Sessions Stanley K, Larson Allan
Museum of Vertebrate Zoology, University of California, Berkeley, CA, 94720.
Department of Biochemistry and Museum of Vertebrate Zoology, University of California, Berkeley, CA, 94720.
Evolution. 1987 Nov;41(6):1239-1251. doi: 10.1111/j.1558-5646.1987.tb02463.x.
We present an analysis of the evolutionary relationship between genome size (C-value, mass of DNA per haploid nucleus) and developmental rate using observations of limb regeneration in salamanders of the family Plethodontidae. Rates of growth and differentiation of regenerating limbs are reported for 27 plethodontid species whose C-values range from 14 to 76 picograms. A phylogenetic analysis employing Felsenstein's method of independent contrasts indicates that rate of differentiation is inversely proportional to genome size, although we have not identified any statistically significant association between genome size and the growth rate of regenerating tissue. Our results are consistent with an interpretation that genome size may place a limit on the maximum rate of regeneration attainable in plethodontid salamanders. The implications of our findings for the "junk DNA," "nucleotypic DNA," "selfish DNA," and "skeletal DNA" hypotheses of genome evolution are discussed.
我们利用无肺螈科蝾螈肢体再生的观察结果，对基因组大小（C值，单倍体细胞核中DNA的质量）与发育速率之间的进化关系进行了分析。报告了27种无肺螈科物种再生肢体的生长和分化速率，其C值范围为14至76皮克。采用费尔斯滕森独立对比法的系统发育分析表明，分化速率与基因组大小成反比，尽管我们尚未发现基因组大小与再生组织生长速率之间存在任何统计学上的显著关联。我们的结果符合这样一种解释，即基因组大小可能限制了无肺螈科蝾螈可达到的最大再生速率。讨论了我们的发现对基因组进化的“垃圾DNA”、“核型DNA”、“自私DNA”和“骨骼DNA”假说的影响。
