近日，德国马克斯-普朗克分子细胞生物学和遗传学研究所Michael Hiller及其研究小组发现，一种葡萄糖异生肌肉酶的丧失有助于蜂鸟适应性代谢特征的形成。相关论文于2023年1月13日发表于国际学术期刊《科学》。

研究人员生成了一个长尾隐蜂鸟染色体水平的基因组组合，并筛选出在蜂鸟祖先血统中已经被特异性失活的基因。研究人员发现，编码葡萄糖异生肌肉酶的FBP2（果糖-二磷酸酶2）在盘旋飞行演化的时间段内丢失。结果表明，FBP2在禽类肌肉细胞系中被敲除后，可以上调糖酵解，增强线粒体呼吸，这与线粒体数量增加相吻合。此外，参与线粒体呼吸和组织的基因在蜂鸟飞行肌中的表达也有所上升。这些结果表明，FBP2的丧失可能是真正悬停飞行所需的代谢性肌肉适应性演化中的一个关键步骤。

据介绍，蜂鸟拥有独特的代谢适应性，从而促进其能量需求的盘旋飞行，但其背后的基因组变化在很大程度上是未知的。

附：英文原文

Title: Loss of a gluconeogenic muscle enzyme contributed to adaptive metabolic traits in hummingbirds

Author: Ekaterina Osipova, Rico Barsacchi, Tom Brown, Keren Sadanandan, Andrea H. Gaede, Amanda Monte, Julia Jarrells, Claudia Moebius, Martin Pippel, Douglas L. Altshuler, Sylke Winkler, Marc Bickle, Maude W. Baldwin, Michael Hiller

Issue&Volume: 2023-01-13

Abstract: Hummingbirds possess distinct metabolic adaptations to fuel their energy-demanding hovering flight, but the underlying genomic changes are largely unknown. Here, we generated a chromosome-level genome assembly of the long-tailed hermit and screened for genes that have been specifically inactivated in the ancestral hummingbird lineage. We discovered that FBP2 (fructose-bisphosphatase 2), which encodes a gluconeogenic muscle enzyme, was lost during a time period when hovering flight evolved. We show that FBP2 knockdown in an avian muscle cell line up-regulates glycolysis and enhances mitochondrial respiration, coincident with an increased mitochondria number. Furthermore, genes involved in mitochondrial respiration and organization have up-regulated expression in hummingbird flight muscle. Together, these results suggest that FBP2 loss was likely a key step in the evolution of metabolic muscle adaptations required for true hovering flight.

DOI: abn7050

Source: https://www.science.org/doi/10.1126/science.abn7050