Morphology and Genetics of the Common Shrew: General Features

Mishta, Alina; Searle, Jeremy B.

doi:10.1017/9780511895531.004

Cited by 5 publications

(3 citation statements)

References 106 publications

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“…The latter represents one of the well‐documented examples of exceptional Rb variation among mammals (Searle et al, 2019; Searle, 1993). Within its extensive Eurasian range—from the British Isles and France up to the southwestern part of Yakutia (Eastern Siberia, Russia)—this species is subdivided into numerous parapatric groups of local populations, with each group having a distinct karyotype: so‐called chromosomal races (Mishta & Searle, 2019; Searle, 1993). The diploid number of chromosomes, 2 n , of this species varies from 20 to 33 due to centric fusions and/or fissions (Rb) of 10 single‐armed autosomes ( g, h, i, k, m, n, o, p, q , and r ), constituting the variable part of a karyotype (Figure 1a–c).…”

Section: Introductionmentioning

confidence: 99%

Natural male hybrid common shrews with a very long chromosomal multivalent at meiosis appear not to be completely sterile

Matveevsky,

Kolomiets,

Shchipanov

et al. 2023

J Exp Zool Pt B

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Among 36 known chromosomal hybrid zones of the common shrew Sorex araneus, the Moscow–Seliger hybrid zone is of special interest because inter‐racial complex heterozygotes (F1 hybrids) produce the longest meiotic configuration, consisting of 11 chromosomes with monobrachial homology (undecavalent or chain‐of‐eleven: CXI). Different studies suggest that such a multivalent may negatively affect meiotic progression and in general should significantly reduce fertility of hybrids. In this work, by immunocytochemical and electron microscopy methods, we investigated for the first time chromosome synapsis, recombination and meiotic silencing in pachytene spermatocytes of natural inter‐racial heterozygous shrew males carrying CXI configurations. Despite some abnormalities detected in spermatocytes, such as associations of chromosomes, stretched centromeres, and the absence of recombination nodules in some arms of the multivalent, a large number of morphologically normal spermatozoa were observed. Possible low stringency of pachytene checkpoints may mean that even very long meiotic configurations do not cause complete sterility of such complex inter‐racial heterozygotes.

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Section: Introductionmentioning

confidence: 99%

Natural male hybrid common shrews with a very long chromosomal multivalent at meiosis appear not to be completely sterile

Matveevsky,

Kolomiets,

Shchipanov

et al. 2023

J Exp Zool Pt B

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“…The common shrew is the most popular research subject in different aspects of evolutionary biology, adaptation, and speciation (see reviews by several authors, e.g., Polly, 2019;Thaw et al, 2019;Taylor et al, 2022) just as the house mouse model (Zima and Searl, 2019). Intensive investigations in the last three decades have revealed high levels of pheno-typic and genotypic polymorphisms among recent samples of the common shrew (Searle and Wójcik, 1998;Polly, , 2005Polly, , 2007Wójcik et al, 2003;Mishta and Searle, 2019;White et al, 2019;Zima and Searl, 2019). To date, 76 chromosomal races have been described (Bulatova et al, 2019), which have been combined into several karyotypic groups.…”

Section: Introductionmentioning

confidence: 99%

Morphospace dynamics and intraspecies variety of Sorex araneus and S. tundrensis according to recent and fossil data

Voyta,

Izvarin,

Shemyakina

et al. 2023

Palaeontol Electron

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Several patterns were revealed in a temporal study on morphological variety of Sorex araneus and S. tundrensis (Soricidae, Mammalia). We examined samples from 18 modern and three fossil Early-Late Holocene Uralian localities. We analyzed shape variation of the first lower molar and hemimandible using two-dimensional geometrical landmarks; size differences were estimated by means of three linear measures. A separate purpose was estimation of the measurement error that arose during the data acquisition. We found that the modern samples of both species share underestimated similarity in both size and shape of morphological structures. Regression analysis revealed different phenotypic traits of the mandibular proportion in the large and small shrews regardless of species attribution. A size decrease of S. araneus and conversely a size increase of S. tundrensis both drive the mandibular shape toward phenotypic convergence. This pattern, however, is violated in the fossil samples, where the largest S. tundrensis from a Late Holocene Sim III locality (South Ural) showed a well-distinguishable mandibular shape located in a separate part of the morphospace. In this work, we found that the m1 shape has only weak resolving power as compared to the mandibular or especially skull shape. Nonetheless, even the moderate resolving power of the mandibular shape allowed us to uncover phenotypic changes during the Holocene that have not been noticed by previous researchers at Uralian late Quaternary localities.

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“…The latter represents one of the well-documented examples of exceptional Rb variation among mammals (Searle 1993;Searle et al, 2019). Within its extensive Euro-Asiatic range-from British Isles and France up to the southwestern part of Yakutia (Eastern Siberia, Russia)-the species is subdivided into numerous parapatric groups of local populations, with each group having a distinct karyotype: so-called chromosomal races (Searle, 1993;Mishta & Searle, 2019). The diploid number of chromosomes, 2n, of the species varies from 20 to 33 due to centric fusions and/or fissions (Rb) of 10 single-armed autosomes (g, h, i, k, m, n, o, p, q, and r), constituting the variable part of a karyotype (Figure 1A-C).…”

Section: | Introductionmentioning

confidence: 99%

Shrew evolution in hybrid zones: a meiotic undecavalent as an exclusive chromosomal supermultivalent and its weak effect on fertility

Matveevsky

Коломиец

Щипанов

et al. 2023

Preprint

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Hybrid zones are natural laboratories for studying speciation. In the common shrew Sorex araneus, the hybrid zone between extremely divergent in karyotypes the Moscow and Seliger chromosomal races is unique, because complex heterozygotes (interracial hybrids) form the longest meiotic configuration consisting of 11 chromosomes with monobrachial homology (undecavalent or chain-of-eleven - CXI). Different studies suggested that such a multivalent would negatively affect meiotic progression and, in general, would significantly reduce fertility. In this work, using immunocytochemical and electron microscopy methods, we investigated chromosome synapsis, recombination, and meiotic silencing in pachytene spermatocytes carrying undecavalent. Despite some abnormalities detected in spermatocytes, such as single associations of chromosomes, stretched centromeres in the multivalent, shifted recombinational peak towards distal parts of chromosomal arms of superchain, heterozygous shrews were able to form a large number of morphologically normal and active spermatozoa. Possible low stringency of pachytene checkpoints, proper segregation of homologous chromosomes, and the ability of hybrids to form mature germ cells imply rapid evolutionary fixation and circulation of Rb chromosomes within shrew populations, leading to a variety of chromosomal races.

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Morphology and Genetics of the Common Shrew: General Features

Cited by 5 publications

References 106 publications

Natural male hybrid common shrews with a very long chromosomal multivalent at meiosis appear not to be completely sterile

Natural male hybrid common shrews with a very long chromosomal multivalent at meiosis appear not to be completely sterile

Morphospace dynamics and intraspecies variety of Sorex araneus and S. tundrensis according to recent and fossil data

Shrew evolution in hybrid zones: a meiotic undecavalent as an exclusive chromosomal supermultivalent and its weak effect on fertility

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