Ustinova Jana, Achmann Roland, Cremer Sylvia, Mayer Frieder
Institute of Zoology II, University of Erlangen, Staudtstrasse 5, Erlangen, D-91058, Germany.
J Mol Evol. 2006 Feb;62(2):158-67. doi: 10.1007/s00239-005-0022-6. Epub 2006 Feb 10.
It is commonly believed that both the average length and the frequency of microsatellites correlate with genome size. We have estimated the frequency and the average length for 69 perfect dinucleotide microsatellites in an insect with an exceptionally large genome: Chorthippus biguttulus (Orthoptera, Acrididae). Dinucleotide microsatellites are not more frequent in C. biguttulus, but repeat arrays are 1.4 to 2 times longer than in other insect species. The average repeat number in C. biguttulus lies in the range of higher vertebrates. Natural populations are highly variable. At least 30 alleles per locus were found and the expected heterozygosity is above 0.95 at all three loci studied. In contrast, the observed heterozygosity is much lower (< or = 0.51), which could be caused by long null alleles.
人们普遍认为，微卫星的平均长度和频率都与基因组大小相关。我们已经估算了一种具有超大基因组的昆虫——大垫尖翅蝗（直翅目，蝗科）中69个完美二核苷酸微卫星的频率和平均长度。二核苷酸微卫星在大垫尖翅蝗中出现的频率并不更高，但重复序列阵列比其他昆虫物种中的长1.4至2倍。大垫尖翅蝗的平均重复次数处于高等脊椎动物的范围内。自然种群具有高度变异性。在所研究的所有三个位点上，每个位点至少发现了30个等位基因，预期杂合度高于0.95。相比之下，观察到的杂合度要低得多（≤0.51），这可能是由长的无效等位基因导致的。
