Breeding dynamics of koalas in open woodlands

2002 ◽  
Vol 29 (1) ◽  
pp. 19 ◽  
Author(s):  
W. A. Ellis ◽  
P. T. Hale ◽  
F. Carrick
Keyword(s):  
Genetic Parameters ◽  
Dna Analysis ◽  
Gene Diversity ◽  
Isolation By Distance ◽  
Genetic Relationships ◽  
Distance Analysis ◽  
Males And Females ◽  
Population Genetic Parameters ◽  
Tropical Woodlands ◽  
Diversity Estimates

The spatial and breeding dynamics of koalas in sub-tropical woodlands at Blair Athol in central Queensland were intensively monitored between 1993 and 1998. Genetic relationships among koalas at this locality were studied to determine the breeding dynamics of males, including whether ‘resident’ or ‘transient’ males dominate as sires. Males and females were radio-collared and tracked periodically throughout each year of the study. Genotypes from hypervariable microsatellite loci identified uniquely all individuals and were used to analyse parentage as well as to determine population genetic parameters when compared with other regional localities. Koalas at Blair Athol comprise a population in genetic equilibrium. Gene diversity estimates show the population to be similar to other populations found in similar habitat in the region, and estimates of genetic differentiation among four regional populations showed that gene flow conforms to a model of isolation by distance. Analysis of parentage found that both resident and transient males sired about equal numbers of offspring. Familial DNA analysis revealed multiple paternities of successive young in this population. The conclusion from this study is that ‘resident’ status among males does not confer any advantage for parentage.

Microsatellite Loci and Population Structure in the Platypus.

1998 ◽  
Vol 20 (2) ◽  
pp. 299
Author(s):  
S. Akiyama ◽  
T. Grant ◽  
N.J. Gemmell ◽  
J.A. Marshall-Graves ◽  
N.D. Murray
Keyword(s):  
Allele Frequency ◽  
Microsatellite Loci ◽  
Tandem Repeats ◽  
Dna Analysis ◽  
Isolation By Distance ◽  
Genetic Relationships ◽  
Molecular Genetic ◽  
Pcr Primers ◽  
Sequence Motifs ◽  
Microsatellite Variation

To investigate the genetic relationships within and between platypus populations, molecular genetic methods employing DNA analysis are very effective, and microsatellite variation has been shown to be the most effective for population studies. Microsatellites are segments of DNA with tandem repeats of short sequence motifs, usually 1-6 base pairs of nucleotides, and they are highly variable and easy to score. Several microsatellite loci have been detected and sequenced, and PCR primers have been constructed and used to identify several polymorphic microsatellite variants. In the main breeding population, from which we have a collection of over 80 animals, two alleles not found among resident or other captured males were detected amongst juveniles. From our combination of microsatellite and mtDNA analysis, these alleles are likely to be derived from uncaptured transient males which participated in breeding. We therefore suggest that the mating system in this population of platypus involves polygyny and sneaking. Allele frequency differences have been detected between sub-populations within the same stream, consistent with observations on mtDNA genotypes. As well, there are allele frequency differences between populations from different streams and these show continuous geographical gradation, consistent with an isolation-by-distance geographical structure.

Genetic diversity and relationships among Dutch elm disease tolerant Ulmus pumila L. accessions from China

Genome ◽  
2008 ◽  
Vol 51 (7) ◽  
pp. 492-500 ◽  
Author(s):  
Juan E. Zalapa ◽  
Johanne Brunet ◽  
Raymond P. Guries
Keyword(s):  
Genetic Diversity ◽  
Gene Diversity ◽  
Genetic Relationships ◽  
Dutch Elm Disease ◽  
Ulmus Pumila ◽  
Breeding Programs ◽  
Republic Of China ◽  
Diversity Assessment ◽  
Diversity Estimates ◽  
Regional Gene

Elm breeding programs worldwide have relied heavily on Asian elm germplasm, particularly Ulmus pumila , for the breeding of Dutch elm disease tolerant cultivars. However, the extent and patterning of genetic variation in Asian elm species is unknown. Therefore, the objective of this research was to determine the extent of genetic diversity among 53 U. pumila accessions collected throughout the People’s Republic of China. Using 23 microsatellite loci recently developed in the genus Ulmus , a total of 94 alleles were identified in 15 polymorphic and 4 monomorphic loci. The average number of alleles per locus was 4.9, with a range of 1–11 alleles. Gene diversity estimates per locus ranged from 0.08 to 0.87, and the non-exclusion probability for the 15 polymorphic loci combined was 0.7 × 10−9. Nineteen region-specific alleles were identified, and regional gene diversity estimates were moderately high (0.48–0.57). The genetic relationships among accessions and regions were estimated by UPGMA and principal coordinate analysis. Both techniques discriminated all accessions and regions. Two microsatellite markers (UR175 + UR123 or Ulm-3) were sufficient to discriminate up to 99.7% of the accessions studied. This research provides useful information for DNA-based fingerprinting, breeding, ecological studies, and diversity assessment of elm germplasm.

