Background Nucleotide excision repair is the primary DNA repair mechanism that removes bulky DNA adducts such as UV-induced pyrimidine dimers. Correspondingly, genome-wide mapping of nucleotide excision repair with eXcision Repair sequencing (XR-seq), provides comprehensive profiling of DNA damage repair. A number of XR-seq experiments at a variety of conditions for different damage types revealed heterogenous repair in the human genome. Although human repair profiles were extensively studied, how repair maps vary between primates is yet to be investigated. Here, we characterized the genome-wide UV-induced damage repair in gray mouse lemur, Microcebus murinus, in comparison to human. Results We derived fibroblast cell lines from mouse lemur, exposed them to UV irradiation, and analyzed the repair events genome-wide using the XR-seq protocol. Mouse lemur repair profiles were analyzed in comparison to the equivalent human fibroblast datasets. We found that overall UV sensitivity, repair efficiency, and transcription-coupled repair levels differ between the two primates. Despite this, comparative analysis of human and mouse lemur fibroblasts revealed that genome-wide repair profiles of the homologous regions are highly correlated, and this correlation is stronger for highly expressed genes. With the inclusion of an additional XR-seq sample derived from another human cell line in the analysis, we found that fibroblasts of the two primates repair UV-induced DNA lesions in a more similar pattern than two distinct human cell lines do. Conclusion Our results suggest that mouse lemurs and humans, and possibly primates in general, share a homologous repair mechanism as well as genomic variance distribution, albeit with their variable repair efficiency. This result also emphasizes the deep homologies of individual tissue types across the eukaryotic phylogeny.

The BTB domain is an oligomerization domain found in over 300 proteins encoded in the human genome. In the family of BTB domain and zinc finger–containing (ZBTB) transcription factors, 49 members share the same protein architecture. The N-terminal BTB domain is structurally conserved among the family members and serves as the dimerization site, whereas the C-terminal zinc finger motifs mediate DNA binding. The available BTB domain structures from this family reveal a natural inclination for homodimerization. In this study, we investigated the potential for heterodimer formation in the cellular environment. We selected five BTB homodimers and four heterodimer structures. We performed cell-based binding assays with fluorescent protein–BTB domain fusions to assess dimer formation. We tested the binding of several BTB pairs, and we were able to confirm the heterodimeric physical interaction between the BTB domains of PATZ1 and PATZ2, previously reported only in an interactome mapping experiment. We also found this pair to be co-expressed in several immune system cell types. Finally, we used the available structures of BTB domain dimers and newly constructed models in extended molecular dynamics simulations (500 ns) to understand the energetic determinants of homo- and heterodimer formation. We conclude that heterodimer formation, although frequently described as less preferred than homodimers, is a possible mechanism to increase the combinatorial specificity of this transcription factor family.

Sequence content is heterogeneous throughout genomes. Therefore, Genome-wide NGS reads biased towards specific nucleotide profiles are affected by the genome-wide heterogeneous nucleotide distribution. Boquila generates sequences that mimic the nucleotide profile of true reads, which can be used to correct the nucleotide-based bias of genome-wide distribution of NGS reads. Boquila can be configured to generate reads from only specified regions of the reference genome. It also allows the use of input DNA sequencing to correct the bias due to the copy number variations in the genome. Boquila uses standard file formats for input and output data, and it can be easily integrated into any workflow for high-throughput sequencing applications.

Nucleotide excision repair is the primary DNA repair mechanism that removes bulky DNA adducts such as UV-induced pyrimidine dimers. Correspondingly, genome-wide mapping of nucleotide excision repair with eXcision Repair sequencing (XR-seq), provides comprehensive pro ling of DNA damage repair. A number of XR-seq experiments at a variety of conditions for di erent damage types revealed heterogenous repair in the human genome. Although human repair pro les were extensively studied, how repair maps vary between primates is yet to be investigated. Here, we characterized the genome-wide UV-induced damage repair in gray mouse lemur,Microcebus murinus, in comparison to human. Mouse lemurs are strictly nocturnal, are the world's smallest living primates, and last shared a common ancestor with humans at least 60 million years ago. We derived broblast cell lines from mouse lemur, exposed them to UV irradiation. The following repair events were captured genome-wide through the XR-seq protocol. Mouse lemur repair pro les were analyzed in comparison to the equivalent human broblast datasets. We found that overall UV sensitivity, repair e ciency, and transcription-coupled repair levels di er between the two primates. Despite this, comparative analysis of human and mouse lemur broblasts revealed that genome-wide repair pro les of the homologous regions are highly correlated. This correlation is stronger for the highly expressed genes. With the inclusion of an additional XR-seq sample derived from another human cell line in the analysis, we found that broblasts of the two primates repair UV-induced DNA lesions in a more similar pattern than two distinct human cell lines do. Our results suggest that mouse lemurs and humans, and possibly primates in general, share a homologous repair mechanism as well as genomic variance distribution, albeit with their variable repair e ciency. This result also emphasizes the deep homologies of individual tissue types across the eukaryotic phylogeny.

Sequence content is heterogeneous throughout genomes. Therefore, genome-wide next-generation sequencing (NGS) reads biased towards specific nucleotide profiles are affected by the genome-wide heterogeneous nucleotide distribution. Boquila generates sequences that mimic the nucleotide profile of true reads, which can be used to correct the nucleotide-based bias of genome-wide distribution of NGS reads. Boquila can be configured to generate reads from only specified regions of the reference genome. It also allows the use of input DNA sequencing to correct the bias due to the copy number variations in the genome. Boquila uses standard file formats for input and output data, and it can be easily integrated into any workflow for high-throughput sequencing applications.