What is gl1-seq?
gl1-seq is a platform for storing, versioning and verifying biological sequences. Each sequence gets an identifier computed from its content, each change is recorded as a commit, and any part of a sequence can be proven against its identifier. When a reference genome changes, it updates read alignments and variant calls by redoing only what the change can affect, with the result a full reanalysis would give. It is built on an open protocol developed by The Bioinformatics Company and is coming soon on the GenesisL1 distributed ledger.
What makes up the platform?
Public reference data in chain state: the human reference genome, openly released genomes, GENCODE and the human proteome. Applications: Studio, a genome browser and the Atlas. A developer platform: the gsq command line, libraries in four languages, an agent interface and EVM contracts. Tools for institutions: certified reanalysis with a pilot kit, and a private data layer of salted commitments. Each part is labelled as built, partly built, in pilot, at launch or planned.
What does certified reanalysis guarantee?
That the updated alignments and calls are identical to what a full reanalysis with the same aligner and caller would produce: every BAM record in the same order, and every VCF record in every field. From a certificate of the reference change and the aligner's declared behaviour, gl1-seq derives which read pairs can align differently, re-aligns those, re-calls where the evidence changed and reuses everything else. Each run also re-aligns a random sample of reused pairs as an audit. In the benchmark behind the preprint, on a 30× genome and several kinds of update to GRCh38, the result was identical every time, and several times faster than full recomputation for a local correction. When an update is genome-wide, the planner says before mapping that reuse would not pay and runs the full analysis. Measured values, intervals and methods will be published with the preprint.
Which pipelines does it work with?
Today, minimap2 in short-read mode with bcftools mpileup and call: alignment, sorting and per-sample variant calls, the pipeline behind every measurement on this page. Reuse is a property of each aligner and caller, so each needs its conditions stated and tested. BWA-MEM as released makes a read's alignment depend on the other reads in its batch; a small patch that breaks ties by read name, with a fixed insert size, makes reuse possible in tests, and a whole-genome contract is still to do. DRAGEN is closed source and cannot be covered from outside. Duplicate marking, base-quality recalibration and joint genotyping across a cohort have no reuse contract yet. Existing BWA-MEM or DRAGEN results are not reused: an institution starts from one analysis that gl1-seq records.
What does a biobank need to start?
One server and a few genomes its governance allows for method validation. The pilot kit runs on Linux with 16 or more hardware threads, 32 GB of memory, and about 300 GB of working space plus 70 GB of sort scratch per 30× genome in flight; one script builds every tool from published sources. For each genome it rebuilds the reads from the CRAM, runs the original analysis with gl1-seq's recording, archives it as CRAM and checks the round trip, applies a certified reference update with gl1-seq from the CRAM, and compares the result with full recomputation record by record. The report gives the verdicts, times, storage and costs at the institution's own prices. Plan for several hours per sample on a 32-thread server, most of it the full analyses the pilot runs to check itself. Nothing leaves the machine unless the institution commits a batch of salted commitments.
How is gl1-seq like Git?
Git gave source code content-addressed storage, commits, branches, diffs and merges. gl1-seq brings the same operations to sequences at single-base resolution, which is why it is described as Git for genomes: add, edit, commit, branch, diff, merge, blame and liftover, plus cryptographic proofs that a range of bases belongs to a specific version.
Which kinds of sequence does it support?
DNA, RNA, protein and general text. Nucleotide sequences keep IUPAC ambiguity codes and soft-masking. The same identifiers, proofs and history work for a 110-residue protein and for a 3.1-gigabase genome.
What will be stored on GenesisL1?
At launch, the complete human reference genome GRCh38 in chain state, at about 2 bits per base and about 0.8 GB with its soft mask and overview layers, together with GENCODE gene annotation on its coordinates and 12 pilot genomes stored as deltas against it. More than 1,000 openly released genomes follow in the months after launch. The human proteome and further protein reference sets are on the roadmap.
Is patient or participant data put on the blockchain?
No. Only public reference data and genomes whose donors consented to open release go on chain. Private genomes stay in the institution's own compliant environment. For those, the chain can hold a salted commitment, a fingerprint that proves a record existed and is unchanged without revealing any of it. Destroying the record's salt unlinks the commitment from the data.
How large is a human genome in gl1-seq?
The reference is stored once, about 0.8 GB with its layers. Another person's genome is stored as the deltas of its two haplotypes against that reference: in the current on-chain format, an estimated 70 to 90 MB, extrapolated from a chromosome written to the contracts. That is about 5% of a full copy of both haplotypes at 2 bits per base. A planned change that writes shared variants once would make it smaller. Specialised compressors are smaller still; the deltas rebuild each haplotype exactly and check it against its identifier.
Does gl1-seq replace FASTA, CRAM or VCF?
No. It imports and exports FASTA, carries GA4GH refget and MD5 identifiers for every sequence, and writes chain files for liftOver and CrossMap. In the pilot kit, certified reanalysis reads the CRAM an archive already keeps and writes standard BAM, CRAM and VCF. Raw reads and alignments stay in their own archives. gl1-seq adds what those formats lack: a verifiable identity, a history and proofs.
What does the GenesisL1 ledger add?
The data itself lives in public chain state, so there is one canonical copy that anyone can read and check. History is timestamped by consensus and can't be rewritten. Smart contracts verify proofs on chain, and no single company operates or controls the network. GenesisL1 already holds more than a million PDB and AlphaFold structures in state through MolNFT.
How can an institution take part?
gl1-seq is in development. Institutions can nominate launch datasets, run the pilot kit on a few of their own genomes, or connect the libraries and contracts to their pipelines. Reach the team through the GenesisL1 community channels or on GitHub.