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Updated: May 14, 2026

Dissection and Downstream Analysis of Zebra Finch Embryos at Early Stages of Development
Published on: June 21, 2014
Evidence from a house finch (Haemorhous mexicanus) spleen transcriptome for adaptive evolution and biased gene
Niclas Backström1, Qu Zhang, Scott V Edwards
1Department of Organismic and Evolutionary Biology, Museum of Comparative Zoology, Harvard University. niclas.backstrom@ebc.uu.se
Abstract:
Identifying genes influenced by natural selection can provide information about lineage-specific adaptations, and transcriptomes generated by next-generation sequencing are a useful resource for identifying such genes. Here, we utilize a spleen transcriptome for the house finch (Haemorhous mexicanus), an emerging model for sexual selection and disease ecology, together with previously sequenced avian genomes (chicken, turkey, and zebra finch), to investigate lineage-specific adaptations within birds. An analysis of 4,398 orthologous genes revealed a significantly higher ratio of nonsynonymous to synonymous substitutions and significantly higher GC content in passerines than in galliforms, an observation deviating from strictly neutral expectations but consistent with an effect of biased gene conversion on the evolutionary rate in passerines. These data also showed that genes exhibiting signs of positive selection and fast evolution in passerines have functional roles related to fat metabolism, neurodevelopment, and ion binding.
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