**6. Diversity of BPVs**

Although the genomic sequences of approximately 150 HPV types have already been charac‐ terized, at the beginning of the 1980s only six BPV types (BPV1 to 6) had been identified from cases of bovine cutaneous papillomatosis and cancer [37-42].

Studies performed from the beginning of the 2000s onward to investigate the actual di‐ versity of BPVs have indicated the existence of many BPV types, which is similar to ob‐ servations made regarding the human virus. The first such study employed the generic primer pair FAP59/FAP64 on swabs of healthy skin from 19 species of vertebrates. In six of the 10 analyzed bovines that did not exhibit any clinical sign compatible with BPV in‐ fection, one or two putative new BPV types were detected. These putative new viral types were named BAA1 through BAA5 [43].

Subsequently, a study aimed at establishing the prevalence of BPV in teat papillomas and teat healthy skin used the primer pairs FAP59/FAP64 and MY09/MY11 to analyze 15 teat papillo‐ mas and 122 swabs of teat healthy skin on cattle from five Japanese prefectures [44]. That study found four previously characterized BPV types (BPV1, 3, 5, and 6), two of the previously identified putative new BPV types (BAA1 and 5), and 11 additional putative new types (named BAPV1 through 10 and BAPV11MY) among the 39 BPV-positive samples. Nevertheless, the putative new types BAA1 and BAPV7 through 10 were detected only in samples of healthy skin. In addition, during one outbreak of mammary papillomatosis that occurred in Japan and affected 560 heifers, the presence of BPV6 was confirmed in the majority of the 16 analyzed samples [45]. The previously described putative new types BAA5 and BAPV1 were also identified in these animals.

**Figure 4.** Phylogenetic reconstruction based on L1 ORF partial nucleotide sequences (FAP amplicons) demonstrating the classification suggested for the putative new BPV types into the genera *Deltapapillomavirus* (δ), Epsilonpapilloma‐ *virus* (ε), *Xipapillomavirus* (ξ), and a yet unnamed genus that includes BPV7. The numbers at the internal nodes repre‐ sent the bootstrap support values determined for 1000 replicates. The BPV/BR-UEL2, 3, 4, and 5 types are indicated by

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Recently, complementary analysis of several putative new BPV types through sequencing of the full viral genomes allowed the characterization of these new viral types [3]. The first such new type to be characterized was BPV7, which was initially named BAPV6. Because the nt

shading. Source: [48].

**7. New BPV types**

Although cutaneous papillomatosis poses a serious sanitary problem in beef and, even more so, dairy cattle, studies aimed at identifying the BPV types involved in the occurrence of skin lesions in Brazilian cattle are only sporadically performed. Recently, the detection of BPV1, 2, 6, and 8 in papillomas of cattle from the state of Parana was accomplished using generic FAP primers [46,47]. In another study, the identification of four previously undescribed putative new BPV types, named BPV/BR-UEL 2 through 5, pointed to the occurrence of considerable viral diversity among Brazilian cattle [48]. The genetic characterization of one of these new BPV types, namely, BPV/BR-UEL2, through sequencing of the full L1 gene, confirmed that it belongs to the genus *Xipapillomavirus* [49] (Figure 4).

**Figure 4.** Phylogenetic reconstruction based on L1 ORF partial nucleotide sequences (FAP amplicons) demonstrating the classification suggested for the putative new BPV types into the genera *Deltapapillomavirus* (δ), Epsilonpapilloma‐ *virus* (ε), *Xipapillomavirus* (ξ), and a yet unnamed genus that includes BPV7. The numbers at the internal nodes repre‐ sent the bootstrap support values determined for 1000 replicates. The BPV/BR-UEL2, 3, 4, and 5 types are indicated by shading. Source: [48].
