New prestalk and prespore inducing signals in Dictyostelium
New prestalk and prespore inducing signals in Dictyostelium
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DOI：
10.1016/j.ydbio.2005.03.023
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发表时间：
2005-06-15
影响因子：
2.7
通讯作者：
Kay, RR
中科院分区：
文献类型：
--
作者：
Serafimidis, I;Kay, RR
目前已知的分化诱导信号（DIF）在Dictyosteoblasts似乎无法解释发育过程中产生的细胞类型的全部多样性。为了寻找新的信号，我们分析了表达前茎（ecmAO、ecmA、ecmO、ecmB和cAR 2）和前孢子（psA）标记物的细胞单层的分化。随着细胞密度的降低，每种标记物的表达都会下降，这表明需要细胞相互作用。每个标记物的表达被浅蓝菌素（一种聚酮化合物合成的抑制剂）抑制，并且可以通过条件培养基恢复。然而，已知的茎诱导聚酮，DIF-1，不能取代条件培养基和诱导ecmA或cAR 2前茎标记，这表明它们需要不同的聚酮诱导剂。镉离子刺激真菌产生聚酮化合物，镉离子也显著刺激网囊藻细胞培养物的分化和培养基因子的积累。从条件培养基中提取产生镉的因子，并通过HPLC进行分级。一个新的诱导前孢子细胞分化的因子，称为PSI-2，和两个诱导茎细胞分化的因子（DIF 6和7）被解析。所有弧;不同于目前确定的因素。DIF-6，而不是DIF-7或PSI-2，似乎具有必需的羰基。因此，网骨藻可能在其发育中使用广泛的聚酮信号。(c)2005年爱思唯尔公司All rights reserved.
The differentiation-inducing signals (DIFs) currently known in Dictyostelium appear unable to account for the full diversity of cell types produced in development. To search for new signals, we analyzed the differentiation in monolayers of cells expressing prestalk (ecmAO, ecmA, ecmO, ecmB and cAR2) and prespore (psA) markers. Expression of each marker drops off as the cell density is reduced, suggesting that cell interaction is required. Expression of each marker is inhibited by cerulenin, an inhibitor of polyketide synthesis, and can be restored by conditioned medium. However, the known stalk-inducing polyketide, DIF-1, could not replace conditioned medium and induce the ecmA or cAR2 prestalk markers, suggesting that they require different polyketide inducers. Polyketide production by fungi is stimulated by cadmium ions, which also dramatically stimulates differentiation in Dictyostelium cell cultures and the accumulation of medium factors. Factors produced with cadmium present were extracted from conditioned medium and fractionated by HPLC. A new factor inducing prespore cell differentiation, called PSI-2, and two inducing stalk cell differentiation (DIFs 6 and 7) were resolved. All arc; distinct from currently identified factors. DIF-6, but not DIF-7 or PSI-2, appears to have an essential carbonyl group. Thus Dictyostelium may use extensive polyketide signaling in its development. (c) 2005 Elsevier Inc. All rights reserved.