Evolution of the hominoid based on differentiation of constitutive hetrochromatin in chromosomes

1. 类人猿中18S rDNA和β-卫星DNA的基因组分布及其进化意义：类人猿中rDNA和β-卫星DNA的染色体定位表明，这两种重复DNA在类人猿、长臂猿、长臂猿、猩猩、大猩猩、人类、黑猩猩和倭黑猩猩中具有支系分化顺序。色散的动力功率假定为中心裂变形成外中心后异位交叉的协同演化。基于交叉图谱分析和端粒构型对交叉配对的新解释：对减数分裂细胞分裂中二价染色体的端粒构型的检测表明，两个同源物的端-端结合呈4个端粒形成的正方形，而交叉臂呈矩形。也就是说，前者可能是端粒-端粒结合的一种表现，而不是基因的重组。后者是两个姐妹染色单体交叉的表现，是真正的基因洗牌。因此，端粒与端粒的结合可能不是交叉。c带区对交叉形成的影响：利用猕猴和黑帽卷尾猴的成岩染色体观察交叉的频率和位置。前者只有着丝粒异染色质，后者有着丝粒异染色质、终末异染色质和间质异染色质。交叉图分析表明，卷尾猴的交叉形成受末端和间质异染色质染色体c带位置的影响。交叉频率为：日本猴Fxi=23.8, Fxit=42；黑冠卷尾猴，Fxi=27.2, Fxit=41.4.4。黑猩猩的交叉：用活组织检查获得的精管制备的减数分裂染色体观察黑猩猩的交叉。虽然目前只对交叉频率进行了检测，但在今后的分子细胞遗传学分析方面，染色体的制备将为黑猩猩减数分裂细胞生物学提供有价值的结果。端粒序列与组成异染色质的关系：利用引物原位标记技术对类人猿的端粒序列进行染色体定位。大部分黑猩猩、倭黑猩猩、大猩猩和暹罗猴的末端c带片段都是用端粒序列进行标记的。这可能是类人猿染色体分化进化途径的一种表现。我们将对此进行更详细的分析。少

1. Genomic dispersion of 18S rDNA and β-satellite DNA in hominoids and its evolutionary aspects : Chromosomal localization of two repetitive DNAs, rDNA and β-satellite DNA, in the hominoid showed that a cladistic divergence order of these DNAs in the apes, gibbon, siamang, orangutan, gorilla, human, chimpanzee, and bonobo. The dynamic power of the dispersion is postulated to be concerted evolution in terms of the hetero-site crossover after acrocentric formation by centric fission.2. A new interpretation of chiasmate based on chiasma graph analysis and telomere configurarion : Examination of telomere configuration on the bivalents of diakinesis in the meiotic cell division of a mouse (Mus platythric, haploid chromosome number n=13) clarified that the end-end association of two homologues showed a square formation by 4 telomeres, while the crossover in arm showed a rectangle. That is, the former could be a manifestation of telomere-telomere association, being not the genetic recombinati … More on in essential meaning of chiasmata. The latter is a manifestation of crossingover between two sisterchromatids, being real gene shuffling. Therefore, the telomere-telomere association might not be chiasmata.3. Influence of C-band regions for chiasma formation : Chiasma frequency and location were observed using diakinesis chromosomes of the Rehsus monkey and black-capped capuchin. The former species has only centromeric heterochrmatin and the latter has centromeric, teiminal and interstitial heterochromatin. Chiasma graph analysis elucidated that chiasma formation of the capuchin was biased by C-band location in some chromosomes with terminal and interstitial heterochromatin. The chiasma frequency was as follows: Japanese monkey Fxi=23.8 and Fxit=42 ; black-capped capuchin, Fxi=27.2 and Fxit=41.4.4. Chiasmate of chimpanzee : Chasmata of chimpanzee was observed using meiotic chromosomes prepared with seminiferous tubules obtained by biopsy. Though only chiasma frequency was examined at this time, th chromosome preparations will produce valuable results of meiotic cell biology in chimpanzee in terms of molecular cytogenetical analyses in the future.5. Relationships of telomere sequence and constitutive heterochromatin : Chromosomal localization of telomere sequence was made in hominoids using a primed in situ labeling technique. Most of terminal C-band blocks of chimpanzee, bonobo, gorilla and siamang were labeled by telomere sequnce. This could be a manifestation of evolutionary pathway of chromosome differentiation in the hominoid. It will be analyze in more detail. Less