BiRNA-BERT Allows Efficient RNA Language Modeling with Adaptive Tokenization

Published in Nature Communications Biology, 2025

Md. Toki Tahmid*, Haz Shahgir*, Sazan Mahbub, Yue Dong, Shamsuzzoha Bayzid

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RNA language models usually have to truncate long sequences, and NLP-style tokenization does not transfer cleanly to nucleotide-level tasks. BiRNA-BERT is a 117M-parameter encoder trained on 36 million RNA sequences with an adaptive dual tokenizer: nucleotide-level encoding for short, structure-sensitive inputs and BPE for long sequences. That lets the model handle arbitrarily long RNAs without truncation, match much larger models on short-sequence tasks, and set strong results on long-sequence downstream work at a fraction of the pretraining compute.