What is the Difference Between Cytogenetics and Molecular Genetics

The main difference between cytogenetics and molecular genetics is that cytogenetics is the study of the influence of chromosomes on cell behavior during mitosis and meiosis, whereas molecular genetics is the study of the structure and function of genes at the molecular level.

Cytogenetics and molecular genetics are two study areas of genetics, focusing on different characteristics of chromosomes. Furthermore, cytogenetics also studies the diseases due to the abnormal number and structure of chromosomes, while molecular genetics also studies hereditary, genetic variation, and mutations through chromosomes and gene expression.

Key Areas Covered 

1. What is Cytogenetics
     – Definition, Characteristics, Importance
2. What is Molecular Genetics
     – Definition, Characteristics, Importance
3. What are the Similarities Between Cytogenetics and Molecular Genetics
     – Outline of Common Features
4. What is the Difference Between Cytogenetics and Molecular Genetics
     – Comparison of Key Differences

Key Terms 

Chromosome Abnormalities, Chromosomes, Cytogenetics, Genetics, Molecular Genetics

What is Cytogenetics

Cytogenetics is a branch of genetics. It mainly studies chromosomes and the related diseases that occur due to the abnormal number and structure of chromosomes. Therefore, the main objective of cytogenetics is to identify the relationship between chromosomes and the behavior of the cell, especially during cell division. Moreover, the main techniques in cytogenetics include karyotyping, analysis of the banding pattern of chromosomes by G-banding or other banding techniques, etc. Also, molecular cytogenetics is the area of cytogenetics at the molecular level. It uses techniques such as fluorescent in situ hybridization (FISH) and comparative genomic hybridization (CGH). 

Figure 1: FISH – Cytogenetics

Furthermore, cytogenetics is responsible for the diagnosis of genetic diseases caused by the abnormal number of chromosomes and structures. Some of these chromosome abnormalities include Down syndrome, aneuploidy, Turner syndrome, Klinefelter syndrome, Edwards syndrome, etc. 

What is Molecular Genetics

Molecular genetics is an area of genetics that study the structure and the function of genes at the molecular level. Therefore, both genetics, as well as molecular biology, are employed in molecular genetics. Significantly, molecular genetics studies chromosomes as well as gene expression and their effect on heredity, genetic variation, and mutations. Therefore, this area is also important for studying developmental biology. Additionally, it is important to diagnose and treat genetic disorders.

Figure 2: Molecular Cloning

Moreover, in molecular genetics, PCR and molecular cloning are the techniques for the amplification of DNA sequences. Also, DNA and RNA isolation, cell cultures, etc. are the techniques for the separation and detection of nucleic acids. 

Similarities Between Cytogenetics and Molecular Genetics 

• Cytogenetics and molecular genetics are two branches of genetics. 
• Basically, both areas study the characteristics, which are inherited over generations through genomes. 
• Both are important for the understanding of genetic diseases, their evolution, diagnosis, and therapy. 

Difference Between Cytogenetics and Molecular Genetics 

Definition 

Cytogenetics refers to the study of inheritance relating to the structure and function of chromosomes, while molecular genetics refers to a branch of genetics dealing with the structure and activity of genetic material at the molecular level.

Type of Study 

Moreover, cytogenetics is the study of the influence of chromosomes on cell behavior during mitosis and meiosis, while molecular genetics is the study of the structure and function of genes at the molecular level. Thus, this is the main difference between cytogenetics and molecular genetics.

Techniques 

The techniques in cytogenetics include karyotyping, chromosome staining, FISH, CGH, etc., while the techniques in molecular genetics include PCR, molecular cloning, DNA and RNA isolation, cell cultures, etc. Hence, this is another difference between cytogenetics and molecular genetics.

Importance 

Furthermore, cytogenetics also studies the diseases due to the abnormal number and structure of chromosomes, while molecular genetics also studies hereditary, genetic variation, and mutations through chromosomes and gene expression. 

Conclusion 

Cytogenetics is a branch of genetics, studying the effect of chromosomes on the behavior cells during mitosis and meiosis. Therefore, it also studies the effect of numerical and structural abnormalities of chromosomes, which relate to the genetic diseases. On the other hand, molecular genetics is also a branch of genetics, studying the structure and the function of genes at the molecular level. Moreover, it studies the patterns of hereditary, genetic variation, mutations using the structure and function of genes. Therefore, the main difference between cytogenetics and molecular genetics is the type of study. 

References:

1. Schrijver, I. et al, “Tools for Genetics and Genomics: Cytogenetics and Molecular Genetics.” UpToDate, Available Here.

Image Courtesy:

1. “Bcrablmet” By Pmx assumed (based on copyright claims). Own work assumed (based on copyright claims). (CC BY-SA 3.0) via Commons Wikimedia   
2. “Figure 17 01 06” By CNX OpenStax (CC BY 4.0) via Commons Wikimedia