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Home , Paenungulata, Proboscidea, Rock hyrax, Tethytheria

© 2015 The Japan Mendel Society Cytologia 80(3): 287–293

Karyotype Determination of Rock Procavia capensis in Saudi Arabia

Saud A. Al-Dakan and Abdulaziz A. Al-Saleh*

Zoology Department, College of Science, King Saud University, P.O. Box 2455, Riyadh 11451, Saudi Arabia

Received November 1, 2014; accepted May 31, 2015

Summary Procavia capensis is considered as a small mammalian which belongs to Hyracoidea, and it is the only species of the order that has been found in Saudi Arabia. Therefore, karyotype analysis of this species has been carried out and the finding summarized as follows. The diploid chromosome number is 54. In the karyotype analysis, the somatic chromosomes were catego- rized into three groups: 21 pairs of acrocentric, 2 pairs of submetacentric and 3 pairs of metacentric chromosomes. The sex chromosomes are one submetacentric X chromosome and one acrocentric Y chromosome. The lengths of chromosomes varied between 1.6–7.6 µm, and the Y chromosome is the shortest. The FN is 65 in the male and 66 in the female, while the FNa is 62. The karyotype formula of Procavia capensis could be deduced as: a sm a sm a sm m (2=54);Ln 14+ L 1 + M 14 + M 2 ++ S 15 S 2 + S 6

Key words Karyotype, Rock hyrex, Chromosome, Procavia capensis.

The (Procavia capensis) is one of small mammalian herbovorous that lives in small family groups ranging from 10 to 80 members headed by a dominant adult male which defends and watches over the group (Turner and Watson 1965, Grzimek 1975, Skinner and Smithers 1990, Estes 1991, Kingdon 1991, Manharth and Harris-Gerber 2002). This animal be- longs to the family and feeds on a wide variety of different plants including both grasses and shrub leaves and sometimes eats insects and lizards (Burton 1941, Grzimek 1975). The rock hyrax is found across , the and particularly in the Arabian Pen- insula and the Levant, including Syria, Palestine and (Kingdon 1971). Procavia capensis is the only species found in the kingdom of Saudi Arabia (Kingdon 1990). This species spreads in the Kingdom of Saudi Arabia in the mountainous regions of Sarawat Mountains in the western region and in the chain Twaiq Mountains in Najd Plateau (Gasperetti 1978, Vincett 1982, Kingdon 1990, Nader 1990, Harrison and Bates 1991, Kamal 1996). It also lives in the middle of vegetation and hides in caves and rock crevices and cavities because it needs secure shelter, but does not reside in burrows because it is unable to dig burrows and cannot drill (Hoeck 1975, Olds and Shoshani 1982, Estes 1991). The rock hyrax can climb rocks skillfully, as the rest of its feet have cushions containing sweat glands that excrete an adhesion solution, enabling it to climb smooth rocks (Bar- tholomew and Rainy 1971, Olds and Shoshani 1982, Estes 1991). This animal is important because it is much like a but mostly larger, has sometimes weighed up to 5 kg, and is always vulnerable to hunting for the purpose of eating or for medical purposes in some cases. In folk medicine, the animal waste from and urine, known as hyra- ceum, is used in the treatment of epilepsy and some women’s diseases (Olds and Shoshani 1982,

* Corresponding author, e-mail: [email protected] DOI: 10.1508/cytologia.80.287 288 S. A. Al-Dakan and A. A. Al-Saleh Cytologia 80(3)

Kraemer 2001). The rock hyrax also is a natural reservoir or favorite host for Leishmania which causes skin Coetaneous leishmaniasis and the infection incidence with this parasite might reach up to 80% (Talmi-Frank et al. 2010). There are also those who believe that the animal can be used like an animal laboratory to conduct some scientific experiments, where it lives under captivity for a period of 12 years (Griner 1968, Fourie 1978). This animal is devastating agricultural crops, par- ticularly fruit trees. Therefore, it is included under harmful or vermin animals and in some areas, electric fences are placed to eliminate the animal (Hanse 1962). Due to the economic and medical importance of this animal and the lack of studies on its chromosomal patterns, we determined to study the nature of the chromosomal pattern and es- tablish its karyotype as the first study to performed on this species from the Kingdom of Saudi Arabia.

