What is the Difference Between Male and Female DNA

The main difference between male and female DNA is that male DNA contains one X chromosome and one Y chromosome, whereas female DNA contains two X chromosomes. Furthermore, a particular variable region on the X chromosome of male DNA may contain either C or G, while that particular region of the X chromosome may contain either C, G or a mixture of C and G in female DNA, proving that there are two types of X chromosomes. Moreover, all the X chromosomes of male DNA contain the same number of a particular STR, while all the X chromosomes of female DNA contains two types of that particular STRs. 

Male and female DNA are the two types of DNA that occur in the two genders of humans. Basically, they differ by the number of X chromosomes present and the characteristics of X chromosomes. 

Key Areas Covered 

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

Key Terms 

Female DNA, Male DNA, STRs, X Chromosome, Y Chromosome

What is Male DNA 

Male DNA is the type of DNA that occurs inside the cells of males. The main feature of male DNA is that it contains one X chromosome with the maternal origin and one Y chromosome with the fraternal origin. Therefore, male DNA contains a single type of X chromosomes.

Figure 1: Male Karyotype

On the other hand, this makes the Y chromosome the sex-determining chromosome in humans. In humans, the Y chromosome contains around 59 million base pairs and around 200 working genes. However, the expression of some of the genes in the Y chromosome occurs heterozygously.  

What is Female DNA 

Female DNA is the other type of DNA set that occurs in humans. They are present inside the female cells, and they contain two X chromosomes with different parental origins. Generally, X chromosome is around 153 million base pairs long. Moreover, it contains around 1000 working genes. Out of this, 200-300 genes are uniquely expressed only in females. Other genes are similar to both males and females. 

Figure 2: Human Chromosome Type XXY

Furthermore, due to the presence of two X chromosomes with different paternal origins, the characteristics of the X chromosome can be used in the discrimination between male and female DNA. Some of these characteristics include the type of nitrogenous base present in a particular variable region on the X chromosome and number of repeats of a particular STR present in the X chromosome. Here, female DNA contains two different X chromosomes, and therefore, two variables of a particular characteristic can be identified in female DNA. However, as male DNA contains a single X chromosome, only one variable should occur out of the two in male DNA. 

Similarities Between Male and Female DNA 

• Male and female DNA are the two sets of DNA found in humans. 
• The characterization of male and female DNA is important for gender discrimination in forensic studies. 

Difference Between Male and Female DNA 

Definition 

Male DNA refers to the set of DNA in males, while female DNA refers to the set of DNA in females. 

Sex Chromosomes 

While male DNA contains one X chromosome and one Y chromosome, female DNA contains two X chromosomes with different origins. Thus, this is the main difference between male and female DNA.

Type of Sex 

Furthermore, male DNA has heterogametic sex, while female DNA has homogametic sex. 

Karyotype 

Besides, the karyotype of male DNA is 46: XY, while the karyotype of female DNA is 46: XX. 

Number of X Chromosomes 

Another major difference between male and female DNA is that male DNA contains only one X chromosome, while female DNA contains two X chromosomes with different origins. 

Number of Genes 

Also, the Y chromosome of males contains around 200 working genes, while the X chromosome of females contains around 1000 working genes.  

Polymorphic Sites 

A particular variable region on the X chromosome of male DNA may contain either C or G, while that particular region of the X chromosome may contain either C, G or a mixture of C and G in female DNA, proving that there are two types of X chromosomes.  

STRs 

Moreover, all the X chromosomes of male DNA contain the same number of a particular STR, while all the X chromosomes of female DNA contains two types of that particular STR. Hence, this is also an important difference between male and female DNA.

Sex Abnormalities 

Klinefelter syndrome (XXY) and XYY syndrome are the sex abnormalities associated with male DNA, while Turner syndrome (X0) and triple X syndrome are the sex abnormalities associated with female karyotypes.  

Conclusion 

Male DNA is the set of chromosomes that occurs inside cells of a male. Moreover, it contains one X chromosome from the mother and one Y chromosome from the father. As it contains a single X chromosome, a particular variable region contains a single type of base. However, in female DNA, there can be two different types of bases in the two X chromosomes. Also, the X chromosomes of male DNA contains a single type of a particular STR. But, in female DNA, there can be two types of a particular STR since female DNA contains two X chromosomes. Basically, these are due to the presence of two X chromosomes in female DNA. Therefore, the main difference between male and female DNA is the type of sex chromosomes present in each type of DNA.  

References:

1. Institute of Medicine (US) Committee on Understanding the Biology of Sex and Gender Differences; Wizemann TM, Pardue ML, editors. Exploring the Biological Contributions to Human Health: Does Sex Matter? Washington (DC): National Academies Press (US); 2001. 2, Every Cell Has a Sex. Available Here. 
2. Jonfwilkins. “HOW DOES THE FBI KNOW IT FOUND ‘FEMALE DNA’?” Lost in Transcription, 30 Apr. 2013, Available Here.

Image Courtesy:

1. “Karyotype of normal male pig” By Liao YJ, Liao CH, Liao JW, Yuan K, Liu YZ, et al. (2014) Establishment and Characterization of Novel Porcine Induced Pluripotent Stem Cells Expressing hrGFP. J Stem Cell Res Ther 4:208. doi:10.4172/2157-7633.1000208 (CC BY 4.0) via Commons Wikimedia   
2. “Human chromosomesXXY01” By User:Nami-ja – Own work (Public Domain) via Commons Wikimedia