Maize Centromere Mapping: A Comparison of Physical and Genetic Strategies

Abstract

Centromere positions on 7 maize chromosomes were compared on the basis of data from 4 to 6 mapping techniques per chromosome. Centromere positions were first located relative to molecular markers by means of radiation hybrid lines and centric fission lines recovered from oat-maize chromosome addition lines. These centromere positions were then compared with new data from centric fission lines recovered from maize plants, half-tetrad mapping, and fluorescence in situ hybridizations and to data from earlier studies. Surprisingly, the choice of mapping technique was not the critical determining factor. Instead, on 4 chromosomes, results from all techniques were consistent with a single centromere position. On chromosomes 1, 3, and 6, centromere positions were not consistent even in studies using the same technique. The conflicting centromere map positions on chromosomes 1, 3, and 6 could be explained by pericentric inversions or alternative centromere positions on these chromosomes.

Recombination frequency variation in maize as revealed by genomewide single‐nucleotide polymorphisms

“…In both cases, there was a threefold difference in the recombination frequency, which was much larger than what would be expected from the difference in location of these core markers (Table S3). Other studies have also reported the same differences in predicted centromere locations for chromosomes 1 and 3 (Okagaki et al. 2008), including a recent precision mapping of centromeres (Wolfgruber et al.…”

Multilocus half-tetrad analysis and centromere mapping in citrus: evidence of SDR mechanism for 2n megagametophyte production and partial chiasma interference in mandarin cv ‘Fortune’

“…Analysis of the pattern of heterozygosity restitution within a linkage group is an alternative way to map the centromere compared with half-tetrad multilocus allelic configuration analysis Centromere mapping has been carried out in several crops (Douches and Quiros, 1988;Okagaki et al, 2008) and animals (Kauffman et al, 1995;Lindner et al, 2000), using HTA. In the present work, HTA has been carried out in two ways: by multilocus allelic conformation analysis, as described in Tavoletti et al (1996) and by comparison of observed and theoretical pattern of heterozygosity restitution rate within the linkage group under several models.…”

A Single Molecule Scaffold for the Maize Genome

“…However, for some maize chromosomes such as Chrs 1, 3, and 6, the proposed centromeric locations differ among different mapping methods; while for other chromosomes - Chrs 2, 4, 9, and 10 - there is a consensus running across different mapping techniques [84]. Recently, maize centromeres were located on the B73 RefGen_v1 sequence using centromeric markers [53] derived from numerous sources: transposon display, repeat junction, centromere repeat, and chromatin immunoprecipitation data [53].…”