[mass noun](Biology)the first stage of the prophase of meiosis, during which each chromosome becomes visible as two fine threads (chromatids) (生)细线期(细胞减数分裂前期第一阶段,其间每一个染色体显现为两条细线)
语源
early 20th cent.: from lepto- 'narrow, fine' + Greek tainia 'band, ribbon'