Synaptic responses to concerted genomic evolution in Lathyrus. II. Intragenomic effects

• Published in: Heredity Vol. 70; no. 1993; pp. 92 - 97
• Main Authors: Wallace, A.J, Callow, R.S
• Format: Journal Article
• Language: English
• Published: 1993
• Subjects: autopolyploidy; chromosome pairing; chromosomes; evolution; genomics; Lathyrus; meiosis; multivalents; pollen; pollen mother cells; polyploidy; repetitive sequences; synapsis
• ISSN: 0018-067X

Intragenomic pairing patterns have been examined in pollen mother cells (PMCs) of high chiasma frequency from C(0) autotetraploids, representing seven diploid Lathyrus species. Six species were known to display intergenomic correlations between numbers of autonomous synaptic sites and the content of moderately repetitive DNA. Intragenomic variance in chromosome length is unaffected by differences in the size of the genome. Each tetrasomic set of homologues within a nucleus has a similar propensity for multivalent formation and for synaptic exchange. These observations are consistent with the view that each chromosome of a complement is equally affected by genomic changes in the content of moderately repetitive DNA, not least those sequences previously implicated in autonomous chromosomal synapsis.