PDF(Pubmed)
Abstract：
When two species hybridize, the two parental genomes are brought together and some alleles might interact for the first time. To date, the extent of the transcriptomic changes in first hybrid generations, along with their functional outcome constitute an important knowledge gap, especially in parasite species. Here we explored the molecular and functional outcomes of hybridization in first-generation hybrids between the blood fluke parasites Schistosoma haematobium and S. bovis. Through a transcriptomic approach, we measured gene expression in both parental species and hybrids. We described and quantified expression profiles encountered in hybrids along with the main biological processes impacted. Up to 7,100 genes fell into a particular hybrid expression profile (intermediate between the parental expression levels, over-expressed, under-expressed, or expressed like one of the parental lines). Most of these genes were different depending on the direction of the parental cross (S. bovis mother and S. haematobium father or the reverse) and depending on the sex. For a given sex and cross direction, the vast majority of genes were hence unassigned to a hybrid expression profile: either they were differentially expressed genes but not typical of any hybrid expression profiles or they were not differentially expressed neither between hybrids and parental lines nor between parental lines. The most prevalent profile of gene expression in hybrids was the intermediate one (24% of investigated genes). These results suggest that transcriptomic compatibility between S. haematobium and S. bovis remains quite high. We also found support for an over-dominance model (over- and under-expressed genes in hybrids compared to parental lines) potentially associated with heterosis. In females in particular, processes such as reproductive processes, metabolism and cell interactions as well as signaling pathways were indeed affected. Our study hence provides new insight on the biology of Schistosoma hybrids with evidences supporting compatibility and heterosis.
摘要：
当两个物种杂交时，这两个亲本基因组被汇集在一起，一些等位基因可能是第一次相互作用。迄今为止,第一代杂种中转录组变化的程度，随着他们的功能结果构成了一个重要的知识差距，尤其是在寄生虫物种中。在这里，我们探索了血吸虫寄生虫血吸虫和牛血吸虫的第一代杂交的分子和功能结果。通过转录组学方法，我们测量了亲本物种和杂种的基因表达。我们描述并量化了杂种中遇到的表达谱以及受影响的主要生物学过程。多达7,100个基因落入特定的杂种表达谱（介于亲本表达水平之间，过度表达,表达不足，或表达为父系之一)。根据亲本杂交的方向，这些基因中的大多数都不同(S.牛母亲和S.hematobium父亲或相反），并取决于性别。对于给定的性别和交叉方向，因此，绝大多数基因未分配给杂种表达谱：它们要么是差异表达的基因，但不是任何杂种表达谱的典型特征，要么在杂种和亲本系之间以及亲本系之间都没有差异表达。杂种中最普遍的基因表达谱是中间基因（24％的基因分配给杂种表达谱）。这些结果表明,血链球菌和牛链球菌之间的转录组相容性仍然相当高。我们还发现了可能与杂种优势相关的过度优势模型（与亲本系相比，杂种中的基因过度表达和表达不足）的支持。尤其是女性，生殖过程等过程，代谢和细胞相互作用以及信号通路确实受到影响。因此，我们的研究为血吸虫杂种的生物学提供了新的见解，并有证据支持相容性和杂种优势。
