Cornejo P, Camadro E L, Masuelli R W
Facultad de Ciencias Agrarias, U.N. de Cuyo and CONICET, Alte. Brown 500, (M5528AHB) Mendoza, Argentina.
Biocell. 2006 Dec;30(3):413-21.
The Endosperm Balance Number (EBN) is an important concept for potato breeding and has evolutionary importance in tuber-bearing Solanum species. The EBN is part of the post-zygotic hybridization barriers in the group and represents a reproductive isolating mechanism. Few genes have been proposed to be involved in its genetic control; until now, however, neither specific genes nor its molecular basis have been well established. Histological observations of embryo and endosperm development in inter-EBN crosses in tuber-bearing Solanum revealed phenotypes similar to those recently described in Arabidopsis seed mutants. The common feature between them is that the endosperm nuclei become greatly enlarged and that embryos are arrested at the globular stage. The proteins encoded by the Arabidopsis TITAN genes are related to chromosome dynamics and cell division. Based on the sequence of titan mutants, genes in potato species related to cell cycle and microtubule assembly were isolated. In this article a perspective model is proposed to explore the utility of Arabidopsis mutants associated with cell cycle control as a tool to elucidate the molecular basis of EBN in potato. Further research focused on the expression pattern of these genes in intra- and inter-EBN crosses in potato species will be performed.
胚乳平衡数（EBN）是马铃薯育种中的一个重要概念，在茄属块茎类物种的进化中具有重要意义。EBN是该类群中合子后杂交障碍的一部分，代表一种生殖隔离机制。很少有基因被认为参与其遗传控制；然而，到目前为止，无论是特定基因还是其分子基础都尚未完全明确。对茄属块茎类物种中不同EBN杂交组合的胚胎和胚乳发育进行组织学观察，发现其表型与最近在拟南芥种子突变体中描述的相似。它们之间的共同特征是胚乳核大幅增大，胚胎在球形期停止发育。拟南芥TITAN基因编码的蛋白质与染色体动态和细胞分裂有关。基于titan突变体的序列，分离出了马铃薯中与细胞周期和微管组装相关的基因。本文提出了一个前瞻性模型，以探索与细胞周期控制相关的拟南芥突变体作为阐明马铃薯EBN分子基础工具的实用性。将进一步开展针对这些基因在马铃薯种内和种间不同EBN杂交组合中的表达模式的研究。
