Prospects for whole genome linkage disequilibrium mapping in domestic dog breeds

Linkage disequilibrium (LD) mapping is commonly used as a fine mapping tool in human genome mapping and has been used with some success for initial disease gene isolation in certain isolated in-bred human populations. An understanding of the population history of domestic dog breeds suggests that LD mapping could be routinely utilized in this species for initial genome-wide scans. Such an approach offers significant advantages over traditional linkage analysis. Here, we demonstrate, using canine copper toxicosis in the Bedlington terrier as the model, that LD mapping could be reasonably expected to be a useful strategy in low-resolution, genome-wide scans in pure-bred dogs. Significant LD was demonstrated over distances up to 33.3 cM. It is very unlikely, for a number of reasons discussed, that this result could be extrapolated to the rest of the genome. It is, however, consistent with the expectation given the population structure of canine breeds and, in this breed at least, with the hypothesis that it may be possible to utilize LD in a genome-wide scan. In this study, LD mapping confirmed the location of the copper toxicosis in Bedlington terrier gene (CT-BT) and was able to do so in a population that was refractory to traditional linkage analysis.

“Success breeds success” or “Pride goes before a fall”? ☆: Teams and individuals in multi-contest tournaments

We study the impact of progress feedback on players' performance in multi-contest team tournaments, in which team members' efforts are not directly substitutable. In particular, we employ a real-effort laboratory experiment to understand, in a best-of-three tournament, how players' strategic mindsets change when they compete on a team compared to when they compete individually. Our data corroborate the theoretical predictions for teams: Neither a lead nor a lag in the first component contest affects a team's performance in the subsequent contests. In individual tournaments, however, contrary to the theoretical prediction, we observe that leaders perform worse—but laggards perform better—after learning the outcome of the first contest. Our findings offer the first empirical evidence from a controlled laboratory of the impact of progress feedback between team and individual tournaments, and contribute new insights on team incentives.

Adaptability of Damara, Dorper and Traditional Meat Sheep Breeds in Semi-Arid Queensland

Reproductive rate is a major contributing factor to the profitability of a sheep meat enterprise. Low reproduction rate is a feature of sheep husbandry in semi-arid Queensland. High ambient temperatures are implicated in poor fertility (Moule 1970) where variation in response can be due to breed and to animals within a breed (Hopkins and Stephenson 1978). Breeds recently imported from South Africa were selected in arid environments and may be better adapted to pastoral conditions of northern Australia than traditional breeds. Animal production for a consuming world : proceedings of 9th Congress of the Asian-Australasian Association of Animal Production Societies [AAAP] and 23rd Biennial Conference of the Australian Society of Animal Production [ASAP] and 17th Annual Symposium of the University of Sydney, Dairy Research Foundation, [DRF]. 2-7 July 2000, Sydney, Australia. This study will investigate (a) the thermoregulatory ability of Damara, Dorper, Poll Dorset, Rambouillet, South African Meat Merino and Queensland medium wool Merino rams prior to joinings in the autumn and spring of 1999, 2000 and 2001 and (b) the association between thermoregulatory parameters (rectal temperature and respiration rate) and ewe fertility. Results for the initial autumn joining are reported in this paper.

Factors associated with calf mortality in tropically adapted beef breeds managed in extensive Australian production systems

Data from 9296 calves born to 2078 dams over 9 years across five sites were used to investigate factors associated with calf mortality for tropically adapted breeds (Brahman and Tropical Composite) recorded in extensive production systems, using multivariate logistic regression. The average calf mortality pre-weaning was 9.5% of calves born, varying from 1.5% to 41% across all sites and years. In total, 67% of calves that died did so within a week of their birth, with cause of death most frequently recorded as unknown. The major factors significantly (P < 0.05) associated with mortality for potentially large numbers of calves included the specific production environment represented by site-year, low calf birthweight (more so than high birthweight) and horn status at branding. Almost all calf deaths post-branding (assessed from n = 8348 calves) occurred in calves that were dehorned, totalling 2.1% of dehorned calves and 15.9% of all calf deaths recorded. Breed effects on calf mortality were primarily the result of breed differences in calf birthweight and, to a lesser extent, large teat size of cows; however, differences in other breed characteristics could be important. Twin births and calves assisted at birth had a very high risk of mortality, but <1% of calves were twins and few calves were assisted at birth. Conversely, it could not be established how many calves would have benefitted from assistance at birth. Cow age group and outcome from the previous season were also associated with current calf mortality; maiden or young cows (<4 years old) had increased calf losses overall. More mature cows with a previous outcome of calf loss were also more likely to have another calf loss in the subsequent year, and this should be considered for culling decisions. Closer attention to the management of younger cows is warranted to improve calf survival.

