difference between inbred and outbred


What is the difference between inbred and outbred mice? The disparity in reproductive success between inbred and outbred males increased over time for both the total number of offspring (not shown) and the number of weaned . Today we look at whether inbred dogs can make normal, healthy pets. Together they form a unique fingerprint. 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 . These age-related cognitive deficits are at least partially caused by pathologic changes that accompany aging. 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. 2004). For all other measures there was no statistically significant difference. Inbred mice are genetically homogeneous and there is very little variation or heterogeneity within a pure inbred strain. Note that . 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. Open in figure viewer PowerPoint. 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 . For a parent to . . 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). . 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 following definition comes from the online book "Mouse Genetics" by Lee Silver (1995): This distinction has several consequences. 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). Differences in anxiety-related behaviours and in sensitivity to diazepam in inbred and outbred strains of mice . . . Vegetative size at the end of each growing season was analyzed to test a priori hypotheses for differences among inbred and outbred parentals and F 1 hybrids and between pairs of reciprocal backcrosses using contrast statements in ANOVA models. We compared inbred 129Sv (n=25), C57BL/6J (n=23), and outbred Swiss (n=23) lactating female mice. Genetically, there are two major classes of laboratory mice: inbred and outbred. Figure 1 Experimental design, viral load and cell subset dynamics following H1N1 pmd09 infection. Inbreeding level was treated as a fixed effect, and block, maternal family, and a family inbreeding interaction were included in the model as random effects. 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. That has certain advantages; for instance, it limits the number of animals needed to detect statistically significant differences in chemical effects. . 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). Under this scenario, the difference in survival between the inbred and the outbred beetles underestimated what would have happened in the absence of immune-priming. Knowing the differences between them, and how scientists are using them, is important as biomedical research enters a new era of incorporating genetic diversity. First, only a fraction of the parents from an outbred population areinformative. Inbred mice are genetically homogeneous and there is very little variation or heterogeneity within a pure inbred strain. When we tested the same treatment with ICR (outbred) mice, however, we obtained largely scattered results. 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 . Eigenvector 2 shows that much of the remaining variation (7%) segregates within the Bangor colony. Humans and domestic animals tend to be outbred or partially inbred, and they live in microbiologically "dirty" environments (exposed to a variety of different pathogenic organisms). 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. What is genetic drift? (A) Pigs were infected with H1N1pdm09 and culled on the days indicated. 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. In other words, they will feature less variability. What does the word inbred mean? Likewise, the probability that x will receive A2 from both 3 and 4 = 1/16. phenotypic differences among different inbred and outbred rodent strains. What is the difference between inbred and outbred mice? 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 . At the population level, variation in inbreeding . An inbred strain is one that: is produced using at least 20 consecutive generations of sister x brother or parent x offspring matings, or; is traceable to a single ancestral pair in the 20th or subsequent generation. In theory, no two individuals are genetically identical within an outbred stock, owing to rotational breeding schemes that intentionally prevent inbreeding. G., Belzung, C., Perrault, G. et al. Worldwide pharmaceutical and CRO research consumes over 70 percent of all of the commercially produced laboratory animals. Definitions of outbred. 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). Inbreeding may also influence performance directly (inbreeding depression), or through non-morphological factors such as behaviour. We also found no significant differences between sexes or strains in the lateral asymmetry in digit ratios. 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 those doing animal research, the choice of whether to use inbred or outbred animals depends on the specific question being . using inbred animals with lower CV values of metabo-lites for accurate evaluation of metabolic alterations. 1996 Jul;60 . Previous studies have found that a time period of 3 h produces the largest differences between individuals (e.g. Genetically, there are two major classes of laboratory mice: inbred and outbred. 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. Age differences in cognition have been found in many learning and memory tasks. Inbred strains are more stable, more uniform, more repeatable, and better defined than outbred stocks. We found a strong family . adjective. Rantala et al. This distinction has several consequences. One way forward would be to use a small battery of inbred strains instead of the single outbred stock currently used in toxicity screening. Each population was . In the latter . 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). 2002). This also demonstrates that DO mice are. Behavioral differences between outbred Wistar, inbred Fischer 344, brown Norway, and hybrid Fischer 344 x brown Norway rats Physiol Behav. Many genes are intermixed from both parents to produce offspring in a population that has little genetic homogeneity. 5. As the differences between inbred strains are usually quite large (which is a feature of the effects of inbreeding [Falconer 1981 . Other aberrations compared to outbred (and wild-derived) mice are less well known and include abnormal stress/anxiety and aggression responses 10, 11, activity levels 12, and social behavior 13, 14. 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'. We developed an assay of social behavior, the tube cooccupancy test. 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. . We recently found a treatment that protected B6 (inbred) mice against hypoxia. Genetic variation would be observed as the difference between strains. Cold (i.e., night) releases failed to show any difference between inbred and outbred flies. .Outbred mice are bred specifically to maximize genetic diversity and heterozygosity within a population. Animal Genetics, 2003 . We compared a range of phenoty 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. The substrains have phenotypic differences [35, 36], and some of the underlying genetic variations have been identified [35, 37]. Safety could be based . 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. An ideal COI is 0%, and at over 5% the puppies are likely to have health problems. The differences between inbred and outbred mice that might affect their relative utility as experimental subjects are well-documented. Inbred and outbred nude 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. A substantial portion of the variation (24%) is explained by differences between Edinburgh and the other colonies . Inbred strains are more stable, more uniform, more repeatable, and better defined than outbred stocks. This type is also characterized by isogenicity, but is heterozygous at the loci where the parental strains differ. Plot position was entered as a blocking factor for both seasons, and size at the end of the first . Probability that A1 will be transmitted to x through 4 = (1/2) = 1/4.

