Jun 28

Jun 28 Celebrating 20 years of Standard Biological Parts

by Linda Kahl, Abigail Sison, and Vinoo Selvarajah

The use and sharing of parts through the Registry of Standard Biological Parts has been at the core of iGEM’s 20-year history. Each year, iGEM teams have used parts from the Registry to design, build and test their biological systems. And each year, teams have contributed to the Registry, both by designing new parts and by redesigning existing parts to improve their functionality.

To truly appreciate what goes into the design and redesign of parts, we thought it would be helpful to look back on the history of standard biological parts and celebrate the nominees and winners of the Special Prizes for parts over the past 20 years of iGEM.

From ad hoc design to standard biological parts

In 2003, Tom Knight published an assembly method for standard biological parts, or “BioBricks”.

Twenty years ago, scientists were using an ad hoc approach to assemble genetic constructs, which required a lot of time and did not always work as anticipated. Tom Knight, an engineer by training, thought that applying standard engineering mechanisms could make the assembly of genetic constructs more reliable. And so, in 2003, Tom published an assembly method for standard biological parts, or “BioBricks”.

Each BioBrick must include specific DNA sequences located before (“prefix”) and after (“postfix” or suffix) the desired coding sequence, so that every BioBrick could easily be combined with any other BioBrick.

Tom’s assembly method required that each part, or BioBrick, include specific DNA sequences located before (“prefix”) and after (“postfix” or suffix) the desired coding sequence, so that every BioBrick could easily be combined with any other BioBrick. The precise requirements for a BioBrick were published through a “Request for Comments” system as RFC 10, and became the first official standard for biological parts in the Registry.

What are Standard Biological Parts?

Standard biological parts, or more simply “parts”, are DNA sequences with well-defined functions that can be readily combined to engineer a novel biological system. They can be promoters, protein coding sequences, or something more complex, and when you assemble them together in living cells, you can create biological solutions that tackle global challenges, such as climate change, food security, and health.

Celebrating excellence in standard biological parts

It’s hard to underestimate the importance and impact of standard biological parts. More than standardized assembly, the concept of a standard biological part prompted scientists to think in terms of the function of a piece of DNA, and how to link functions together to create more complex biological systems.

Consider, for example, one of the earliest standard biological parts entered into the Registry: BBa_B0034.

BBa_B0034, a Ribosomal Binding Site (RBS) based on the Elowitz Repressilator, is one of the earliest standard biological parts entered into the iGEM Registry of Standard Biological Parts (parts.igem.org) in 2003.

Students in the 2003 MIT course that gave rise to iGEM designed standard biological parts to create biological systems to make cells “blink”. Among this first collection of standard biological parts designed by students that year was BBa_B0034, a ribosome binding site (RBS) based on the Elowitz Repressilator.

The 2004 UT Austin team designed and built a biofilm that could perform distributed edge detection on a light-encoded image - **bacterial photo film!** Photo: Jeff Tabor.

As one of the most popular parts in the Registry, BBa_B0034 has been used over 5400 times to modulate the expression of various coding sequences, to compare the expression of coding sequences in various contexts, and to refine our understanding of how RBS sequences influence gene expression.

In 2004, iGEM started the competition with student teams from five schools (Princeton, MIT, Caltech, UT Austin, and Boston University). This was the year that iGEM began sending out physical samples of the standard biological parts in the Registry to each team as part of the Distribution. Check out the history of the iGEM Distribution here!

In 2005, iGEM grew to 13 teams and became an international competition. That year, each team was recognized for its individual successes. Awards recognizing the creativity and productivity of teams in developing parts and devices included:

Best Brick Award: Penn State (BBa_S03271)
Most Innovative Brick Award: Berkeley (BBa_J01002)
Coolest Part: UCSF
Most Parts Award: Harvard
Second Most Parts Award: MIT
Coolest Part Award and Best Device Award: UCSF

Beginning in 2006, the achievements of teams demonstrating excellence in standard biological parts have been recognized through the Medal Criteria and through Special Prizes, including Best New Basic Part, Best New Composite Part, and Best Parts Collection.

Project Inspiration

Here are some of the highlights from the winners and nominees of past iGEM Competitions:

Best New Basic Part

Basic parts are a functional unit of DNA that (usually) cannot be subdivided into smaller component parts. The iGEM community can use these basic parts to create new devices that will be assembled and work predictably.

