Journal Article
Comparative cytogenetic analyses in Ancistrus species (Siluriformes: Loricariidae)
Glugoski, L., Deon, G., Schott, S., Vicari, M.R., Nogaroto, V. and Moreira-Filho, O.
Record Number:
5390
Year:
2020
Journal:
Neotropical Ichthyology
Pages:
1-16
Volume:
18(2):e200013
Abstract:
Ancistrus is a specious genus of armored catfishes that has been extensively
used for cytogenetic studies in the last 17 years. A comparison of the extensive
karyotypic plasticity within this genus is presented with new cytogenetic
analysis for Ancistrus cf. multispinis and Ancistrus aguaboensis. This study aims to
improve our understanding of chromosomal evolution associated with changes
in the diploid number (2n) and the dispersion of ribosomal DNAs (rDNAs)
within Ancistrus. Ancistrus cf. multispinis and A. aguaboensis exhibit 2n of 52 and
50 chromosomes, respectively. Given that A. cf. multispinis shares a 2n = 52 also
found in Pterygoplichthyini, the sister group for Ancistrini, a Robertsonian
(Rb) fusion event is proposed for the 2n reduction in A. aguaboensis. 5S rDNAs
pseudogenes sites have already been associated with Rb fusion in Ancistrus and
our analysis suggests that the 2n reduction in A. aguaboensis was triggered by
double strand breaks (DSBs) and chromosomal rearrangements at 5S rDNA sites.
The presence of evolutionary breakpoint regions (EBRs) into rDNA cluster is
proposed to explain part of the Rb fusion in Ancistrus. Cytogenetic data presented
extends the diversity already documented in Ancistrus to further understand the
role of chromosomal rearrangements in the diversification of Ancistrini.
Keywords: Armored catfish, FISH, 5S rDNA, 18S rDNA, telomeric sequence.
Times Cited:
4