Materials and methods

Ten adult males and 10 adult females were collected from the central province and the south- ern province of the Kingdom of Saudi Arabia and were kept in a room containing some rocks and fresh branches of Acacia. Each animal was injected with intraperitoneal with 2 mL colchicine solu- tion (1 mg mL－1) and kept for 4–6 h before the animal was sacrificed. The femoral bones were re- moved and their bone marrow was flushed with 7 mL of hypotonic solution (0.56% potassium chlo- ride). The bone marrow cells were suspended very well and cells kept in the hypotonic solution for 30 min at 37°C. The bone marrow cells were centrifuged at 1000 rpm for 5 min and the cell pellet was suspended in 7 mL of fresh fixative (3 : 1 methanol–acetic acid). The fixation procedure was re- peated twice and finally the cells were fixed in 2 mL of fresh fixative. One drop of cells was spread onto the microscopic slide. The cells were stained with 5% Giemsa stain for 5 min and left to dry completely before examination. More than 100 metaphase stages have been scanned for each male and female under Zeiss microscope provided with digital imaging high-resolution camera. Good metaphase stages were selected, photographed under immersion oil lens and mounted into the computer for analysis. The length of the arms of the chromosomes was measured directly under the microscope using an ocular eyepiece with reticule, and the centromeric position and relative arms length were calculated using the terminology described by Levan et al. (1964). The fundamental number of the chromosomes or the number of arms of the chromosomes was calculated according to the hypothesis of Matthey (1945).

Results

In this study, the chromosomes of the male and female rock hyrax Procavia capensis have been identified and described. The rock hyrax animals that have been collected from the Riyadh and Mecca provinces are technically the same except that the animals collected from Riyadh prov- ince are light brown (Fig. 1), while those obtained from Mecca province are dark brown and the blackness is due to the black color of the mountains of the province (Fig. 2). Figures 3 and 4 show the karyotype of the male and female Procavia capensis, respectively. The karyotype consists of a diploid number (2n)=54 chromosomes. These chromosomes are 21 pairs of acrocentric (1–21), 2 pairs of submetacentric (22–23) and 3 pairs of metacentric chromo- somes (24–26). The sex chromosomes are one metacentric X chromosome and one acrocentric Y chromosome. The measurement of the length of the chromosomes was calculated from five different karyo- types and the relative length represented in Table 1. Acrocentric chromosomes were classified according to their length into three types: 1) Chromosomes 1–7 are large-size chromosomes; 2) Chromosomes 8 to 14 are medium-size chromosomes; 3) Chromosomes 15 to 21 are small-size 2015 Karyotype Determination of Rock Hyrax Procavia capensis in Saudi Arabia 289

Fig. 1. Rock hyrax from Riyadh province. Fig. 2. Rock hyrax from Mecca province.

Table 1. Mean length of the total chromosome length, length of its arms and the type of centromeres of Procavia capensis. No. Short arm P Long arm Q Total length p+q Arm ratio q/p Centromere 1 1.1 6.5 7.6 6.0 a 2 1.0 5.8 6.8 5.8 a 3 1.1 5.4 6.5 4.9 a 4 1.1 5.3 6.4 4.8 a 5 1.0 4.9 5.9 4.9 a 6 1.1 4.3 5.4 3.9 a 7 1.0 4.2 5.2 4.2 a 8 1.0 3.8 4.8 3.8 a 9 0.8 3.8 4.6 5.3 a 10 0.6 3.2 3.8 5.3 a 11 0.6 3.0 3.6 5.0 a 12 0.6 3.0 3.6 5.0 a 13 0.6 2.9 3.5 4.8 a 14 0.7 2.5 3.2 3.6 a 15 0.6 2.3 2.9 3.8 a 16 0.5 2.3 2.8 4.6 a 17 0.5 2.2 2.7 4.4 a 18 0.5 1.9 2.4 3.8 a 19 0.3 1.9 2.2 6.3 a 20 0.5 1.6 2.1 3.2 a 21 0.3 1.7 2.0 5.6 a 22 2.0 4.5 6.5 2.2 sm 23 1.3 3.5 5.0 2.3 sm 24 1.3 1.4 2.7 1.1 m 25 1.2 1.3 2.5 1.1 m 26 1.1 1.2 2.3 1.1 m X 1.8 4.2 6.0 2.3 sm Y 0.0 1.6 1.6 ∞ a Metacentric (m)=1–1.69; Submetacentric (sm)=1.7–3.00; Acrocentric (a)=3.1–∞. chromosomes. The submetacentric chromosomes are classified according to the length into two types: 1) Chromosome 22 is a medium-size chromosome; 2) Chromosome 23 is a small-size chro- mosome. The metacentric chromosomes 24–26 are small-size chromosomes. The X chromosome is large submetacentric, while the Y chromosome is a small acrocentric chromosome. The type of centromeres was determined according to the formula of Matthey and the find- ings are represented in Fig. 5. The fundamental number (FN) for the male was calculated to be 65 and the FN for the female was found to be 66, while the fundamental number of autosomes was found to be 62 (Table 2). 290 S. A. Al-Dakan and A. A. Al-Saleh Cytologia 80(3)

