A linkage map of 243 DNA markers in an intercross of Göttingen miniature and Meishan pigs

Abstract

A resource family of pigs has been constructed by using a boar of Göttingen miniature pig and two sows of Meishan pig as parents. In the construction of the family, two F1 males and 18 F1 females were intercrossed to generate 143 F2 offspring. The members of the family were genotyped using 243 genetic markers including 26 markers developed in our laboratory in order to generate a linkage map of markers for use in detecting quantitative trait loci (QTLs) in the family. The markers consisted of 237 microsatellites, five PRE-1 markers, and one RFLP marker. The linkage map was revealed to cover all 18 autosomes and the X chromosome; and the total length of the sex-averaged linkage map was calculated to be 2561.9 CM. Four out of the 26 markers developed in our laboratory exended the current linkage map at the termini of chromosomes 1p, 5p, 11p, and Xq. The linkage maps of all the chromosomes except for chromosome 1 were found to be longer in females than in males. Concerning chromosome 1, the length of the linkage map showed no difference between females and males, which was attributed to low recombination rates between markers localized in the centromeric region in females. The average ratio of female-to-male recombination was calculated to be 1.55.

A Genetic Linkage Map of the House Musk Shrew, Suncus murinus, Constructed with PCR-Based and RFLP Markers

“…65(65-1) 13.5/41}. This estimated length seems to be compatible with estimates for other mammalian species, which range from 1,398 cM for the mouse [29] to >3,500 cM in humans [14], cattle [3,13], and sheep [19]. Given this genetic linkage map length of 1,400 cM and with the current average inter-marker distance of 13.5 cM, approximately 100 markers would be needed to cover the entire genome map.…”

Linkage Maps for the Pacific Abalone (Genus Haliotis) Based on Microsatellite DNA Markers

“…Sex-related difference in recombination rate: Since the discovery of heterogeneous fractions of meiotic recombination between sexes in Drosophila (Morgan 1912), sex-specific differences in recombination rates have been found in a diverse range of organisms, for example, in plants (Burt et al 1991;De Vicente and Tanksley 1991;Graner et al 1991;Sewell et al 1999), mammals (Donis-Keller et al 1987;Mikawa et al 1999;Neff et al 1999;Lynn et al 2005), and aquatic animals such as teleost fishes (Sakamoto et al 2000;Kondo et al 2001;Singer et al 2002;Woram et al 2004;Kai et al 2005;Lee et al 2005;Gharbi et al 2006). Although limited information is available for molluscan species, higher recombination rates in females have been reported (eastern oyster, Yu and Guo 2003;Pacific oyster, Li and Guo 2004;Hubert and Hedgecock 2004), and in H. discus hannai as well (Liu et al 2006).…”

First-Generation Linkage Map of the Gray, Short-Tailed Opossum,Monodelphis domestica, Reveals Genome-Wide Reduction in Female Recombination Rates

“…The impression of mixed conservation and rearrangement relative to eutherian genomes agrees with extensive physical mapping results from M. eugenii and a few other marsupial species (reviewed by Samollow and Graves 1998). Un- there is almost no overlap among the type I loci mapped human (Broman et al 1998;Kong et al 2002), baboon (Rogers et al 2000), mouse (Rhodes et al 1998), rat (Bonné et al Ferretti et al 1997; 2001), so there is currently no opportunity for synteny Kappes et al 1997), pig (Mikawa et al 1999), sheep (Maddox comparisons between these two marsupial species.…”

“…With so few mammalian species maps female than male recombination rates, and, among those with extensive maps, the F/M ratio is almost completed, such speculation might be premature; however, cytologic data from the brushtail possum, Trichoalways Ͼ1.0; e.g., 1.56-1.65 in humans (Broman et al 1998;Kong et al 2002) Neff et al 1999), and 1.30-1.55 in pigs (Archibald et al 1995;Mikawa et al 1999). In cattle, than that in M. domestica and S. crassicaudata .…”

“…bination in female marsupials was much lower than that in males. This pattern is contrary to the general mammalian one in which recombination rates are simi-MATERIALS AND METHODS lar between the sexes or are reduced in males: e.g., Animal resources and genetic mapping panel: Gray, shorthumans (Broman et al 1998;Kong et al 2002), dogs tailed opossums (M. domestica) were obtained from the re- (Mellersh et al 1997;Neff et al 1999), pigs (Archisearch colony maintained at the Southwest Foundation for bald et al 1995;Mikawa et al 1999), cattle (Barendse Biomedical Research (SFBR), San Antonio, Texas. The "GMBX" mapping panel was established by crossing members Kappes et al 1997), and mice (Dunn and of laboratory stocks that were descended from the most geo- Bennett 1964;Davisson et al 1989;Copeland et al graphically separated populations available ‫0021ف(‬ km) at 1993).…”