Evolution of Plant B Chromosome Enriched Sequences

B - chromosome evolution Juan

B-chromosome evolution.

B chromosomes are extra chromosomes to the standard complement that occur in many organisms. They can originate in a number of ways including derivation from autosomes and sex chromosomes in intra- and interspecies crosses. Their subsequent molecular evolution resembles that of univalent sex chromosomes, which involves gene silencing, heterochromatinization and the accumulation of repetitive DN...

Plant contributions to our understanding of sex chromosome evolution.

A minority of angiosperms have male and female flowers separated in distinct individuals (dioecy), and most dioecious plants do not have cytologically different (heteromorphic) sex chromosomes. Plants nevertheless have several advantages for the study of sex chromosome evolution, as genetic sex determination has evolved repeatedly and is often absent in close relatives. I review sex-determining...

Application of nrDNA-ITS Sequences in Plant Phylogeny and Evolution

The application of nuclear rDNA ITS sequences in plant phylogeny and evolution analysis was discussed in this paper. Nuclear rDNA is an important nuclear gene fragment, which had been widely used in phylogenetic studies. The internal transcribed spacer of nuclear rDNA was divided into ITS1 and ITS2 by 5.8S rDNA. The length of ITS1 ranges from 165 bp to 298 bp in angiosperms, and the length of I...

Characterization of AFLP sequences from regions of maize B chromosome defined by 12 B-10L translocations.

Maize B chromosome sequences have been previously cloned by microdissection, and all are proven to be highly repetitive, to be homologous to the normal complement, and to show no similarity to any published gene other than mobile elements. In this study, we isolated sequences from defined B regions. The strategy involved identification and then mapping of AFLP-derived B fragments before cloning...