Genetic diversity of Yunnan local pig breeds inferred from blood protein electrophoresis

Protein electrophoresis was used to examine the blood protein polymorphism in Yunnan local pig breeds, i.e., the Saba pig, Dahe pig, and Diannan small-ear pig breeds, Of 38 genetic loci surveyed 9 were found to be polymorphic. The percentage of polymorphic loci (P) varies from 0.1875 to 0.2121, and the mean individual heterozygosity (H) varies front 0.0712 to 0.1027 in three pig breeds. The results indicate that blood protein polymorphism in Yunnan pig breeds is high. Yunnan local pig breeds have a wealth of genetic diversity at the level of blood proteins.

The origin and genetic diversity of Chinese native chicken breeds

The first 539 bases of mitochondrial DNA D-loop region of six Chinese native chicken breeds (Gallus gallus domesticus) were sequenced and compared to those of the red junglefowl (Gallus gallus), the gray junglefowl (Gallus sonneratii), the green junglefow

Genetic diversity and relationship of Yunnan native cattle breeds and introduced beef cattle breeds

In this study, random amplified polymorphic DNA (RAPD) analysis was used to estimate genetic diversity and relationship in 134 samples belonging to two native cattle breeds from the Yunnan province of China (DeHong cattle and DiQing cattle) and four intro

Sequence Characterization of the MC1R Gene in Yak (Poephagus grunniens) Breeds with Different Coat Colors

Melanocortin 1 receptor (MC1R) gene plays a key role in determining coat color in several species, including the cattle. However, up to now there is no report regarding the MC1R gene and the potential association of its mutations with coat colors in yak (

THE ORIGIN AND GENETIC DIFFERENTIATION OF NATIVE BREEDS OF PIGS IN SOUTHWEST CHINA - AN APPROACH FROM MITOCHONDRIAL-DNA POLYMORPHISM

Mitochondrial DNA (mtDNA) of six breeds of native domestic pigs from Yunnan province, southwest China, and two wild boars obtained from Sichuan, China, and Vietnam was analyzed using 20 restriction endonucleases that recognize six nucleotides. Restriction maps were made by double-digestion methods and polymorphic sites were located on the map. According to their mtDNA restriction types, all the breeds were classified into six groups. Genetic distances among groups were calculated to define their phylogenetic relationships. The relationship between the Sichuan wild boar and domestic pigs is close, while the Vietnamese wild boar is relatively far from them, so the domestic pigs in southwest China are likely to have originated from a wild pig which distributed in west China. We compare our results with previous reports in literature and discuss the relationship among Chinese pigs, Japanese pigs, and European pigs. The mtDNA cleavage pattern of the Mingguang pig digested by EcoRV was identical to that of Duroc; mutations at the EcoRI site, detected in the mtDNA of two Dahe pigs, are the same as in the Vietnamese wild boar, suggesting that mutational hot spots exist in the mtDNA of pigs.

Energetics and litter size variation in domestic dog Canis familiaris breeds of two sizes

We measured resting metabolic rate (RMR), daily energy expenditure (DEE) and metabolisable energy intake (MEI) in two breeds of dog during peak lactation to test whether litter size differences were a likely consequence of allometric variation in energetics. RMR of Labrador retrievers (30 kg, n = 12) and miniature Schnauzers (6 kg, n = 4) averaged 3437 and 1062 kJ/day, respectively. DEE of Labradors (n = 6) and Schnauzers (n = 4) averaged 9808 and 2619 kJ/day, respectively. MEI of Labradors (n = 12) was 22448 kJ/day and of Schnauzers (a = 7) was 5382 kJ/day. DEE of Labrador pups (2.13 kg, n = 19) was 974 kJ/day and Schnauzers (0.89 kg, n = 7) were 490 kJ/day. Although Labradors had higher MEIs than Schnauzers during peak lactation, there was no difference in mass-specific energy expenditure between the two breeds. Hence, it is unlikely that litter size variation is a likely consequence of differences in maternal energy expenditure. Individual offspring were relatively more costly for mothers of the smaller breed to produce. Therefore, litter size variations were consistent with the expectation that smaller offspring should be more costly for mothers, but not that smaller mothers should per se invest more resources in reproduction. (C) 2001 Elsevier Science Inc. All rights reserved.

