Echt C S, May-Marquardt P
United States Department of Agriculture, Forest Service Research, Rhinelander, WI 54501, USA.
Genome. 1997 Feb;40(1):9-17. doi: 10.1139/g97-002.
A large insert genomic library from eastern white pine (Pinus strobus) was probed for the microsatellite motifs (AC)n and (AG)n, all 10 trinucleotide motifs, and 22 of the 33 possible tetranucleotide motifs. For comparison with a species from a different subgenus, a loblolly pine (Pinus taeda) genomic library was also probed with the same set of di- and tri-nucleotide repeats and 11 of the tetranucleotide repeats. The four most abundant microsatellite motifs in both species were (AC)n, (AG)n, (AAT)n, and (ATC)n, which as a group accounted for over half the microsatellite sites investigated. The two dinucleotide repeats were the most abundant microsatellite motifs tested in both species, each at 2-4.5 sites/megabase pair (Mbp), but the two trinucleotide motifs were nearly as abundant and are considered good candidates for pine microsatellite marker development efforts. Eastern white pine had more than twice as many (AC)n as (AG)n loci, in contrast with loblolly pine and most other plant species in which (AG)n is more abundant. In both pine species the minimum estimated genome density for all microsatellites, excluding (AT)n repeats, was 16 sites/Mbp.
利用微卫星基序（AC）n和（AG）n、所有10种三核苷酸基序以及33种可能的四核苷酸基序中的22种，对来自东部白松（Pinus strobus）的一个大型插入基因组文库进行了探测。为了与来自不同亚属的一个物种进行比较，还利用同一组二核苷酸和三核苷酸重复序列以及11种四核苷酸重复序列对火炬松（Pinus taeda）基因组文库进行了探测。两个物种中最丰富的四种微卫星基序是（AC）n、（AG）n、（AAT）n和（ATC）n，它们共同占所研究微卫星位点的一半以上。两种二核苷酸重复序列是两个物种中测试的最丰富的微卫星基序，每种的密度为2 - 4.5个位点/兆碱基对（Mbp），但两种三核苷酸基序的丰富程度几乎相同，被认为是松树微卫星标记开发工作的良好候选对象。与火炬松以及大多数其他（AG）n更为丰富的植物物种相反，东部白松的（AC）n位点数量是（AG）n位点的两倍多。在两种松树中，排除（AT）n重复序列后，所有微卫星的最低估计基因组密度为16个位点/Mbp。
