CpG Islands (Islands < 300 Bases are Light Green) Tracks
短于300bp长度的CpG岛的选项卡
CpG Islands (Islands < 300 Bases are Light Green)
CpG岛： 浅绿色；短于300bp长度。
CpG Islands on All Sequence (Islands < 300 Bases are Light Green)
广义的CpG岛：浅绿色全基因组范围内，不限定为只是启动子区，短于300bp长度。
Deion
选项卡描述
CpG islandsare associated with genes, particularly housekeeping genes, in vertebrates.
CpG岛在脊椎动物与基因相关，尤其是看家基因,。
CpG islands are typically common near tranion start sitesand may be associated withpromoter regions.
转录起始点的CpG岛附近通常是常见和可能与启动子区域。
Normally a C (cytosine) base followed immediately by a G (guanine) base (a CpG) is rare in vertebrate DNA because the Cs in such an arrangement tend to be methylated.
通常一个C(胞嘧啶碱基)跟随G(鸟嘌呤碱基)(CpG)是罕见的在脊椎动物DNA，因为这种安排的Cs往往是甲基化。
This methylation helps distinguish the newly synthesized DNA strand from the parent strand, which aids in the final stages of DNA proofreading after duplication.
However, over evolutionary time, methylated Cs tend to turn into Ts because of spontaneous deamination.
然而，在进化过程中：甲基化C往往变成T因为自发脱氨基作用。
The result is that CpGs are relatively rare unless there is selective pressure to keep them or a region is not methylated for some other reason, perhaps having to do with the regulation of gene expression.
结果是，除非选择压力使他们或一个地区不是甲基化由于一些其他的原因；可能与基因表达的调节有关。
CpG islands are regions where CpGs are present at significantly higher levels than is typical for the genome as a whole.
CpG岛的基因组DNA区域水平显著高于在整个基因组中是很常见的。
The unmasked version of the track displays potential CpG islands that exist in repeat regions and would otherwise not be visible in the repeat masked version.
广义的CpG岛显示潜在的CpG岛要么存在的重复区域，否则就完全不在基因组重复序列区。
By default, only the masked version of the track is displayed. To view the unmasked version, change the visibility settings in the track controls at the top of this page.
默认设置下，只有启动子相关的CpG岛显示。查看广义的CpG岛需要调整设置。
Methods
计算方法
CpG islands were predicted by searching the sequence one base at a time, scoring each dinucleotide (+17 for CG and -1 for others) and identifying maximally scoring segments.
CpG岛预测通过每次搜索一个碱基序列来计分：每二核苷酸(CG + 17分 其他情况-1分)并确定最大得分。
Each segment was then evaluated for the following criteria:
每个片段有以下标准选择标准:
1，GC content of 50% or greater
GC在50%以上或更多
2，length greater than 200 bp
DNA序列长度200bp以上
3 ratio greater than 0.6 of observed number of CG dinucleotides to the expected number on the basis of the number of Gs and Csin the segment
观察值的比值大于0.6， DNA序列中CG观察的数量比上预期的数量。
The entire genome sequence, masking areas included, was used for the construction of the track Unmasked CpG.
整个基因组序列：包括启动子相关的CpG岛，还有另外功能区CpG的发掘。
The track CpG Islands is constructed on the sequence after all masked sequence is removed.
默认CpG岛构造序列 仅仅包含启动子相关的CpG岛。
The CpG count is the number of CG dinucleotides in the island.
CpG岛计数方法是 CG二核苷酸的数量。
The Percentage CpG is the ratio of CpG nucleotide bases (twice the CpG count) to the length.
CpG百分比的比值CpG核苷酸碱基长度(CpG数的两倍)。
The ratio of observed to expected CpG is calculated according to the formula (cited in Gardiner-Garden et al. 1987):
CpG的岛CG观察值比预期值 比例是根据1987年公式来计算的。
Obs/Exp CpG = Number of CpG * N / (Number of C * Number of G)
观察值/ 期望值 CpG = CpG数量* N /(C *数量的G)
where N = length of sequence.
其中：N =序列的长度。
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