Fig. 3. A, Photomicrograph of metaphase spreading from male Procavia capensis; B, Karyotype of male Procavia capensis.

Discussion

This study is important not only because the karyotype of Procavia capensis has not been investigated by scientists in Saudi Arabia, but also because this animal can be used as an animal for laboratory experiments and it can be easily bred and raised in the laboratory (Griner 1968). - thermore, this animal can be used as a biological model for cytogenetic studies, particularly for the study of the effect of drugs on its tissues and mainly on the chromosomes, which seems suitable for this purpose. The present study showed that the chromosome diploid number for this animal is composed of 54 chromosomes, which corresponds to the only study that has been observed for Procavia capensis carried out by Hungerford and Snyder in 1969. The study carried out by the Hungerford 2015 Karyotype Determination of Rock Hyrax Procavia capensis in Saudi Arabia 291

Fig. 4. A, Photomicrograph of metaphase spreading from female Procavia capensis; B, Karyotype of female Procavia capensis. and Snyder has been on a tissue sample taken from one animal from California gardens and cul- tured as cellular culture for chromosomes preparation. Our study has been carried on samples collected from two different regions of the Kingdom of Saudi Arabia and 10 samples of males and 10 samples of females from two separate regions (10 samples/region), and such work has not been done in the previous study. This does not mean that the study of Hungerford and Snyder is not correct, but rather, our study has backed it in a more credible way as the karyotype of Procavia capensis has been investigated extensively. If the karyotype is the basis of the definition of the species, the studies at molecular level no doubt will determine the species more accurately. Pardini et al. has found in 2007 that the seals, 292 S. A. Al-Dakan and A. A. Al-Saleh Cytologia 80(3)

Fig. 5. An ideogram showing the mean length of arms of the chromosomes and the position of the cen- tromeres of Procavia capensis.

Table 2. Chromosome fundamental number (FN) and the fundamental number of autosomes of Procavia capensis.

Centromere Haploid no. Diploid no. FN Male

a 21 42 42 sm 02 04 08 m 03 06 12 Y or X 01 02 Y+X 03 X=2 and Y=1 Total =3 Total arms 27 54 65

Centromere Haploid no. Diploid no. FN Female

a 21 42 42 sm 02 04 08 m 03 06 12 X 01 02 04 X=2+X=2 Total = 4 Total arms 27 54 66

Centromere Haploid no. Diploid no. FNa

a 21 42 42 sm 02 04 08 m 03 06 12 Total arms 26 52 62

FN=fundamental number; FNa=fundamental number of autosomes. and share many of the characteristics of the nature karyotype, and this supports the development of African animal that group within the superorder of . Not only that, but it is known that the and hyrax share some other attributes, such as the presence of intra-abdominal testes, as well the gut has two vermiform appendix instead of one as in customary (Pardini et al. 2007). Furthermore, Kellogg in 2007 proved at the molecular cytogenetics that seals calves, elephants and hyraxes have familiarity of some chromosomal fragments in their genome (Kellogg et al. 2007). As previously stated, in the absence of previous studies except the study of Hungerford and Snyder in 1969, it must be emphasized that the rock hyrax, Procavia capensis, which has been the subject of this study is the same rock hyrax that has been studied by Hungerford and Snyder and scientifically named under Procavia capensis species. 2015 Karyotype Determination of Rock Hyrax Procavia capensis in Saudi Arabia 293

