Notable homologous variation in chromosomal races of the common shrew

This paper is a review of the rare phenomenon of chromosome intraspecies variation manifested in monobrachial homology series in the comprehensively investigated karyotype of the common shrew Sorex araneus Linnaeus, 1758 (Eulipotyphla, Mammalia). The detailed dataset on the account of this mammalian species was drawn from the recently published monograph by Searle et al. (2019) “Shrews, Chromosomes and Speciation”. The parallels to the law of homologous series in variation by Nikolai Vavilov are discussed.

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Chromosomal races of the common shrew (Sorex araneus L.) inhabiting Northeastern European Russia: Do physical obstacles restrict their distribution?

Doklady Biological Sciences ◽

10.1134/s0012496608050219 ◽

2008 ◽

Vol 422 (1) ◽

pp. 348-351 ◽

Cited By ~ 5

Author(s):

N. A. Shchipanov ◽

N. Sh. Bulatova ◽

T. B. Demidova ◽

A. V. Bobretsov

Keyword(s):

Common Shrew ◽

Sorex Araneus ◽

European Russia ◽

Chromosomal Races ◽

The Common ◽

Common Shrew Sorex Araneus

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Factors responsible for a karyotypic polymorphism in the common shrew, Sorex araneus

Proceedings of the Royal Society of London Series B Biological Sciences ◽

10.1098/rspb.1986.0086 ◽

1986 ◽

Vol 229 (1256) ◽

pp. 277-298 ◽

Cited By ~ 63

Keyword(s):

High Frequency ◽

Common Shrew ◽

Sorex Araneus ◽

General Terms ◽

Chromosome Arm ◽

The Common ◽

Common Shrew Sorex Araneus ◽

The 1950S ◽

Monobrachial Homology

A Robertsonian karyotypic polymorphism in the common shrew in the Oxford area, first described in the 1950s, was re-examined. The polymorphism involves chromosome arm combinations no and pr (characteristic of the Oxford karyotypic race), ko (characteristic of the Hermitage karyotypic race) and jl (found in both races). The poly- morphism for jl was sporadic along a north-south transect through the Oxford area, with the frequency of the twin-acrocentric morph never exceeding 10%. The frequency of the Oxford race-specific metacentrics decreased and the frequency of the Hermitage race-specific metacentric ko increased from north to south along the transect. At a latitudinal grid reference of about 180 km, there was a high frequency of individuals with chromosome arms k, n, o and q in the ancestral acrocentric state. This was coincident with the area of occurrence of ko-kq and ko-no OxfordHermitage hybrids. Such hybrids are double Robertsonian heterozygotes with monobrachial homology and are likely to suffer reduced fertility in consequence. It is proposed that this is a source of selection against the monobrachial hybrids and hence results in an increase in frequency of the acrocentric morphs. This scheme goes some way to explain the dines of polymorphism for arm combinations kq, and ko, but it is suggested that other selective factors are involved. It cannot explain the cline of polymorphism for pr, which is in general terms similar to that for kq and no, but is more shallow and centred further north.

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