Genetics 101 Resource Guide

Anatomy of a Gene

Introns, exons, and regulatory sequences: Examine the parts of a gene from "start" to "stop." Genes are best known as the instructions for building proteins. However, only a portion of the nucleotides in a gene actually code for the protein itself. Other parts of the gene provide additional information—including sequences that control when, where, and how much protein to make.

Citation: Anatomy of a Gene [Internet]. Salt Lake City (UT): Genetic Science Learning Center; 2016 [cited 2024 Jan 18] Available from https://learn.genetics.utah.edu/content/basics/geneanatomy/

What is a gene?

A gene is the basic physical and functional unit of heredity. Genes are made up of DNA. 

Citation: MedlinePlus [Internet]. Bethesda (MD): National Library of Medicine (US); 2024. What is a gene?; [updated 2021 Mar 22; cited 2024 Jan 22]; [about 2 p.]. Available from: https://medlineplus.gov/genetics/understanding/basics/gene/

What is DNA?

DNA, or deoxyribonucleic acid, is the hereditary material in humans and almost all other organisms. The information in DNA is stored as a code made up of four chemical bases: adenine (A), guanine (G), cytosine (C), and thymine (T). 

Citation: MedlinePlus [Internet]. Bethesda (MD): National Library of Medicine (US); 2024. What is DNA?; [updated 2021 Jan 19; cited 2024 Jan 22]; [about 2 p.]. Available from: https://medlineplus.gov/genetics/understanding/basics/dna/

Central Dogma of Molecular Biology

The central dogma of molecular biology is a theory stating that genetic information flows only in one direction, from DNA, to RNA, to protein, or RNA directly to protein.

Citation: Talking Glossary of Genomic and Genetic Terms: Central Dogma [Internet]. National Human Genome Research Institute; 2024 [cited 2024 Jan 22]. Available from: https://www.genome.gov/genetics-glossary/Central-Dogma  

How do genes direct the production of proteins?

The flow of information from DNA to RNA to proteins is one of the fundamental principles of molecular biology. It is so important that it is sometimes called the “central dogma.”

Citation: MedlinePlus [Internet]. Bethesda (MD): National Library of Medicine (US); 2024. How do genes direct the production of proteins?; [updated 2021 Mar 26; cited 2024 Jan 22]; [about 5 p.]. Available from: https://medlineplus.gov/genetics/understanding/howgeneswork/makingprotein

Transcription

Transcription, as related to genomics, is the process of making an RNA copy of a gene’s DNA sequence. This copy, called messenger RNA (mRNA), carries the gene’s protein information encoded in DNA. In humans and other complex organisms, mRNA moves from the cell nucleus to the cell cytoplasm (watery interior), where it is used for synthesizing the encoded protein.

Citation: Talking Glossary of Genomic and Genetic Terms: Transcription [Internet]. National Human Genome Research Institute; 2024 [cited 2024 Jan 22]. Available from: https://www.genome.gov/genetics-glossary/Transcription  

Overview of transcription 

Transcription is the first step in gene expression and is the process of copying a segment of DNA into RNA. This article describes transcription and the three stages of transcription: initiation, elongation, and termination.

Citation: Overview of transcription (article) [Internet]. Khan Academy; c2024 [cited 2024 Jan 22]. Available from: https://www.khanacademy.org/science/biology/gene-expression-central-dogma/transcription-of-dna-into-rna/a/overview-of-transcription

DNA Transcription and mRNA processing (video)

This video explains transcription, which involves rewriting genetic information from DNA to mRNA. 

Transcription involves rewriting genetic information from DNA to mRNA, with RNA polymerase playing a crucial role. In eukaryotic cells, DNA to mRNA transcription occurs within the nucleus, producing pre-mRNA. This pre-mRNA undergoes processing, including the addition of a 5' cap, a poly-A tail, and splicing out introns, resulting in mature mRNA, which then leaves the nucleus for protein translation. Created by Sal Khan.

