Goday C, Ciofi-Luzzatto A, Pimpinelli S
Chromosoma. 1985;91(2):121-5. doi: 10.1007/BF00294055.
Ultrastructural analysis of the centromere in germ-line mitotic chromosomes of Parascaris univalens and Parascaris equorum revealed that these chromosomes are holocentric. In thin longitudinal sections of both species the kinetochore appeared as a continuous plate (up to 3.8 micron long) and displayed a layered structure. This structure consisted of electron-dense inner and outer layers (average width 10 nm) separated by a less dense middle layer (25 nm wide), which had transverse electron-dense bars (10 nm wide) regularly spaced every 25-30 nm. Thus the ladderlike kinetochore profile observed in Parascaris gonial mitotic chromosomes represents a different type of organization from that of the classical trilaminar kinetochore found in both holocentric and monocentric chromosomes.
对单宫副蛔虫和马副蛔虫生殖系有丝分裂染色体着丝粒的超微结构分析表明，这些染色体是全着丝粒的。在这两个物种的薄纵向切片中，动粒呈现为连续的板状（长达3.8微米），并显示出分层结构。这种结构由电子致密的内层和外层（平均宽度10纳米）组成，中间由密度较小的中间层（宽25纳米）隔开，中间层有横向的电子致密条带（宽10纳米），每隔25 - 30纳米有规律地间隔排列。因此，在副蛔虫生殖细胞有丝分裂染色体中观察到的梯状动粒轮廓代表了一种与在全着丝粒和单着丝粒染色体中发现的经典三层动粒不同的组织类型。
