Genomic Reorganization in the Concolor Gibbon (Hylobates concolor) Revealed by Chromosome Painting

Chromosome rearrangements in small apes are up to 20 times more frequent than in most mammals. Because of their complexity, the full extent of chromosome evolution in these hominoids is not yet fully documented. However, previous work with array painting, BAC-FISH, and selective sequencing in two of the four karyomorphs has shown that highresolution methods can precisely define chromosome breakpoints and map the complex flow of evolutionary chromosome rearrangements. Here we use these tools to precisely define the rearrangements that have occurred in the remaining two karyomorphs, genera Symphalangus (2n = 50) and Hoolock (2n = 38). This research provides the most comprehensive insight into the evolutionary origins of chromosome rearrangements involved in transforming small apes genome. Bioinformatics analyses of the human-gibbon synteny breakpoints revealed association with transposable elements and segmental duplications, providing some insight into the mechanisms that might have promoted rearrangements in small apes. In the near future, the comparison of gibbon genome sequences will provide novel insights to test hypotheses concerning the mechanisms of chromosome evolution. The precise definition of synteny block boundaries and orientation, chromosomal fusions, and centromere repositioning events presented here will facilitate genome sequence assembly for these close relatives of humans.

Section: Variant Chromosomes and The Gibbon Radiationmentioning

confidence: 99%

A comprehensive molecular cytogenetic analysis of chromosome rearrangements in gibbons

Capozzi

Carbone²,

Stanyon

et al. 2012

“…The delineation of homologies between chromosomal complements of various primates by use of whole chromosome-specific paints was facilitated by the high degree of molecular homology among primate genomes (Wienberg et al 1994;Koehler et al 1995a,b;Consigliere et al 1996;. Presently, data of comparative chromosome painting with all human chromosomespecific libraries (CSLs) are available for macaque , siamang (Koehler et al 1995a), gibbon Koehler et al 1995b), two subspecies of red howler monkey (Consigliere et al 1996), Capuchin monkey (Richard et al 1996), marmoset (Sherlock et al 1996), silvered leaf monkey , and black-handed spider monkey (Morescalchi et al 1997). Methodological improvements allowed comparative chromosome painting to extend to distantly related species (Zoo-FISH; Scherthan et al 1994).…”

mentioning

confidence: 99%

Emerging Patterns of Comparative Genome Organization in Some Mammalian Species as Revealed by Zoo-FISH

Chowdhary¹,

Raudsepp²,

Frönicke³

et al. 1998

212

143

Although gene maps for a variety of evolutionarily diverged mammalian species have expanded rapidly during the past few years, until recently it has been difficult to precisely define chromosomal segments that are homologous between species. A solution to this problem has come from the development of Zoo-FISH, also known as cross-species chromosome painting. The use of Zoo-FISH to identify regions of chromosomal homology has allowed the transfer of information from map-rich species such as human and mouse to a wide variety of other species. From a Zoo-FISH analysis spanning four mammalian orders (Primates, Artiodactyla, Carnivora, and Perissodactyla), and involving eight species (human, pig, cattle, Indian muntjac, cat, American mink, harbor seal, and horse), three distinct classes of synteny conservation have been designated: (1) conservation of whole chromosome synteny, (2) conservation of large chromosomal blocks, and (3) conservation of neighboring segment combinations. This analysis has also made it possible to identify a set of chromosome segments (based on human chromosome equivalents) that probably made up the karyotype of the common ancestor of the four orders. This approach provides a basis for developing a picture of the ancestral mammalian karyotype, but a full understanding will depend on studies encompassing more diverse combinations of mammalian orders.

“…In situ hybridization techniques, using whole chromosome probes on metaphases from various species (Zoo-FISH) proved to be a good complement, especially for the comparison of these small chromosomal segments. These methods are also particularly adapted to study taxa with highly rearranged chromosomes, such as gibbons Koehler et al 1995;Müller et al 1998) and Muridae (Scalzi and Hozier 1998;Guilly et al 1999), for which chromosome banding failed to propose complete comparisons. They also confirmed the proposed analogies between man and great apes (Dutrillaux 1975;, man and macaques (Muleris et al 1984;Wienberg et al 1992), and man and lemurs (Apiou et al 1996;Mü ller et al 1997).…”

mentioning

confidence: 99%

Phylogenetic Origin of Human Chromosomes 7, 16, and 19 and their Homologs in Placental Mammals

Richard

Lombard²,

Dutrillaux³

2000

The origin of human chromosomes (HSA) 7, 16, and 19 was studied by comparing data obtained from chromosome banding, chromosome painting, and gene mapping in species belonging to 11 orders of placental mammals (Eutherians). This allowed us to propose the reconstruction of their presumed ancestral forms. The HSA7 homologs were composed of two parts, the largest forming an acrocentric. The smallest formed one arm of a small submetacentric; the other arm was composed of sequences homologous to the short arm of HSA16 (HSA16p). The sequences homologous to the long arm of HSA16 (HSA16q) were associated with sequences homologous to the long arm of HSA19 (HSA19q) and formed another submetacentric. From their origin, these chromosomes underwent the following rearrangements to give rise to current human chromosomes: centromeric fission of the two submetacentrics in ancestors of all primates (∼80 million years ago); fusion of the HSA19p and HSA19q sequences, originating the current HSA19, in ancestors of all simians (∼55 million years ago); fusions of the HSA16p and HSA16q sequences, originating the current HSA16 and the two components of HSA7 before the separation of Cercopithecoids and Hominoids (∼35 million years ago); and finally, pericentric and paracentric inversions of the homologs to HSA7 after the divergence of orangutan and gorilla, respectively. Thus, compared with HSA16 and HSA19, HSA7 is a fairly recent chromosome shared by man and chimpanzee only.