The complete mitogenome of Talpa occidentalis, the Iberian mole, was sequenced using a combination of the Illumina and Sanger methods. The 16,962 bp genome obtained contains 13 protein-coding genes, 22 transfer RNAs, 2 ribosomal RNAs, and a control region. Thirty-seven identical repetitions of a 10-nucleotide (CACACGTACG) repeat element were identified in the non-coding control region (D-loop). The number, order, and orientation of the mitochondrial genes are the same as in T. europaea, the only mitogenome published so far for this genus. These two mitogenomes differ only at the repeat element included in the control region. The phylogeny obtained for the Talpidae species using the protein-coding genes of these mitogenomes agrees with the current classification of this family.

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In the genus Talpa a new species, named Talpa aquitania, has been recently described. Only cytogenetic data are available for the nuclear genome of this species. In this work, we characterize the satellitome of the T. aquitania genome that presents 16 different families, including telomeric sequences, and they represent 1.24% of the genome. The first satellite DNA family (TaquSat1-183) represents 0.558%, and six more abundant families, including TaquSat1-183, comprise 1.13%, while the remaining 11 sat-DNAs represent only 0.11%. The average A + T content of the SatDNA families was 50.43% and the median monomer length was 289.24 bp. The analysis of these SatDNAs indicated that they have different grades of clusterization, homogenization, and degeneration. Most of the satDNA families are present in the genomes of the other Talpa species analyzed, while in the genomes of other more distant species of Talpidae, only some of them are present, in accordance with the library hypothesis. Moreover, chromosomal localization by FISH revealed that some satDNAs are localized preferentially on centromeric and non-centromeric heterochromatin in T. aquitania and also in the sister species T. occidentalis karyotype. The differences observed between T. aquitania and the close relative T. occidentalis and T. europaea suggested that the satellitome is a very dynamic component of the genomes and that the satDNAs could be responsible for chromosomal differences between the species. Finally, in a broad context, these data contribute to the understanding of the evolution of satellitomes on mammals.

Karyotypes of 3 male Talpa specimens from northern Spain were analyzed. The mesostyles of upper molars and cytochrome b sequence analysis identified these specimens as belonging to Talpa aquitania, a new Talpa species recently described from northern Spain and southern France. We describe here for the first time the karyotype of Talpa aquitania. Its diploid number is 2n = 34 and NFa = 64, and all chromosomes including the sex chromosomes are biarmed, either metacentric or submetacentric. G-banding demonstrated that the karyotypes of T. aquitania and T. occidentalis (the most closely related species) are almost identical. However, the karyotype of T. aquitania differs from the karyotypes of both T. europaea and T. occidentalis in that it has a medium-sized biarmed Y chromosome rather than a dot-like chromosome and that chromosome 16 is submetacentric in T. aquitania but has a small p-arm in both T. europaea and T. occidentalis. Pericentromeric C-bands were scarce and only clearly visible in a few chromosomal pairs. In addition, C-banding demonstrated that half of the 14p, the 16p, and the Y chromosome are all heterochromatic. rDNA genes were located at the secondary constriction in autosomal pair 3, a common feature in the karyotypes of all Talpa species. Hybridization signals for telomeric repeats were found on the telomeres and the pericentric regions of some chromosomes and co-localized in the secondary constriction of pair 3 with the rDNA genes. In conclusion, the karyotype of T. aquitania from northern Spain is very similar to the karyotype of other species belonging to the genus Talpa.

some pairs 14 and 16 and, to a lesser degree, with the pericentromeric regions of other autosomes. Together, our analyses demonstrate that the repetitive DNA content of chromosomes from Talpa species is highly conserved.