Nomenclature for the chromosomes of the common shrew (Sorex araneus)

Abstract

Editorial comment. The common shrew, one of the characteristic small mammal species of Europe and neighbouring Asia, has for decades been a focus of cytogenetic investigation due to remarkable chromosome variation at an individual as well as at a population level. It is a fi ne example of long-term international collaboration through a scientifi c grouping founded in 1987 as the International Sorex araneus Cytogenetics Committee (ISACC). The cytogenetic characterisation of common shrews over the whole species range, from Britain in the west to the Lake Baikal in the east, was predicated on standard rules developed by the Committee. Thus, the basic nomenclature for Sorex araneus chromosomes and chromosome races was published in the proceedings of the second ISACC meeting held in Lausanne, Switzerland in 1990 and published in a local journal not available to many young people involved in chromosome studies of the species, in particular those based in Russia. The Editorial Board thanks Société vaudoise des Sciences Naturelles for permission to republish this paper here. Original: © Mém. Soc. Vaudoise Sci. Natur. 19: 13-22 (1991). Abstract.A G-band composite karyotype has been prepared for the common shrew (Sorex araneus Linnaeus, 1758). This includes multiple cut-outs of each chromosome arm (in different stages of contraction) derived from chromosome spreads prepared by a variety of methods by the different authors. The important features of each chromosome arm are described. The nomenclature for the chromosome arms follows that of Halkka et al. (1974) as clarifi ed by Fredga, Nawrin (1977) and subsequent authors, i.e. italicised letters of the alphabet are used with a as the largest chromosome arm. Different authors have used a variety of methods to describe the karyotype of (a) individuals and (b) the pattern of variation within populations. Also, defi nitions of chromosomal 'race' differ. We suggest a standardised scheme for the description of individuals, populations and chromosomal races.

A distinct chromosome race of the common shrew (Sorex araneus Linnaeus, 1758) within the Arctic Circle in European Russia

“…The racial status of each specimen was determined according to the standard nomenclature for the S. araneus karyotype (Searle et al, 1991).…”

Chromosomal rearrangements and gene flow over time in an inter-specific hybrid zone of the Sorex araneus group

“…In this study, we will focus on a hybrid zone located at the Haslital in the Swiss Alps (Innertkirchen, canton Bern). This hybrid zone occurs between Sorex antinorii, which is characterized by the metacentrics gi, hj, kn and l/o (notation: l/o, the slash indicating that the Robertsonian fusion is polymorphic), and the Vaud race of S. araneus, which is characterized by mg, hi, jl, kr and no, according to the nomenclature by Searle et al (1991) (Figure 1). F1 hybrids between these taxa should be relatively infertile because their chromosomes would assemble into a long chain of 11 elements during meiosis ('complex' heterozygotes, CXI; Figure 1) Fredga, 1997, 1998;Banaszek et al, 2002).…”

Karyotypic differentiation of populations of the common shrew Sorex araneus L. (Mammalia) in Belarus

“…h,i/k,m,n,o,p,q,r 2 Bi 28 g,h,i,k,m,n,o,p,q,r Chromosome preparations were obtained from bone marrow and spleen cells after a routine technique with colchicine treatment (Ford and Hamerton 1956). Chromosome identification was carried out by G-banding method with trypsin (Seabright 1971) in accordance with the international common shrew chromosome nomenclature (Searle et al 1991). …”

“…Four metacentric autosomes (af, bc, jl, and tu) and sex chromosomes (XX in females and XY1Y2 in males) are characteristic of species S. araneus (acrocentric morphs of chromosome arms j and l sporadically occur in populations through the species area), while ten autosomal arms (g, h, i, k, m, n, o, p, q, and r) can be presented as acrocentrics or be fused as metacenetrics (Searle et al 1991). The designations of chromosome arms are constant irrespective of their condition either as separate acrocentrics (g, h, i, k, m, n, o, p, q, r) or as arms of metacentrics (gm, hk, ip, no, qr).…”