Fungal Reproduction

Pheromone

A chemical signal released by an organism and meant to trigger a response in another individual organism; used by animal and non-animal (plant, fungal) organisms.

Spore

A robust unicellular reproductive structure formed by asexual mitosis or sexually by meiosis.

Conidia

Asexual spores produced on specialized hypha in ascomycote fungi.

Describe sexual and asexual reproduction in fungi with spores.

Fungi reproduce both sexually and asexually, and both types of reproduction result in the release of spores. A haploid spore will germinate and give rise to a structure that will make more identical spores and then release them, as seen with conidia in Ascomycote fungi. Sexual reproduction often involves the joining of two different mating types of the same species. After a period of fused cytoplasms (plasmogamy), the nuclei can also come together to make a diploid zygote (karyogamy). The zygote can give rise via meiosis to new haploid spores that are genetically different from either parent. Many differences occur between groups of fungi in the timing of karyogamy, the structures produced for sexual reproduction and how they make their particular type of sexually derived haploid spore. Ascomycotes make ascospores in asci, basidiomycotes make basidiospores on basidia, and zygomycotes make zygospores by the fusion of two gametangia.

Plasmogamy

Fusion of cytoplasm, but not nuclei, of opposite mating types of fungal hyphae.

Karyogamy

Fusion of nuclei, usually following plasmogamy, in fungi.

Dikaryotic

Hyphae with two nuclei per cell.

Heterokaryon

Meaning different nuclei; newly combined mycelia in which each cell has at least two nuclei.

Describe the structure and function of a fungal spore.

Most fungal spores exist as haploid cells that can often enter into either asexual or sexual cycles. A fungal spore can germinate into a new mycelium if it lands in the proper conditions. Some spores can maintain an inactive state until desirable conditions arise. Nearly all spores are haploid.

Budding

Process of asexual reproduction in yeast by which a new cell grows directly from the parent cell body and then proceeds with mitotic cell division.

Describe the importance of tracking fungal spores by monitoring.

Since fungi can live on anything from drywall to fruit and produce an abundance of spores, monitoring for fungi is critical because of the health threat posed by spores. Inhaling fungal spores can represent a serious health problem for many individuals, especially those suffering from asthma or a weakened immune system.

Describe budding in yeast as a form of asexual reproduction.

Some unicellular fungi, such as yeast, reproduce asexually by simple cell division in a process called budding. One yeast cell simply makes a copy of its DNA and then divides, much like basic cell division — separating the two copies of the genetic information and pinching off a section of the cytoplasm, including all necessary cellular components.