Twenty-eight inbred (I, inbreeding coefficient 0-375 and 0-5) and 28 matching outbred (O) sheep, aged 26 weeks, were housed and allocated in equal number to two planes of nutrition, a high plane (H), involving ad libitum feeding on a pelleted diet, the other a low plane (L), restricted to an amount of the same diet which would maintain live weight. A substantial portion of the variation (24%) is explained by differences between Edinburgh and the other colonies . Twenty-eight inbred (I, inbreeding coefficient 0-375 and 0-5) and 28 matching outbred (O) sheep, aged 26 weeks, were housed and allocated in equal number to two planes of nutrition, a high plane (H), involving ad libitum feeding on a pelleted diet, the other a low plane (L), restricted to an amount of the same diet which would maintain live weight. Outbred laboratory animal strains used in ecotoxicology are intended to represent wild populations. Reference Rantala . Eigenvector 2 shows that much of the remaining variation (7%) segregates within the Bangor colony. Thus, in most instances the inbred population was not less noisy than outbreds. For all other measures there was no statistically significant difference. The failure to find an overall sex effect is surprising. Two in-contact animals were included in each experiment one culled at day 11 and one at day 13 . The best way to reduce the chances of inbreeding is to look at co-efficient of inbreeding (COI) before matching two parent dogs, or when choosing which litter of puppies to buy from. At the population level, variation in inbreeding . To test for differences between populations of C. maculatus in inbreeding depression we calculated a measure of the proportional reduction in survival due to inbreeding depression, d=(Mean outbred x Mean inbred)/Mean outbred, calculated separately for each family, then used a Mann-Whitney U-test to test for differences in d between populations . Third, the fitness difference between inbred and outbred progeny can change with the environment if dominance is environment-dependent (see for instance Bourguet et al., 1996). Levels of activity of xanthine dehydrogenase in homogenates of individual flies were measured by fluorometry for three inbred strains and two large, randomly breeding, laboratory populations of Drosophila melanogaster.
F 1 hybrids will not breed true and so have to be produced time and again by mating of the parental strains. Definitions of outbred. An outbred mouse stock is a closed population (for at least four generations) of genetically variable animals that is bred to maintain maximum heterozygosity. . First, only a fraction of the parents from an outbred population areinformative. We developed an assay of social behavior, the tube cooccupancy test. There was no size difference between inbred and outbred male founders when the enclosure populations were begun (outbred male mass = 17.29 0.54 g, inbred male mass . Genetically, there are two major classes of laboratory mice: inbred and outbred. This distinction has several consequences. Today we look at whether inbred dogs can make normal, healthy pets. Models for Inbred and Outbred Systems* GERALD BORGIA+ Division of Biological Sciences and Museum of Zoology, University of Michigan, Ann Arbor, Michigan . Figure 1 Experimental design, viral load and cell subset dynamics following H1N1 pmd09 infection. This distinction has several consequences. Inbreeding reduces fitness by exposing recessive or partially recessive deleterious alleles or by decreasing heterozygote advantage (Charlesworth and Charlesworth 1987; Keller and Waller 2002), both of which lead to negative effects on the fitness of inbred compared with outbred individuals. These age-related cognitive deficits are at least partially caused by pathologic changes that accompany aging. Safety could be based . Inbred strains are more stable, more uniform, more repeatable, and better defined than outbred stocks. This assay is able to identify deficits in social behavior of known "autistic-like" mouse strains. This difference between inbred and outbred females was statistically significant for number of investigations (Table 1; Within-subjects contrasts, interaction term: OB versus IB male female inbreeding status), and there was a similar, but non-significant trend for duration of investigations. We also found no significant differences between sexes or strains in the lateral asymmetry in digit ratios. Probability that x will be . An inbred mouse has more genetic uniformity than an outbred mouse. However, breeding history may vary considerably between strains, driving differences in genetic variation and phenotypes used for assessing effects of chemical exposure. What is genetic drift? The differences between inbred and outbred mice that might affect their relative utility as experimental subjects are well-documented. What is the difference between inbred and outbred mice? significant difference in the reproductive loss or net fertility was observed between the inbred and outbred groups. .Outbred mice are bred specifically to maximize genetic diversity and heterozygosity within a population. What is the difference between inbred and outbred mice? Inbred strain From Wikipedia, the free encyclopedia Inbred strains (also called inbred lines, or rarely for animals linear animals) are individuals of a particular species which are nearly identical to each other in genotype due to long inbreeding. Likewise, the probability that x will receive A2 from both 3 and 4 = 1/16. Outbred Mouse Good reproductive performance and fast growth rate Often used as an embryo donor and/or recipient mother in transgenic mouse labs It has been used extensively