Question

What is the importance of Neurospora in genetic research?

Answer 1

Neurospora crassa - Crossing over:

• Neurospora is a fungi.
• It reproduces sexually as well as asexually.
• It is haploid, hence recessive genes are expressed and not supressed by dominant gene.
• Products of meiosis are maintained in linear order in ascus.
• Genotype of all 4 products of single cross over can be ascertained by analyzing the spores of ascus.
• This analysis is known as Tetrad analysis.

1st Division segregation:

• No crossing over.
• Segregationof allelesoccurs during the first division of meiosis.
• Ascospores are arranged in 4:4 pattern.
• Ascus with this type of arrangement is known as Parental Ditype.

2nd Division segregation:

• Crossing over occurs.
• Segregation of alleles occur during the 2nd division of meiosis.
• Ascosporesarearranged in 2:2:2:2 pattern.
• This type of ascus is known as Tetratype.
• 4 different segregation pattern occurs.
• It depends upon the recombinant chromatids during Anaphase II.

•  Neurospora is used as a very important genetic tool.
• This is because it is easy to grow.
• It has a haploid life cycle which makes genetic analysis simple since recessive traits will show up in the offspring.