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+[[!meta title="The amphioxus genome and the evolution of the chordate karyotype."]]
+[[!tag chromosome synteny]]
+
+Putnam NH, Butts T, Ferrier DE, Furlong RF, Hellsten U, Kawashima T,
+Robinson-Rechavi M, Shoguchi E, Terry A, Yu JK, Benito-Gutiérrez EL, Dubchak I,
+Garcia-Fernàndez J, Gibson-Brown JJ, Grigoriev IV, Horton AC, de Jong PJ, Jurka
+J, Kapitonov VV, Kohara Y, Kuroki Y, Lindquist E, Lucas S, Osoegawa K,
+Pennacchio LA, Salamov AA, Satou Y, Sauka-Spengler T, Schmutz J, Shin-I T,
+Toyoda A, Bronner-Fraser M, Fujiyama A, Holland LZ, Holland PW, Satoh N, Rokhsar
+DS.
+
+Nature. 2008 Jun 19;453(7198):1064-71. doi:10.1038/nature06967
+
+The amphioxus genome and the evolution of the chordate karyotype.
+
+[[!pmid 18563158 desc="17 ancestral chordate chromosomes."]]
+
+“We estimate that the haploid amphioxus genome contains 21,900 protein-coding loci. [...] The observed heterozygosity shows correlations at short distances that decay on scales greater than ∼1 kb, indicating extensive recombination in the population. [...] Wwe reconstructed the gene complements of 17 linkage groups (that is, proto-chromosomes) of the last common chordate ancestor. [...] This analysis shows that most of the human genome (112 segments spanning 2.68 Gb, or 95% of the euchromatic genome) was affected by large-scale duplication events on the vertebrate stem before the bony vertebrate radiation (that is, the teleost/tetrapod split), and that nearly all of the ancient chordate chromosomes were quadruplicated. [...] Allowing for a range of nearly parsimonious reconstructions of 2R, we estimate that the bony vertebrate ancestor had between 37 and 49 chromosomes.”
distribution follows a power law and explain it with a model that requires
breakpoints to be in open regions (ENCODE) interacting with each other (Hi-C).
+The ancestral chordate has 17 chromosomes according to [[Putnam and coll, 2008|biblio/18563158]].
+
The ancestral amniote has 49 chromosomes according to [[Sacerdot and coll., 2018|biblio/30333059]].
[[Renschler and coll. (2019)|biblio/31601616]] found 20 synteny breakpoints