EARLY CYTOLOGICAL EVENTS AFTER INDUCTION OF CELL-DIVISION IN EGG CELLS AND ZYGOTE DEVELOPMENT FOLLOWING IN-VITRO FERTILIZATION WITH ANGIOSPERM GAMETES
EARLY CYTOLOGICAL EVENTS AFTER INDUCTION OF CELL-DIVISION IN EGG CELLS AND ZYGOTE DEVELOPMENT FOLLOWING IN-VITRO FERTILIZATION WITH ANGIOSPERM GAMETES
复制标题
DOI：
10.1046/j.1365-313x.1995.08010009.x
复制
发表时间：
1995-07-01
期刊：
影响因子：
7.2
通讯作者：
LORZ, H
中科院分区：
文献类型：
--
作者：
KRANZ, E;VONWIEGEN, P;LORZ, H
研究了玉米（Zea mays L.）单卵和精子原生质体体外融合后细胞壁形成、第一次核分裂和第一次受精卵不等分裂等早期事件。这些事件的时间进程已经确定。在卵精融合后30秒观察细胞壁成分的形成，此后持续进行。融合后15小时内，大多数细胞器更加密集地聚集在受精卵核周围。在离体产生的受精卵中，细胞器和分裂核的位置呈现极性。配子融合后18h，第一次观察到两个核仁。合子核保持未分裂状态约40 h，第一次细胞分裂发生在卵精融合后40-60 h，一般为42-46 h。在离体条件下，高剂量的2,4- d脉冲可以触发未融合的卵细胞进行孢子体发育。在没有这种处理的情况下，不同玉米系培养的卵细胞不分裂。虽然核聚变似乎发生了，但两个卵细胞的融合产物也没有分裂。细胞壁形成不完全且不均匀，表现为培养的卵细胞和两个卵细胞原生质体的融合产物的极性。玉米卵与遗传距离较远的种（如薏苡仁、高粱、高粱或小麦）的精子融合后也能诱导细胞分裂。这些配子异种融合产物发育成小愈伤组织。此外，细胞分裂发生在玉米卵细胞和二倍体体细胞悬浮原生质体的融合产物中。
Early events, such as formation of the cell wall, first nuclear division and first unequal division of the zygote, were examined following in vitro fusion of single egg and sperm protoplasts of maize (Zea mays L.). The time course of these events was determined. The formation of cell wall components was observed 30 sec following egg-sperm fusion and proceeded continuously thereafter. Within 15 h after fusion most of the organelles became more densely grouped around the nucleus of the zygote. In the in vitro produced zygote the location of the cell organelles and of the dividing nucleus showed polarity. Two nucleoli were first observed 18 h after gamete fusion. The zygotic nucleus remained undivided for about 40 h. The first cell division was observed 40-60 h, generally 42-46 h, after egg-sperm fusion. The non-fused egg cell could be triggered to sporophytic development in vitro by pulses of high amounts of 2,4-D. Without such a treatment, cultured egg cells of different maize lines did not divide. Although nuclear fusion seemed to occur, fusion products of two egg cells also did not divide. Cell wall formation was incomplete and non-uniform, showing a polarity of cultured egg cells and fusion products of two egg protoplasts. Cell division was also induced after fusion of maize egg with sperms of genetically remote species, such as Coix, Sorghum, Hordeum or Triticum. These gametic heterologous fusion products developed to microcalli. Moreover, cell division occurred in fusion products of an egg and a diploid somatic cell-suspension protoplast from maize.