Gene regulatory divergence underlies tissue-specific and sex-specific misexpression in hybrids of C. remanei and C. latens nematodes
Athmaja Viswanath
Email: [email protected]
Gene regulatory divergence has emerged as a key feature in speciation, influencing gene expression differences within and between species. Transcriptional regulation, mediated by cis- and trans-acting factors, modulates developmental processes and maintains species-specific distinctions in gene expression. Within individuals containing an inter-species hybrid genome, negative interactions between divergent regulatory elements can lead to gene misexpression and contribute to hybrid dysfunction at the organismal level. Gene regulatory changes can also impact sex-biased and tissue-biased gene regulatory networks due to unique selective pressures experienced by such genes. Despite extensive research on regulatory divergence and hybrid misexpression, establishing the relationship between gene misregulation and hybrid incompatibility remains difficult. Importantly, however, comparing hybrids from reciprocal crosses with asymmetric hybrid incompatibility can reveal gene regulatory patterns associated with cross-specific dysfunction. I investigated the role of regulatory divergence in asymmetric hybrid incompatibility between C. remanei and C. latens. Despite severe hybrid male sterility, hybrid males showed less misexpression of sex-biased genes than hybrid females, in both reciprocal crosses, suggesting that the outputs of male-biased gene regulatory networks are more vulnerable to disruptions than female-biased genetic networks. Additionally, I found cis-only divergence to be more common than trans-only divergence, supporting the notion that cis-only divergence plays a larger role in gene expression differences between species. Moreover, male-specific cis-trans compensatory divergence is widespread, especially for X-linked genes, indicating distinct molecular evolutionary outcomes of stabilizing selection on regulatory controls between males and females. Through this work, I generated the most comprehensive transcriptomic dataset for C. remanei and C. latens to date, uncovered insights on asymmetric misexpression and identified candidate genes contributing to reproductive isolation.
On-going analysis for C. remanei and C. latens datasets focused on regulatory divergence and hybrid incompatibility
- Input data files currently not made available
- Contains scripts for Differential Gene Expression Analysis and Allele Specific Expression Analysis
- Scripts are part of on-going analyses and are subject to change
- Contains all the generated figures and additional files resulting from the analyses