Hedgehogs belong to one of the several mammalian taxa in which karyotype differences are based on variations in heterochromatin content. Furthermore, the number and location of nucleolar organizer regions (NORs) can also vary widely. In the present study these cytogenetic features were investigated in the Algerian hedgehog, Erinaceus (Aethechinus) algirus. The heterochromatin and NOR distribution patterns in the karyotype of this species are new among hedgehogs, whereas the euchromatic regions, including their G-band pattern, are similar to those reported by others. In addition, silver staining revealed a cytogenetic feature exclusive to the heterochromatic blocks of E. algirus: their silver staining with standard cytogenetic procedures. Because no similar phenomenon has been described previously in a mammalian species, several hypotheses about the significance and specificity of silver staining to NOR sites are discussed. Finally, the existence of different types of heterochromatin in the species analysed here, lead us to propose that what hedgehogs have inherited from their common ancestor is a mechanism which permits the accumulation of heterochromatin on specific chromosomes, rather than the heterochromatin itself.
Ando, K, Tagawa, T, and Uchida, T A. 1980. C-banding pattern on the chromosomes of the Japanese house shrew, Suncus murinus riukiuanus, and its implication. Experientia, 36, 1040–1041.
Barros, M A, and Patton, J L. 1985. Genome evolution in pocket gophers (Genus Thomomys) III. Fluorochrome-revealed heterochromatin heterogeneity. Chromosoma, 92, 337–343.
Baverstock, P R, Gelder, M, and Jahnke, A. 1982. Cytogenetic studies of the Australian rodent, Uromys caudimaculatus, a species showing extensive heterochromatin variation. Chromosoma, 84, 517–533.
Bickham, J W, and Rogers, D S. 1985. Structure and variation of the nucleolus organizer regions in turtles. Genetica, 67, 171–184.
Burgos, M, Jiménez, M, and Díaz De La Guardia, R. 1986. A rapid, simple and reliable combined method for G-banding mammalian and human chromosomes. Stain Technol 61, 257–260.
Burgos, M, Jiménez, R, Olmos, D M, and Díaz De La Guardia, R. 1988. Heterogeneous heterochromatin and size variation in the sex chromosomes of Microtus cabrerae. Cytogenet Cell Genet, 41, 75–19.
Burgos, M, Jiménez, R, Sánchez, A, and Díaz De La Guardia, R. 1992. Replication of the heterogeneous heterochromatin of the sex chromosomes of Microtus cabrerae. Experientia, 48, 1151–1153.
Burgos, M, Olmos, D M, Jiménez, R, Sánchez, A, and Dtaz De La Guardia, R. 1990. Fluorescence banding in four species of Microtidae: an analysis of the evolutive changes of the constitutive heterochromatin. Genetica, 81, 11–16.
Buys, C H C M, and Osinga, J. 1980. Abundance of protein-bound sulfhydryl and disulfide groups at chromosomal nucleolus organizer regions. Chromosoma, 77, 1–11.
Dev, V G, Miller, D A, Tantravahi, R, Schreck, R R, Roderick, T H, Erlanger, B F, and Miller, O J. 1975. Chromosome markers in Mus musculus: differences in C-banding between the subspecies M. m. musculus and M. m. molosinus. Chromosoma, 53, 335–344.
Fredga, K, and Mandahl, N. 1973. Autosomal hetero-chromatin in some carnivores. In: Caspersson, T. and Zech, L. (eds) Chromosome Identification, pp. 104–117. Academic Press, New York.
Freitas, T R O, Mattevi, M S, and Oliveira, L F B. 1984. Unusual C-band patterns in three karyotypically rearranged forms of Scapteromys (Rodentia, Cricetidae) from Brazil. Cytogenet Cell Genet, 38, 39–44.
Galetti, P M, Jr., Barbosa Da Silva, E, and Germinaro, R J. 1985. A multiple NOR system in the fish Serrasalmus spilopleura (Serrasalminae, Characidae). Rev Brazil Genet, 8, 479–484.
Goodpasture, C, and Bloom, S E. 1975. Visualization of nucleolar organizer regions in mammalian chromosomes using silver staining. Chromosoma, 53, 37–50.
Gropp, A. 1969. Cytologic mechanism of karyotype evolution in insectivores. In: Benirschke, K. (ed.) Comparative Mammalian Cytogenetics, pp. 247–266. Springer, New York.
Gropp, A, and Natarajan, A. 1972. Karyotype and heterochromatin pattern of the Algerian hedeghog. Cytogenetics, 11, 259–269.
Hubbell, H R. 1985. Silver staining as an indicator of active ribosomal genes. Stain Technol, 60, 285–294.
Hubbell, H R, Rothblum, L I, and Hsu, T C. 1979. Identification of a silver binding protein associated with the cytological silver staining of actively transcribing nucleolar regions. Cellbiol Int Rep, 3, 615–622.
Jiménez, R, Burgos, M, and Dtaz De La Guardia, R. 1988. A study of the Ag-staining significance in mitotic NOR'S. Heredity, 60, 125–127.
King, M. 1980. C-banding studies on Australian hylid frogs: secondary constriction structure and the concept of euchromatin transformation. Chromosoma, 80, 191–217.
Lischwe, M A, Smetana, K, Olson, M O J, and Busch, H. 1979. Proteins C23 and B23 are the major silver staining proteins. Life Sci, 25, 701–708.
Mandahl, N. 1978. Variation in C-stained chromosome regions in European hedgehogs (Insectivora, Mammalia). Hereditas, 89, 107–128.
