Genetic lag in a Meishan x Large White pig backcross population: A simulation study

2002 ◽  
Vol 2002 ◽  
pp. 59-59
Author(s):  
E.E. Wall ◽  
J.A. Woolliams ◽  
P.M. Visscher
Keyword(s):  
Linkage Drag ◽  
Large White ◽  
Donor Genome ◽  
Backcross Population ◽  
Identical By Descent ◽  
Target Locus ◽  
Trace Back ◽  
Donor Line ◽  
New Alleles ◽  
Large White Pig

Backcrossing can be used as a tool to introduce new alleles into a population. Having detected an allele of interest in a non-commercial (donor) line, backcrossing methods introduce the allele into a commercial (recipient) population whilst minimising the contribution of the less superior donor genome. Many alleles linked to the desired donor allele are incorporated into the recipient line by a phenomenon called linkage drag. Loci in the region of the target locus may trace back to a common ancestor and become identical by descent (IBD). This leads to a loss of diversity around the target locus. The linkage drag and contributions from ancestral recipient populations mean that the backcross population suffers genetic lag for commercial traits. This study aims to investigate the effect of population size and number of backcross generations on genetic lag, linkage drag and IBD around a target allele reducing back fat found in the Chinese Meishan breed when backcrossed to a commercial Large White population.

scholarly journals Unexpectedly High Allelic Diversity at the KIT Locus Causing Dominant White Color in the Domestic Pig

Genetics ◽  
2002 ◽  
Vol 160 (1) ◽  
pp. 305-311
Author(s):  
G Pielberg ◽  
C Olsson ◽  
A-C Syvänen ◽  
L Andersson
Keyword(s):  
Coat Color ◽  
Allelic Diversity ◽  
Growth Factor Receptor ◽  
Small Sample ◽  
Color Variation ◽  
Large White ◽  
High Genetic Diversity ◽  
High Allelic Diversity ◽  
Stem Cell Growth Factor ◽  
New Alleles

Abstract Mutations in KIT encoding the mast/stem cell growth factor receptor (MGF) are responsible for coat color variation in domestic pigs. The dominant white phenotype is caused by two mutations, a gene duplication and a splice mutation in one of the copies leading to skipping of exon 17. Here we applied minisequencing and pyrosequencing for quantitative analysis of the number of copies with the splice form. An unexpectedly high genetic diversity was revealed in white pigs. We found four different KIT alleles in a small sample of eight Large White females used as founder animals in a wild boar intercross. A similar number of KIT alleles was found in commercial populations of white Landrace and Large White pigs. We provide evidence for at least two new KIT alleles in pigs, both with a triplication of the gene. The results imply that KIT alleles with the duplication are genetically unstable and new alleles are most likely generated by unequal crossing over. This study provides an improved method for genotyping the complicated Dominant white/KIT locus in pigs. The results also suggest that some alleles may be associated with negative pleiotropic effects on other traits.

Associations of QTL Region Genes of Chromosome 2 with Meat Quality Traits and Productivity of the Ukrainian Large White Pig Breed

2021 ◽  
Vol 55 (1) ◽  
pp. 53-62
Author(s):  
V. N. Balatsky ◽  
Y. K. Oliinychenko ◽  
T. V. Buslyk ◽  
I. B. Bankovska ◽  
S. N. Korinnyi ◽  
...  
Keyword(s):  
Meat Quality ◽  
Quality Traits ◽  
Chromosome 2 ◽  
Large White ◽  
Meat Quality Traits ◽  
Large White Pig

Mapping genes for growth rate and fatness in a Large White x Meishan F2 pig population

1998 ◽  
Vol 1998 ◽  
pp. 7-7 ◽  
Author(s):  
G.A. Walling ◽  
A.L Archibald ◽  
P.M. Visscher ◽  
C.S. Haley
Keyword(s):  
Growth Rate ◽  
Genetic Variation ◽  
Experimental Design ◽  
Statistical Methods ◽  
Population Based ◽  
Genetic Maps ◽  
Large White ◽  
Backcross Population ◽  
Livestock Species ◽  
Reproduction Traits

DNA-based markers and genetic maps of major livestock species have been developed in the last few years. These, together with experimental populations and appropriate statistical methods, provide the tools to dissect causes of economically important genetic variation in livestock. A cross between genetically diverse lines is a powerful experimental design for such a study. In an F2 or backcross population from such a cross, markers are likely to be highly informative and the genes that control the differences between the lines will be segregating. We have been developing such a resource population based on a cross between the British Large White and Chinese Meishan pigs. These breeds differ for many traits, with the Meishan being inferior for growth rate and fatness, but superior for reproduction traits. Here we report the mapping of major genetic effects on growth rate and fatness in our cross.

Inbreeding, migration, and structure of the pedigree Large White pig population in Australia

1965 ◽  
Vol 5 (18) ◽  
pp. 270 ◽  
Author(s):  
CP McPhee
Keyword(s):  
Sampling Methods ◽  
Strain Development ◽  
Genetic Progress ◽  
Large White ◽  
Breeding Stock ◽  
Frequent Exchange ◽  
Breeding Techniques ◽  
Large White Pig

Inbreeding, migration and structure of the pedigree Large White pig population in Australia were investigated by pedigree sampling methods. Inbreeding since 1905 of pigs registered in 1960 was 7.5 per cent. This comprised 1.0 per cent current and 6.5 per cent long term inbreeding. Strain development was indicated by an index of subdivision of 6.88. The most important ancestors, the sow 'Rossmoyne Duchess 31st' and the boar 'Lea Avon Jerry' had direct relationships to the 1960 population of 12 per cent and 8 per cent respectively. Migration of breeding stock within Australia was restricted. Breeders sought further afield for boars than for sows. Queensland and Victoria were favoured sources of breeding stock. Through four generations of ancestors, eight major herds contributed 83.07 per cent of the genes for the 1960 registrations, the most important herd contributing 14.54 per cent. The structure of the breed was represented by four strata of a hierarchy. Herds in all strata were widely distributed and obtained most of their sires from herds in the top stratum. The identities and relative positions of herds in the top stratum are indicated. There was a frequent exchange of stock between herds in the same locality. Most herds fluctuated in importance and were short lived, 61 per cent operating for fewer than five years. The need for the use of scientific breeding techniques is stressed, particularly for breeders with herds in the top stratum since they determine genetic progress in the breed.

scholarly journals Differences in MC4R mRNA levels between Casertana and Large White pig breeds

2005 ◽  
Vol 4 (sup2) ◽  
pp. 94-96 ◽  
Author(s):  
M. D’Andrea ◽  
M. Fidotti ◽  
F. Pilla
Keyword(s):  
Mrna Levels ◽  
Large White ◽  
Pig Breeds ◽  
Large White Pig

scholarly journals Genome-wide study on intramuscular fat in Italian Large White pig breed using the PorcineSNP60 BeadChip

2015 ◽  
Vol 133 (4) ◽  
pp. 277-282 ◽  
Author(s):  
R. Davoli ◽  
D. Luise ◽  
V. Mingazzini ◽  
P. Zambonelli ◽  
S. Braglia ◽  
...  
Keyword(s):  
Intramuscular Fat ◽  
Large White ◽  
Genome Wide ◽  
Genome Wide Study ◽  
Large White Pig
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