Karyological Study on Kloss's Mole Euroscaptor Klossi (Insectivora

Mammal Study 31: 105–109 (2006) © the Mammalogical Society of Japan

Karyological study on Kloss’s mole Euroscaptor klossi (Insectivora, Talpidae) collected in Chiang Rai Province, Thailand

Shin-ichiro Kawada1,*, Shuji Kobayashi2, Hideki Endo3, Worawut Rerkamnuaychoke4 and Sen-ichi Oda5

1 Department of Zoology, National Science Museum, Tokyo, Shinjuku, Tokyo 169-0073, Japan 2 Department of Biosphere-Geosphere System Science, Faculty of Informatics, Okayama University of Science, Okayama 700-0005, Japan 3 Section of Morphology, Primate Research Center, Kyoto University, Inuyama, Aichi 484-8506, Japan 4 Department of Veterinary Medicine, Kasetsart University, Bangkok 10900, Thailand 5 Graduate School of Agricultural Sciences, Nagoya University, Nagoya, Aichi 464-8601, Japan

Abstract. We present the first karyological study on Kloss’s mole Euroscaptor klossi from Chiang Rai Province of Thailand. We used differential chromosome staining methods and determined the diploid and fundamental autosomal numbers to be 36 and 54, respectively. Compared with the G- and C-banded karyotypes of the Japanese mountain mole E. mizura, the karyotype of E. klossi involved a reciprocal translocation followed by a pericentric inversion of chromosomes 1 and 16 of the ancestral karyotype of E. mizura. Some minor C-band duplications supplemented the karyological differences between the two species. The karyotype of E. klossi is distinct from that of the Malaysian mole E. micrura malayana examined previously and these species have distinct scenarios in diverging from the ancestral karyotype of the genus Euroscaptor.

Key words: Kloss’s mole, Euroscaptor klossi, karyotype, G-band, C-band, taxonomy.

Kloss’s mole Euroscaptor klossi occurs in western and of Kloss’s mole, e.g., the tail ratio and fur color docu- northern Thailand. This species was previously thought mented by the Earl of Cranbrook (1962). Nevertheless, to be a conspecific to the short-tailed mole E. micrura in morphological analysis has not resolved the taxonomic the Himalayas (Schwarz 1948; Ellerman and Morrison- problem due to the insufficient number of specimens Scot 1951; Corbet and Hill 1992), but recent taxonomic in museum collections. For further taxonomic revision revisions show that it is a valid species (Yoshiyuki 1988; would be genetic research based on the karyology and Hutterer 2005). Morphologically, E. klossi is much molecular phylogeny required. Recently, karyological smaller in body size than E. micrura, but has a longer and molecular phylogenetic studies of the Malaysian tail. Thomas (1929) first described E. klossi as a mole mole and Japanese mountain mole E. mizura were collected in Raheng (present name Tak) in western Thai- published (Shinohara et al. 2004; Kawada et al. 2005). land by C. Boden Kloss and K. G. Gairdner (Chasen and This paper presents the G- and C-banded karyotypes of Kloss 1930) and a few reports on this species have been Kloss’s mole. The taxonomic relationship of Kloss’s published (Kawada 2005). mole and the Malaysian mole is discussed based on a Much more information is available on the mole from comparison of karyotypes of the genus Euroscaptor. Peninsular Malaysia discovered by Chasen (1940). The Malaysian mole was first considered as a subspecies of Materials and methods Kloss’s mole, but recent study (Kawada et al. 2003) has not supported this idea. The external morphological We collected two male specimens of E. klossi in Mae traits of the Malaysian mole are very different from those Salong, Chiang Rai Province, Thailand (20°09'57.4''N,

*To whom correspondence should be addressed. E-mail address: [email protected] 106 Mammal Study 31 (2006)

Table 1. Collecting data and measurements of Kloss’s moles from Mae Sa Long, Chiang Rai, Thailand.

Measurements* Specimen Sex Date Number Weight Head & Body Tail Fore foot Hind foot Testis Tail ratio Skull (g) (mm) (mm) (mm) (mm) (mm) (%) (mm) NSMT-M 34363 ♂ 8, Jan., 2004 47.80 135.5 9.5 16.5 × 16.0 15.0 3.81 × 2.15 6.55 33.41 NSMT-M 34364 ♂ 8, Jan., 2004 55.50 130.0 10.5 16.0 × 16.0 15.0 4.25 × 2.71 7.47 –

* Fore foot: length × width, Testis: long × short diameters, Tail ratio: tail/Head & Body × 100, –: not measured.

99°37'23.2''E). The elevation is about 1200 m. specimen data are shown in Table 1. Specific identification was based on fur color, the nostrils, and skull dimensions (Kawada et al., in prep.). These specimens were depos- ited in the National Science Museum, Tokyo, Japan (specimen numbers: NSMT-M 34363 and 34364). Bone marrow cells from the collected animals were cultured and fixed according to standard procedures in the collecting locality using a manual centrifuge. Skin fiblobrasts of moles were cultured. Giemsa-stained chro- mosomes were classified as meta-submetacentric (M), subtelocentric (ST), and acrocentric (A) chromosomes according to Levan et al. (1963). G- and C-banding were performed according to the ASG method of Sumner et al. (1971) and BSG method of Sumner (1972), respectively. The karyotypes were arranged according to their affinity to the standard karyotype of the genus Euroscaptor reported by Kawada et al. (2001). To compare the G-banding, we used the G-banded karyotypes of the Japanese mountain mole E. mizura, and the Malaysian mole (Kawada et al. 2001, 2005).

