首页 > 分享 > 向日葵驯化过程中可变剪接进化的遗传学研究。

向日葵驯化过程中可变剪接进化的遗传学研究。

花匠小妙招
2025-10-27 05:19

Abstract

Alternative splicing enables organisms to produce the diversity of proteins necessary for multicellular life by using relatively few protein-coding genes. Although differences in splicing have been identified among divergent taxa, the shorter-term evolution of splicing is understudied. The origins of novel splice forms, and the contributions of alternative splicing to major evolutionary transitions, are largely unknown. This study used transcriptomes of wild and domesticated sunflowers to examine splice differentiation and regulation during domestication. We identified substantial splicing divergence between wild and domesticated sunflowers, mainly in the form of intron retention. Transcripts with divergent splicing were enriched for seed-development functions, suggesting that artificial selection impacted splicing patterns. Mapping of quantitative trait loci (QTLs) associated with 144 differential splicing cases revealed primarily -acting variation affecting splicing patterns. A large proportion of identified QTLs contain known spliceosome proteins and are associated with splicing variation in multiple genes. Examining a broader set of wild and domesticated sunflower genotypes revealed that most differential splicing patterns in domesticated sunflowers likely arose from standing variation in wild and gained frequency during the domestication process. However, several domesticate-associated splicing patterns appear to be introgressed from other species. These results suggest that sunflower domestication involved selection on pleiotropic regulatory alleles. More generally, our findings indicate that substantial differences in isoform abundances arose rapidly during a recent evolutionary transition and appear to contribute to adaptation and population divergence.

摘要

可变剪接使生物体能够利用相对较少的蛋白质编码基因产生多细胞生命所需的蛋白质多样性。尽管在不同分类群中已经鉴定出剪接的差异，但剪接的短期进化仍研究不足。新剪接形式的起源以及可变剪接对主要进化转变的贡献在很大程度上是未知的。本研究使用野生和栽培向日葵的转录组来研究驯化过程中可变剪接的分化和调控。我们鉴定了野生和栽培向日葵之间大量的剪接分化，主要形式是内含子保留。具有不同剪接的转录本富集了种子发育功能，表明人工选择影响了剪接模式。与 144 个差异剪接案例相关的数量性状位点 (QTL) 的映射显示，主要是 - 作用变异影响剪接模式。鉴定出的大量 QTL 包含已知的剪接体蛋白，并与多个基因的剪接变异相关。检查更广泛的野生和栽培向日葵基因型表明，栽培向日葵中的大多数差异剪接模式可能源于野生的固定变异，并在驯化过程中获得了频率。然而，几种与驯化相关的剪接模式似乎是从其他物种渗入的。这些结果表明，向日葵的驯化涉及对多效调节等位基因的选择。更一般地说，我们的发现表明，在最近的进化转变中，异构体丰度的显著差异迅速出现，并且似乎有助于适应和种群分化。