Name: genomics and dna sequencing
Uploaded: 2020-02-27T08:54:11.000Z
Duration: 2 min 2 s
Channel: JoVE

המחקר של גנים בודדים הביא תובנות יוצאות דופן כמעט בכל תחומי הביולוגיה, החל ממחלות ותורשה וכלה בחקלאות ואבולוציה. עם זאת, שאלות רבות על אופן הגנים עובדים ומתפתחות ניתנות למענה רק על ידי מחקר של כל ה-DNA של האורגניזם הגנום שלו יחד כשלם. המחקר של גנומים שלמים ידוע בשם גנומיקה.זה כרוך ברצף של גנומים שלמים לבחינת ארגון, תפקודם ויסותם, והתפתחותם. הגנומיקה יושבת בצומת הגנטיקה, הביולוגיה המולקולרית ומדעי המחשוב. לאחר שזוהה מבנה ה-DNA בשנת 1953, מדענים החלו לפתח טכניקות לרצף גנים בודדים.פריצת דרך חשובה ברצף ה-DNA הגיעה בשנת 1977 כאשר פרדריק סנגר פיתח שיטה המאפשרת רצף של גנומים שלמים. הדבר הוביל לרצף הגנום לשמרים אפייה ולזבוב הפירות באמצעות גישת shotgun sequencing. פרויקט הגנום האנושי שהחל בשנת 1990 היה מאמץ בינלאומי בן 13 שנים ו-2.7 מיליארד דולר שרצף בהצלחה את הגנום האנושי הראשון בשנת 2003.ההצלחה של פרויקט זה הוביל לחידושים בטכנולוגיות רצף וגנומים אנושיים שכעת ניתן לרצף תוך יום תמורת פחות מאלף דולר. כמויות הנתונים הגדולות שנוצרו גורמות להופעתו של תחום הביואינפורמטיקה המשלב טכניקות מתמטיות ומדעי מחשב לארגון, ניתוח והשוואה בין הכמויות העצומות של נתונים גנומיים. גנומיקה היא כיום מרכיב מרכזי ברפואה המותאמת אישית, למשל בטיפול בסרטן, והיא ממשיכה למלא תפקיד מפתח בתחומים כמו אנתרופולוגיה, אבולוציה, משפטי וחקלאות, בין רבים אחרים.

עליית הגנומיקה. Comptes Rendus Biologies. כרך 339, גיליונות 8-7, יולי-אוגוסט 2016, עמודים 239-231. [<a href="https://doi.org/10.1016/j.crvi.2016.05.002" target="_blank">מקור</a>]
גישות מולטי-אומיות למחלות. גנום ביול. 2017; 18: 83. [<a href="https://www.ncbi.nlm.nih.gov/pmc/articles/PMC5418815/" target="_blank">מקור</a>]

גנומיקה

Genomics

<div style="direction:rtl">גנומיקה היא מדע הגנום: זהו מחקר של כל החומר הגנטי של אורגניזם. בבני אדם, הגנום מורכב ממידע הנישא ב-23 זוגות של כרומוזומים בגרעין, כמו גם DNA מיטוכונדריאלי. בגנומיקה, DNA מקודד וגם DNA לא מקודד עובר רצף ומנתח. הגנומיקה מאפשרת הבנה טובה יותר של כל היצורים החיים, האבולוציה שלהם והמגוון שלהם. יש לו אינספור שימושים: למשל, לבניית עצים פילוגנטיים, לשיפור התפוקה והקיימות של יבולים, סיוע בחקירות פליליות, זיהוי גנים הקשורים למחלות, או מיקוד לטיפול מיטבי בחולי סרטן. במהלך 30 השנים האחרונות התרחשו התפתחויות טכנולוגיות משמעותיות בריצוף DNA, במיוחד הודות למאמץ הבינלאומי של פרויקט הגנום האנושי. כיום קיימת טכנולוגיה לרצף של 60 מיליארד בסיסי DNA, שהם פי 20 מגודל הגנום האנושי. עם השפע הזה של מידע וביג דאטה, מדעני מחשב וביואינפורמטיקה עובדים יד ביד עם ביולוגים על מנת לאסוף, לאחסן ולנתח את פלטי רצף ה-DNA, תוך מתן אפשרות לגשת לנתונים בצורה מאובטחת. הצלחת הגנומיקה פתחה את הדרך לשיטות אחרות בקנה מידה גדול לחקור מערכות ביולוגיות בשלמותן. כעת ניתן להשלים מחקרים גנומיים על ידי מדעי אוֹמיקה (omics) אחרים על מנת לאסוף נתונים על קבוצות חיים בכל הרמות: מינים, אוכלוסיות, פרטים, תאים, חלבונים, RNA, DNA. Transcriptomics הוא המחקר של האופן שבו הביטוי הכולל של גנים משתנה בתנאים ניסויים או פתולוגיים שונים. פרוטאומיקה היא חקר כל החלבונים המהווים אורגניזם או מערכת. מטבולומיקה היא חקר כל המטבוליטים (סוכר, שומנים, מולקולות אחרות) הכלולים במערכת ביולוגית נתונה והאינטראקציות ביניהם. מדעי אומיקה לא ניתנים להפרדה מביואינפורמטיקה, מאפשרות מבט גלובלי על מערכות חיים מורכבות בסביבתם, וככאלה, סוללות את הדרך לרפואה מותאמת אישית.</div>

גנומיקה היא מדע הגנום: זהו המחקר של כל החומר הגנטי של אורגניזם. בבני אדם, הגנום מורכב ממידע הנישא ב ...

