English to Spanish Medical Livestock / Animal Husbandry

I would like to know how to translate into Spanish "spike genome" in this context:

"Amino acid changes occur in the S1 part of the virus’s spike genome, but the rest of the virus genome remains unchanged".

I know that "genome" is "genoma" but I am not sure about the proper translation for that part of the genome.

Thank you very much for your help.