TY - JOUR
T1 - Chromosome pairing in allotetraploid hybrids of Festuca pratensis × Lolium perenne revealed by genomic in situ hybridization (GISH)
AU - Jones, R. N.
AU - Zwierzykowski, Zbigniew
AU - Zwierzykowska, Elżbieta
AU - Taciak, Magdalena
AU - Kosmala, Arkadiusz
AU - Krajewski, Paweł
N1 - Zwierzykowski, Z., Zwierzykowska, E., Taciak, M., Jones, R. N., Kosmala, A., Krajewski, P. (2008). Chromosome pairing analysis in allotetraploid hybrids of Festuca pratensis x Lolium perenne using genomic in situ (GISH). Chromosome Research, 16, (4), 575-585.
IMPF: 03.40 RONO: 00
PY - 2008/6/1
Y1 - 2008/6/1
N2 - Genomic in situ hybridization (GISH) was used to make a detailed study of chromosome pairing at metaphase I (MI) of meiosis in six F1 hybrid plants of the allotetraploid Festuca pratensis × Lolium perenne (2n = 4x = 28; genomic constitution FpFpLpLp). The mean chromosome configurations for all hybrids analysed were 1.13 univalents + 11.51 bivalents + 0.32 trivalents + 0.72 quadrivalents, and the mean chiasma frequency was 21.96 per cell. GISH showed that pairing was predominantly intragenomic, with mean numbers of L. perenne (Lp/Lp) and F. pratensis (Fp/Fp) bivalents being virtually equal at 5.41 and 5.48 per cell, respectively. Intergenomic pairing between Lolium and Festuca chromosomes was observed in 33.3% of Lp/Fp bivalents (0.62 per cell), in 79.7% of trivalents – Lp/Lp/Fp and Lp/Fp/Fp (0.25 per cell), and in 98.4% of quadrivalents – Lp/Lp/Fp/Fp and Lp/Lp/Lp/Fp (0.71 per cell). About 4.0% of the total chromosome complement analysed remained as univalents, an average 0.68 Lp and 0.45 Fp univalents per cell. It is evident that in these hybrids there is opportunity for recombination to take place between the two component genomes, albeit at a low level, and this is discussed in the context of compromising the stability of Festulolium hybrid cultivars and accounting for the drift in the balance of the genomes over generations. We speculate that genotypic differences between hybrids could permit selection for pairing control, and that preferences for homologous versus homoeologous centromeres in their spindle attachments and movement to the poles at anaphase I could form the basis of a mechanism underlying genome drift.
AB - Genomic in situ hybridization (GISH) was used to make a detailed study of chromosome pairing at metaphase I (MI) of meiosis in six F1 hybrid plants of the allotetraploid Festuca pratensis × Lolium perenne (2n = 4x = 28; genomic constitution FpFpLpLp). The mean chromosome configurations for all hybrids analysed were 1.13 univalents + 11.51 bivalents + 0.32 trivalents + 0.72 quadrivalents, and the mean chiasma frequency was 21.96 per cell. GISH showed that pairing was predominantly intragenomic, with mean numbers of L. perenne (Lp/Lp) and F. pratensis (Fp/Fp) bivalents being virtually equal at 5.41 and 5.48 per cell, respectively. Intergenomic pairing between Lolium and Festuca chromosomes was observed in 33.3% of Lp/Fp bivalents (0.62 per cell), in 79.7% of trivalents – Lp/Lp/Fp and Lp/Fp/Fp (0.25 per cell), and in 98.4% of quadrivalents – Lp/Lp/Fp/Fp and Lp/Lp/Lp/Fp (0.71 per cell). About 4.0% of the total chromosome complement analysed remained as univalents, an average 0.68 Lp and 0.45 Fp univalents per cell. It is evident that in these hybrids there is opportunity for recombination to take place between the two component genomes, albeit at a low level, and this is discussed in the context of compromising the stability of Festulolium hybrid cultivars and accounting for the drift in the balance of the genomes over generations. We speculate that genotypic differences between hybrids could permit selection for pairing control, and that preferences for homologous versus homoeologous centromeres in their spindle attachments and movement to the poles at anaphase I could form the basis of a mechanism underlying genome drift.
KW - allopolyploids
KW - chromosome pairing
KW - Festuca pratensis × Lolium perenne hybrids
KW - genomic in situ hybridization (GISH)
U2 - 10.1007/s10577-008-1198-6
DO - 10.1007/s10577-008-1198-6
M3 - Article
SN - 1573-6849
VL - 16
SP - 575
EP - 585
JO - Chromosome Research
JF - Chromosome Research
IS - 4
ER -