Two major R1 lineages, A and B, that diverged about 100 MYA were found to exist in Drosophila. In D. neotestacea, one family corresponded to the R1A lineage, while the second was >50% divergent in nucleotide sequence from the A lineage and was referred to as the R1B lineage. An extensive sampling of elements in 35 species confirmed that the R1B lineage is relatively rare in Drosophila.
Two major R1 lineages, A and B, that diverged about 100 MYA were found to exist in Drosophila. In D. neotestacea, one family corresponded to the R1A lineage, while the second was >50% divergent in nucleotide sequence from the A lineage and was referred to as the R1B lineage. An extensive sampling of elements in 35 species confirmed that the R1B lineage is relatively rare in Drosophila.