Table 1.
Cytogenetic characteristics of Oryzomyini species of clade D, with diploid number (2n), fundamental number (FN), morphologies of autosomal pairs and sex chromosomes, polymorphisms described and references. *Supernumerary chromosomes are not included in autosomal morphologies. A=acrocentric; M=metacentric; SM=submetacentric; ST=subtelocentric; ITS=interstitial telomeric signals; NA=not available.<br/>
| Species | 2n | FN | Autosomal morphologies* | Sex chromosome morphologies | Cytogenetic characteristics | References |
|---|---|---|---|---|---|---|
| Aegialomys xanthaeolus | 56 | 58 | 25 A<br/> 2 M/SM | X: large A<br/> Y: small A | Gardner and Patton (1976) | |
| Melanomys caliginosus | 56 | 58 | 25 A<br/> 2 M | X: large ST<br/> Y: medium ST | Gardner and Patton (1976) | |
| Sigmodontomys alfari | 56 | 54 | 27 A | X: large A<br/> Y: small A | Gardner and Patton (1976) | |
| Tanyuromys aphrastus | NA | NA | NA | NA | ||
| Nesoryzomys narboroughi | 32 | 50 | 5 A<br/> 8 M/SM<br/> 2 ST | X: medium A<br/> Y: small A | Gardner and Patton (1976) | |
| Nesoryzomys swarthi | NA | NA | NA | NA | ||
| Oryzomys couesi | 56 | 56 | 26 A<br/> 1 M | X: large SM<br/> Y: medium A/ST | Y heteromorphisms | Haiduk et al. (1979) |
| Oryzomys palustris | 56 | 56 | 26 A<br/> 1 M | X: large A<br/> Y: minute A | Haiduk et al. (1979); Gardner and Patton (1976) | |
| Amphinectomys savamis | 52 | 66 | NA | NA | Malygin et al. (1994) apud Musser and Carleton (2005) | |
| Nectomys apicalis | 42 | 40 | 20 A | X and Y: A | Patton et al. (2000) | |
| Nectomys squamipes | 56–59 | 56 | 26 A<br/> 1 M | X: large SM/ ST<br/> Y: medium/ small SM/ST | 0-2 B chromosomes; sex chromosomes polymorphisms | Maia et al. (1984) |
| Cerradomys subflavus | 54–56 | 62 | 21 A, 3 SM, 2M<br/> 23 A, 2 SM, 2M | X: large A/ ST<br/> Y: medium A/ large A | Centric fusion/fission, pericentric inversion, sex chromosomes polymorphisms | Almeida and Yonenaga-Yassuda (1985) |
| Sooretamys angouya | 58, 60 | 60, 64 | 26 A<br/> 2 M | X: large A<br/> Y: medium ST | 0 or 2 B chromosomes | Andrades-Miranda et al. (2001); Silva and Yonenaga-Yassuda (2004) |
| Holochilus brasiliensis | 56–58 | 56, 58, 60 | 26 A<br/> 1 M | X: large ST<br/> Y: small SM | 0 to 2 B chromosomes | Yonenaga-Yassuda et al. (1987) |
| Pseudoryzomys simplex | 56 | 54, 55 | 27 A | X: large A<br/> Y: medium A | Heteromorphic pair 17 due to addition of constitutive heterochromatin | Voss and Myers (1991); Moreira et al. (in press) |
| Lundomys molitor | 52 | 58 | 21 A<br/> 4 M | X: large SM<br/> Y: small M | X heteromorphism | Freitas et al. (1983) |
| Drymoreomys albimaculatus | 62 | 62 | 29 A<br/> 1M | X: large SM<br/> Y: medium SM | ITS in both sex chromosomes | Present study |
| Eremoryzomys polius | NA | NA | NA | NA | NA |