The monk parakeet (Myiopsitta monachus)

Parrot genomes characteristically have a reduced chromosome number compared with other birds. Using high-quality chromosome-level assemblies of monk parakeet and several other parrot genomes, the evolutionary processes and patterns of chromosomal rearrangements among parrot lineages are depicted. A burst of one transposable element (CR1-psi) unique to parrots has been identified, which is thought to have directly or indirectly contributed to chromosomal rearrangements. Furthermore, the loss of two genes (ALC1 and PARP3), related to genome stability, serves as a likely explanation for the elevated rate of chromosomal rearrangements in parrots. The fusion of chromosomes 11 and 25 with ZW sex chromosomes has created a pair of neo-sex chromosomes. The chromosome number (2n = 48) of monk parakeets is the lowest among parrots, with only ten microchromosome pairs compared with ~30 pairs for a typical bird genome. The genome of monk parakeet is ~1.17 Gb in size, containing 24 pairs of chromosomes. The repeat content is ~14.6% and the GC content is 42.3%. In total, 17 294 protein-coding genes were annotated. Compared with other birds, at least 72 genes were lost in all parrots, including the monk parakeet. The size of the Z chromosome accounts for ~1/10 of the genome and it has experienced fusion with ancestral chromosome 11 and chromosome 25. The W chromosome has lost ~85% of the ancestral gene content but maintains a large size due to recent expansions of satellite DNA. The monk parakeet originates from South America but has become an invasive species in North America and Europe. In some regions, they are bred as bird pets. Many different breeds that vary in feather color have been established. Monk parakeet is the only parrot known to build a stick nest. Single nests can be integrated in a large compound nest. In the wild, they form large breeding colonies. The intelligence level of monk parakeets can reach that of a 3–5-year-old child. They have developed complex social and breeding behaviors. The average lifespan of monk parakeets is 25–30 years. This is very long considering the relatively small body size (~29 cm) of the monk parakeet. KINGDOM: Animalia PHYLUM: Chordata CLASS: Aves ORDER: Psittaciformes FAMILY: Psittacidae GENUS: Myiopsitta No interests are declared.