Browsing by Author "Castiglia, R."

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Chromosomal diversity in the genus Arvicanthis (Rodentia, Muridae) from East Africa: a taxonomic and phylogenetic evaluation
(Blackwell Verlag, Berlin, 2006) Castiglia, R.; Bekele, A.; Makundi, R.; Oguge, N.; Corti, M.
In this paper we discuss the contribution of cytogenetics to the systematics of Arvicanthis in East Africa, by reviewing all the known chromosomal cytotypes of the genus in the area. We also provide G- and C-banding comparisons for two recently described karyotypes, provisionally named ANI-5 (2n 1⁄4 56, NFa 1⁄4 62) and ANI-6 (2n 1⁄4 60, NFa 1⁄4 72). This, therefore, brings the total number of known cytotypes in this area to 10. Five of these correspond to the species recognized by the latest rodent checklist, i.e. A. nairobae (2n 1⁄4 62, NFa 1⁄4 78), A. neumanni (2n 1⁄4 52–53, NFa 1⁄4 62), A. blicki (2n 1⁄4 48, NFa 1⁄4 62), A. abyssinicus (2n 1⁄4 62, NFa 1⁄4 64) and A. niloticus (2n 1⁄4 62, NFa 1⁄4 60–62). The taxonomic status of the remaining five cytotypes (A. cf. somalicus, 2n 1⁄4 62 NFa 1⁄4 62–63; ANI-5, 2n 1⁄4 56, NFa 1⁄4 62; ANI-6/6a 2n 1⁄4 60, NFa 1⁄4 72/76; ANI-7, 2n 1⁄4 56, NFa 1⁄4 78; and ANI-8, 2n 1⁄4 44, NF 1⁄4 72) is discussed. Finally, we reconstruct the phylogenetic relationships among all the known karyotypes on the basis of banding data available for the genus in Africa and show the occurrence of two main clades, each characterized by different types of chromosomal rearrangements. The times of the cladogenetic events, inferred by a molecular clock, indicate that karyotype evolution has accomplished almost all the dichotomic events from the end of the Miocene to the present day. The discovery of a large chromosomal differentiation between populations showing low genetic distances and intrapopulation chromosomal polymorphism suggests that the process of chromosomal differentiation in Arvicanthis is still ongoing and may possibly be responsible for speciation
Cytotaxonomy of rodent species from Ethiopia, Kenya, Tanzania and Zambia
(Belg. J. Zool, 2005) Corti, M.; Castiglia, R.; Colangelo, P.; Capanna, E.; Beolchini, F.; Bekele, A.; Oguge, N. O.; Makundi, R. H.; Sichilima, A. M.; Leirs, H.; Verheyen, W.; Verhagen, R.
An extended survey of taxa belonging to two genera of Cricetomyinae (Cricetomys and Saccostomus), one Gerbillinae (Gerbilliscus), eight Murinae (Acomys, Aethomys, Arvicanthis, Lemniscomys, Mus (Nannomys), Mastomys, Grammomys, Stenocephalemys) and one Myoxidae (Graphiurus) was carried out as part of the EU programme “Staplerat” involving Ethiopia, Kenya, Tanzania and Zambia. Here we report the diploid and autosomal fundamental numbers of these rodent taxa. Seventeen of them were unknown, for four we report chromosomal variants and for another 16 new localities where they occur. We discuss their specific status taking into consideration our results together with data from literature and highlight the problems in taxonomy and systematics that are yet to be solved, due do their extended range and the occurrence of species complexes. We highlight cases for which there should be a re-evaluation of specific names that were not included in the last rodent checklist.
The Rodent fauna of Tanzania : a cytotaxonomic report from the Maasai Steppe
(Nella seduta del 12 gennaio, 2001) Fadda, N. di C.; Castiglia, R.; Colangelo, P.; Corti, M.; Machang’u, R.; Makundi, R.; Scanzani, A.; Tesha, P.; Capanna, W. V. E.
The rodent fauna of Tanzanian savannahs is poorly known. For this reason, the Accademia Nazionale dei Lincei sponsored a project together with the Biology Department of Antwerp and the Sokoine University of Agriculture (Morogoro, Tanzania) on Eastern African rodents. The aim was to study the taxonomy and systematics of rodents of these areas and the processes through which rodent biodiversity has increased in these African regions. We present here a report of the expeditions carried out in the Maasai steppe of Tanzania during 1999, with the description of the karyotypes of 13 rodent species. These are: Saccostomus cf. mearnsi (Cricetomynae), Tatera cf. robusta, Gerbillus cf. pusillus (Gerbillinae), Acomys spinosissimus, Acomys wilsoni, Acomys ignitus, Aethomys cf. chrysophilus, Arvicanthis cf. neumanni, Arvicanthis cf. nairobae, Grammomys sp., Lemniscomys rosalia, Lemniscomys cf. zebra, Mastomys natalensis (Murinae). The karyotypes of eight species are described for the first time (Saccostomus cf. mearnsi, Gerbillus cf. pusillus, Acomys wilsoni, Acomys ignitus, Arvicanthis cf. neumanni, Arvicanthis cf. nairobae, Grammomys sp., Lemniscomys rosalia).