Genomic affinities revealed by GISH suggest intergenomic restructuring between ancestral genomes of the paleopolyploid genus Zea.

GONZALEZ, G.E.; POGGIO, L.

GENOME

NATL RESEARCH COUNCIL CANADA-N R C RESEARCH PRESS

Lugar: Otawa; Año: 2015 vol. 58 p. 433 - 439

0831-2796

The present work compares the molecular affinities revealed by GISH with theanalysis of meiotic pairing in intra e interspecific hybrids between Zea species, obtainedin previous works. The joint analysis of these data provided evidence about theevolutionary relationships among the species from the paleopolyploid genus Zea (maizeand teosintes). GISH and meiotic pairing of intraspecific hybrids revealed high genomicaffinity between maize (Zea mays ssp. mays) and both Zea mays ssp. parviglumis andZea mays ssp. mexicana. On the other hand, when Zea mays ssp. huehuetenanguensisDNA was probed on maize chromosomes, a lower affinity was detected, and the patternof hybridization suggested intergenomical restructuring between the parental genomesof maize. When DNA from Zea luxurians was used as probe, homogeneoushybridization signals were observed through all maize chromosomes. Lower genomicaffinity was observed when DNA from Zea diploperennis was probed on maizechromosomes, especially at knob regions. Maize chromosomes hybridized with Zeaperennis DNA showed hybridization signals on four chromosome pairs: twochromosome pairs presented hybridization signal in only one chromosomal arm,whereas four chromosome pairs did not show any hybridization. These results are inagreement with previous GISH studies that enabled to recognize the genomic source ofthe chromosomes involved in the meiotic configurations of the Zea perennis x maizehybrids. These findings allow postulating that maize has a parental genome not sharedwith Zea perennis, and the existence of intergenomic restructuring between the parentalgenomes of maize. Moreover, the absence of hybridization signals in all maize knobsindicate that these heterochromatic regions were lost during the Zea perennis genomeevolution.