Mandahl, N. 1979. Localization of nucleolar organizing regions in European hedgehogs (Insectivora, Mammalia). Hereditas, 91, 149–161.
Mandahl, N, and Fredga, K. 1980. A comparative chromosome study by means of G-, C-, and NOR-bandings of the weasel, the pygmy weasel and the stoat (Mustela, Carnivora, Mammalia). Hereditas, 93, 75–83.
Medina, F J, Risueño, M C, Sánchez-Pina, M A, and Fernández-Gómez, M E. 1983. A study of nucleolar silver staining in plant cells. The role of argyrophilic proteins in nucleolar physiology. Chromosoma, 88, 149–155.
Merry, D E, Pathak, S, and Vandeberg, J L. 1983. Differential NOR activities in somatic and germ cells of Monodelphis domestica (Marsupialia, Mammalia). Cytogenet. Cell Genet, 35, 244–251.
Modi, W S. 1993a. Rapid, localized amplification of a unique satellite DNA family in the rodent Microtus chrotorrhinus. Chromosoma, 102, 484–490.
Modi, W S. 1993b. Heterogeneity of the concerted evolution process in a tandem satellite array from meadow mice (Microtus). J Mol Evol, 37, 48–56.
Ritosa, R, and Spiegelman, S. 1965. Localization of DNA complementary to ribosomal RNA in the nucleolus organizer regions of Drosophila melanogaster. Proc Natl Acad Sci USA, 53, 737–745.
Sánchez, A, Burgos, M, Jiménez, R, and Dfaz De La Guardia, R. 1989a. Variable conservation of nucleolus organizer regions during karyotypic evolution in Microtidae. Genome, 33, 119–122.
Sánchez, A, Burgos, M, Jiménez, R, and Dfaz De La Guardia, R. 1989b. Quantitative analysis of silver staining of the nucleolar organizing region in Eliomys quercinus. Genome, 32, 978–982.
Sánchez, A, Jiménez, R, Burgos, M, Bullejos, M, and Díaz De La Guardia, R. 1994. Further cytogenetic variations in the karyotype of Erinaceus europaeus (Insectivora, Mammalia). Cytobios (in press).
Sánchez-Pina, M A, Medina, F J, Fernández-Gómez, M E, and Risueno, M C. 1984. “Ag-NOR” proteins are present when transcription is impaired. Biol Cell, 50, 199–202.
Schmid, M. 1982. Chromosome banding in amphibia. VII. Analysis of the structure and variability of NORs in Anura. Chromosoma, 87, 327–344.
Schwarzacher, H G, Mikelsaar, A-V, and Schnedl, W. 1978. The nature of the Ag-staining of nucleolus organizer regions. Cytogenet Cell Genet, 20, 24–39.
Sperling, K, Kerem, B-S, Goitein, R, Kottusch, V, Cedar, H, and Marcus, M. 1985. DNase I sensitivity in facultative and constitutive heterochromatin. Chromosoma, 93, 38–42.
Sumner, A T. 1972. A simple technique for demonstrating centromeric heterochromatin. Exp Cell Res, 75, 304–306.
Varley, J M. 1977. Patterns of silver staining of human chromosomes. Chromosoma, 61, 207–214.
Varley, I M, and Morgan, G T. 1978. Silver staining of the lampbrush chromosomes of Tritums cristatus camifex. Chromosoma, 67, 233–244.
Wahl, G M, Vitto, L, and Rubnitz, J. 1983. Co-amplification of rRNA genes with CAD genes in N-(phosphonacetyl)-L-aspartate-resistant Syrian hamster cells. Mol Cell Biol, 3, 2066–2075.
Williams, M A, Kleinschmidt, J A, Krohne, G, and Franke, W W. 1982. Argirophihc nuclear and nucleolar proteins of Xenopus laevis oocytes identified by gel electrophoresis. Exp Cell Res, 137, 341–351.
Yongshan, Y, and Ncin, S. 1987. Sister chromatid exchange points in the heterochromatin and euchromatin regions of Chinese hedgehog chromosomes. Theor Appl Genet, 73, 469–475.
Yosida, M C, and Kodama, Y. 1983. C-band patterns of chromosomes in 17 strains of mice. Cytogenet Cell Genet, 35, 51–56.
Zima, J, and Kral, B. 1984. Karyotypes of European mammals I. Acta Sc Nat Brno, 18, 1–51.
We would like to thank Dr Thelma Slezyger from the Universidad Simon Bolivar (Venezuela) for providing us with the rDNA probes used in this study, and Ms Karen Shashok for revising the English style of the manuscript. This work was supported by the Spanish DGICYT through Project No. PB92-0951.
About this article
Cite this article
Sánchez, A., Jiménez, R., Burgos, M. et al. Cytogenetic peculiarities in the Algerian hedgehog: silver stains not only NORs but also heterochromatic blocks. Heredity 75, 10–16 (1995). https://doi.org/10.1038/hdy.1995.98
This article is cited by
Chromosome Research (2011)
Gene mapping of 28S and 5S rDNA sites in the spined loach Cobitis taenia (Pisces, Cobitidae) from a diploid population and a diploid–tetraploid population
Multiple nucleolus organizer regions in Leptodactylus mystacinus (Amphibia, Anura) and comments on its systematic position in the L. fuscus group based on cytogenetic and molecular analyses
Analysis of the nucleolar organizing regions in the ant Tapinoma nigerrimum (Hymenoptera, Formicidae)
High resolution physical mapping of 45S (5.8S, 18S and 25S) rDNA gene loci in the tomato genome using a combination of karyotyping and FISH of pachytene chromosomes