We found a match
Your institution may have access to this item. Find your institution then sign in to continue.
- Title
Monocentric chromosomes in Juncus (Juncaceae) and implications for the chromosome evolution of the family.
- Authors
Guerra, Marcelo; Ribeiro, Tiago; Felix, Leonardo P
- Abstract
Holocentric chromosomes are rare among angiosperms, but have been suggested to be shared by all or most of the species of Cyperaceae and Juncaceae. However, no clear demonstration of the centromere type in Juncus , the largest genus of Juncaceae, has so far been published. Thus, we conducted a detailed chromosomal investigation of four Juncus spp. aiming to identify their centromere type. Mitotic chromosomes were analysed using the fluorochromes CMA and DAPI, fluorescent in situ hybridization (FISH) with rDNA probes and immunodetection of histones H3 phosphorylated at serine 10 (H3-S10ph) and H2A phosphorylated at threonine 133 (H2A-T133ph). DAPI-stained chromosomes of all species displayed typical primary constrictions, which were not related to AT-poor CMA+ heterochromatin or rDNA sites (usually negatively stained with DAPI). Immunodetection with H3-S10ph and H2A-T133ph revealed hyperphosphorylation of pericentromeric and centromeric regions, respectively, in a restricted area, as observed in monocentric chromosomes. Meiotic analyses in J. microcephalus showed no indication of inverted meiosis, commonly found in plants with holocentric chromosomes. Since the species investigated here belong to four different sections of Juncus and all of them display typical monocentric chromosomes, it seems that this kind of centromere is common in the genus and may represent the standard centromere organization for Juncus. If Juncus has monocentric chromosomes, there is no reason to hypothesize that other genera of Juncaceae for which centromeres have not been carefully investigated have holocentric chromosomes.
- Subjects
CENTROMERE; KARYOTYPES; CHROMOSOMES; FLUORESCENCE in situ hybridization; MEIOSIS; PLANT chromosomes
- Publication
Botanical Journal of the Linnean Society, 2019, Vol 191, Issue 4, p475
- ISSN
0024-4074
- Publication type
Article
- DOI
10.1093/botlinnean/boz065