Comparison of the Chromosome Structures between the Chicken and Three Anserid Species, the Domestic Duck (<i>Anas platyrhynchos</i>), Muscovy Duck (<i>Cairina moschata</i>), and Chinese Goose (<i>Anser cygnoides</i>), and the Delineation of their Karyotype Evolution by Comparative Chromosome Mapping

Abstract

To better understand the process of karyotype evolution in Galloanserae (Galliformes and Anseriformes), we performed comparative chromosome painting with chicken chromosome-specific DNA probes and FISH mapping of the 18S-28S ribosomal RNA (rRNA) genes, telomeric (TTAGGG)n repeats, and cDNA clones of 37 genes for three anserid species, the domestic duck (Anas platyrhynchos), Muscovy duck (Cairina moschata), and Chinese goose (Anser cygnoides). Each chicken probe of chromosomes 1-9 and the Z chromosome painted a single pair of chromosomes in the three species except for the chromosome 4 probe, which painted acrocentric chromosome 4 and a pair of microchromosomes. The 18S-28S rRNA genes were localized to four pairs of microchromosomes in the domestic duck and Muscovy duck, and eight pairs of microchromosomes in the Chinese goose. The (TTAGGG)n repeats were localized to both telomeric ends of all chromosomes in the three species, and were additionally located in the interstitial region of the short arm of chromosome 1 in the domestic duck and in the centromeric region of chromosome 1 in the Muscovy duck. Comparative gene mapping of 37 chicken chromosome 1-4-linked and Zlinked genes revealed high chromosome homologies among three anserid species and also between the chicken and the three anserid species, although there were several chromosome rearrangements: pericentric inversion in chromosome 2, pericentric and paracentric inversions or centromere repositioning in the Z chromosome between the chicken and the anserid species, and pericentric inversions in chromosome 4 and the Z chromosome between the Chinese goose and the two duck species. These results collectively suggest that karyotypes have been highly conserved in Anseriformes and that chromosome rearrangements also occurred less frequently between Galliformes and Anseriformes after they diverged around 100 million years ago.

Comparative Cytogenetics between Two Important Songbird, Models: The Zebra Finch and the Canary

“…For instance, in birds, information on the number and distribution of 18/28S is available for a limited number of species, usually using the Ag-NOR technique. In most of these 18/28S rDNA clusters are found on only one pair, usually a microchromosome, although there are already well documented variations [ 36 – 39 ]. For Passeriformes, most species analyzed show only one pair of microchromosomes bearing 18/28S rDNA [ 22 , 40 ], such as we found in zebra finch and canary.…”

Recent speciation and elevated Z‐chromosome differentiation between sexually monochromatic and dichromatic species of Australian teals

“…The three loci with the highest differentiation (BRIX1, ADAMTS6, and BRM) are clustered within this region in the chicken genome. Given that gene order on the Z‐chromosome is fairly conserved between chickens and ducks (Skinner et al , Islam et al ), these loci are also likely clustered in the duck genome. Although we did not detect strong linkage disequilibrium among loci contained with this region, which is a feature of islands of differentiation (Hohenlohe et al , Ellegren et al ), this region might have had an important role in the evolution of Australian teals.…”

“…We mapped the chromosomal positions of Z‐loci by aligning scaffolds from the duck genome to the chicken Z using Narcisse Release 2.3.2‐duck‐20100216Beta (Courcelle et al ). The approximate location of the centromere was identified by comparing this physical map to published maps from the mallard Anas platyrhynchos and the muscovy duck Cairina moschata (Skinner et al , Islam et al ).…”

Chromosomal studies onCoscoroba coscoroba(Aves: Anseriformes) reinforce theCoscoroba-Cereopsisclade

“…The correspondence of GGA4 to two different pairs has been found in most species of bird, and is considered as an ancestral state, whereas the fusion of these two elements in some species not phylogenetically related possibly represents a homoplasy, which needs further investigation (Griffin et al ., ). Hence, despite the different diploid number, Coscoroba shares morphology and synteny of macrochromosomes with other Anseriformes (Guttenbach et al., ; Islam et al ., ), suggesting that diploid number variation is a result of rearrangements involving only the microchromosomes. This view is consistent with the model of microchromosome formation by chromosome fission proposed by Burt (), with most (if not all) chicken microchromosomes representing ancestral syntenies.…”