Influence of Genetic Inheritance on Behavior Objective

Conclusion

Although it is important to note that genetics plays a role in determining behavior and characteristics, it is essential to bear in mind that other factors such as the environment can influence and thus alter certain behaviour.

Waterland and Jirtle (2003) - Conclusion

Genetic expression could be altered simply by change in diet.

Introduction

Genetic inheritance is the process by which genetic information is passed on from parent to offspring. Genes are consideered responsible for the development of behavioral characteristics. However, epigenetics, the newest area of genetic research, shows genetics alone do not influence behavior. Epigenetics refers to the regulation of gene expression and gene repression. Depending on a person's life experiences and environment, their genes can be expressed or repressed, determining which genes take effect. The most well known way your body represses a gene is by methylation, which is the process of addding a methyl group to a gene. Some studies that supports epigenetics through methylation is Heijmans and Lumey and Waterland and Jirtle (2003)

Heijmans and Lumey - Relation

Heijmans and Lumey shows that genetics is not your destiny because stressed caused by the famine resulted in gene repression.

Waterland and Jirtle (2003) - Method

In order to conduct their study, the researchers has to identify a gene. Agouti mice that have an expressed agouti gene will have yellow fur and tend to become obese due to overeating. The researchers obtained mice that were offspring of over 200 generations of agouti mice. At the age of 8 weeks, the mice were randomly assigned into two conditions: the control and experimental condition. The control condition was fed a normal diet of mouse food in pellet form. While the experimental condition was fed a normal diet of mouse pellets as well as pellets supplemented with substances known to be incredibly high in menthyl groups (methy enriched diet). These diets were provided two weeks prior to mating, as well as during pregnancy and lactation.

Heijmans and Lumey - Procedure

In the study, the researchers took DNA samples from people born during the famine and their siblings, born before or after the famine. Using new technology, the researchers searched for methyl groups that were common in the Dutch Winter Hunger cohort, but missing from their siblings.

Heijmans and Lumey - Conclusion

Researchers concluded that the Dutch Winter Hunger added a methyl group to fetuses born to starving mothers, which made the PIM3 gene less active at birth and continued to do so through life.

Heijmans and Lumey - Results

Researchers found a few methyl groups which were a pattern in the Dutch Winter Hunger. These methyl groups were linked to famine and health conditions in later life.

Waterland and Jirtle (2003) - Aim

The aim of the study was the investigate the role of nutrition in epignetic processes.

Waterland and Jirtle (2003) - Results

The results of the study show the agouti mothers have birth to brown mice who, when monitored into adulthood, maintained normal weight and lifespand. In constrast, the mice with an expressed agouti gene who die prematurely due to their obesity.

Heijmans and Lumey - Limitation

The study is not replicable because it is case study of a famine.

Heijmans and Lumey - Strength

This study is highly supported by other studies that adding a methyl group can alter gene expression and result in gene repression.

Waterland and Jirtle (2003) - Relation

This study lucidly shows that epigenetics, which allows for environmental alterations in gene expression.

Waterland and Jirtle (2003) - limitation

Waterland and Jirtle introduced an inordinate amount of methyl-based chemicals into the agouti mice via diet, but that's where their control over the situation ended. They simply hypothesised that the methyl groups would find their way to the agouti gene, and it did. However, the researchers had no idea what other genes were methylated and therefore silenced as a result of the methyl-enriched diet. Also, creating methyl-rich diets to silence genes detrimental to our existence is not so easy.

Heijmans and Lumey

studied the Dutch Winter Hunger

Waterland and Jirtle (2003) - Strengths

this study has the potential to spark future research into developing epigenetic interventions in order to treat diseases.