Citation: Khan, S. Transcription and mRNA processing (video) [Internet]. Khan Academy; c2024 [cited 2024 Jan 22]. Available from: https://www.khanacademy.org/science/biology/gene-expression-central-dogma/transcription-of-dna-into-rna/v/transcription-and-mrna-processing

Transcription (from Human Biology)

This reading explains the three main stages of transcription: initiation, elongation and termination.

Malmquist  S and Prescott  K. Human Biology. “Chapter 2.3: Transcription.” Copyright © by Sarah Malmquist and Kristina Prescott CC BY-NC 4.0. Available from: https://open.lib.umn.edu/humanbiology/chapter/2-3-translation/ 

Differential Gene Transcription (from Developmental Biology, 6th edition)

Differential gene transcription is the combination of transcription factors that causes particular genes to be transcribed (the process of making an RNA copy of a gene's DNA sequence.) This reading explains anatomy of a gene, examples of transcription factors, and processes that inhibit or enhance the transcription process. 

Citation: Gilbert SF. Developmental Biology. 6th edition. Sunderland (MA): Sinauer Associates; 2000. Differential Gene Transcription. Available from: https://www.ncbi.nlm.nih.gov/books/NBK10023/

Translation

Translation, as related to genomics, is the process through which information encoded in messenger RNA (mRNA) directs the addition of amino acids during protein synthesis. Translation takes place on ribosomes in the cell cytoplasm, where mRNA is read and translated into the string of amino acid chains that make up the synthesized protein.

Citation: Talking Glossary of Genomic and Genetic Terms: Translation [Internet]. National Human Genome Research Institute; 2024 [cited 2024 Jan 22]. Available from: https://www.genome.gov/genetics-glossary/Translation  

Translation (mRNA to protein) (video)

This video explains translation, the process whereby mRNA is converted into proteins. 

Translation is the process whereby mRNA is converted into proteins by ribosomes. Translation occurs in ribosomes, which are cellular structures made of proteins and ribosomal RNA (rRNA). Here, mRNA is converted into amino acid sequences, forming polypeptides. Transfer RNA (tRNA) carries amino acids and matches them with mRNA codons, allowing ribosomes to synthesize proteins. Created by Sal Khan.

Citation: Kahn, S. Translation (mRNA to protein) (video) [Internet]. Khan Academy; c2024 [cited 2024 Jan 22]. Available from: https://www.khanacademy.org/science/biology/gene-expression-central-dogma/translation-polypeptides/v/translation-mrna-to-protein

Translation (from Human Biology)

Translation is the process through which information encoded in messenger RNA (mRNA) directs the addition of amino acids during protein synthesis. This reading explains the players in translation, including the mRNA template, ribosomes, tRNAs, and various enzymatic factors. 

Citation: Malmquist  S and Prescott  K. Human Biology. “Chapter 2.4: Translation.” Copyright © by Sarah Malmquist and Kristina Prescott CC BY-NC 4.0. Available from: https://open.lib.umn.edu/humanbiology/chapter/2-4-translation/

The following databases are explored in the class Bioinformatics and Biology Essentials For Librarians. Databases listed in alphabetical order.

ClinVar 

ClinVar aggregates information about genomic variation and its relationship to human health.

Citation: ClinVar [Internet]. Bethesda (MD): National Library of Medicine (US), National Center for Biotechnology Information; 2013 – [cited 2024 Jan 24]. Available from: https://www.ncbi.nlm.nih.gov/clinvar/

Gene 

Gene integrates information from a wide range of species. A record may include nomenclature, Reference Sequences (RefSeqs), maps, pathways, variations, phenotypes, and links to genome-, phenotype-, and locus-specific resources worldwide.

Citation: Gene [Internet]. Bethesda (MD): National Library of Medicine (US), National Center for Biotechnology Information; 2003 – [cited 2024 Jan 24]. Available from: https://www.ncbi.nlm.nih.gov/gene/

Genetic Testing Registry (GTR)

The Genetic Testing Registry (GTR®) provides a central location for voluntary submission of genetic test information by providers. The scope includes the test's purpose, methodology, validity, evidence of the test's usefulness, and laboratory contacts and credentials. The overarching goal of the GTR is to advance the public health and research into the genetic basis of health and disease.

