The Karyotype of the Hoatzin ( < b > < i > Opisthocomus hoazin < /i > < /b > ) - A Phylogenetic Enigma of the Neornithes

The hoatzin (Opisthocomus hoazin M üller, 1776) is a folivorous bird, endemic to the Amazonian region. It presents some unique characteristics, including wing claws and foregut fermentation, which make its phylogenetic relationship to other birds difficult to determine. There have been various attempts to place it among the Gallifor mes, Gruiformes, Musophagiformes, Cuculiformes, and Charadriiformes, but phylogenetic analyses always show low supporting values. Nowadays, the hoatzin is included in the monotypic order Opisthocomiformes, but the relationship of this order to other groups of birds is still unclear. Although its kar yotype resembles the typical avian model, fissions of the syntenic groups corresponding to chicken chromosomes 1 and 2 and 2 fusions were found. The presence of 18S rDNA clusters in 2 pairs of microchromosomes is another derived character. Hence, different rearrangements were detected in the karyoty pe of the hoatzin, indicating it has been derived from the putative ancestral karyotype by the occurrence of fissions and fusions. However, as these rearrangements are not exclusive toO. hoazin, they do not clarify the phylogenetic position of this enigmatic species.Cytogenet Genome Res

Source: Cytogenetic and Genome Research - November 23, 2018 Category: Genetics & Stem Cells Source Type: research