Moore J D, Elston R A, Drum A S, Wilkinson M T
Battelle Marine Sciences Laboratory, Sequim, Washington 98382.
J Invertebr Pathol. 1991 Sep;58(2):231-43. doi: 10.1016/0022-2011(91)90067-z.
The proliferative disease systemic neoplasia, also termed hemic neoplasia or disseminated sarcoma, was studied in four Puget Sound, Washington populations of the bay mussel (Mytilus sp.). Using flow cytometric measurement of DAPI-stained cells withdrawn from the hemolymph, DNA content frequency histograms were generated for 73 individuals affected by the disease. The cells manifesting systemic neoplasia were found to exist as either of two separate types, characterized by G0G1 phase nuclear DNA contents of either approximately 4.9 x haploid (pentaploid form) or approximately 3.8 x haploid (tetraploid form). The two disease forms were found to coexist in all four mussel populations sampled, with overall relative prevalences of 66% pentaploid form, 29% tetraploid form, and 5% exhibiting both disease forms simultaneously. These findings represent the first unequivocal demonstration of multiple cell types in a bivalve neoplasia. The two forms appear to represent separate pathogenetic processes rather than sequential stages of a single pathogenesis. Two cell cycling parameters associated with proliferative activity were employed to compare the alternate forms: (i) the percentage of cells assigned to the DNA Synthesis (S) phase of the neoplastic cell cycle, and (ii) the proportion of neoplastic cell mitotic figures in hemocytological preparations. Mean values for both parameters were significantly higher for mussels with the tetraploid form of the disease, suggesting a higher rate of proliferation relative to the pentaploid form. Qualitatively, cells of the tetraploid form contained slightly lower nuclear and cytoplasmic volumes compared to those of the pentaploid form. An observed wide variation in neoplastic cell nuclear size within either disease form may reflect the distribution of cells in the G0G1, S, and G2M phases of the cell cycle. Potential etiologic relationships between the two forms are discussed.
在华盛顿普吉特海湾的四个海湾贻贝（紫贻贝属）种群中，对增殖性疾病系统性肿瘤形成（也称为血液肿瘤形成或播散性肉瘤）进行了研究。通过对从血淋巴中提取的经4',6-二脒基-2-苯基吲哚（DAPI）染色的细胞进行流式细胞术测量，为73只受该疾病影响的个体生成了DNA含量频率直方图。发现表现出系统性肿瘤形成的细胞存在两种不同类型，其特征在于G0G1期核DNA含量分别约为单倍体的4.9倍（五倍体形式）或约3.8倍（四倍体形式）。在所有四个采样的贻贝种群中均发现这两种疾病形式共存，总体相对患病率为五倍体形式占66%，四倍体形式占29%，5%同时表现出两种疾病形式。这些发现首次明确证明了双壳贝类肿瘤形成中存在多种细胞类型。这两种形式似乎代表了不同的致病过程，而非单一发病机制的连续阶段。采用了与增殖活性相关的两个细胞周期参数来比较这两种不同形式：（i）处于肿瘤细胞周期DNA合成（S）期的细胞百分比，以及（ii）血细胞学制剂中肿瘤细胞有丝分裂相的比例。对于患有四倍体形式疾病的贻贝，这两个参数的平均值均显著更高，表明相对于五倍体形式，其增殖速率更高。定性地说，与五倍体形式的细胞相比，四倍体形式的细胞核和细胞质体积略小。在任何一种疾病形式中观察到的肿瘤细胞核大小的广泛差异可能反映了细胞在细胞周期的G0G1、S和G2M期的分布情况。文中讨论了这两种形式之间潜在的病因学关系。