Fudan 2022 (China) – Hammerhead Ribozyme (BBa_K4162005), a short catalytic RNA molecule that can anneal to and cleave other RNA molecules. Winner Best New Basic Part, Winner Best Part Collection, Undergrad Division.
Marburg 2021 (Germany) - rrn16 promoter from tobacco (BBa_K3758042). Winner Best New Basic Part, Winner Best New Composite Part, Overgrad Division.
UPF_Barcelona 2020 (Spain) - an intein-mediated T3 biosensor (BBa_K3484000). Winner Best New Basic Part, Overgrad Division.
UCL 2019 (United Kingdom) - DARPin929 (BBa_K3111011), a Designed Ankyrin Repeat Protein that binds specifically to the human epidermal growth factor 2 (HER2) receptor. Winner Best New Basic Part, Undergrad Division.
SYSU-CHINA 2018 (China) - a reversible safe switch for CAR T therapy based on the tet-inducible CMV promoter and U24 protein of Human Herpesvirus 6 (BBa_K2748000). Co-Winner Best New Basic Part, Undergrad Division.
Toulouse-INSA-UPS 2018 (France) – Cerberus, a molecular binding platform (mSA2-CBM3a-AzF) (BBa_K2668010). Co-Winner Best New Basic Part, Undergrad Division.
NTU-Singapore 2018 (Singapore) - RNA base editors: dCas13b-ADAR2DD (BBa_K2818002) and dCas13d-ADAR2DD (BBa_K2818001). Winner Best New Basic Part, Overgrad Division.
Bielefeld-CeBiTec 2017 (Germany) - Variants of the nucleotide transporter PtNTT2 (BBa_K2201004) from the algae Phaeodactylum tricornutum. Winner Best New Basic Part, Overgrad Division.
Imperial_College 2016 (United Kingdom) - Small Transcription Activating RNA (STAR) (BBa_K1893013), a novel and entirely synthetic technology that can be used for implementing RNA logic in bacterial cells. Winner Best New Basic Part, Undergrad Division.
Arizona_State 2016 (United States) - N-Acyl Homoserine Lactone (AHL) Modular Sender Vector (BBa_K2033011). Winner Best New Basic Part and Best Part Collection, Overgrad Division.
Tianjin 2015 (China) - sJanus from Trichoderma reesei (BBa_K1582001), a hydrophobin which aims to change the hydrophobicity of the outer surface of the cell wall. Winner Best New Basic Part, Undergrad Division.
BGU Israel 2015 (Israel) Human short TERT promoter (BBa_K1699001). Winner Best New Basic Part, Overgrad Division.
UCLA 2015 (United States) - Bombyx mori silk co-spinning module (BBa_K1763444). Nominee Best New Basic Part and Best Part Collection, Undergrad Division.
NCTU Formosa 2014 (Taiwan) Converted 9 pheromone biosynthesis activating neuropeptide (PBAN) sequences into standard biobricks. Winner Best New Basic Part, Undergrad Division.

REGISTRY: BEST BASIC PARTS

Best New Composite Part

A composite part is a functional unit of DNA consisting of two or more basic parts assembled together. Generally, the Best Composite Part Award is given to a "device," a composite part that can function independently, without the need for further assembly. The iGEM community can improve upon these devices, use them as part of their designs, and/or use them as a foundation for new devices.

Thessaloniki_Meta 2022 (Greece) - SUMO-LbuCas13a coding device under T7 promoter (BBa_K4170016). Nominated for Best New Composite Part, Best New Basic Part and Best Part Collection, Overgrad Division.
USP-Brazil 2021 (Brazil) - Pollen expressed CYP6G1 and GUS reporter circuit (BBa_K3890000). Nominated for Best New Composite Part, Overgrad Division.
BITSPilani-Goa_India 2020 (India) - pFruB-Cra System (BBa_K3512012) and Atmosphere Regulated Killswitch (BBa_K3512042). Co-Winner Best New Composite Part, Undergrad Division.
NCTU_Formosa 2020 (Taiwan) - Harmonized Gloeobacter rhodopsin (GR) with linker, GFP, T7 promoter and RBA (BBa_K3370601). Co-Winner Best New Composite Part, Undergrad Division.
TUDelft 2020 (Netherlands) - Fox-1 RNA Binding domain (BBa_K3407004) with T7 promoter, RBS, and T1 terminator (BBa_K3407020), and short hairpin RNA targeting eGFP(del6) (BBa_K3407022). Winner Best New Basic Part and Winner Best New Composite Part, Overgrad Division.
LZU-China 2018 (China) - ECOB-miniCMV, biotin promoter (BBa_K2796040). Winner Best New Composite Part, Undergrad Division.
TU_Darmstadt 2018 (Germany) - YcdW generator, E. coli glyoxylate reductase (BBa_K2770002). Winner Best New Composite Part, Overgrad Division.
CLSB-UK 2017 (United Kingdom) - Toehold switch for hsa-miR-15b-5p with GFPmut3b and inducible promoter (BBa_K2206006). Winner Best New Composite Part, High School Division.
TUDelft 2017 (Netherlands) Secretory-abundant heat soluble protein (SAHS) 33020 (BBa_K2306003) with inducible T7 promoter, RBS and double terminator (BBa_K2306008), Winner Best New Composite Part and Best Part Collection, Overgrad Division.
SYSU-MEDICINE 2016 (China) - CXCR5-IRES-eGFP (BBa_K1993005) and CXCR4-T2A-Luciferase-IRES-eGFP (BBa_K1993009). Winner Best New Composite Part, Undergrad Division.
TUDelft 2016 (Netherlands) - OmpA-silicatein: Silicatein gene fused to transmembrane domain of OmpA, with strong RBS (BBa_K1890002). Winner Best New Composite Part, Overgrad Division.
ATOMS-Turkiye 2015 (Turkey) - a miRNA sensing system based on the pTET off-pTRE and mLacI-LacO systems (BBa_K1639009, BBa_K1639010, BBa_K1639011, BBa_K1639015, BBa_K1639016). Nominee Best New Composite Part, Undergrad Division.
Stanford-Brown 2015 (United States) - codon optimized PAL with T7 promoter and Flag Tag (BBa_K1692004). Nominee Best New Composite Part and Best Part Collection, Undergrad Division.
INSA-Lyon 2014 (France) - P70-csgA-His2, double His-tagged csgA under control of the short curli promoter (BBa_K1404008). Winner Best New Composite Part, Overgrad Division.

