Browsing by Author "Makundi, 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
Genetic distinction between contiguous urban and rural multimammate mice in Tanzania despite gene flow
(Journal of evolutionary biology., 2016) Gryseels, S.; Goüy de Bellocq, J.; Makundi, R.; Vanmechelen, K.; Broeckhove, J.; Mazoch, V.; Šumbera, R.; Zima Jr, J.; Leirs, H.; Baird, S. J. E.
Special conditions are required for genetic differentiation to arise at a localgeographical scale in the face of gene ﬂow. The Natal multimammatemouse, Mastomys natalensis, is the most widely distributed and abundantrodent in sub-Saharan Africa. A notorious agricultural pest and a naturalhost for many zoonotic diseases, it can live in close proximity to humansand appears to compete with other rodents for the synanthropic niche. Wesurveyed its population genetic structure across a 180-km transect in centralTanzania along which the landscape varied between agricultural land in arural setting and natural woody vegetation, rivers, roads and a city (Moro-goro). We sampled M. natalensis across 10 localities and genotyped 15microsatellite loci from 515 individuals. Hierarchical STRUCTURE analysesshow a K-invariant pattern distinguishing Morogoro suburbs (located in thecentre of the transect) from nine surrounding rural localities. Landscapeconnectivity analyses in Circuitscape and comparison of rainfall patternssuggest that neither geographical isolation nor natural breeding asynchronycould explain the genetic differentiation of the urban population. Using theisolation-with-migration model implemented in IMa2, we inferred that asplit between suburban and rural populations would have occurred recently(<150 years ago) with higher urban effective population density consistentwith an urban source to rural sink of effective migration. The observedgenetic differentiation of urban multimammate mice is striking given theuninterrupted distribution of the animal throughout the landscape and thehigh estimates of effective migration (2NeM = 3.0 and 29.7), suggesting astrong selection gradient across the urban boundary
Polymorphism in vkorc1 gene of natal multimammate Mice, Mastomys natalensis, in Tanzania
(Journal of Heredity, 2015) Gryseels, S.; Leirsa, H.; Makundi, R.; De Bellocq, J. G.
Resistance of rodents to anticoagulant rodenticides has emerged in several areas across the world. Single nucleotide mutations in the vkorc1 gene have been shown to elicit various levels of anticoagulant resistance, and these mutations are prevalent in several Rattus and Mus musculus populations. In sub-Saharan Africa, the Natal multimammate mouse, Mastomys natalensis, is one of the most damaging pests to crops, and anticoagulant poisons such as bromadiolone are frequently used to control these rodents in agricultural fields. Here, we investigate if vkorc1 shows any polymorphism in natural populations of M. natalensis. We sequenced the third exon of vkorc1 of 162 M. natalensis captured from 14 different agricultural sites in Morogoro Region, Tanzania. In addition to 6 SNPs in the noncoding flanking region, we detected 3 nonsynonymous SNPs in this exon: 10 animals (6.2%) carried a Leu108Val variant, 2 animals (1.2%) an Ala140Thr variant, and 1 animal (0.6 %) an Arg100His variant, all 3 in heterozygous form. Ala140Thr is just one residue from a mutation known to be involved in anticoagulant resistance in Rattus and Mus. While in vitro or in vivo experiments are needed to link vkorc1 genetic polymorphisms to level of VKOR activity and anticoagulant susceptibility, our results suggest that M. natalensis individuals may vary in their response to anticoagulant rodenticides. This is the first vkorc1 sequence data from a species outside the Rattus or Mus genera, and for the first time from a rodent species endemic to Africa.
Preliminary investigation on rodent–ectoparasite associations in the highlands of Tigray, Northern Ethiopia: implications for potential zoonoses
(Integrative Zoology, 2011) Yonas, M.; Welegerima, K.; Laudisoit, A.; Bauer, H.; Gebrehiwot, K.; Deckers, S.; Katakweba, A.; Makundi, R.; Leirs, H.
We studied associations between rodents and their arthropod ectoparasites in crop fields and household compounds in the highlands of Tigray, Northern Ethiopia. Ectoparasite infestation indices, such as percent infestation, mean abundance, prevalence and host preferences, were calculated for each taxon. In total, 172 rodents from crop fields and 97 from household compounds were trapped. Rodent species and numbers trapped from the crop fields and household compounds were Mastomys awashensis (Lavrenchenko, Likhnova & Baskevich, 1998) (88 and 44), Arvicanthis dembeensis (Ruppel, 1842) (63 and 37) and Acomys sp. (21 and 16), respectively. A total of 558 insects and acarids (belonging to 11 taxa) were recovered from the rodents trapped in the crop fields, and 296 insects and acarid (belonging to 6 taxa) from the rodents trapped in the household compounds. Approximately 66% of the rodents trapped from the crop fields and 47% of those trapped from the household compounds were infested with ectoparasites. Laelaps sp. (64.9%) and Xenopsylla sp. (20.6%) comprised the highest proportion of the ectoparasites recovered in the crop fields, and the same ectoparasites, but in reverse order, comprised the highest proportions in the household compounds (Xenopsylla [50.3%] and Laelaps sp. [29%]). Our study revealed that crop fields and household compounds in the highlands share similar rodents and several ectoparasites. Furthermore, at least 1 of the rodent species and some of the ectoparasites identified in this study were reported to have posed medical and veterinary threats in other parts of Ethiopia and neighboring countries.
