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Leif Andersson - One of the best experts on this subject based on the ideXlab platform.
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quantitative trait loci analysis of egg and meat production traits in a red junglefowl White Leghorn cross
Animal Genetics, 2006Co-Authors: Dominic Wright, Per Jensen, Susanne Kerje, K Lundstrom, J Babol, Karin E Schutz, Leif AnderssonAbstract:Egg and production traits are of considerable economic importance in chickens. Using a White Leghorn × red junglefowl F2 intercross, standard production measures of liver weight and colour, egg siz ...
Masaoki Tsudzuki - One of the best experts on this subject based on the ideXlab platform.
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mapping quantitative trait loci for egg production traits in an f2 intercross of oh shamo and White Leghorn chickens
Animal Genetics, 2011Co-Authors: Tatsuhiko Goto, Masahide Nishibori, Akira Ishikawa, S Onitsuka, Naoki Goto, Y Fujikawa, Tetsuya Umino, Masaoki TsudzukiAbstract:Summary We performed quantitative trait locus (QTL) analyses for egg production traits, including age at first egg (AFE) and egg production rates (EPR) measured every 4 weeks from 22 to 62 weeks of hen age, in a population of 421 F2 hens derived from an intercross between the Oh-Shamo (Japanese Large Game) and White Leghorn breeds of chickens. Simple interval mapping revealed a main-effect QTL for AFE on chromosome 1 and four main-effect QTL for EPR on chromosomes 1 and 11 (three on chromosome 1 and one on chromosome 11) at the genome-wide 5% levels. Among the three EPR QTL on chromosome 1, two were identified at the early stage of egg laying (26–34 weeks of hen age) and the remaining one was discovered at the late stage (54–58 weeks). The alleles at the two EPR QTL derived from the Oh-Shamo breed unexpectedly increased the trait values, irrespective of the Oh-Shamo being inferior to the White Leghorn in the trait. This suggests that the Oh-Shamo, one of the indigenous Japanese breeds, is an untapped resource that is important for further improvement of current elite commercial laying chickens. In addition, six epistatic QTL were identified on chromosomes 2, 4, 7, 8, 17 and 19, where none of the above main-effect QTL were located. This is the first example of detection of epistatic QTL affecting egg production traits. The main and epistatic QTL identified accounted for 4–8% of the phenotypic variance. The total contribution of all QTL detected for each trait to the phenotypic and genetic variances ranged from 4.1% to 16.9% and from 11.5% to 58.5%, respectively.
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a chicken linkage map based on microsatellite markers genotyped on a japanese large game and White Leghorn cross
Animal Genetics, 2005Co-Authors: Hideaki Takahashi, Masaoki Tsudzuki, O Sasaki, J Niikura, Miho Inouemurayama, M MinezawaAbstract:A detailed linkage map is necessary for efficient detection of quantitative trait loci (QTL) in chicken resource populations. In this study, microsatellite markers isolated from a (CA)n-enriched library (designated as ABR Markers) were mapped using a population developed from a cross between Japanese Game and White Leghorn chickens. In total, 296 markers including 193 ABR, 43 MCW, 31 ADL, 22 LEI, 3 HUJ, 2 GCT, 1 UMA and 1 ROS were mapped by linkage to chicken chromosomes 1-14, 17-21, 23, 24, 26-28 and Z. In addition, five markers were assigned to the map based on the chicken draft genomic sequence, bringing the total number of markers on the map to 301. The resulting linkage map will contribute to QTL mapping in chicken.
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complete nucleotide sequence of mitochondrial dna in White Leghorn and White plymouth rock chickens
Animal Science Journal, 2003Co-Authors: Masahide Nishibori, Makoto Hanazono, Yoshio Yamamoto, Masaoki Tsudzuki, Hiroshi YasueAbstract:Among the chicken breeds, White Leghorn (WL) and White Plymouth Rock (WR) are major breeds and have different history in their establishments. Whole mitochondrial DNA of the breeds were sequenced in order to elucidate the genetic relationship between the breeds. The lengths of the two WL and two WR mitochondrial DNA were found to be 16 788 and 16 785 base pairs, respectively. When the DNA sequences were compared, the similarity was found to be 99.96% (six nucleotide differences). In addition, the present study conformed the existence of an extra nucleotide ‘C’ in NADH dehydrogenase subunit 3 (ND3) of the chicken mitochondrial DNA, which has been consistently observed in Galliformes.
Guro Vasdal - One of the best experts on this subject based on the ideXlab platform.
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keel bone fractures are more prevalent in White Leghorn hens than in red jungle fowl hens a pilot study
PLOS ONE, 2021Co-Authors: Kathe Elise Kittelsen, Per Jensen, Pall Gretarsson, Jens Peter Christensen, Ingrid Toftaker, Randi Oppermann Moe, Guro VasdalAbstract:Fractures and deviations to the keel bone are common in commercial laying hens, with reported variations in occurrence across strains and breeds. The aetiology is not fully understood, however, modern genetics and selection for efficient egg production has been claimed to be important factors for the keel bone fractures. To explore this further, we investigated keel bones from two different breeds, representing different degrees of selection for egg production: Red jungle fowl (n = 82), and White Leghorn (n = 32), where the latter is a selected laying breed which is the origin for many modern laying hen hybrids. Keel bones from a total of 116 birds, 53 hens and 63 roosters, were examined by necropsy at 80 weeks of age. All birds were raised in modified aviaries in the same holding facility. Overall, 24.5% of the hens had one or more fractures to the keel, with a difference in the prevalence between hens from the two breeds (p<0.01): 10% (95% CI: 3.7-24%) in the Red Jungle fowl hens and 69% (95% CI: 37-90%) in the White Leghorn hens. No roosters, regardless of breed, had keel bone fractures. Mild to moderate keel bone deviations were present in 54% (95% CI: 25-80%) of the hens and 4.7% (95% CI: 0.5-30%) of the roosters, all White Leghorns.
