解碼牛樟基因體闡明被子植物的演化 Stout camphor tree genome fills gaps in understanding of flowering plant genome evolution

樹沃客 2/09/2025 Add Comment Edit

解碼牛樟基因體闡明被子植物的演化

Stout camphor tree genome fills gaps in understanding of flowering plant genome evolution

a, Schematic representation of the intragenomic relationship among the 637 synteny blocks in the SCT genome. Synteny blocks (denoted by peach blocks) were assigned unambiguously into five linkage clusters representing ancient karyotypes and are colour coded. Purple blocks denote the synteny block assigned in the first linkage group (see also Supplementary Fig. 13). b, Schematic representation of the first linkage group within the SCT genome and their corresponding relationship in A. trichopoda.

a, Number of heterozygous biallelic SNPs per 100-kb non-overlapping windows is plotted along the largest 12 scaffolds. Indels were excluded. b, The history of effective population size was inferred using the PSMC method. One hundred bootstraps were performed and the margins are shown in light red. c, For every non-overlapping 100-kb window, the distribution is shown from top to bottom: gene density (percentage of nucleotides with predicted model), transcriptome (percentage of nucleotides with evidence of transcriptome mapping) and three different classes of repetitive sequences (percentage of nucleotides with transposable element annotation). The red T letter denotes the presence of a telomeric repeat cluster at the scaffold end. LINE, long interspersed nuclear element.

樟樹和牛樟染色體都是 n=12，但牛樟分子證據有發生全基因體複製(Whole genome duplication)，是基因倍體化沒有染色體數量倍增與增加，而是染色體變大不是整倍的，是每條染色體基因量有變多，和一般樟樹比對基因，牛樟有些基因份數是1到4倍。如果生長不好，很多基因是不表現的，看起來會像樟樹。

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