REGISTRY: BEST COMPOSITE PARTS

Best Part Collection

A part collection is a selection of basic and/or composite parts that are grouped together based on common function, usage, etc. The iGEM community can use these part collections as entire toolkits or ways to select single parts that they find most useful.

UCopenhagen 2022 (Denmark) - a collection of 27 parts that enable the easy assembly and well-documented production of core silks fibers and their protective proteins. The silk fibers include minispidroins of different lengths, the first anemone fiber protein to be added to the iGEM Registry (Aneroin) and the first silk protein based on a marine spider. Winner Best Part Collection, Overgrad Division.
NUS_Singapore 2021 (Singapore) – a curated 'toolkit' collection of parts that enable the development of blue-light inducible systems in S. cerevisiae (BBa_K3927001, BBa_K3927002, BBa_K3927020, BBa_K3927006, BBa_K3927003). Future researchers/iGEM teams can easily access this part collection and use the parts in a 'plug and play' manner, without the need to search for additional parts. Winner Best Part Collection, Undergrad Division.
DTU-Denmark 2020 (Denmark) - morphology toolbox for Aspergillus niger. Winner Best Part Collection, Overgrad Division.
XMU-China 2020 (China) - a part collection related to surface display systems, which includes four kinds of anchor proteins: INPNC, AIDA, BrkA and Lpp-OmpA. Winner Best Part Collection, Undergrad Division.
TUDelft 2019 (Netherlands) - modular cloning (MoClo) compatible parts that can be used for predictable expression of genes across different bacterial species. Winner Best Part Collection, Overgrad Division.
GreatBay_SZ 2019 (China) - Complete parts collection for design of recombinant spider silks. Winner Best New Basic Part and Winner Best Part Collection, High School Division.
Jilin_China 2018 (China) - a toolkit of RNA-based thermosensors: heat-inducible, heat-repressible, cold-inducible and cold-repressible. Winner Best Part Collection, Undergrad Division.
Marburg 2018 (Germany) - a golden-gate-based toolbox containing parts compatible with the PhytoBrick system and MoClo. Winner Best Part Collection, Overgrad Division.
GreatBay_China 2018 (China) - Transcription-activator-like effector (TALE) stabilized promoter family. Winner Best New Basic Part, Best New Composite Part and Best Part Collection, High School Division.
Vilnius-Lithuania 2017 (Lithuania) – a collection of parts that can be used to create a flexible and precise plasmid system. Winner Best Basic Part, Best New Composite Part, and Best Part Collection, Undergrad Division.
NCTU Formosa 2016 (Taiwan) - a collection of spider toxins, lectin, and GS linker as basic parts, and the composite parts with T7 promoter and RBS. Winner Best Part Collection, Undergrad Division.
BostonU 2016 (United States) - Gemini, a design space that combines digital and analog expression systems to easily modulate exogenous gene expression levels in human cells.], including 2 gRNA expression devices (BBa_K1875011-BBa_K1875012) and 7 gRNA-operator devices (BBa_K1875013-BBa_K1875019). Nominee Best New Basic Part and Best Part Collection, Undergrad Division.
Peking 2015 (China) – a collection comprising a Paired dCas9 (PC) Reporter System. Winner Best New Composite Part and Best Part Collection, Undergrad Division.
Imperial 2014 (United Kingdom) - toolbox consisting of 5 new plasmid backbones and ~40 widely used genes for Gluconacetobacter xylinus genetic engineering. Co-Winner Best Part Collection, Undergrad Division.

REGISTRY: BEST PART COLLECTIONS

Over the years, the awards for excellence in standard biological parts and devices have continued to evolve. This year, iGEM is introducing a new Special Prize – Best New Improved Part – to recognize excellence in the redesign and characterization of existing parts. This is the ultimate engineering challenge: improve upon the work that was contributed before. For example, by creating a reporter that shines brighter, or making a more sensitive detector, or improving the specificity of a regulator.

We’re excited to see the new and improved standard biological parts that the 2023 iGEM teams will create, and wish you the best in this year’s Competition!

For more complete information about the Winners and Nominees of awards for parts and devices over the past 20 years of iGEM, check out these pages on iGEM Registry: Best Basic Part, Best Composite Part, Best Part Collection.