Related Experiment Videos
An asexual fungus has the potential for sexual development
A Sharon1, K Yamaguchi, S Christiansen
1Botany Department, Tel-Aviv University, Israel.
Molecular & General Genetics : MGG
|April 24, 1996
Summary
Asexual fungi like Bipolaris sacchari possess functional mating type (MAT) genes, yet remain asexual. This suggests other essential genes, beyond MAT, are required for successful sexual reproduction in these fungi.
Area of Science:
- Mycology
- Genetics
- Fungal Reproduction
Background:
- Sexual reproduction in fungi is controlled by mating type (MAT) genes.
- Asexual fungi present a unique case for studying the genetic basis of mating failure.
- Understanding the genetic mechanisms of mating is crucial for fungal biology.
Purpose of the Study:
- To investigate the reasons for mating failure in the asexual fungus Bipolaris sacchari.
- To determine if the absence or mutation of MAT genes is responsible for the asexual nature of B. sacchari.
- To explore the functionality of MAT genes from a sexual relative in an asexual fungus.
Main Methods:
- Sequence analysis of the MAT-2 gene homolog in B. sacchari.
- Functional analysis of B. sacchari MAT-2 in transgenic Cochliobolus heterostrophus.
- Transformation of C. heterostrophus MAT genes into B. sacchari.
- Analysis of sexual development initiation and completion in interspecific pairings.
- Transcript analysis of native and transformed MAT genes.
Main Results:
- Bipolaris sacchari contains a functional homolog of the MAT-2 gene, highly similar to that in Cochliobolus heterostrophus.
- Transgenic C. heterostrophus strains expressing B. sacchari MAT-2 could mate, indicating the gene's functionality.
- Transformation of C. heterostrophus MAT genes into B. sacchari did not restore mating ability; these strains remained asexual.
- Transgenic B. sacchari strains showed partial initiation of sexual development with C. heterostrophus but could not complete it.
- Both B. sacchari MAT-2 and C. heterostrophus MAT genes were expressed when present in heterologous hosts, but the native B. sacchari MAT-2 transcript was undetectable.
Conclusions:
- The asexual reproduction of B. sacchari is not due to the absence or mutation of its MAT genes.
- B. sacchari likely requires additional genes, beyond the MAT genes, for successful sexual reproduction.
- The inability to complete sexual development in transgenic B. sacchari highlights complex genetic requirements for mating in fungi.