Folia Zool. – 58(1): 9–13 (2009)

C-banded karyotype and NORs of the long-eared , auritus from Turkey

Atilla ARSLAN1*, İrfan ALBAYRAK2, Nahit PAMUKOĞLU2, Tarkan YORULMAZ2 and Kubilay TOYRAN2

1 Department of Biology, Faculty of Science, Selcuk University, 42031 Konya-Turkey; e-mail: [email protected] 2 Department of Biology, Faculty of Science and Arts, Kırıkkale University, 71450 Kırıkkale, Turkey

Received 11 September 2007; Accepted 5 January 2009

Abstract. The karyotype, C-banding, and nucleolar organizer regions (NORs) of six specimens of Hemiechinus auritus from Turkey were examined. The diploid number of chromosomes was 2n = 48, the fundamental number of chromosome arms FN = 96, and the number of autosomal arms FNa = 92. Most of the chromosomes possessed centromeric constitutive heterochromatin, except of the pairs nos. 4, 6, 7, 8, 9, 12, and 17. The X and Y chromosomes appeared to be euchromatic, and possible geographic variation in their morphology was indicated in comparison with previously published data. The NORs were located in the terminal regions of the long arms of four metacentric or submetacentric chromosomes. The localization of the NORs was not associated with C-positive autosomal regions as in of the genus .

Key words: chromosomal variation, , insectivores

Introduction

The family comprises six genera and 15 species distributed in Africa, Europe, and Asia, including certain parts of Indo-Malaysia (Wilson & Reeder 2005). The karyotype of Hemiechinus auritus (Gmelin, 1770) was studied by Gropp et al. (1969) from Afghanistan, Orlov (1969) from Daghestan, Gropp et al. (1969) and De Hondt (1988) from Egypt, Bhatnagar & El-Azawi (1978) from Iraq, Sharma et al. (1975) and Sobti & Gill (1980) from , Zima & Král (1984) from the Kara- kum desert in Turkmenistan, and Kefelioğlu (1997) and Çolak et al. (1998) from Turkey. The G-, C-banding and NORs patterns were reported by Gropp et al. (1969), Graphodatsky et al. (1991), Yang et al. (1991), O’Brien et al. (2006), and Yang et al. (2006). Mandahl (1978, 1979) and Zima & Král (1984) emphasized that the species belonging to the family Erinaceidae have similar karyotypes but the localization of C-bands and NORs on chromosomes should be considered in their karyotypical structure, because their distribution may vary among both the species and populations. In this study, we aim to examine the karyotype of H. auritus from Turkey, with a special emphasis to the C-banding pattern and the distribution of nucleolar organizer regions (NORs).

Materials and Methods

The examined total six specimens (2 males, 4 females) of long-eared hedgehogs were collected from the Urfa (Ceylanpınar) and the central part of the Kilis province in Turkey. Chromosomal preparations were made using air-drying method from bone marrow (Ford

* Corresponding author

9 & Hamerton 1956) after short cell cultivation, and conventional Giemsa-staining was applied. Constitutive heterochromatin and nucleolar organizer regions (NORs) were detected with C-banding (Sumner 1972) and Ag-NOR staining (Howell & Black 1980), respectively. A total of 10 to 20 slides were prepared from each specimen, and at least 20 well-spread metaphase plates were analysed. Chromosome morphologies were determined according to Zima (1978) by calculating centromeric indices.

Results and Discussion

The karyotype contained 48 chromosomes, the fundamental number of chromosomal arms was FN = 96, and the number of autosomal arms FNa = 92. All the autosomes and the sex chromosomes were bi-armed. The karyotype contained one pair of large subtelocentric autosomes (no. 23), two pairs of very small metacentric autosomes (nos. 21-22), and 20 pairs of metacentric and submetacentric autosomes with gradually decreasing size (nos. 1-20). The X chromosome was a medium-sized metacentric and the Y chromosome was the smallest bi-armed element of the complement (Fig. 1). The karyotype and chromosome characteristics of the specimens examined are quite similar to those reported in Afghanistan, Daghestan, Egypt, Iraq, India, Kara-kum, China and Turkey (Gropp et al. 1969, Orlov 1969, Bhatnagar & El-Azawi 1978, Sharma et al. 1975 Sobti & Gill 1980, Zima & Král 1984, De Hondt 1988, Yang et al. 1991, 2006, Kefelioğlu 1997, Çolak et al. 1998). Slightly different chromosome complements of H. auritus were reported from India (Sharma et al. 1975), Iraq (Bhatnagar & El-Azawi 1978), and Iran-Zenjan (Karataş et al. 2007). The karyotypes of hedgehogs from Iraq and India differed by morphology and size of the sex chromosomes, whereas the specimens from Iran

Fig. 1. Metaphase spread and karyotype of Hemiechinus auritus.

10 Fig. 2. Metaphase spread and C-banded karyotype of Hemiechinus auritus. had a slightly different autosomal set characterized by the presence of dot-like and acrocentric chromosomes. These differences indicate possible geographic variation in the karyotype of H. auritus. The C-banded karyotype is shown in Fig. 2. Most of the autosomes contained a distinct block of centromeric constitutive heterochromatin, which was not observed in the autosomal pairs nos. 4, 6, 7, 8, 9, 12, and 17. The chromosome pair no. 21 appeared to be entirely C-heterochromatic. The X and Y chromosomes were stained C-negatively, and appeared to be euchromatic. Gropp et al. (1969) determined heterochromatin regions in the karyotype of H. auritus by autoradiography. They observed heterochromatin in centromeric regions of some of the autosomes and in the sex chromosomes. Graphodatsky et al. (1991) and Yang et al. (1991) found a similar C-banding pattern in the autosomes, but the sex chromosomes were stained C-negatively. Mandahl (1978) detected indistinct C-bands in the centromeric regions of some chromosomes in species of the genus Erinaceus. By using silver-nitrate staining, NORs were determined in the telomeric region of the long arm of two pairs of metacentric or submetacentric chromosomes (Fig. 3). Yang et al. (1991) determined active NORs in the terminal and interstitial position on long arms of 3-5 chromosomes. Mandahl (1979) observed six NORs in different autosomal pairs of hedgehogs of the genus Erinaceus. The localization of NORs in H. auritus is not associated with heterochromatic regions as in the species of the genus Erinaceus.

11 Fig. 3. Silver-stained metaphase of Hemiechinus auritus. Arrow indicates the Ag-NOR bearing chromosomes.

Acknowledgements We thank Prof. Dr Jan Zima and two anonymous referees for your valuable comments on an earlier version of the manuscript.

LITERATURE

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