An F1hybrid is the first generation cross of two inbred strains. Today we look at whether inbred dogs can make normal, healthy pets. In a recent review, Forster states "the Outbred mice are somewhat like the human population, with profound genetic differences between individuals. In contrast, such differences can be detected easily in inbred strains [2] due to stabil- 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. Some ICR mice were already relatively resistant to hypoxia without the treatment, while others were still vulnerable even with the treatment. 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. Studies have shown that some of these differences in levels of susceptibility to NDV infection may be accounted for by variability in the innate immune response amongst various breeds of poultry to NDV infection. 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). There is great controversy surrounding the origin of the exercise hyperpnea, and investigation of this phenomenon has recently come to a virtual standstill (8). .Outbred mice are bred specifically to maximize genetic diversity and heterozygosity within a population. For a parent to . The failure to find an overall sex effect is surprising. 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. This distinction has several consequences. 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 . However, hybrids do not always display better scores . . They show that C57BL/6 miceconsidered to be a prototypical Th1-biased mouse strainpresent . bearing on or characterised by the custom of marrying only out of doors the boundaries of a clan or tribe. The morbidity was also not af-fected by the practice of inbreeding. Two experiments with outbred (OB1 and OB2, black line) and two with inbred Babraham pigs (BM1 and BM2, red line) were performed. Reference Rantala . Abstract. Two in-contact animals were included in each experiment one culled at day 11 and one at day 13 . Likewise, the probability that x will receive A2 from both 3 and 4 = 1/16. bred of oldsters no longer closely comparable; having oldsters of various categories or tribes. Probability that x will be . Bold values of indicate a significant difference between inbred and outbred males. 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 . 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). . Outbred stocks characterized by genotype and phenotype

