating behaviours and reproductive biology of crayfishes. [source] | ||||||||||