Figure 1.
Phylogenetic reconstruction of the evolutionary history of CatSpers and CatSperβ in metazoans.
The phylogenetic trees of the CatSper protein family (A) and the CatSperβ protein family (B) were constructed using the maximum likelihood approach [37]. Two putative primitive Ca2+ channels (MbrCaVS5 and NveCaVS17) were used as the outgroup for the CatSper family. Bootstrap values of more than 60 are shown at corresponding branches. The CatSper1-4 groups are indicated by rectangular bars, with invertebrate CatSpers filled with white and vertebrate CatSpers with gray. Note that protein sequences that failed in the chi-square test in Tree-Puzzle [69] or contained more than 15% gaps in the refined alignments were not subjected to phylogenetic analysis (Table S1). Abbreviations used: Aca, A. carolinensis; Bfl, B. floridae; Bta, B. taurus; Cfa, C. familiaris; Cin, C. intestinalis; Cja, C. jacchus; Cpo, C. porcellus; Csa, C. savignyi; Eca, E. caballus; Hsa, H. sapiens; Mdo, M. domestica; Mmu, M. mulatta; Mus, M. musculus; Nve, N. vectensis; Oan, O. anatinus; Pan, P. anubis; Ptr, P. troglodytes; Rno, R. norvegicus; Spu, S. purpuratus.
Figure 2.
Conservation of the putative pore domain of CatSpers from invertebrate and vertebrate species.
The putative pore regions of CatSpers from selected species, corresponding to amino acids 210–239 of human CatSper3 (GenBank Accession No., NP_821138.1), were aligned and manually edited to improve alignments. Invertebrate CatSpers are indicated with white rectangular bars and vertebrate CatSpers with gray rectangular bars. The key aspartate residue of CatSpers is overlined with an asterisk symbol. For abbreviations, please refer to the Fig. 1 legend.
Figure 3.
The metazoan phylogeny describing the presence or absence of CatSpers and CatSperβ in examined metazoan genomes.
The phylogenetic branching patterns of metazoans (not proportional to the evolutionary rates) were extracted from the Tree of Life project (http://www.tolweb.org/tree/) as of July 30, 2008. The metazoan lineages known to contain the CatSper channel complex are indicated by boxes with a solid line and gray background, while those believed to lack the channel complex are marked by boxes with a broken line and white background. Two lineages (Porifera and cartilaginous fishes) are underlined since the results obtained from these lineages are based solely on survey genome or genomic traces rather than complete genome sequences. The availability of more metazoan genome sequences in the future will probably expand and/or refine the lineage branches shown here.
Figure 4.
Chromosomal synteny between human and chicken genomes and sequence alignment of degenerated CatSperβ and CatSper3 fragments from bird genomes.
A, chromosomal regions harboring degenerate DNA fragment of putative CatSperβ on chicken chromosome 5 with synteny to human chromosome 14. Shown here are ten genes flanking H. sapiens CatSperβ on human chromosome 14 and syntenic genes on chicken chromosome 5 (not to the scale of base-pair length). CatSperβ is indicated with a black rectangle and other genes with gray rectangles. The location of the degenerate genomic fragment of putative chicken CatSperβ is specified with an open rectangle, and the translated sequence is aligned with HsaCatSperβ. B, H. sapiens CatSper3 is aligned with the short stretch of sequences translated from putative degenerate chicken and zebra finch CatSper3 fragments. Abbreviations for flanking genes can be found in Table S2.
Figure 5.
Phylogenetic tree of the 6-TMS bacterial ion channel family.
A bootstrapped maximum parsimony tree was constructed with a NaV channel homologue in choanoflagellates (MbrNaV-S3L) as an outgroup. Two CatSper sequences, NveCatSper2 and HsaCatSper2, and two putative CaV channel homologues, MbrCaVS5-1 and NveCaV-S17, are also included. The position of the key aspartate residue in the pore region of two bacterial proteins is marked by gray circles. Bootstrap values of >50 are shown at corresponding branches. Each branch of the tree is labeled with the GI numbers in the NCBI protein database for most organisms. NaChBac, NaVSP and NaVPZ channels were functionally characterized previously [36], [61]. Abbreviations: Hsa, H. sapiens; Mbr, M. brevicollis; Nve, N. vectensis.
Table 1.
dN/dS ratios between human and mouse CatSper and CatSperβ genes.