Breukelman H J, van der Munnik N, Kleineidam R G, Furia A, Beintema J J
Department of Biochemistry, University of Groningen, Nijenborgh 4, 9747 AG, Groningen, The Netherlands.
Gene. 1998 Jun 8;212(2):259-68. doi: 10.1016/s0378-1119(98)00177-2.
Mammalian pancreatic ribonucleases (RNase) form a family of extensively studied homologous proteins. Phylogenetic analyses, based on the primary structures of these enzymes, indicated that the presence of three homologous enzymes (pancreatic, seminal and brain ribonucleases) in the bovine species is due to gene duplication events, which occurred during the evolution of ancestral ruminants. In this paper the sequences are reported of the coding regions of the orthologues of the three bovine secretory ribonucleases in hog deer and roe deer, two deer species belonging to two different subfamilies of the family Cervidae. The sequences of the 3' untranslated regions of the three different secretory RNase genes of these two deer species and giraffe are also presented. Comparison of these and previously determined sequences of ruminant ribonucleases showed that the brain-type enzymes of giraffe and these deer species exhibit variations in their C-terminal extensions. The seminal-type genes of giraffe, hog deer and roe deer show all the features of pseudogenes. Phylogenetic analyses, based on the complete coding regions and parts of the 3' untranslated regions of the three different secretory ribonuclease genes of ox, sheep, giraffe and the two deer species, show that pancreatic, seminal- and brain-type RNases form three separate groups.
哺乳动物的胰腺核糖核酸酶（RNase）构成了一类经过广泛研究的同源蛋白质家族。基于这些酶的一级结构进行的系统发育分析表明，牛物种中三种同源酶（胰腺、精液和脑核糖核酸酶）的存在是由于基因复制事件，这些事件发生在反刍动物祖先的进化过程中。本文报道了豚鹿和狍这两种属于鹿科两个不同亚科的鹿种中三种牛分泌型核糖核酸酶直系同源物编码区的序列。还给出了这两种鹿种和长颈鹿三种不同分泌型核糖核酸酶基因3'非翻译区的序列。对这些序列以及先前确定的反刍动物核糖核酸酶序列的比较表明，长颈鹿和这些鹿种的脑型酶在其C末端延伸区域存在差异。长颈鹿、豚鹿和狍的精液型基因表现出假基因的所有特征。基于牛、绵羊、长颈鹿以及这两种鹿种三种不同分泌型核糖核酸酶基因的完整编码区和部分3'非翻译区进行的系统发育分析表明，胰腺型、精液型和脑型核糖核酸酶形成了三个独立的组。