in toxicology and pharmacology studies and is often used for product safety testing Origin: The ICR outbred model was developed by Dr. T. S. . As heterozygotes result from outbreeding, the fitness of outbred progeny depends on whether the favorable or disadvantageous allele is dominant . Likewise, there was no difference between inbred and outbred females in the number of larvae present before carcasses were exchanged (t 23 = 0.69, p = 0.49). Genetic variation would be observed as the difference between strains. When we tested the same treatment with ICR (outbred) mice, however, we obtained largely scattered results. This also demonstrates that DO mice are. What they found was quite amazing. Marked differences between a number of strains of mice in their sensitivity to the anxiolytic-like action of diazepam were observed in both the light/dark and the elevated plus-maze tests. The following definition comes from the online book "Mouse Genetics" by Lee Silver (1995): Knowing the differences between them, and how scientists are using them, is important as biomedical research enters a new era of incorporating genetic diversity. We compared a range of phenoty For a parent to . The patterns of activity during the first five days following eclosion differed significantly between the inbred strains and the randomly breeding populations. Synonyms: exogamic, exogamous. Abstract. Comparisons for each inbred-outbred pair of male canaries showed no differences for the first three of the four analyzed song parameters, indicating that inbreeding status had no role in the birds . Solutions: Probability that the allele A1 will be transmitted to x through animal 3 = (1/2)=1/4. On the other hand, the Fst values between crossbred structure of the inbred and outbred groups, admixture analysis groups were in the range 0.06-0.08 (Table 2). Bold values of indicate a significant difference between inbred and outbred males. Previous studies have found that a time period of 3 h produces the largest differences between individuals (e.g. Two experiments with outbred (OB1 and OB2, black line) and two with inbred Babraham pigs (BM1 and BM2, red line) were performed. The magnitude of inbreeding depression became smaller with increasing , but such decreasing difference between inbred and outbred fitness could not be ascribed to purging, because the fitness of inbred progeny did not increase with increasing .
First, only a fraction of the parents from an outbred population are informative. Note that . None of the axes differed between inbred and outbred calls: m 1 (P= 0.084), m 2 (P= 0.107), m 3 (P= 0.573), m 4 (P= 0.702) and m 5 (P= 0.695), suggesting inbred and outbred males do not differ in multivariate attractiveness. Worldwide pharmaceutical and CRO research consumes over 70 percent of all of the commercially produced laboratory animals. Outbred stocks characterized by genotype and phenotype The present results illustrate the existing differences between two multipurpose and widely used inbred and outbred laboratory mouse strains (C57BL/6J and CD1, respectively) regarding susceptibility to ZIGI and systemic C. albicans infection models. What is the difference between inbred and outbred mice?
Digit ratios differed significantly between the inbred strains but not between the sexes. Solutions: Probability that the allele A1 will be transmitted to x through animal 3 = (1/2)=1/4. Differences in anxiety-related behaviours and in sensitivity to diazepam in inbred and outbred strains of mice . Under close inbreeding, however, differences between haploid and diploid males are reduced because gametes of diploids, even though produced by meisosis, may become nearly identical due to . For this to be an appropriate test for variance in , we divided all trait values by the mean trait value of outbreds in that block (Mean outbred), such that the interaction term in the ANOVA . For a parent to . Plot position was entered as a blocking factor for both seasons, and size at the end of the first . . Differences between inbred and outbred plants in pollen viability were analyzed with a generalized linear model using SAS Proc Glimmix and a logit link function. In a discussion of the choice of inbred strains versus outbred stocks, the guidelines suggest, "An investigator working with species for which inbred strains are available would be well advised to use them. bearing on or characterised by the custom of marrying only out of doors the boundaries of a clan or tribe. Today we look at whether inbred dogs can make normal, healthy pets. the linear difference between tness of inbred beetles vs. outbred beetles (i.e., tests for variance among blocks in Mean outbred - Mean inbred). What does the word inbred mean? On the other hand, the crossing of the inbred lines did substantially increase fitness and indicates that the strategy could work, providing extinction can be avoided. Under close inbreeding, however, differences between haploid and diploid males are reduced because gametes of diploids, even though produced by meisosis, may become nearly identical due to . Recent studies, in inbred Fayoumi and Leghorn lines, uncovered conserved, breed-dependent, and subline-dependent responses. For example, female mice of different inbred strains are less sensitive than male mice to the depressant effects of nicotine on spontaneous motor activity (Hatchell & Collins, 1980; Lopez, Simpson, White, & Randall, 2003), although no sex differences were observed between male and female mice of the outbred strain ICR (Damaj, 2001). 4. Some ICR mice were already relatively resistant to hypoxia without the treatment, while others were still vulnerable even with the treatment.
