RESUMO
A comparative study of the ultrastructure in sections of the ascospores of six Hanseniaspora species showed three types of spores: (1) hat-shaped in H. valbyensis and H. guilliermondii, (2) spherical with an equatorial or subequatorial ledge, smooth or rough in H. occidentalis and H. uvarum, (3) spherical with warts in H. osmophila and H. vineae. Development and germination of the spores of Hanseniaspora guilliermondii is described in more detail.
Assuntos
Leveduras/ultraestrutura , Núcleo Celular/ultraestrutura , Especificidade da Espécie , Esporos Fúngicos/ultraestrutura , Leveduras/fisiologiaRESUMO
Ascus formation in Debaryomyces hansenii includes fusion of two cells, usually mother and daughter while still attached to each other, through short protuberances developed from the cross wall between them. Nuclear fusion takes place in the channel connecting the two cells; meiosis apparently occurs in the mother cell. Generally, only one lobe of the meiotic nucleus is surrounded by a prospore wall and it becomes the nucleus of a spore with a warty wall. The rest of the nucleus disappears. The spores germinate by swelling in the ascus and forming one or more buds.