Genetic Relationships of Cory's Shearwater: Parentage, Mating Assortment, and Geographic Differentiation Revealed by DNA Fingerprinting

The Auk ◽  
2000 ◽  
Vol 117 (3) ◽  
pp. 651-662 ◽  
Author(s):  
Corinne Rabouam ◽  
Vincent Bretagnolle ◽  
Yves Bigot ◽  
Georges Periquet
Keyword(s):  
Genetic Variation ◽  
Genetic Structure ◽  
Dna Fingerprinting ◽  
Genetic Relatedness ◽  
Isolation By Distance ◽  
Genetic Relationships ◽  
Cory’S Shearwater ◽  
Genetic Structure Of Populations ◽  
The Social ◽  
Calonectris Diomedea

Abstract We used DNA fingerprinting to assess genetic structure of populations in Cory's Shearwater (Calonectris diomedea). We analyzed mates and parent-offspring relationships, as well as the amount and distribution of genetic variation within and among populations, from the level of subcolony to subspecies. We found no evidence of extrapair fertilization, confirming that the genetic breeding system matches the social system that has been observed in the species. Mates were closely related, and the level of genetic relatedness within populations was within the range usually found in inbred populations. In contrast to previous studies based on allozymes and mtDNA polymorphism, DNA fingerprinting using microsatellites revealed consistent levels of genetic differentiation among populations. However, analyzing the two subspecies separately revealed that the pattern of genetic variation among populations did not support the model of isolation by distance. Natal dispersal, as well as historic and/or demographic events, probably contributed to shape the genetic structure of populations in the species.

Genetic Diversity of Wild Oat (Avena fatua)Populations from China and the United States

Weed Science ◽  
2007 ◽  
Vol 55 (2) ◽  
pp. 95-101 ◽  
Author(s):  
Runzhi Li ◽  
Shiwen Wang ◽  
Liusheng Duan ◽  
Zhaohu Li ◽  
Michael J. Christoffers ◽  
...  
Keyword(s):  
United States ◽  
Genetic Diversity ◽  
Gene Diversity ◽  
Genetic Relationships ◽  
The United States ◽  
Mantel Test ◽  
Wild Oat ◽  
Chinese Populations ◽  
Nei's Distance ◽  
The Impact

Weed genetic diversity is important for understanding the ability of weeds to adapt to different environments and the impact of herbicide selection on weed populations. Genetic diversity within and among six wild oat populations in China varying in herbicide selection pressure and one population in North Dakota were surveyed using 64 polymorphic alleles resulting from 25 microsatellite loci. Mean Nei's gene diversity (h) for six wild oat populations from China was between 0.17 and 0.21, and total diversity (HT) was 0.23. A greater proportion of this diversity, however, was within (Hs= 0.19) rather than among (Gst= 0.15) populations. For the wild oat population from the United States,h= 0.24 andHT= 0.24 were comparable to the values for the six populations from China. Cluster analysis divided the seven populations into two groups, where one group was the United States population and the other group included the six Chinese populations. The genetic relationships among six populations from China were weakly correlated with their geographic distribution (r= 0.22) using the Mantel test. Minimal difference in gene diversity and small genetic distance (Nei's distance 0.07 or less) among six populations from China are consistent with wide dispersal of wild oat in the 1980s. Our results indicate that the wild oat populations in China are genetically diverse at a level similar to North America, and the genetic diversity of wild oat in the broad spatial scale is not substantially changed by environment, agronomic practices, or herbicide usage.

EFFECTS OF CORRECTING FOR FEEDING LEVELS ON ESTIMATES OF GENETIC PARAMETERS OF MILK YIELD AND COMPOSITION

1976 ◽  
Vol 56 (3) ◽  
pp. 523-529 ◽  
Author(s):  
A. K. W. TONG ◽  
B. W. KENNEDY ◽  
J. E. MOXLEY
Keyword(s):  
Energy Intake ◽  
Milk Fat ◽  
Genetic Parameters ◽  
Genetic Relationships ◽  
Protein Yield ◽  
Net Energy ◽  
Yield Traits ◽  
Genetic And Phenotypic Correlations ◽  
Net Energy Intake ◽  
Quadratic Effects

A total of 13,561 Holstein 305-day lactation records were studied to examine the effects of correcting records for linear and quadratic effects of 305-day net energy intake from silage, hay, pasture and meal feeding on estimates of genetic parameters of milk, fat and protein yield and fat and protein percent. Correcting records for net energy intake reduced variances of yield traits, but had little effect on composition trait variances. When expressed as a percentage of the total variance, the relative importance of sire and sire–herd components were unchanged using corrected records, and heritabilities, except for that of protein yield, were unaltered. Cow components of yield traits were reduced relative to other components after records were corrected for feeding levels. Consequently, repeatabilities were reduced as well, suggesting that a large portion of the permanent environmental effects on yield traits may be of nutritional origin. Genetic and phenotypic correlations between yield traits were also reduced appreciably after records were corrected for feed intake. Genetic relationships between milk, fat and protein yield may not be as great as commonly believed.