In theory, no two individuals are genetically identical within an outbred stock, owing to rotational breeding schemes that intentionally prevent inbreeding. Specifically, we aimed to determine: (1) whether inbreeding significantly affects floral traits that are likely involved in pollinator recruitment (specifically floral volatiles and corolla size); (2) whether the observed differences, if any, correlate with floral rewards, and hence the relative resource value of inbred and outbred flowers for . 1997; Tang et al. However, a final caveat must be noted, namely that the difference between the inbred and outbred lines could have occurred not because of purging but as a result of drift. Open in figure viewer PowerPoint.
Inbred strains are more stable, more uniform, more repeatable, and better defined than outbred stocks. Inbred and outbred nude mice? . Many genes are intermixed from both parents to produce offspring in a population that has little genetic homogeneity. adjective. The major difference between QTL analysis using inbred-line crosses vs. outbred populations is that while the parents in the former are genetically uniform, parents in the latter are genetically variable. They show that C57BL/6 miceconsidered to be a prototypical Th1-biased mouse strainpresent . As the differences between inbred strains are usually quite large (which is a feature of the effects of inbreeding [Falconer 1981 . We found a strong family . Inbred strains can be very sensitive to changes in environment and, while some inbred strains breed quite well, others may continue to struggle with poor reproductive performance and small litter sizes, making them vulnerable to extinction. For instance, differences are found between inbred and F1 mice in terms of activity patterns and performance in tests (e.g. Levels of activity of xanthine dehydrogenase in homogenates of individual flies were measured by fluorometry for three inbred strains and two large, randomly breeding, laboratory populations of Drosophila melanogaster.The patterns of activity during the first five days following eclosion differed significantly between the inbred strains and the randomly breeding populations. using inbred animals with lower CV values of metabo-lites for accurate evaluation of metabolic alterations. However, once a strain becomes fully inbred, further inbreeding will have no effect. Released inbred flies only did poorly (i.e., weren't caught as frequently meaning that they probably were less successful in finding food and perished) relative to outbred flies when the temperature was warm (daytime). To ensure there was no . Use of a novel outbred by inbred F1 cross to detect genetic markers for growth. Probability that x will receive A1 from both 3 and 4 = (1/4) (1/4) = 1/16. . Together they form a unique fingerprint. phenotypic differences among different inbred and outbred rodent strains. There is great controversy surrounding the origin of the exercise hyperpnea, and investigation of this phenomenon has recently come to a virtual standstill (8). Each population was . In other words, they will feature less variability. Likewise, the probability that x will receive A2 from both 3 and 4 = 1/16. 5. Inbred mice are genetically homogeneous and there is very little variation or heterogeneity within a pure inbred strain. An ideal COI is 0%, and at over 5% the puppies are likely to have health problems. bred of oldsters no longer closely comparable; having oldsters of various categories or tribes. Genetically, there are two major classes of laboratory mice: inbred and outbred. - Close inbreeding unusual in natural populations Approximately 75 percent of all rats and mice produced commercially are non-inbred (outbred). 1996 Jul;60 . No such sex effect on digit ratio asymmetry exists in humans (Putz et al. Dive into the research topics of 'Inbreeding depression increases susceptibility to bovine tuberculosis in lions: An experimental test using an inbred-outbred contrast through translocation'. For those doing animal research, the choice of whether to use inbred or outbred animals depends on the specific question being . Geneticists often prefer inbred mice over the healthier and more robust 'outbred' animals because they do not differ genetically. In the present study, we examine aspects of maternal care differentiating mice strains and explore the relationship between postpartum behavior and measures obtained by a standard test of maternal responsivity (Retrieval Test). . . We recently found a treatment that protected B6 (inbred) mice