Friesen V L, Montevecchi W A, Davidson W S
Department of Biology, Memorial University of Newfoundland, St. John's, Canada.
Hereditas. 1993;119(3):245-52. doi: 10.1111/j.1601-5223.1993.00245.x.
Analysis of cytochrome b nucleotide sequences of the six extant species of Atlantic alcids and a gull revealed an excess of adenines and cytosines and a deficit of guanines at silent sites on the coding strand. Phylogenetic analyses grouped the sequences of the common (Uria aalge) and Brünnich's (U. lomvia) guillemots, followed by the razorbill (Alca torda) and little auk (Alle alle). The black guillemot (Cepphus grylle) sequence formed a sister taxon, and the puffin (Fratercula arctica) fell outside the other alcids. Phylogenetic comparisons of substitutions indicated that mutabilities of bases did not differ, but that C was much more likely to be incorporated than was G. Imbalances in base composition appear to result from a strand bias in replication errors, which may result from selection on secondary RNA structure and/or the energetics of codon-anticodon interactions.
对六种现存的大西洋海雀和一种鸥的细胞色素b核苷酸序列分析显示，编码链上沉默位点处腺嘌呤和胞嘧啶过量，鸟嘌呤不足。系统发育分析将普通海鸠（海鸠属）和厚嘴海鸠（厚嘴海鸠属）的序列归为一组，其次是刀嘴海雀和小海雀。黑海鸠序列形成一个姐妹分类单元，角嘴海雀则处于其他海雀之外。替换的系统发育比较表明，碱基的突变率没有差异，但胞嘧啶比鸟嘌呤更易被整合。碱基组成的不平衡似乎源于复制错误中的链偏好，这可能是由对二级RNA结构的选择和/或密码子-反密码子相互作用的能量学导致的。