1997; Tang et al. Figure 3. Outbred mice tend to be heartier, larger, and better breeders than inbred mice. There was no difference between inbred and outbred females in the likelihood for larvae to be present before carcasses were exchanged ( 2 = 0.15, p = 0.69). Inbred mice are somewhat like identical twins, except that instead of just two, there can be many, many of them. F 1 hybrids will not breed true and so have to be produced time and again by mating of the parental strains. Logue et al. An outbred mouse stock is a closed population (for at least four generations) of genetically variable animals that is bred to maintain maximum heterozygosity. 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. 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 . Outbred laboratory animal strains used in ecotoxicology are intended to represent wild populations. Probability that A1 will be transmitted to x through 4 = (1/2) = 1/4. Introduction It is generally believed that . Therefore, experiments can be more powerful, faster . significant difference in the reproductive loss or net fertility was observed between the inbred and outbred groups. 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. 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 Use of a novel outbred by inbred F1 cross to detect genetic markers for growth. This assay is able to identify deficits in social behavior of known "autistic-like" mouse strains. body composition and several physiological variables in an F2 intercross between fat and lean . BackgroundInhalation of benzene at levels below the current exposure limit values leads to hematotoxicity in occupationally exposed workers.ObjectiveWe sought to evaluate Diversity Outbred (DO) mice as a tool for exposure threshold assessment and to identify genetic factors that influence benzene-induced genotoxicity.MethodsWe exposed male DO mice to benzene (0, 1, 10, or 100 ppm; 75 mice . Synonyms: exogamic, exogamous. 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.

However, once a strain becomes fully inbred, further inbreeding will have no effect. These characteristics were often selected in the development of the inbred strains as models for particular diseases. First, only a fraction of the parents from an outbred population are informative. 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 . Recent studies, in inbred Fayoumi and Leghorn lines, uncovered conserved, breed-dependent, and subline-dependent responses. Outbred mice are bred specifically to maximize genetic diversity and heterozygosity within a population. However, breeding history may vary considerably between strains, driving differences in genetic variation and phenotypes used for assessing effects of chemical exposure. The same qualitative finding was made between inbred and outbred flies . Probability that x will receive A1 from both 3 and 4 = (1/4) (1/4) = 1/16. 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. 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. An inbred mouse has more genetic uniformity than an outbred mouse. An ideal COI is 0%, and at over 5% the puppies are likely to have health problems. 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. First, only a fraction of the parents from an outbred population are informative. Genetic variation would be observed as the difference between strains. What is the difference between inbred and outbred mice? Solutions: Probability that the allele A1 will be transmitted to x through animal 3 = (1/2)=1/4. 4. What they found was quite amazing. 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. Only the proportions of childhood deaths were found to be significantly higher in the inbred marriages (p < 0.005). To ensure there was no . 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. For instance, differences are found between inbred and F1 mice in terms of activity patterns and performance in tests (e.g. In outbred stocks, it is sometimes difficult to detect a significant difference in biochemical parameters among treatments in toxicology [1]. 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. Models for Inbred and Outbred Systems* GERALD BORGIA+ Division of Biological Sciences and Museum of Zoology, University of Michigan, Ann Arbor, Michigan . The twofold difference in adult size between the red junglefowl and White Leghorn chickens is largely explained by a limited number of QTLs . No such sex effect on digit ratio asymmetry exists in humans (Putz et al. As heterozygotes result from outbreeding, the fitness of outbred progeny depends on whether the favorable or disadvantageous allele is dominant . Models for Inbred and Outbred Systems* GERALD BORGIA+ Division of Biological Sciences and Museum of Zoology, University of Michigan, Ann Arbor, Michigan . Geneticists often prefer inbred mice over the healthier and more robust 'outbred' animals because they do not differ genetically. By contrast, there was no significant difference in gene expression between inbred and outbred individuals (p = 0.76; figure 1b), and the inbreeding treatment did not interact significantly with either sex or chromosomal location (p = 0.44 and 0.91; table 1). Solutions: Probability that the allele A1 will be transmitted to x through animal 3 = (1/2)=1/4. 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 x will receive A1 from both 3 and 4 = (1/4) (1/4) = 1/16. 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. Differences .

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. 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 . Digit ratios differed significantly between the inbred strains but not between the sexes. 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. the linear difference between tness of inbred beetles vs. outbred beetles (i.e., tests for variance among blocks in Mean outbred - Mean inbred). - Close inbreeding unusual in natural populations Approximately 75 percent of all rats and mice produced commercially are non-inbred (outbred). Scientists share the assumption that data that we have gathered from inbred mice will be more consistent. The patterns of activity during the first five days following eclosion differed significantly between the inbred strains and the randomly breeding populations. Thus, in most instances the inbred population was not less noisy than outbreds.