References

Bartholomew, G. A. and Rainy, M. 1971. Regulation of body temperature in the rock hyrax, Hetero hyrax brucei. J. . 52: 81–95. Burton, R. 1941. International Wildlife Encyclopaedia. Marshall Cavendish Corporation, New York. Estes, R. D. 1991. The Behavior Guide to African Mammals Including Hoofed Mammals, Carnivores, . University of California Press, Los Angeles. pp. 250–258. Fourie, P. B. 1978. The life-span of mammals: Estimates for the dassie (Procavia capensis). J. S. Afr. Vet. Assoc. 49: 143–145. Gasperetti, P. 1978. A note on Procavia capensis. J. Saudi Arabian Nat. Hist. Soc. 22: 6–10. Griner, L. A. 1968. The rock hyrax (Procavia capensis): A potential laboratory animal. Lab. Anim. Care 18: 144–150. Grzimek, B. 1975. Grzimek’s Animal Life Encyclopedia. Van Nostrand Reinhold, New York. Hanse, W. A. 1962. Preliminary studies on the dassie. Its relation to farming and methods of control. Rep. Dep. Nat. Con- serv. 19: 108–121. Harrison, D. L. and Bates, P. J. 1991. The Mammals of Arabia. 2nd ed. Harrison Zoological Museum Pub., London. Hoeck, H. N. 1975. Differential feeding behavior of the sympatric hyrax (Procavia johnstoni and Heterohyrax bru- cei). Oecologia 22: 15–47. Hungerford, D. A. and Snyder, R. L. 1969. Chromosomes of the rock hyrax, Procavia capensis (Pallas), 1767. Experientia 25: 870. Kamal, K. B. 1996. Distribution, morphology and behavior of rock hyrax (Procavia capensis) in the western region of Saudi Arabia. Proceedings of the Zoological Society, A.R. 27: 75–80. Kellogg, M., Burkett, S., Dennis, T. R., Stone, G., Gray, B. A., McGuire, P. M., Zori, R. T. and Stanyon, R. 2007. Chromo- some painting in support and Paenungulata. BMC Evol. Biol. 7: 1–7. Kingdon, J. 1971. East African Mammals. Vol. I. Academic Press, London. pp. 329–339. Kingdon, J. 1990. Arabian Mammals: A Natural History. Academic Press, London. Harcourt Brace Jovnovich Publish- ers. London, San Diego, New York, Sydney. Kingdon, J. 1991. Arabian Mammals: A Natural History. Academic Press, London. Kraemer, M. S. 2001. Rehabilitation notes: Rock hyrax (Procavia capensis). J. Wildlife Rehab. 24: 18–20. Levan, A., Fredga, K. and Sandberg, A. A. 1964. Nomenclature for centromeric position on chromosomes. Hereditas 52: 201–220. Manharth, A. and Harris-Gerber, L. 2002. Surgical castration and the effect on in rock hyrax (Procavia capen- sis). J. Zoo Wildl. Med. 33: 80–82. Matthey, R. 1945. L’évolution de la formule chromosomiale chez les Vertebres. Experientia 2: 1–20. Nader, I. A. 1990. Checklist of the mammals of Arabia. In: Büttiker, W. and Krupp, F. (eds.). Fauna of Saudi Arabia, vol. 11. Karger Libri, Basel. pp. 329–381. Olds, N. and Shoshani, J. 1982. Procavia capensis. Mamm. Species 171: 1–7. Pardini, A. T., O’Brien, P. C. M., Fu, B., Bonde, R. K., Edler, F. F. B., Fergson-Smith, M. A., Yang, F. and Robinson, T. J. 2007. Chromosome painting among , Hyracoidea and : Support for Paenungulata (Afro- , Mammalia) but not . Proc. Biol. Sci. 274: 1333–1340. Skinner, J. D. and Smithers, R. H. N. 1990. The Mammals of the Southern African Subregion, 2nd ed. University of Pre- toria, . Talmi-Frank, D., Jaffe, C. L., Nasereddin, A., Warburg, A., King, R., Svobodova, M., Peley, O. and Baneth, G. 2010. Leishmania tropica in rock hyraxes (Procavia capensis) in a focus of human cutaneous leishmani- asis. Am. J. Trop. Med. Hyg. 82: 814–818. Turner, M. I. M. and Watson, R. M. 1965. An introductory study on the ecology of hyrax (Dendrohyrax brucei and Proca- via johnstoni) in the Serengeti National Park. Afr. J. Ecol. 3: 49–60. Vincett, B. A. L. 1982. Animal Life in Saudi Arabia. Garzanti Editore, Cernusco sul Naviglio.