Chromosome size in diploid eukaryotic species centers on the average length with a conserved boundary.
Understanding genome and chromosome evolution is important for understanding genetic inheritance and evolution. Universal events comprising DNA replication, transcription, repair, mobile genetic element transposition, chromosome rearrangements, mitosis, and meiosis underlie inheritance and variation of living organisms. Although the genome of a species as a whole is important, chromosomes are the basic units subjected to genetic events that coin evolution to a large extent. Now many complete genome sequences are available, we can address evolution and variation of individual chromosomes across species. For example, "How are the repeat and nonrepeat proportions of genetic codes distributed among different chromosomes in a multichromosome species?" "Is there a general rule behind the intuitive observation that chromosome lengths tend to be similar in a species, and if so, can we generalize any findings in chromosome content and size across different taxonomic groups?" Here, we show that chromosomes within a species do not show dramatic fluctuation in their content of mobile genetic elements as the proliferation of these elements increases from unicellular eukaryotes to vertebrates. Furthermore, we demonstrate that, notwithstanding the remarkable plasticity, there is an upper limit to chromosome-size variation in diploid eukaryotes with linear chromosomes. Strikingly, variation in chromosome size for 886 chromosomes in 68 eukaryotic genomes (including 22 human autosomes) can be viably captured by a single model, which predicts that the vast majority of the chromosomes in a species are expected to have a base pair length between 0.4035 and 1.8626 times the average chromosome length. This conserved boundary of chromosome-size variation, which prevails across a wide taxonomic range with few exceptions, indicates that cellular, molecular, and evolutionary mechanisms, possibly together, confine the chromosome lengths around a species-specific average chromosome length.
Department of Agronomy, Kansas State University, KS, USA.
Xianran
X
Li
Chengsong
C
Zhu
Zhongwei
Z
Lin
Yun
Y
Wu
Dabao
D
Zhang
Guihua
G
Bai
Weixing
W
Song
Jianxin
J
Ma
Gary J
GJ
Muehlbauer
Michael J
MJ
Scanlon
Min
M
Zhang
Jianming
J
Yu
D000465:Algorithms; D000818:Animals; D002875:Chromosomes / Q000235:genetics*; D003198:Computer Simulation; D004171:Diploidy; D056890:Eukaryota / Q000235:genetics*; D019143:Evolution, Molecular; D016678:Genome / Q000235:genetics; D006801:Humans; D008957:Models, Genetic; D015233:Models, Statistical; D012091:Repetitive Sequences, Nucleic Acid / Q000235:genetics; D014178:Translocation, Genetic / Q000235:genetics
Cell. 1997 Feb 21;88(4):515-20
9038342
Nat Rev Genet. 2005 Nov;6(11):805-14
16304596
Cytogenet Cell Genet. 2001;93(3-4):175-81
11528109
J Cell Biol. 1965 Apr;25:SUPPL:119-35
14342826
Nat Rev Genet. 2010 Mar;11(3):175-80
20051985
Heredity (Edinb). 2005 Aug;95(2):118-28
15931241
Genome Res. 2007 May;17(5):594-601
17420184
Nature. 2000 Sep 7;407(6800):41-7
10993066
Science. 2001 Aug 10;293(5532):1098-102
11498581
Nature. 2001 Feb 15;409(6822):860-921
11237011
Cytogenet Genome Res. 2002;98(1):101-7
12584450
Proc Natl Acad Sci U S A. 2008 Sep 23;105(38):14254-61
18787111
Chromosoma. 2006 Aug;115(4):311-9
16607510
Curr Biol. 2005 Feb 22;15(4):R129-31
15723783
J Comput Biol. 2006 Mar;13(2):554-66
16597256
Nat Cell Biol. 2009 Jan;11(1):27-35
19060894
Evolution. 2010 Jul;64(7):2097-109
20148953
Curr Opin Plant Biol. 2007 Apr;10(2):109-15
17289425
Nat Rev Genet. 2010 Jan;11(1):31-46
19997069
Chromosome Res. 2002;10(8):707-15
12575798
J Theor Biol. 2001 Jun 21;210(4):475-97
11403567
Proc Natl Acad Sci U S A. 2006 Apr 4;103(14):5349-54
16567616
Genome Res. 1996 Jan;6(1):1-9
8681133
Nature. 2005 Sep 1;437(7055):69-87
16136131
Mol Cells. 2000 Dec 31;10(6):619-25
11211865
Curr Biol. 2009 Dec 1;19(22):1937-42
19879145
Proc Natl Acad Sci U S A. 2005 Mar 22;102(12):4353-8
15767580
Science. 1992 Apr 10;256(5054):228-32
1566070
Science. 2003 Nov 21;302(5649):1401-4
14631042
Cell. 2007 Feb 23;128(4):787-800
17320514
Nat Rev Genet. 2009 Oct;10(10):725-32
19652647
Heredity (Edinb). 2010 Jun;104(6):520-33
19935826