家蚕核仁和核仁染色体的初步研究

在家蚕的染色体制片中.以精巢为材料,采用涂片.Giemsa染色法,对一代杂种苏5×苏6的核仁和核仁染色体进行了观察和分析.结果表明,在间期细胞核内.大多数有一个核仁,少数有两个或三个核仁.在减数分裂粗线期至终变期的细胞核内,有一个核仁和三条贴附在核仁上的核仁染色体,这三条核仁染色体分别是第2号、第5号和第22号.有丝分裂中期的细胞核内未见核仁,但至少观察到四条染色体有明显的缢痕(Chromosome constriction),它们是两对与核仁形成的有关的核仁染色体.其他染色体均呈短杆状,未见明显缢痕.

THE PRELIMINARY STUDIES ON THE NUCLEOLI AND NUCLEOLAR CHROMOSOMES OF SILKWORM

In the preparation of the slide specimen of silkworm chromosome, using testes as meteirals, by the Giemsa's staining method, the nucleoli and nucleolar chromosomes of the(Su5 XXXXXX Su6)F1 have been surveyed and analysed. The results showed that during interphase, the major nucleus have one nucleolus and a few have two or three. From pachytene to diakinesis of meiosis, there is nucleolus attached to three nucleolo-chromosomes in the nucleus. The three bivalents are named the second, fifth and twenty-second ones respectively. During meta-phase of mitosis,no nucleoli presented, but two pairs of nucleolar chromosomes are observed which may relate to the formation of nucleoli. The other chromosomes appear oblong shape and no constricting obviously.