against hypoxia. Only the proportions of childhood deaths were found to be significantly higher in the inbred marriages (p < 0.005). To address whether inbreeding affects variation in offspring sex ratios, and to infer the mechanisms governing it, we conducted inbred and outbred single-donor crosses (with pollen from a male related to the females and from an unrelated male, respectively) and compared them to two-donor crosses with a 1:1 mixture of pollen from the related and . Two of these four stocks were highly inbred (404-407 generations for Oregon and 294-297 generations for Samarkand, with inbreeding broken at the hundredth generation by one generation of . Probability that A1 will be transmitted to x through 4 = (1/2) = 1/4. Inbred mice are somewhat like identical twins, except that instead of just two, there can be many, many of them. Outbred mice tend to be heartier, larger, and better breeders than inbred mice. Scientists share the assumption that data that we have gathered from inbred mice will be more consistent. (A) Pigs were infected with H1N1pdm09 and culled on the days indicated. We compared inbred 129Sv (n=25), C57BL/6J (n=23), and outbred Swiss (n=23) lactating female mice. This type is also characterized by isogenicity, but is heterozygous at the loci where the parental strains differ. Differences . Inbred mice are also extremely small compared to outbred mice (average 70 day-old male weights: inbred, 25.4 g; outbred, 34.7 g) 7. The twofold difference in adult size between the red junglefowl and White Leghorn chickens is largely explained by a limited number of QTLs . However, hybrids do not always display better scores . the difference in average heterozygosity between inbred and outbred patrilines, the level of homozygosity in inbred patrilines would need to be increased by a generation of A caveat in interpreting apparent differences between the inbred and outbred matrices is that two qualities are different between the animals used in the respective experiments: the degree of genetic diversity, but also (necessarily) the genetic background of the flies. Because toxicity depends in part on how chemicals and genes interact, genetically inbred micegenerated by breeding siblingstend to respond similarly to the agents tested in a given study. Animal Genetics, 2003 . In outbred stocks, it is sometimes difficult to detect a significant difference in biochemical parameters among treatments in toxicology [1]. Using the test, we revealed a major difference in social behavior between inbred and outbred strains, with only the latter behaving similar to wild mice. The morbidity was also not af-fected by the practice of inbreeding. An F1hybrid is the first generation cross of two inbred strains. The major difference between QTL analysis using inbred-line crosses vs. outbred populations is that while the parents in the former are genetically uniform, parents in the latter are genetically variable. One way forward would be to use a small battery of inbred strains instead of the single outbred stock currently used in toxicity screening. In the latter . In a recent review, Forster states "the Inbreeding may also influence performance directly (inbreeding depression), or through non-morphological factors such as behaviour. Genetic variation would be observed as the difference between strains. The same qualitative finding was made between inbred and outbred flies . G., Belzung, C., Perrault, G. et al. Logue et al. Cold (i.e., night) releases failed to show any difference between inbred and outbred flies. was performed in adegenet for values of ancestries (K) from The Nei-based genetic distances between the inbred and 1 to 10 with 10 repeats for each value of K, decided based outbred . Rantala et al. . First, only a fraction of the parents from an outbred population are informative. CD-1 mice stand out among the most commonly used research mice as an outbred stock (note: inbred mice are referred as strains, whereas outbred mice are referred to as stocks). Models for Inbred and Outbred Systems* GERALD BORGIA+ Division of Biological Sciences and Museum of Zoology, University of Michigan, Ann Arbor, Michigan . Outbred mice are somewhat like the human population, with profound genetic differences between individuals.
The key difference between inbreeding and outbreeding is that inbreeding is a process of mating or breeding genetically close relatives for 4 to 6 generations while outbreeding is a process of mating distantly related or unrelated individuals over 4 to 6 generations.