Citation: Genetic Testing Registry (GTR®) [Internet]. Bethesda (MD): National Library of Medicine (US), National Center for Biotechnology Information; 2012 – [cited 2024 Jan 24]. Available from: https://www.ncbi.nlm.nih.gov/gtr/

MedGen 

Organizes information related to human medical genetics, such as attributes of conditions with a genetic contribution.

Citation: MedGen [Internet]. Bethesda (MD): National Library of Medicine (US), National Center for Biotechnology Information; 2013 – [cited 2024 Jan 24]. Available from: https://www.ncbi.nlm.nih.gov/medgen/

Nucleotide

The Nucleotide database is a collection of sequences from several sources, including GenBank, RefSeq, TPA and PDB. Genome, gene and transcript sequence data provide the foundation for biomedical research and discovery.

Citation: Nucleotide [Internet]. Bethesda (MD): National Library of Medicine (US), National Center for Biotechnology Information; 2004 – [cited 2024 Jan 24]. Available from: https://www.ncbi.nlm.nih.gov/nucleotide/

Protein

The Protein database is a collection of sequences from several sources, including translations from annotated coding regions in GenBank, RefSeq and TPA, as well as records from SwissProt, PIR, PRF, and PDB. Protein sequences are the fundamental determinants of biological structure and function.

Citation: Protein [Internet]. Bethesda (MD): National Library of Medicine (US), National Center for Biotechnology Information; 2004 – [cited 2024 Jan 24]. Available from: https://www.ncbi.nlm.nih.gov/protein/

Structure

Three dimensional structures provide a wealth of information on the biological function and the evolutionary history of macromolecules. They can be used to examine sequence-structure-function relationships, interactions, active sites, and more.

Citation: Structure [Internet]. Bethesda (MD): National Library of Medicine (US), National Center for Biotechnology Information; 2004 – [cited 2024 Jan 24]. Available from: https://ncbi.nlm.nih.gov/structure/

Taxonomy 

The Taxonomy Database is a curated classification and nomenclature for all of the organisms in the public sequence databases. This currently represents about 10% of the described species of life on the planet.

Citation: Taxonomy [Internet]. Bethesda (MD): National Library of Medicine (US), National Center for Biotechnology Information; 2004 – [cited 2024 Jan 24]. Available from: https://www.ncbi.nlm.nih.gov/taxonomy

About NCBI Databases

The National Center for Biotechnology Information (NCBI) provides online information resources for biology, including the GenBank® nucleic acid sequence database and the PubMed® database of citations and abstracts published in life science journals. NCBI maintains a diverse set of 35 databases that together contain 4.3 billion records most of which are available through https://www.ncbi.nlm.nih.gov/search/. 

Citation: Sayers EW, et al. Database resources of the National Center for Biotechnology Information. Nucleic Acids Res. 2024 Jan 5;52(D1):D33-D43. doi: 10.1093/nar/gkad1044. PMID: 37994677; PMCID: PMC10767890.

NLM Navigators to NCBI Biology Databases

These brief tutorials guide you through searches and explorations of the NCBI Biology Databases. These tutorials were written for librarians and other information specialists as part of the course, Bioinformatics and Biology Essentials for Librarians, but could be used by any NCBI user.

Be sure to ALLOW pop-ups in your browser to use an NLM Navigator.

Citation: NLM navigators to NCBI Biology databases [Internet]. Bethesda (MD): National Library of Medicine (US); 2023 [cited 2024 Jan 23]. Available from: https://learn.nlm.nih.gov/documentation/training-packets/T000261112/

NNLM Product Guides

Download guides to NCBI molecular biology databases. The product guides highlight popular uses and key points, intended audiences, teaching and real-life examples, and potential predicaments. Content contributed and edited by National Library of Medicine and University of North Texas Health Science Center Lewis Library.

