Mechanisms of Fixation and Accumulation of Centric Fusions in Natural Populations of Mus musculus L. I. Karyological Analysis of a Hybrid Zone Between Two Populations in the Central Apennines

Spirito, Franco; Modesti, Antonella; Perticone, Paolo; Cristaldi, M.; Federici, Roberto; Rizzoni, Marco

doi:10.2307/2408215

Cited by 26 publications

(37 citation statements)

References 13 publications

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“…Contact between the two morphs always occurred within towns in the more recent areas, and did not always yield detectable hybrids. The transition from one morph to the other was very sharp and the width of the hybrid zone estimated for Monastir was extremely narrow, much more so than that observed for Italian mice di¡ering by the same number of Rb fusions (14 km) (Spirito et al 1980). These results agree well with the low fertility measured in laboratory-reared hybrids between the two races (Sa|« d et al 1993).…”

Section: Discussion (A) Habitat Partitioningsupporting

confidence: 71%

Microgeographical distribution of two chromosomal races of house mice in Tunisia: pattern and origin of habitat partitioning

Chatti

Ganem²,

Benzekri

et al. 1999

Proc. R. Soc. Lond. B

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Two chromosomal races of the house mouse occur in Tunisia, a standard morph (40St) found all over the country, and a derived morph (22Rb) occurring only in central Tunisia. In this region, habitat partitioning between the two morphs was investigated by a microgeographical analysis of their distribution, assessing habitat characteristics and demographic parameters. Results showed that the 22Rb mice always occurred in the oldest sections of towns (medinas), often extending to more recent surrounding neighbourhoods where the 40St morph was most abundant. The latter was never trapped within the medinas. The transition between the two morphs was located within cities in the more recent areas, the hybrid zone being estimated at less than 0.5 km in width by a clinal analysis of chromosomal data. Although di¡erences between habitats exist, almost no demographic di¡erences were found between populations of the two morphs when they occurred in the same or in di¡erent habitats. Two hypotheses are discussed to account for the origin of habitat partitioning. The ¢rst relies on competitive exclusion of the 40St mice from the medinas by the derived 22Rb mice; the second is based on stochastic processes related to historical evolution of Tunisian urban communities.

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Section: Discussion (A) Habitat Partitioningsupporting

confidence: 71%

Microgeographical distribution of two chromosomal races of house mice in Tunisia: pattern and origin of habitat partitioning

Chatti

Ganem²,

Benzekri

et al. 1999

Proc. R. Soc. Lond. B

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“…The first is an area of natural hybridisation between the Cittaducale (CD) 2n = 22-chromosome population and the population with the standard 40-chromosome karyotype (Castiglia and Capanna, 1999a, 2000,2002). This transect is the same one studied 25 years ago by Spirito and co-workers (Spirito et al, 1980). The second is a zone of parapatric contact between two populations characterized by Robertsonian rearranged karyotypes: the CD population with 22 chromosomes and the Ancarano (ACR) with 24 chromosomes Capanna, 1999, 2002).…”

Section: Effectiveness Of the Post-mating Barriermentioning

confidence: 76%

“…Hence we cannot exclude the sporadic presence of F1 females with a certain level of fertility in our parapatric contact zone. Spirito et al (1980) and Castiglia and Capanna (1999b).…”

Section: The Parapatric Contact Areamentioning

confidence: 99%

“…We had this chance (Castiglia and Capanna, 1999b). We analysed 75 animals along the 18-km transect crossing the hybrid zone between the CD 22-chromosome and standard all-acrocentric karyotypes which Spirito et al (1980) analysed 25 years ago (data were collected in 1976); this time period corresponds to about one hundred generations in mice. The results show that this long hybridisation time has not had a significant effect on the position of the hybrid zone nor on the location of its extreme margin (Fig.…”

Section: The Selective Advantage Of the Chromosomal Noveltymentioning

confidence: 99%

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Chromosomes and speciation in <i>Mus musculus domesticus</i>

Capanna¹,

Castiglia²

2004

Cytogenet Genome Res

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Thirty years after its identification, the model of chromosomal speciation in Mus musculus domesticus is reevaluated using the methods of population biology, molecular cytogenetics and functional genomics. Three main points are considered: (1) the structural predisposition of M. m. domesticus chromosomes to Robertsonian fusion; (2) the impediment of structural heterozygosity to gene flow between populations of mice with karyotypes rearranged by Robertsonian fusion and between them and populations with the standard all-acrocentric 40-chromosome karyotype; (3) the selective advantage of chromosomal novelty, essential for the attainment of homozygosis and the rapid fixation of the new karyotype in the population.

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“…In Italy narrow hybrid zones between Robertsonian and normal populations occur, but complete reproductive isolation between two sympatric Robertsonian populations has also been observed (Spirito et a!., 1980;Capanna and Corti, 1982). There is evidence from laboratory studies that heterozygotes suffer reduced fertility (Capanna et a!., 1977Cattanach, 1982.…”

Section: Introductionmentioning

confidence: 99%

The Robertsonian translocation house-mouse populations of North East Scotland: a study of their origin and evolution

1983

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The house mice, Mus musculus, of N. F. Scotland and some of the neighbouring Orkney islands carry Robertsonian translocations (centromeric fusions). By comparing the karyotypes, mandible morphology and biochemical variation of samples from four of these populations we suggest that despite chromosonial differences the populations are closely related. Available evidence suggests that the mice may have arrived with the Vikings as early as 600 A.D. and that the chromosomal changes have occurred since then. We found no evidence that the normal, 2n = 40, mice are, by other measures, different from those with Robertsonian translocations. The evidence suggests that these populations have been isolated for a considerable period of time during which there has been a marked reduction of polymorphism and heterozygosity in the island samples, which we tentatively suggest may explain differences observed in the chromosomal evolution of the four populations.

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Mechanisms of Fixation and Accumulation of Centric Fusions in Natural Populations of Mus musculus L. I. Karyological Analysis of a Hybrid Zone Between Two Populations in the Central Apennines

Cited by 26 publications

References 13 publications

Microgeographical distribution of two chromosomal races of house mice in Tunisia: pattern and origin of habitat partitioning

Microgeographical distribution of two chromosomal races of house mice in Tunisia: pattern and origin of habitat partitioning

Chromosomes and speciation in <i>Mus musculus domesticus</i>

The Robertsonian translocation house-mouse populations of North East Scotland: a study of their origin and evolution

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