Laboratorio de Genética Acuícola, Departamento de Biología Funcional, Universidad de Oviedo, IUBA, 33071 Oviedo, Spain.
Fish Shellfish Immunol. 2011 Oct;31(4):548-56. doi: 10.1016/j.fsi.2011.07.003. Epub 2011 Jul 20.
Transferrin (Tf) is a multi-function protein with a central role in iron metabolism, and it is this function that is associated with a role in the innate immune system response. The clear link between Tf and immune defense mechanism lead to propose Tf as a candidate gene for disease resistance. In this study, genomic and cDNA sequences of Tf gene in gilthead seabream (Sparus aurata L.) (SaTf gene), were identified and characterized. SaTf gene structure consists of a coding region of 2076 nucleotides divided into 17 exons and a no-coding region that includes 16 introns and spans 5495 nucleotides. The deduced Tf protein for gilthead seabream is composed of 691 amino acids and consists of an initial peptide and two lobes (N- and C-lobes). This gene structure is similar to that of previously described Tf genes in other fish species. RT-PCR analyses carried out in different tissues and two developmental stages showed tissue-and stage-specific Tf expression in gilthead seabream. Finally, by sequencing the transferrin genomic sequences of 20 unrelated seabreams, 31 SNPs were identified. These data allowed the estimation of the frequency of nucleotide substitution in the SaTf gene as 1SNP per 253 bp. SNPs were detected in different regions of the genomic sequence but they were mainly localized in non-coding regions, specifically, SNP frequency in non-coding regions was fifteen-fold higher than within coding regions.
转铁蛋白（Tf）是一种多功能蛋白，在铁代谢中起核心作用，正是这种功能与先天免疫系统反应有关。Tf 与免疫防御机制之间的明确联系导致人们提出 Tf 是抗病候选基因。在这项研究中，鉴定并表征了真鲷（Sparus aurata L.）（SaTf 基因）的 Tf 基因的基因组和 cDNA 序列。SaTf 基因结构由 2076 个核苷酸的编码区组成，分为 17 个外显子和一个非编码区，包含 16 个内含子，跨越 5495 个核苷酸。真鲷的 Tf 蛋白由 691 个氨基酸组成，由初始肽和两个叶（N-和 C-叶）组成。这种基因结构类似于其他鱼类中描述的 Tf 基因。在不同组织和两个发育阶段进行的 RT-PCR 分析表明，真鲷的 Tf 表达具有组织和阶段特异性。最后，通过对 20 条无关真鲷的转铁蛋白基因组序列进行测序，鉴定出 31 个 SNP。这些数据允许估计 SaTf 基因中核苷酸取代的频率为 1SNP 每 253bp。SNP 检测到在基因组序列的不同区域，但它们主要定位于非编码区域，特别是 SNP 频率在非编码区域比编码区域高十五倍。
