© 2005 The Japan Mendel Society Cytologia 70(2): 161–165, 2005

Chromosomal Studies on Four Egyptian Species of Genus Androctonus (Family: )

Mohsen A. Moustafa1,*, A. M. Alaa2, M. H. Sarhan1 and A. E. Yaseen3

1 Zoology Department, Faculty of Science, Al Azhar University, (Assiut branch), Assiut, Egypt 2 Zoology Department, Faculty of Science, Suez Canal University, Ismielia, Egypt 3 Faculty of Education, Suez Canal University, (Al Areesh Branch), Egypt

Received January 18, 2005; accepted February 28, 2005

Summary Chromosomal analysis of 4 Egyptian species of family Buthidae (, Androctonus bicolor, Androctonus amoreuxi and Androctonus crassicauda) have been studied. The 4 buthid species have the same diploid chromosome number of 2n24. These species have a unique combination of cytogenetic features including holocentric chromo- somes. Multivalent chromosomes of regular and irregular form were observed during the first meiot- ic division. To the best of the authors knowledge, these results are reported for the first time in Egypt.

Key words Chronrosomes, Karyotypes, Holocentric, Multivalent, Egyptian Scorpion

From the taxonomic stand-point, the number and behaviour of chromosomes seem to have a great deal of uniformity in species within a single genus, even among species of closely related genera and therefore may be of some significance (White 1976, Hirai et al. 1985) Buthidae is the largest family of extant scorpions. It includes 73 genera and 529 species (Fet and Lowe 2000). In 28 species of buthid scorpions from South America, Africa, India and North America, most chromosomes number fall in the range of 2n14 to 2n26 with some examples of chromosome fusion leading to lower chromosome numbers. Only one species Uroplectes carinatus, shows an increase in chromosome number between individuals (2n20, 48) (Newlands and Martin- dale 1980). Buthids are also a cytogenetically interesting group, because they have holocentric chromo- somes which lack a localized centromere (Rhoades and Kerr 1949, Benavente 1982, Sarhaan 2000), and achiasmate male meiosis (Piza 1957, Ashish and Sanat 1965). The most singular feature of male meiosis in buthid scorpions is the presence at metaphase I of complex rings and chains of chromosomes resulting from interchange heterozygosity (Piza 1947, illustrated in White 1973, Sharma et al. 1959). The present study is further contribution to the cytology of 4 species belonging to genus Androctonus collected from the areas in and around Egypt together with observation on the meiotic chromosomes of these species.

Material and methods Specimens of the 4 species (Androctonus australis, A. bicolor, A. amoreuxi and A. crassicauda) were collected from different localities in Egypt (Figs. 1, 7). Healthy and active speci- mens were selected. Chromosomal analysis was carried out by the air drying method of Galian et al. (1992) as follows: Specimens were dissected in insect saline solution, testes were removed

* Corresponding author: e-mail: [email protected] 162 Mohsen A. Moustafa et al. Cytologia 70(2)

Fig. 1. Photograph of different species of scorpions and their locations.

Fig. 2. Mitotic metaphase spread of testicular cell (A) Fig. 3. Mitotic metaphase spread of testicular cell (A) and karyotype (B) of scorpion Androctonus aus- and karyotype (B) of scorpion Androctonus tralis. amoreuxi. 2005 Chromosome of Egyptian Scorpion 163 species. Androctonus Different polymorphic multivalent rings with 3, 4 polymorphic multivalent Different recorded in meioses and 7 chromosomes (arrows) I of Fig. 6. Androctonus cras- Androctonus . Mitotic metaphase spread of testicular cell (A) and karyotype (B) of scorpion sicauda . Fig. 5 Androctonus bi- Androctonus . color Mitotic metaphase spread of testicular cell (A) and karyotype (B) of scorpion Fig. 4. 164 Mohsen A. Moustafa et al. Cytologia 70(2)

26 28 30 32 34 36

EGYPT MEDITERRANEAN SEA

International boundary 32 32 National capital Provincial capital Gaza P Other city Matruh Damietta Port Said ALESTINE Alexandria 050100

Damanhu Tanta CANAL SUEZ Miles Az Zaqaziq 050100 ression Ismailia Dep Shibin al Kawm Banha Kilometers ra 30 ta 30 at CAIRO Suez Q El Giza TRANSJORDAN Sinai El Faiyvm GULF OF SUEZ Bani Suwayt

Nile SAUDI Bawill Dahab GULF OFAQABA 28 28 El Minya Jamsah ARABIA

Hurghada Asyut Port Safaga RED LIBYA Sohag SEA 26 26 Qena

A. crassicauda A. amoreuxi A. australis A. bicolor

Fig. 7. Collecting sites of scorpion species.

and instantly immersed in 0.02% colchicine. After 30 min, testes were immersed in 1% Sodium Citrate solution and incubate for 1 h at room temperature. The tissues were then fixed in ethanol acetic acid (3 : 1). A drop of the cell suspension was pipetted out and placed on heated clean glass slides. The dried slides were stained for 20 min by 2% Giemsa solution (pH 6.8) at room tempera- ture. Suitable metaphases were photographed. karyotypes for these species were done relating to chromosome length according to Goyffon et al. (1971) and Shanhan (1989).

Results and discussion The chromosome number from the 4 species Androctonus austalis, A. bicolor, A. amoreuxi and A. crassicauda were determined from testicular cells. Over than 10 well spread metaphase chromosomes were scored from each species. The cell spread of the 4 species was found to have the same diploid chromosome number of 2n24. Because of the Buthid scorpions exhibit a unique cytogenetic system which include a holocen- tric chromosome (Benavente 1982), the complete chromosomal sets from the analyzed cells for the 4 species were arranged in descending order according to chromosomal length (Figs. 2–5). These results are in agreement with Goyffon et al. (1971) who reported that the diploid chromosome num- ber of the Androctonus mauretanicus is 2n24 and with Newlands and Martindale (1980) who re- ported that the diploid chromosome number of the family Buthidae ranging from 2n14 to 2n26. Meiotic behaviour of the 4 species revealed that they have interchange heterozygosity manifest as regular and irregular ring multivalent at metaphase I with with 3, 4 and 7 chromosomes involved as shown in Fig. 6a, b. Our results confirms the results of Shanahan and Hayman (1990) who report- 2005 Chromosome of Egyptian Scorpion 165 ed that multivalent associations present during the achismate meiosis of both buthid and scorpionid scorpions are retained from prophase to metaphase. They also revealed the presence of regular and irregular multivalent rings and chains of chromosomes. Ahmed (1973) reported that the different forms of multivalent may be interpreted as the result of either interchange heterozygosity or associ- ation of non-homologus, or at best partly homologus chromosome ends.

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