Preliminary investigation on rodent–ectoparasite associations in the highlands of Tigray, Northern Ethiopia: implications for potential zoonoses
(Integrative Zoology, 2011) Yonas, M.; Welegerima, K.; Laudisoit, A.; Bauer, H.; Gebrehiwot, K.; Deckers, S.; Katakweba, A.; Makundi, R.; Leirs, H.
We studied associations between rodents and their arthropod ectoparasites in crop fields and household compounds in the highlands of Tigray, Northern Ethiopia. Ectoparasite infestation indices, such as percent infestation, mean abundance, prevalence and host preferences, were calculated for each taxon. In total, 172 rodents from crop fields and 97 from household compounds were trapped. Rodent species and numbers trapped from the crop fields and household compounds were Mastomys awashensis (Lavrenchenko, Likhnova & Baskevich, 1998) (88 and 44), Arvicanthis dembeensis (Ruppel, 1842) (63 and 37) and Acomys sp. (21 and 16), respectively. A total of 558 insects and acarids (belonging to 11 taxa) were recovered from the rodents trapped in the crop fields, and 296 insects and acarid (belonging to 6 taxa) from the rodents trapped in the household compounds. Approximately 66% of the rodents trapped from the crop fields and 47% of those trapped from the household compounds were infested with ectoparasites. Laelaps sp. (64.9%) and Xenopsylla sp. (20.6%) comprised the highest proportion of the ectoparasites recovered in the crop fields, and the same ectoparasites, but in reverse order, comprised the highest proportions in the household compounds (Xenopsylla [50.3%] and Laelaps sp. [29%]). Our study revealed that crop fields and household compounds in the highlands share similar rodents and several ectoparasites. Furthermore, at least 1 of the rodent species and some of the ectoparasites identified in this study were reported to have posed medical and veterinary threats in other parts of Ethiopia and neighboring countries.
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).
Seasonal and habitat dependence of fleas parasitic on small mammals in Tanzania
(ISZS, Blackwell Publishing and IOZ/CA, 2009) Laudisoit, A.; Leirs, H.; Makundi, R.; Krasnov, B. R.
We investigated host and flea species composition across different habitats during dry and rainy seasons in the Western Usambara Mountains in Tanzania. During both seasons, similarity in flea species composition increased with an increase in the similarity in host species composition. Nevertheless, between-season within-habitat as well as within-season between-habitat similarity in host species composition was higher than similarity in flea species composition. Ordination of habitats according to their host and flea species composition demonstrated that the pattern of between-habitat similarity in both host and flea species composition varied seasonally. Despite the relatively rich mammal and flea fauna of the study region, the major contribution to variation in species composition between seasons and among habitats was due to a few species only. Flea assemblages on Lophuromys kilonzoi Verheyen et al., 2007 and Praomys delectorum Thomas, 1910 in different habitats were equally similar in either season. In contrast, flea assemblages on Mastomys natalensis (Smith, 1834) occurring in different habitats were more similar in the dry than in the rainy season, whereas the opposite was the case for fleas on Grammomys sp. In different hosts, the main differences in species composition of flea assemblages between seasons as well as among habitats were due to different flea species. Although our results support the earlier idea that parasite species composition is determined by both host species composition and habitat properties, the former appears to explain variance in flea species composition between localities in the tropics better than between localities in temperate and arid zones.
When viruses don’t go viral: the importance of host phylogeographic structure in the spatial spread of arenaviruses
(Public Library of Science, 2017) Gryseels, S.; Baird, S. J. E.; Borremans, B.; Makundi, R.; Leirs, H.; Bellocq, J. G.
Many emerging infections are RNA virus spillovers from animal reservoirs. Reservoir identification is necessary for predicting the geographic extent of infection risk, but rarely are taxonomic levels below the animal species considered as reservoir, and only key circumstances in nature and methodology allow intrinsic virus-host associations to be distinguished from simple geographic (co-)isolation. We sampled and genetically characterized in detail a contact zone of two subtaxa of the rodent Mastomys natalensis in Tanzania. We find two distinct arenaviruses, Gairo and Morogoro virus, each spatially confined to a single M. natalensis subtaxon, only co-occurring at the contact zone’s centre. Inter-subtaxon hybridization at this centre and a continuum of quality habitat for M. natalensis show that both viruses have the ecological opportunity to spread into the other substaxon’s range, but do not, strongly suggesting host-intrinsic barriers. Such barriers could explain why human cases of another M. natalensisborne arenavirus, Lassa virus, are limited to West Africa