Poecile atricapillus Genome sequencing and assembly. Poecile atricapillus

The generation of the black-capped chickadee reference genome, here assembled into pseudo-chromosomes, is part of a study investigating the black-capped chickadee/Carolina chickadee hybrid zone. The higher resolution data that a reference genome provides was important for this study, because it allowed us to identify a higher amount of differentiated single nucleotide polymorphisms (SNPs) between the two hybridizing species. This study focused on potential genomic evidence for the observed low fitness of hybrid individuals in this system, specifically SNPs resistant to introgression across the hybrid zone. Investigation of this chickadee hybrid zone provides an example of genomic incompatibilities in hybrids that may result in deleterious fitness consequences and constrain hybrid zone width and gene flow between the two species.

本研究旨在探究黑顶山雀（black-capped chickadee）与卡罗莱纳山雀（Carolina chickadee）的杂交带，而组装至假染色体（pseudo-chromosomes）水平的黑顶山雀参考基因组（reference genome）的构建，正是该研究的组成部分。参考基因组所提供的高分辨率数据对本研究至关重要，因为其使得我们能够在这两个杂交物种之间鉴定出更多的分化型单核苷酸多态性（single nucleotide polymorphisms, SNPs）。本研究聚焦于该系统中已观测到的杂交个体适合度低下现象的潜在基因组证据，尤其关注在整个杂交带中表现出抗渐渗特性的单核苷酸多态性。对该山雀杂交带的研究可为杂交种中存在的基因组不相容现象提供典型实例——这类不相容性可能会引发有害的适合度后果，并限制杂交带的宽度以及两个物种间的基因流。