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KEY TERMS AND CONCEPTS

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genomics and dna sequencing

Genomics studies the full set of genetic material in an organism. In humans, that genome includes the DNA carried in 23 pairs of chromosomes in the nucleus, along with mitochondrial DNA. Genomics looks at both coding DNA and non-coding DNA, which helps scientists study how living things are built and how they differ.

This field is useful in many areas of biology and medicine. Scientists use genomics to build phylogenetic trees, improve crop productivity and sustainability, help with criminal investigations, find genes linked to disease, and support better cancer treatment choices. It also gives researchers a clearer view of evolution and biological diversity.

DNA sequencing has changed genomics over the past 30 years. Major progress came from the international Human Genome Project, which helped drive faster and more powerful sequencing methods. Today, technology can sequence about 60 billion DNA bases, or around 20 times the size of a human genome.

That amount of data requires bioinformatics, the use of computers to manage and study biological information. Computer scientists and bioinformaticians work with biologists to collect, store, analyze, and secure DNA sequencing results. Their teamwork makes it possible to handle large-scale genomic data.

Genomics also led to other large-scale &quot;omics&quot; studies. Transcriptomics examines how gene expression changes under different experimental or disease conditions. Proteomics studies all the proteins in an organism or system, and metabolomics studies the metabolites, such as sugars, fats, and other molecules, and how they interact.

Together, these omics fields give a broad view of living systems at the level of species, populations, individuals, cells, proteins, RNA, and DNA. Because they rely on bioinformatics, they help scientists understand complex biology in context. They also support the growth of personalized medicine.

Genomics and DNA Sequencing

what is genetic engineering?

How Scientists Edit DNA for New Traits

Genetic engineering changes an organism’s DNA to add useful traits. Scientists use it in bacteria, plants, animals, and even viruses for research, medicine, agriculture, and industry. It can bring major benefits, but it also raises ethical concerns about humans and the food supply. This work is possible because DNA has the same basic structure and genetic code across life. That shared code lets scientists modify DNA in several ways. One method is CRISPR/Cas9, often called molecular scissors,...

dna isolation

Steps in DNA Extraction

DNA extraction is the process of removing and purifying DNA from cells. It is used in many biotechnology and research applications, including molecular cloning. The main goal is to free DNA from the cell and prepare it for later study or use. The first step is cell lysis, which means breaking cells open. Researchers may use a homogenizer, sonicator, or bead beater to physically lyse the cells. They also often add detergent to chemically disrupt the lipid-based cell membranes. This helps...

recombinant dna technology

Recombinant DNA in Cloning and GMOs

Recombinant DNA is made by joining DNA from different sources in the lab. Scientists often use it to clone genes and study them in cells that are easy to handle, such as bacteria. Organisms that carry recombinant DNA are called genetically modified organisms, or GMOs. This technology gives scientists new tools for research, medicine, and agriculture. To build recombinant DNA, researchers place a gene of interest into a vector, which is a DNA carrier that moves foreign DNA into a host cell. The...

PCR Cycle for DNA Amplification

PCR is a laboratory method for making many copies of a DNA segment. It can turn a small amount of DNA into millions or even billions of copies in just a few hours. The process uses a heat-resistant DNA polymerase inside a machine called a thermocycler. PCR was developed by Kary Mullis in 1983, and he received the 1993 Nobel Prize in Chemistry for it. The method is fast, relatively inexpensive, and precise. It has become useful for molecular cloning, gene mutagenesis, pathogen detection, gene...

complementary dna

From mRNA to cDNA for Gene Studies

Complementary DNA, or cDNA, is made from messenger RNA (mRNA) so scientists can study which genes are active in cells and tissues. Only genes that are transcribed into mRNA are expressed. By extracting mRNA from cells, researchers can compare gene expression across samples. cDNA is produced by reverse transcription. This process copies mRNA into DNA, which is useful because mRNA does not contain introns, or non-coding regions, and other regulatory sequences. As a result, cDNA can help...

antibiotic selection

Antibiotic Resistance in Cloning

Antibiotic resistance genes help scientists find bacteria that took up a plasmid with a gene of interest. In genetic engineering, this resistance is used as a marker, not just as a medical concern. The same process also connects to the growing problem of resistant bacteria in the real world. Antibiotics, such as penicillin, stop bacterial growth or kill bacteria. When bacteria naturally have, or are engineered to carry, an antibiotic resistance gene, the antibiotic no longer works on them.

