Abstract

Linker histone H1 (LHH1) is an abundant nuclear protein that condenses chromatin to form higher-order structure. The present study reported cloning and sequencing of 942 bp of LHH1 from liver tissue of rohu, Labeo rohita, with a complete coding sequence of 792 bp of having 263 amino acids. The phylogenetic tree of L. rohita LHH1 (LrLHH1) shared maximum similarity with that of Carassius auratus. The three dimensional model and domain architecture of LrLHH1 protein was also predicted using Swiss-Prot and SMART domain software. The expression of LHH1 during ontogeny showed significantly higher transcript level in milt, unfertilized eggs and up to 3 h post–fertilization followed by a dramatic decrease thereafter. The tissue-specific expression showed constitutive expression of LrLHH1 in all examined tissues. The expression of LHH1 during different infection models, namely, bacteria (Aeromonas hydrophila); ectoparasite (Argulus siamensis) and poly I:C induction revealed modulation in the level of expression at varied time points post-exposure in the liver and anterior kidney tissues of rohu. However, a synthetic peptide derived from LHH1 sequence of rohu did not have any detectable antibacterial activity. The present study provided necessary information on the role of this protein during ontogeny and innate immunity in Indian major carp species.

摘要

接头组蛋白 H1 (LHH1) 是一种丰富的核蛋白，可将染色质浓缩形成高级结构。本研究报道了从野兔（Labeo rohita）的肝组织中克隆并测序了942 bp的LHH1，完整的编码序列为792 bp，有263个氨基酸。L. rohita LHH1 ( Lr LHH1)的系统发育树与鲫鱼具有最大的相似性。Lr的三维模型和领域架构还使用 Swiss-Prot 和 SMART 域软件预测了 LHH1 蛋白。LHH1 在个体发育过程中的表达在精液、未受精卵和受精后 3 小时内表现出显着更高的转录水平，随后显着下降。组织特异性表达在所有检查的组织中显示Lr LHH1 的组成型表达。LHH1在不同感染模型中的表达，即细菌（嗜水气单胞菌）；体外寄生虫（Argulus siamensis）) 和 poly I:C 诱导揭示了在暴露后不同时间点在野胡的肝脏和前肾组织中表达水平的调节。然而，一种来源于罗胡 LHH1 序列的合成肽没有任何可检测的抗菌活性。本研究提供了关于这种蛋白质在印度主要鲤鱼物种个体发育和先天免疫过程中的作用的必要信息。