懒猴属的核糖体DNA变异及其种间分化关系

用１５种限制性内切酶和人２８Ｓ、１８ＳｒＤＮＡ探针构建了懒猴属各物种核糖体ＤＮＡ重复单位的限制性内切酶图谱。在进化速率较高的非转录间隔区，在大、中、小懒猴中分别定位了２３、２４、２４个酶切位点。大懒猴与中懒猴有１２个位点不同，与小懒猴有１４个位点不同，而中、小懒猴间则只有一个位点的差异。经过计算，大懒猴与中懒猴的遗传距离值为１２．６５％，与小懒猴的差异为１４．２４％，中、小懒猴间的差异则仅为０．７

INTERSPECIFIC DIFFERENTIATION OF THE SLOW LORISES (GENUS Nycticebus) INFERRED FROM RIBOSOMAL DNA RESTRICTION MAPS

Restriction maps of ribosomal DNA repetypes of the three putative slow lorises species, Nycticebus coucang, N. intermedius and N. pygmaeus, were constructed with 15 restriction endonucleases and 285, 185 rDNA probes cloned from human. The site numbersmapped on the non-transcribed spacers for N. coucang, N. intermedius, and N.Mpygmaeus, were 23, 24, and 24 respectively. N. coucang differs from N. intermidius at 13 sites, and 14 sites from N. Pygmaeus. There are only one site difference between N. intermedius and N. pygmaeus. The sequence divergence between N. coucang and N. intermedius was estimated as 12.65%, and that between the former and N. Pygmaeus was 14.24%. However, N. intermedius and N. Pygmaeus have only 0.71 % sequence divergence. Integrating information from morphology, karyotype, mitochondrial DNA and ribosomal DNA variation, we refer to the hypothesis that there are two valid species in the genus Nycticebus, namely, N. coucang and N. Pygmaeus while N. intermedius may be at the level of semispecies of N. pygmaeus at the most. The giant difference between N. coucang and N. pygmaeus implies that the former has strongly diverged from the latter.