Farias M de F, Kohn A, Barth O M
Departamento de Helmintologia, Instituto Oswaldo Cruz, Rio de Janeiro, Brasil.
Mem Inst Oswaldo Cruz. 1995 Sep-Oct;90(5):597-604. doi: 10.1590/s0074-02761995000500010.
Ultrastructural aspects of spermatogenesis, spermiogenesis and of the mature spermatozoon of a microcotylid monogenean Metamicrocotyla macracantha parasite from Mugil liza, are described. The irregularly-shaped spermatogonia divides by successive mitoses, forming the primary spermatocytes, identified by the presence of synaptonemal complexes in their nuclei. The spermatids formed by meiotic cell divisions of the secondary spermatocytes, differentiate into a mature spermatozoon. Cross sections of the head and the middle region of mature spermatozoa show the nucleus with strong condensed chromatin, the mitochondria with short cristae, peripheral microtubules and two axonemes with a 9 + 1 pattern, confirming the characteristics of this genus.
描述了寄生于尖吻鲈的一种微杯叶目单殖吸虫——大棘巨微杯叶吸虫精子发生、精子形成及成熟精子的超微结构特征。形状不规则的精原细胞通过连续有丝分裂进行分裂，形成初级精母细胞，其细胞核中存在联会复合体可作为识别依据。由次级精母细胞减数分裂形成的精子细胞分化为成熟精子。成熟精子头部和中部区域的横截面显示，细胞核内染色质高度浓缩，线粒体嵴短，外周有微管，还有两条呈9+1模式的轴丝，证实了该属的特征。