Results

Karyotype of E. klossi The diploid number (2n) of two male E. klossi was Fig. 1. Conventional (a), G-banded (b), and C-banded (c) karyo- types of Kloss’s mole Euroscaptor klossi. Asterisks and an arrowhead determined to be 36, and the fundamental autosomal indicate chromosome crossovers and secondary constrictions, respec- number (Nfa) was 54. The conventional karyotype of tively. In the conventional and C-banded karyotypes, chromosomes E. klossi is shown in Fig. 1a. The karyotype consisted M2–M7 and A1–A8 were not identifiable, and are unnumbered. of one large metacentric chromosome (M1), six medium to small-sized metacentrics (M2–M7), two large and and 1c. The G-banded chromosomes enabled us to dis- medium subtelocentrics (ST1 and ST2), and eight acro- tinguish homologs from the distinct banding patterns. centric pairs (A1–A8) with decreasing sizes. Chromo- The C-bands were observed in the centromeric positions some M2 had a remarkable secondary constriction on of all chromosomes, and small C-blocks were also local- the proximal region of short arm (Fig. 1a, arrowhead). ized on the short arm of chromosomes A1 and Y. Chromosomes A1–A4 were large, and a small short arm was observed characteristically in A1. The X- and Y- Comparison between E. klossi and E. mizura chromosomes were a small metacentric chromosome and Euroscaptor klossi and E. mizura shared the same dip- a minute dot-shaped chromosome, respectively. loid and fundamental autosomal numbers, but differed The G- and C-banded karyotypes are shown in Fig. 1b slightly in G-banding patterns, which is compared in Fig. Kawada et al., Karyological study of Euroscaptor klossi 107

Fig. 2. Composite G-banded karyotype of Kloss’s mole and the Japanese mountain mole Euroscaptor mizura.

number of the Asian species of the moles were concen- trated to 36 (Tsuchiya 1988; Yates and Moore 1990), however the G-banding pattern had been repeatedly assigned to be distinct between each other (Kawada et al. 2001, 2005). In the present case, partial differences were evident in the composite karyotype (Fig. 2) and the G- band homology between E. klossi and E. mizura is explained by the reciprocal translocation followed by one pericentric inversion (Fig. 3). Taxonomic treatment of E. klossi had been contro- Fig. 3. Summary of the G-band homology of chromosomes M1 and versial, whether to include the Malaysian mole or not. A8 of Kloss’s mole and chromosomes 1 and 16 of the Japanese moun- Kawada et al. (2005) reported the result of G-banding tain mole. Dotted lines indicate regions homologous between species. analysis on the Malaysian mole, thus a karyological comparison of the Malaysian mole and Kloss’s mole is 2. These two species shared all the chromosomes, except important for evaluating the taxonomy of the moles from for chromosomes M1 and A8, which correspond to num- Thailand and Malaysia in this paper. bers 1 and 6 in the standard karyotype of E. mizura, with The diploid and fundamental autosomal numbers of some partial homologies. Detailed comparisons of these the Malaysian mole were 2n = 36 and NFa = 54, respec- chromosomes are shown in Fig. 3. The G-band pattern tively. In comparing the karyotypes of the Malaysian of the short arm of chromosome 1 in E. mizura was mole and Kloss’s mole, the chromosomal makeup is homologous to the long arm of A8 in E. klossi. The long quite similar to each other, while the G-banding pattern arm of chromosome 1 in E. mizura had the banding pat- differs markedly. Kawada et al. (2005) suggested that tern same as almost half of the proximal long arm of M1 the karyotype of the Malaysian mole had been reorga- in E. klossi. The proximal and distal parts of chromo- nized via one reciprocal translocation in chromosomes 1 some 16 in E. mizura were allotted to the short arm and and 13 of E. mizura. The results in the present study also distal part of the long arm of M1 in E. klossi, respec- show a translocation event, but involves different chro- tively. mosomes, chromosomes 1 and 16 (Fig. 2). Therefore, the Malaysian mole and E. klossi underwent a distinct Discussion translocation from the ancestral type of E. mizura (Fig. 4). Euroscaptor klossi has an additional pericentric in- The diploid and fundamental autosomal numbers of version from the ancestral E. mizura (Fig. 3). As noted E. klossi were the same as those of E. mizura and the above, the karyological distinctness of the moles from greater Japanese mole Mogera wogura (Kawada et al. Thailand and Malaysia is obvious and reproductive 2001), seeming the karyological conservatism of talpid isolation undoubtedly occurs between them based on moles. As shown in the previous reports, the diploid the drastic karyotype reorganization (King 1993). The 108 Mammal Study 31 (2006)

Research Institute for providing information about Thai mammals. Most of the experiments were conducted in the Shitara Field Research Center of Nagoya University, with the help of their staff. This study was supported financially by a Grant for Biodiversity Research from the 21st Century COE (A14), Grant-in-Aids for Scientific Research nos. 17405018, 17637004, and 17657081 from the Ministry of Education, Culture, Sports, Science and Technology of Japan, and by the JSPS core-to-core pro- gram HOPE.

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