The Building Blocks of Life

In 2012, the world — and human civilization along with it — changed forever. Although there was little fanfarefanfare언론·대중의 떠들썩한 관심 when Dr. Jennifer Doudna and Dr. Emmanuelle Charpentier first published their discovery that the CRISPR-Cas9 bacterial immune system could be repurposedrepurposed다른 용도로 바꿔 쓰다 to edit DNA, their research soon led to an explosion of papers.

Methods to edit genes existed before, but they were slow and expensive. CRISPR changed that. Its simplicity meant it was soon adopted by labs around the world and has permeatedpermeated구석구석 퍼지다·스며들다 more and more of our lives, opening new frontiersfrontiers어떤 분야에서 이해의 최전선·미개척 영역 within biology and spawningspawning대량으로 만들어 내다·생겨나게 하다 experimental medical treatments.

In bacteria, the CRISPR system is used for adaptive immunity. When a bacterium is infected by a virus, it uses a Cas nuclease (an enzyme which can cut DNA) to remove a piece of the viral DNA, storing this fragmentfragment잘려 나온 작은 조각 within its own genomegenome세포·생물에 있는 유전자 전체 as a kind of library — so it can quickly respond if reinfected.

For gene editing, scientists give the Cas9 nuclease a new RNA guide to find a matching section of DNA and cut it. If they give it a guide for a defectivedefective결함이 있는·불완전한 gene, it finds and cuts that gene. The body’s DNA repair mechanisms then kick inkick in효력·작동이 시작되다, but the method is proneprone~하기 쉬운 (특히 나쁜 일) to errors — useful for disabling a deleteriousdeleterious해를 끼치는·유해한 gene, or for studying what a gene does.

CRISPR can be used in diagnosticsdiagnostics무엇이 잘못됐는지 진단하는 의학 분야 to identify genetic abnormalitiesabnormalities정상이 아닌 특징·이상, to diagnose infections, and in agriculture to create crops resistant to high salinitysalinity염도·소금 함량. Most controversially, a 2019 landmarklandmark중요한 전환점이 되는 (사건·발견) trial edited patients’ DNA to produce an alternative form of hemoglobinhemoglobin혈액에서 산소를 운반하는 적색 단백질 — and research now targets diseases with genetic componentscomponents더 큰 것의 구성 요소, from cancers to Huntington’s.

He Jiankui, the controversialcontroversial논쟁을 일으키기 쉬운 Chinese scientist who shocked the world when he modified the genomes of children in 2018, has unveiledunveiled처음으로 공개·발표하다 new plans to modify human embryosembryos발생 초기의 배아. That research earned him a three-year prison sentencesentence법원이 내리는 형벌 in 2019, but he has since returned to the spotlight.

According to the succinctsuccinct간결하고 명료한 research proposal, He plans to first modify mouse embryos, then human embryos, to investigate whether certain mutations could protect against Alzheimer’s. Experts have already condemnedcondemned공개적으로 비난하다 the plans, noting the similarities to his earlier work.

Like the research which landedlanded곤란한 상황에 처하게 하다 him in jail, the proposal could involve making irreversibleirreversible되돌릴 수 없는 changes to human DNA that would be passed down to subsequentsubsequent뒤이어 오는·후속의 generations — raising profound ethical questions about consent, as well as a raftraft아주 많은 양·다수 of safety concerns. He framed it as a gravegrave심각한 socioeconomicsocioeconomic사회·경제적인 issue, citing the aging population.

Perhaps to allayallay(부정적 감정을) 가라앉히다·완화하다 fears, He stated his experiment would use abnormal fertilized egg cells that could not be implantedimplanted몸 안에 삽입·이식하다 or carried to termcarried to term출산 가능할 때까지 임신을 유지하다. Still, questions remain about whether authorities would approve such work given He’s past transgressionstransgressions법·규칙을 어긴 행위. The disgraceddisgraced명예가 크게 실추된 scientist’s proposal has reignitedreignited다시 불붙게 하다 the debate around human gene editing — where the ethics of modifying someone before they can consent remain a lot murkiermurkier더 불분명한·모호한.