A review of scientific literature on inherited disorders in domestic horse breeds

The full extent to which inherited disorders occur in different breeds of domestic horse (Equus caballus) has not been previously been investigated. A systematic search was carried out to review scientific literature on inherited disorders in domestic horse breeds and examine patterns in potentially inherited disorders. A two-part search was conducted: (i) electronic bibliographic databases for published studies; and (ii) existing online databases of inherited disorders in animals. A total of 230 papers were identified, discussing 102 inherited disorders in the horse. Few cases (17) were found in which disorders were reported to have a direct link to a conformational or phenotypic trait. Forty-nine breeds of domestic horse were described as being predisposed to one or more inherited disorders, but such predispositions did not distinguish between genetic or environmental causes. There were few patterns in the number of disorders to which breeds were reportedly predisposed or in the extent to which disorders were researched. The structure and grouping of disorders presented here could assist with standardisation in the terminology used for describing inherited disorders. © 2012 Universities Federation for Animal Welfare The Old School.

SnaPshot based genotyping of the RYR1 mutation in Portuguese breeds of pigs

The porcine stress syndrome or malignant hyperthermia is an inherited autosomic recessive disease, which results in neuromuscular disorders leading to death in homozygous individuals and is associated with deterioration of meat quality. The defect in susceptible animals results from modifications in the calcium release channel or Ryanodine Receptor (RYR1), with a mutation leading to a C to T transition in nucleotide 1843 of the gene. The objective of this work was to develop a method based on analysis of SNPs to detect the mutation described in the RYR1 locus in pigs, and study polymorphisms of the gene in four exotic (Large White, Landrace, Duroc and Pietrain) and three native (Bísaro, Alentejano and Malhado de Alcobaça) breeds of pigs in Portugal. The method was successful in identifying the mutation by analysis of SNPs, and results indicate a high incidence of the mutant allele in Pietrain (0.75) and, to a lesser degree, in Malhado de Alcobaça (0.34) and Landrace (0.28); frequencies in Alentejano, Bísaro and Large White ranged between 0.04 and 0.09. These results suggest the need to establish breeding programs aimed at eliminating the susceptibility allele from those populations.

Genetic structure, relationships and admixture with wild relatives in native pig breeds from Iberia and its islands

Background: Native pig breeds in the Iberian Peninsula are broadly classified as belonging to either the Celtic or the Mediterranean breed groups, but there are other local populations that do not fit into any of these groups. Most of the native pig breeds in Iberia are in danger of extinction, and the assessment of their genetic diversity and population structure, relationships and possible admixture between breeds, and the appraisal of conservation alternatives are crucial to adopt appropriate management strategies. Methods: A panel of 24 microsatellite markers was used to genotype 844 animals representing the 17 most important native swine breeds and wild populations existing in Portugal and Spain and various statistical tools were applied to analyze the results. Results: Genetic diversity was high in the breeds studied, with an overall mean of 13.6 alleles per locus and an average expected heterozygosity of 0.80. Signs of genetic bottlenecks were observed in breeds with a small census size, and population substructure was present in some of the breeds with larger census sizes. Variability among breeds accounted for about 20% of the total genetic diversity, and was explained mostly by differences among the Celtic, Mediterranean and Basque breed groups, rather than by differences between domestic and wild pigs. Breeds clustered closely according to group, and proximity was detected between wild pigs and the Mediterranean cluster of breeds. Most breeds had their own structure and identity, with very little evidence of admixture, except for the Retinto and Entrepelado varieties of the Mediterranean group, which are very similar. Genetic influence of the identified breed clusters extends beyond the specific geographical areas across borders throughout the Iberian Peninsula, with a very sharp transition from one breed group to another. Analysis of conservation priorities confirms that the ranking of a breed for conservation depends on the emphasis placed on its contribution to the betweenand within-breed components of genetic diversity. Conclusions: Native pig breeds in Iberia reveal high levels of genetic diversity, a solid breed structure and a clear organization in well-defined clusters.