Gudrun A Brockmann - One of the best experts on this subject based on the ideXlab platform.
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quantitative trait loci segregating in crosses between new hampshire and White Leghorn chicken lines iv growth performance
Animal Genetics, 2015Co-Authors: M K Nassar, Z S Goraga, Gudrun A BrockmannAbstract:Summary Reciprocal crosses between the inbred lines New Hampshire (NHI) and White Leghorn (WL77) comprising 579 F2 individuals were used to map QTL for body weight and composition. Here, we examine the growth performance until 20 weeks of age. Linkage analysis provided evidence for highly significant QTL on GGA1, 2, 4, 10 and 27 which had specific effects on early or late growth. The highest QTL effects, accounting for 4.6–25.6% of the phenotypic F2 variance, were found on the distal region of GGA4 between 142 and 170 cM (F ≥ 13.68). The NHI QTL allele increased body mass by 141.86 g at 20 weeks. Using body weight as a covariate in the analysis of body composition traits provided evidence for genes in the GGA4 QTL region affecting fat mass independently of body mass. The QTL effect size differed between sexes and depended on the direction of cross. TBC1D1, CCKAR and PPARGC1A are functional candidate genes in the QTL peak region. Our study confirmed the importance of the distal GGA4 region for chicken growth performance. The strong effect of the GGA4 QTL makes fine mapping and gene discovery feasible.
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quantitative trait loci segregating in crosses between new hampshire and White Leghorn chicken lines i egg production traits
Animal Genetics, 2012Co-Authors: Z S Goraga, M K Nassar, Gudrun A BrockmannAbstract:Summary A genome scan was performed to detect chromosomal regions that affect egg production traits in reciprocal crosses between two genetically and phenotypically extreme chicken lines: the partially inbred line New Hampshire (NHI) and the inbred line White Leghorn (WL77). The NHI line had been selected for high growth and WL77 for low egg weight before inbreeding. The result showed a highly significant region on chromosome 4 with multiple QTL for egg production traits between 19.2 and 82.1 Mb. This QTL region explained 4.3 and 16.1% of the phenotypic variance for number of eggs and egg weight in the F2 population, respectively. The egg weight QTL effects are dependent on the direction of the cross. In addition, genome-wide suggestive QTL for egg weight were found on chromosomes 1, 5, and 9, and for number of eggs on chromosomes 5 and 7. A genome-wide significant QTL affecting age at first egg was mapped on chromosome 1. The difference between the parental lines and the highly significant QTL effects on chromosome 4 will further support fine mapping and candidate gene identification for egg production traits in chicken.
M K Nassar - One of the best experts on this subject based on the ideXlab platform.
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quantitative trait loci segregating in crosses between new hampshire and White Leghorn chicken lines iv growth performance
Animal Genetics, 2015Co-Authors: M K Nassar, Z S Goraga, Gudrun A BrockmannAbstract:Summary Reciprocal crosses between the inbred lines New Hampshire (NHI) and White Leghorn (WL77) comprising 579 F2 individuals were used to map QTL for body weight and composition. Here, we examine the growth performance until 20 weeks of age. Linkage analysis provided evidence for highly significant QTL on GGA1, 2, 4, 10 and 27 which had specific effects on early or late growth. The highest QTL effects, accounting for 4.6–25.6% of the phenotypic F2 variance, were found on the distal region of GGA4 between 142 and 170 cM (F ≥ 13.68). The NHI QTL allele increased body mass by 141.86 g at 20 weeks. Using body weight as a covariate in the analysis of body composition traits provided evidence for genes in the GGA4 QTL region affecting fat mass independently of body mass. The QTL effect size differed between sexes and depended on the direction of cross. TBC1D1, CCKAR and PPARGC1A are functional candidate genes in the QTL peak region. Our study confirmed the importance of the distal GGA4 region for chicken growth performance. The strong effect of the GGA4 QTL makes fine mapping and gene discovery feasible.
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quantitative trait loci segregating in crosses between new hampshire and White Leghorn chicken lines i egg production traits
Animal Genetics, 2012Co-Authors: Z S Goraga, M K Nassar, Gudrun A BrockmannAbstract:Summary A genome scan was performed to detect chromosomal regions that affect egg production traits in reciprocal crosses between two genetically and phenotypically extreme chicken lines: the partially inbred line New Hampshire (NHI) and the inbred line White Leghorn (WL77). The NHI line had been selected for high growth and WL77 for low egg weight before inbreeding. The result showed a highly significant region on chromosome 4 with multiple QTL for egg production traits between 19.2 and 82.1 Mb. This QTL region explained 4.3 and 16.1% of the phenotypic variance for number of eggs and egg weight in the F2 population, respectively. The egg weight QTL effects are dependent on the direction of the cross. In addition, genome-wide suggestive QTL for egg weight were found on chromosomes 1, 5, and 9, and for number of eggs on chromosomes 5 and 7. A genome-wide significant QTL affecting age at first egg was mapped on chromosome 1. The difference between the parental lines and the highly significant QTL effects on chromosome 4 will further support fine mapping and candidate gene identification for egg production traits in chicken.
