Chromosomal Evolution in the Phylogenetic Context: A Remarkable Karyotype Reorganization in Neotropical Parrot Myiopsitta monachus (Psittacidae).

Rafael Kretschmer,Ricardo José Gunski,Jorge C. Pereira,Rebecca E. O’Connor,Malcolm Andrew Ferguson-Smith,Darren Karl Griffin,Analía del Valle Garnero,Anderson José Baia Gomes,Ivanete de Oliveira Furo,Patricia Caroline O’Brien,Edivaldo Herculano Correa de Oliveira

doi:10.3389/fgene.2020.00721

Abstract

Myiopsitta monachus is a small Neotropical parrot (Psittaciformes: Arini Tribe) from subtropical and temperate regions of South America. It has a diploid chromosome number 2n = 48, different from other members of the Arini Tribe that have usually 70 chromosomes. The species has the lowest 2n within the Arini Tribe. In this study, we combined comparative chromosome painting with probes generated from chromosomes of Gallus gallus and Leucopternis albicollis, and FISH with bacterial artificial chromosomes (BACs) selected from the genome library of G. gallus with the aim to shed light on the dynamics of genome reorganization in M. monachus in the phylogenetic context. The homology maps showed a great number of fissions in macrochromosomes, and many fusions between microchromosomes and fragments of macrochromosomes. Our phylogenetic analysis by Maximum Parsimony agree with molecular data, placing M. monachus in a basal position within the Arini Tribe, together with Amazona aestiva (short tailed species). In M. monachus many chromosome rearrangements were found to represent autopomorphic characters, indicating that after this species split as an independent branch, an intensive karyotype reorganization took place. In addition, our results show that M. monachus probes generated by flow cytometry provide novel cytogenetic tools for the detection of avian chromosome rearrangements, since this species presents breakpoints that have not been described in other species.

Highlights

The order Psittaciformes comprises some 330–350 species, grouped into three families according to a new classification: Strigopidae, Cacatuidae and Psittacidae (Rheindt et al, 2014; Winkler et al, 2015)
Gallus gallus whole chromosome probes corresponded to 21 homologous segments in the Myiopsitta monachus (MMO) genome, and revealed fissions in several ancestral pairs, and fusions involving the segments that were fissioned
We observed the fusion between GGA6/GGA7, as observed in all members of Arini Tribe (Seabury et al, 2013; Furo et al, 2015a, 2018)

Summary

Introduction

The order Psittaciformes comprises some 330–350 species, grouped into three families according to a new classification: Strigopidae, Cacatuidae and Psittacidae (Rheindt et al, 2014; Winkler et al, 2015). Within the Psittaciformes, the earliest divergence was between the New Zealand-restricted Strigopidae family (Kakapo, Kea, and Kaka) and other parrots, followed by the divergence between the Australasian cockatoos (Cacatuidae) and remaining parrots (Tavares et al, 2006; Wright et al, 2008). Some studies have proposed the division of Psittacidae family into Old World and New World parrots (Miyaki et al, 1998). According to Tavares et al (2006), the New world Parrots share a much earlier common ancestor with Australian parrots (59 million years ago, Mya), prior to the separation of Australia from Antarctica and South America

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Discussion

Conclusion