transgenic organisms

Creating Transgenic Plants and Animals

Transgenic organisms are genetically engineered to carry a transgene, which is a gene from a different species, in their genome. The inserted gene may be a new gene for that organism or a different version of one it already has. Scientists usually make transgenes with recombinant DNA and DNA cloning methods. Researchers use transgenic bacteria, plants, and animals to answer biological questions and to build useful tools. To make a transgenic organism, they first choose a transgenesis method,...

in-vitro mutagenesis (gene knockouts)

Knockout Mice and Gene Replacement

Knockout mice help researchers study gene function by showing what happens when a gene is turned off. These engineered animals are also useful for modeling human diseases such as cancer, Parkinson’s disease, and diabetes. A specific gene can be targeted by using a targeting vector, which is a piece of engineered DNA that replaces the normal gene and inactivates it. The vector has matching DNA sequences on both ends. These homologous sequences let the vector swap in for the target gene through...

crispr

CRISPR-Cas9 Gene Editing in Action

CRISPR-Cas9 is a genome editing tool that lets scientists change DNA at a specific location. It can add, remove, or rearrange genetic material. Researchers study it because it may help treat genetic disorders such as hemophilia and sickle cell anemia. CRISPR stands for Clustered Regularly Interspaced Short Palindromic Repeats, and Cas9 is a CRISPR-associated protein 9. The basic system includes a Cas9 endonuclease, which is an enzyme that cuts DNA, and a small RNA that guides Cas9 to the...

gene therapy

Gene Delivery for Serious Diseases

Gene therapy is a technique used to treat serious disease by adding a gene to a person’s cells. The added gene may be a healthy copy of a mutated gene. It may also be a different gene that inactivates or compensates for the disease-causing gene. One example is severe combined immunodeficiency, or SCID, caused by a mutation in the gene for adenosine deaminase. In that case, a working copy of the gene can be inserted so the patient’s cells make the enzyme again. This can cure the disease in some...

embryonic stem cells

How Embryonic Stem Cells Become Specialized

Embryonic stem cells are pluripotent cells that have not yet specialized. Pluripotent means they can give rise to many different cell types in the body. Because of this, they are useful in science and medicine for making cells needed in research or for replacing cells lost to damage or disease. These cells come from the inner cell mass of a blastocyst, which is an early embryo about 3 to 5 days after fertilization in humans. At this stage, the embryo has not yet implanted in the uterus. Human...

adult stem cells

Adult Stem Cells in the Small Intestine

Adult stem cells help maintain tissues by replacing old or damaged cells. These undifferentiated cells divide to make more stem cells or progenitor cells, which then become mature, specialized cells. Small groups of adult stem cells are found in many tissues, including the bone marrow, brain, skin, and gut. The small intestine shows this process clearly. Its lining, called the epithelium, is renewed continuously by adult stem cells. It is also the fastest replaced tissue in the human body,...

induced pluripotent stem cells

Reprogramming Mature Cells into Stem Cells

Reprogramming mature cells into stem cells lets scientists turn specialized cells back into an unspecialized state. These cells are called induced pluripotent stem cells, or iPSCs. Like embryonic stem cells, iPSCs are pluripotent, which means they can form all cell types. To make iPSCs, researchers start with mature cells such as skin fibroblasts or blood cells. The cells are grown in culture, and genes for several transcription factors are delivered with a viral vector. The cells then make...

reproductive cloning

Cloning Animals with SCNT

Reproductive cloning can produce a genetically identical copy of an entire organism. In adult animals, this is usually done with somatic cell nuclear transfer, or SCNT. Another way clones can form is by splitting an early embryo, which is similar to how identical twins arise naturally. In SCNT, an egg cell is taken from an animal and its nucleus is removed. This creates an enucleated egg. A somatic cell, which is any body cell that is not a sex cell, is then taken from the animal to be cloned.

genomics

Genomics studies the full set of genetic material in an organism. In humans, that genome includes the DNA carried in 23 pairs of chromosomes in the nucleus, along with mitochondrial DNA. Genomics looks at both coding DNA and non-coding DNA, which helps scientists study how living things are built and how they differ. This field is useful in many areas of biology and medicine. Scientists use genomics to build phylogenetic trees, improve crop productivity and sustainability, help with criminal...

key terms and concepts

Explore genomics, DNA sequencing, and bioinformatics. Learn how scientists study genomes, use omics, and apply this data in medicine, crops, and forensics.

Genomics and DNA Sequencing | JoVE K12

JoVE Core series brings biology to life through over 300 concise and easy-to-understand animated video lessons that explain key concepts in biology, plus more than 150 scientist-in-action videos that show actual research experiments conducted in today’s laboratories.

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Genomics and DNA Sequencing

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