The process of budding begins in a mature yeast cell at predetermined areas of its cell wall. In Saccharomyces cerevisiae , for example, budding takes place at the poles of the cell. As the bud enlarges, mitosis of the nucleus occurs, with one of the nuclei moving into the newly formed cell. When the cell reaches the approximate size of the original cell, cell wall material is laid down in the passage between the two cells, which will then shortly separate. Formation of new cell begins with blowing out of a new cell, at the pole of the cell.
Mitosis follows with migration of one nucleus to the new cell.
New wall material is then laid down in the passage between the two cells and separation of the cells will occur. Fission is a simpler process. In Schizosaccharomyces, during fission mitosis of the nucleus occurs, followed elongation of cell and the laying down of a cell wall that divides the cell in half, separating the two nuceli. Mitosis of the nucleus occurs, followed by elongation of the cell and formation of a cell wall that divides the cell in half, separating the two nuclei. We will describe the life cycle examples of a budding and a fission yeast.