Basic Local Alignment Search Tool (BLAST) PDF

BLAST is a product of NLM’s National Center for Biotechnology Information (NCBI). This resource finds regions of similarity between biological sequences. The program compares nucleotide or protein sequences to sequence databases and provides statistical information that helps identify biologically meaningful similarities. In other words, BLAST looks at bits of DNA, RNA, or proteins and calculates how similar they are to one another. Intended Users: Information Professionals and Researchers.

Citation: National Library of Medicine and University of North Texas Health Science Center Lewis Library. Basic Local Alignment Search Tool (BLAST) Product Guide. Fort Worth, TX: University of North Texas Health Science Center Lewis Library; 2022 [cited 2024 Jan 23]. Available from: https://www.nnlm.gov/Brd3m

NIH Comparative Genomics Resources (CGR) MS Word

The NIH Comparative Genomics Resource (CGR) is a multiyear project, dataset and toolkit intended to maximize the impact of research on eukaryotic (non-bacterial, non-viral organisms such as animals, plants, and fungi) lifeforms and their genomic data. CGR facilitates reliable comparative genomics analyses, including the study of structure, function, evolution, and mapping of eukaryotic genomes. Intended Users: Information Professionals, Researchers.

Citation: National Library of Medicine and University of North Texas Health Science Center Lewis Library. NIH Comparative Genomics Resource (CGR) Product Guide. Fort Worth, TX: University of North Texas Health Science Center Lewis Library; 2023 [cited 2024 Jan 23]. Available from: https://www.nnlm.gov/BHKwV

PubChem - PDF

PubChem is the world's largest collection of freely accessible chemical information. Search PubChem by name, structure, and other identifiers. The site provides information on physical and biological properties, safety, toxicity, patents, and available literature. PubChem mostly contains small molecules, but includes certain larger molecules such as nucleotides, carbohydrates, lipids, peptides, and chemically modified macromolecules. Intended Users: Students (High School and Above), Information Professionals and Researchers.

Citation: National Library of Medicine and University of North Texas Health Science Center Lewis Library. PubChem Product Guide. Fort Worth, TX: University of North Texas Health Science Center Lewis Library; 2022 [cited 2024 Jan 23]. Available from: https://www.nnlm.gov/Brq5S 

Educational Opportunities

A Biology Student’s Guide to Finding & Organizing NCBI Data for Research Projects

NCBI online workshop (June 2023) for life scientists at all experience levels, including student researchers and the educators and mentors who want to help students use these resources. Explore content through self-guided tutorials or watch a recorded video.

Citation: Morris R, Chang E. A biology student’s guide to finding & organizing NCBI data for Research Projects [Internet]. National Institutes of Health; 2023 [cited 2024 Jan 23]. Available from: https://www.nlm.nih.gov/ncbi/workshops/2023-06_organizing-biology-data/workshop-details.html

Bioinformatics and Biology Essentials for Librarians

This 14-week online class addresses increasing health information access and use by highlighting information about the National Library of Medicine’s NCBI Molecular Biology Databases. 

Citation: Bioinformatics and biology essentials for librarians: Databases, tools, and clinical applications [Internet]. Network of the National Library of Medicine; 2023 [cited 2024 Jan 23]. Available from: https://www.nnlm.gov/training/class-catalog/bioinformatics-and-biology-essentials-librarians-databases-tools-and

NCBI Learn: Tutorials

Training materials from the National Center for Biotechnology Information in HTML, PDF and video formats.

Citation: Tutorials - Learn - NCBI [Internet]. U.S. National Library of Medicine; [cited 2024 Jan 23]. Available from: https://www.ncbi.nlm.nih.gov/home/tutorials/

NCBI Workshops

Upcoming workshops, webinars, codeathons & conferences with NCBI experts.

Citation: NCBI outreach events - NCBI insights [Internet]. U.S. National Library of Medicine; 2024 [cited 2024 Jan 23]. Available from: https://ncbiinsights.ncbi.nlm.nih.gov/ncbi-outreach-events/