Kunchala Srinivasa Reddy, van Dijk Albert, Veldhuizen Edwin J A, Haagsman Henk P, Orgeig Sandra
Clinical and Health Sciences, University of South Australia, Adelaide SA 5000, Australia.
Department of Biomolecular Health Sciences, Faculty of Veterinary Medicine, Utrecht University, Utrecht, The Netherlands.
Philos Trans R Soc Lond B Biol Sci. 2025 Feb 27;380(1920):20230425. doi: 10.1098/rstb.2023.0425.
The common avian origin of many zoonotic infections and epidemics warrants investigation into the mechanism of respiratory surface protection in reservoir species such as birds. Our recent molecular investigations on the evolution and pulmonary expression of an ancient family of proteins, the C-type lectins, have revealed unique molecular adaptations in the surfactant proteins avian SP-A1 (aSP-A1), aSP-A2 and aSP-C coupled with the loss of surfactant protein-D (SP-D) in the avian lineage. As surfactant proteins are members of the collectin family, a subgroup of the C-type lectins, an search for related non-surfactant collectin proteins (Collectin-10 (CL-10) and Collectin-11 (CL-11)) in the NCBI genome database was conducted to understand their evolution in the avian lineage. In addition, both CL-10 and CL-11 gene expression in the lungs and other organs of zebra finches and turkeys was confirmed by PCR. These PCR-confirmed zebra finch and turkey CL-10 and CL-11 sequences were compared with sequenced and -predicted vertebrate homologues to develop a phylogenetic tree. Compared with avian surfactant proteins, CL-10 and CL-11 are highly conserved among vertebrates, suggesting a critical role in development and innate immune protection. The conservation of CL-11 EPN and collagen domain motifs may compensate to some extent for the loss of SP-D in the avian lineage.This article is part of the theme issue 'The biology of the avian respiratory system'.
许多人畜共患感染和流行病的共同鸟类起源，使得有必要对鸟类等宿主物种呼吸道表面保护机制进行研究。我们最近对一个古老蛋白质家族——C型凝集素的进化和肺部表达进行了分子研究，结果显示，在鸟类谱系中，表面活性蛋白禽SP-A1（aSP-A1）、aSP-A2和aSP-C存在独特的分子适应性变化，同时表面活性蛋白-D（SP-D）缺失。由于表面活性蛋白是C型凝集素亚群collectin家族的成员，因此我们在NCBI基因组数据库中搜索了相关的非表面活性collectin蛋白（Collectin-10（CL-10）和Collectin-11（CL-11）），以了解它们在鸟类谱系中的进化情况。此外，通过PCR证实了斑胸草雀和火鸡的肺及其他器官中CL-10和CL-11基因的表达。将这些经PCR证实的斑胸草雀和火鸡的CL-10和CL-11序列与已测序和预测的脊椎动物同源物进行比较，构建了系统发育树。与鸟类表面活性蛋白相比，CL-10和CL-11在脊椎动物中高度保守，这表明它们在发育和先天免疫保护中起关键作用。CL-11的EPN和胶原结构域基序的保守性可能在一定程度上弥补了鸟类谱系中SP-D的缺失。本文是主题为“鸟类呼吸系统生物学”的一部分。
