Abstract：
The number of chromosomes varies tremendously across species. It is not clear whether having more or fewer chromosomes could be advantageous. The probability of non-disjunction should theoretically decrease with smaller karyotypes, but too long chromosomes should enforce spatial constraint for their segregation during the mitotic anaphase. Here, we propose a new experimental cell system to acquire novel insights into the mechanisms underlying chromosome segregation. We collected the endemic Australian ant Myrmecia croslandi, the only known species with the simplest possible karyotype of a single chromosome in the haploid males (and one pair of chromosomes in the diploid females), since males are typically haploid in hymenopteran insects. Five colonies, each with a queen and a few hundreds of workers, were collected in the Canberra district (Australia), underwent karyotype analysis to confirm the presence of a single pair of chromosomes in worker pupae, and were subsequently maintained in the laboratory in Paris (France). Starting from dissociated male embryos, we successfully conducted primary cell cultures comprised of single-chromosome cells. This could be developed into a unique model that will be of great interest for future genomic and cell biology studies related to mitosis.
摘要：
染色体的数量在不同物种之间差异很大。尚不清楚具有更多或更少的染色体是否可能是有利的。理论上，核型较小，不分离的概率应降低，但是太长的染色体应该在有丝分裂后期对它们的分离施加空间约束。这里,我们提出了一种新的实验细胞系统，以获得对染色体分离机制的新见解。我们收集了澳大利亚特有的蚂蚁Myrmeciacroslandi，唯一已知的物种具有单倍体雄性中单个染色体的最简单核型（和二倍体雌性中的一对染色体），因为雄性在膜翅目昆虫中通常是单倍体。五个殖民地，每个人都有女王和数百名工人，收集在堪培拉地区（澳大利亚），进行了核型分析，以确认工人p中存在一对染色体，随后被保存在巴黎（法国）的实验室中。从分离的雄性胚胎开始，我们成功地进行了由单染色体细胞组成的原代细胞培养。这可以发展成一个独特的模型，将对未来与有丝分裂相关的基因组和细胞生物学研究非常感兴趣。
