Insight on segregation distortions in two intraspecific crosses between annual species of Medicago (Leguminosae)

Jenczewski, Eric; Ghérardi, M.; Bonnin, Isabelle; Prospéri, Jean-Marie; Olivieri, Isabelle; Huguet, Thierry

doi:10.1007/s001220050466

Cited by 135 publications

(99 citation statements)

References 65 publications

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“…Here we report that 45% of the loci in our mapping population deviated significantly from the 1:1 expectation (Table 3; Figure 3). This estimate is similar to that found in intraspecific crosses in angiosperms (Zamir and Tadmor 1986;Jenczewski et al 1997;Lu et al 2000;Fishman et al 2001;Harushima et al 2001;Schwarz-Sommer et al 2003;Kuittinen et al 2004;Hall and Willis 2005;Bratteler et al 2006). The distorted loci tended to be clustered along the linkage groups; 6 of the 12 regions showing significant distortion contained at least three markers, suggesting that the distorted markers were nonrandomly distributed throughout the genome (Figure 3).…”

Section: Discussionsupporting

confidence: 85%

A Linkage Map Reveals a Complex Basis for Segregation Distortion in an Interpopulation Cross in the Moss Ceratodon purpureus

2007

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We report the construction of a linkage map for the moss Ceratodon purpureus (n ¼ 13), based on a cross between geographically distant populations, and provide the first experimental confirmation of maternal chloroplast inheritance in bryophytes. From a mapping population of 288 recombinant haploid gametophytes, genotyped at 121 polymorphic AFLP loci, three gene-based nuclear loci, one chloroplast marker, and sex, we resolved 15 linkage groups resulting in a map length of $730 cM. We estimate that the map covers more than three-quarters of the C. purpureus genome. Approximately 35% of the loci were sex linked, not including those in recombining pseudoautosomal regions. Nearly 45% of the loci exhibited significant segregation distortion (a ¼ 0.05). Several pairs of unlinked distorted loci showed significant deviations from multiplicative genotypic frequencies, suggesting that distortion arises from genetic interactions among loci. The distorted autosomal loci all exhibited an excess of the maternal allele, suggesting that these interactions may involve nuclear-cytoplasmic factors. The sex ratio of the progeny was significantly male biased, and the pattern of nonrandom associations among loci indicates that this results from interactions between the sex chromosomes. These results suggest that even in interpopulation crosses, multiple mechanisms act to influence segregation ratios.

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Section: Discussionsupporting

confidence: 85%

A Linkage Map Reveals a Complex Basis for Segregation Distortion in an Interpopulation Cross in the Moss Ceratodon purpureus

2007

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“…A much smaller proportion of markers (16; 14.81%) showed a significant deficiency (a ¼ 0.05) of one of the parental genotypes compared to that among DHLs (26.89%), although a direct comparison is difficult because of much lower statistical power among F 2 's. Nonetheless, the proportions of markers with distorted parental genotypic ratios among DHLs and F 2 's are comparable to that of some intraspecific crosses ½13À18% (Zamir and Tadmor 1986;Jenczewski et al 1997;Lu et al 2002), but much lower than that of some interspecific crosses; 80% (Devicente and Tanksley 1993); 49% (Fishman et al 2001a). Of 16 markers with distorted parental genotypic ratios among F 2 's, 11 showed overrepresentation of FN8 genotypes, again consistent with the trend among DHLs.…”

Section: Resultsmentioning

confidence: 93%

A Genomewide Study of Reproductive Barriers Between Allopatric Populations of a Homosporous Fern,Ceratopteris richardii

et al. 2007

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Biological factors involved in reproductive barriers between two divergent races of Ceratopteris richardii were investigated. We used a combination of spore germination rates, QTL analysis of spore germination rates, and transmission ratio distortion (TRD) of 729 RFLPs, AFLPs, and isozyme markers distributed across the genome on the basis of hybrid populations of 488 doubled haploid lines (DHLs) and 168 F 2 's. Substantial reproductive barriers were found between the parental races, predominantly in the form of spore inviability (23.7% F 1 spore viability). Intrinsic genetic factors such as Bateson-Dobzhansky-Muller (BDM) incompatibilities involving both nuclear-nuclear and nuclear-cytoplasmic factors and chromosomal rearrangements appear to contribute to intrinsic postzygotic isolation. The genomewide distribution patterns of TRD loci support the hypothesis that reproductive barriers are a byproduct of divergence in allopatry and that the strong reproductive barriers are attributable to a small number of genetic elements scattered throughout the genome.

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“…On chromosome VII, alleles from the cultivated parent were overrepresented on the short arm and the prox imal region of the long arm, whereas alleles from the wild parent were overrepresented on the long arm. Segregation distortion is common in wide crosses in the angiosperms, especially interspecies crosses 25,26 , and may reflect reproductive barriers or inadvertent selection during the inbreeding process. Previous studies have shown that segrega tion distortion does not affect marker order determination 27,28 , as confirmed in this study by the excellent concordance between the genetic map and the sequence assembly, including in regions where segregation distortion was observed.…”

Section: A Genetic Map For Setariamentioning

confidence: 99%

Reference genome sequence of the model plant Setaria

et al. 2012

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Insight on segregation distortions in two intraspecific crosses between annual species of Medicago (Leguminosae)

Cited by 135 publications

References 65 publications

A Linkage Map Reveals a Complex Basis for Segregation Distortion in an Interpopulation Cross in the Moss Ceratodon purpureus

A Linkage Map Reveals a Complex Basis for Segregation Distortion in an Interpopulation Cross in the Moss Ceratodon purpureus

A Genomewide Study of Reproductive Barriers Between Allopatric Populations of a Homosporous Fern,Ceratopteris richardii

Reference genome sequence of the model plant Setaria

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