scholarly journals Genetic Relationships Among Representatives of Dasypyrum, Secale and Triticum Species Revealed with RAPD and ISSR Markers

2014 ◽  
Vol 42 (2) ◽  
pp. 420-430
Author(s):  
Agnieszka GRADZIELEWSKA ◽  
Mirosław TYRKA ◽  
Justyna LESNIOWSKA-NOWAK ◽  
Justyna NAZARUK
Keyword(s):  
Gene Diversity ◽  
Genetic Relationships ◽  
Issr Markers ◽  
Genetic Distances ◽  
Fixation Index ◽  
Triticum Species ◽  
The Difference ◽  
Bridge Species ◽  
Differentiation Gene ◽  
Rapd And Issr

In this study the genetic similarity among Dasypyrum, Secale andTriticum species with RAPDs and ISSRs was analyzed. To show a level of similarity between the species, 12 populations of Dasypyrum (11 D. villosum and 1 D. breviaristatum), together with 12 accessions belonging to 3 Secale species and 12 accessions from 4 Triticum species were used. Genetic distances (GD) and bootstrap values were calculated and PCA analysis was conducted to present the relationships among the species. To estimate the genetic structure among and inside genera, as well as population differentiation, gene diversity (He), total genetic variation (Ht) and Wright’s fixation index (Fst) were computed. The highest values were found in Triticum, within which Ht was equal to 0.332±0.023 and Fst was 0.42. It confirmed that the material studied was highly differentiated. Both systems found Dasypyrum more related with Triticum, as compared to Secale. With RAPDs, genetic distance (GD) between Triticum and Dasypyrum was 0.435, respectively 0.460 for Secale vs Dasypyrum. In the case of ISSRs these values were 0.374 and 0.407, respectively. Despite the fact that the difference between the two GD indices was insignificant, one should not exclude the possibility of successful hybridization of Dasypyrum and Secale, especially when using bridge species.

scholarly journals Population genetic characteristics of horse chestnut in Serbia

2013 ◽  
Vol 65 (1) ◽  
pp. 1-7 ◽  
Author(s):  
Mirjana Ocokoljic ◽  
Dragica Vilotic ◽  
Mirjana Sijacic-Nikolic
Keyword(s):  
Population Genetic ◽  
Genetic Parameters ◽  
Individual Variability ◽  
Horse Chestnut ◽  
Statistical Parameters ◽  
Genetic Characteristics ◽  
Different Populations ◽  
Growth Phenotype ◽  
Population Genetic Parameters ◽  
Cultivated Populations

The general population genetic characteristics of cultivated horse chestnut trees excelling in growth, phenotype characteristics, type of inflorescence, productivity and resistance to the leafminer Cameraria ohridella Deschka and Dimic were analyzed in Serbia. The analyzed population genetic parameters point to fundamental differences in the genetic structure among the cultivated populations in Serbia. The study shows the variability in all properties among the populations and inter-individual variability within the populations. The variability and differential characteristics were assessed using statistical parameters, taking into account the satisfactory reflection of the hereditary potential. The assessed differences in the vitality and evolution potential of different populations can determine the methods of horse chestnut gene pool collection, reconstruction and improvement.

Gene Differentiation in Pacific Salmon (Oncorhynchus sp.): Facts and Models with Reference to Pink Salmon (O. gorbuscha)

1994 ◽  
Vol 51 (S1) ◽  
pp. 223-232 ◽  
Author(s):  
Lev A. Zhivotovsky ◽  
A. J. Gharrett ◽  
A. J. McGregor ◽  
M. K. Glubokovsky ◽  
Marcus W. Feldman
Keyword(s):  
Pacific Salmon ◽  
Gene Diversity ◽  
Genetic Relationships ◽  
Pink Salmon ◽  
Theoretical Models ◽  
Genetic Distances ◽  
Gene Drift ◽  
Gene Differentiation ◽  
Or Gene ◽  
And Migration

Analyzing population genetic data usually involves examining relationships among populations followed by analysis of the distribution of genetic variability. Genetic relationships are often depicted with multidimensional scaling or trees constructed from genetic distances; genetic variation within and among populations is partitioned using gene diversity measures such as FST or GST. Genetic distances or gene diversity are often used to estimate influences of gene drift, migration, and/or selection on observed gene differentiation. We used allozyme data for pink salmon populations to examine the theoretical models available for estimating magnitudes of these factors in Pacific salmon populations. The models included (1) mutation and gene drift; (2) mutation and migration; (3) migration and gene drift; and (4) gene drift, migration, and selection. These models suggest that gene drift and migration are probably important at the lowest levels of population hierarchy, but even very small forces such as weak heterogeneous selection and low migration levels may be important at higher levels. The accuracy of some estimates should be questioned because for many situations appropriate models are either not yet available or are not sufficiently refined. Also, the dynamic genetic structure of salmon populations makes it unlikely that the steady state assumed for many theoretical models has obtained.

Sign in / Sign up

Export Citation Format

Share Document