A long-range repeat cluster in chromosome 1 of the house mouse, Mus musculus, and its relation to a germline homogeneously staining region

Amplified sequences constitute a large part of mammalian genomes. A chromosome 1 containing 2 large (up to 50 Mb) homogeneously staining regions (HSRs) separated by a small inverted euchromatic region is present in many natural populations of the house mouse (Mus musculus musculus). The HSRs are composed of a long-range repeat cluster, Sp100-rs, with a repeat length of 100 kb. In order to understand the organization and function of HSRs in meiotic chromosomes, we examined synapsis and recombination in male mice hetero- and homozygous for the HSR-carrying chromosome using FISH with an HSR-specific DNA probe and immunolocalization of the key meiotic proteins. In all homozygous and heterozygous pachytene nuclei, we observed fully synapsed linear homomorphic bivalents 1 marked by the HSR FISH probe. The synaptic adjustment in the heterozygotes was bilateral: the HSR-carrying homolog was shortened and the wild-type homolog was elongated. The adjustment was reversible: desynapsis at diplotene was accompanied by elongation of the HSRs. Immunolocalization of H3K9me2/3 indicated that the HSRs in the meiotic chromosome retained the epigenetic modification typical for C-heterochromatin in somatic cells. MLH1 foci, marking mature recombination nodules, were detected in the proximal HSR band in heterozygotes and in both HSR bands of homozygotes. Unequal crossing over within the long-range repeat cluster can cause variation in size of the HSRs, which has been detected in the natural populations of the house mouse.

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Transcripts from amplified sequences of an inherited homogeneously staining region in chromosome 1 of the house mouse (Mus musculus)

Molecular and Cellular Biology ◽

10.1128/mcb.11.4.2229-2235.1991 ◽

1991 ◽

Vol 11 (4) ◽

pp. 2229-2235

Author(s):

W A Eckert ◽

C Plass ◽

A Weith ◽

W Traut ◽

H Winking

Keyword(s):

House Mouse ◽

Dna Sequences ◽

Mus Musculus ◽

Genomic Sequence ◽

Gene Families ◽

Chromosome 1 ◽

Homologous Sequence ◽

Sequence Motifs ◽

Reading Frame ◽

Hybridization Data

Several populations of the house mouse, Mus musculus, are polymorphic for the presence or absence of an inherited homogeneously staining region (HSR) in chromosome 1. The HSR consists of highly amplified DNA sequences, present in low copy numbers in the HSR- genome. A cloned HSR-derived genomic sequence detected transcripts of about 1.3 and 4.5 kb on blots of poly(A)+ RNA from liver of HSR+ mice but not from that of HSR- mice. A cDNA library was established from RNA of HSR+ mice and screened with the HSR-derived genomic clone. Positive clones were isolated and shown to be complementary to the 1.3-kb RNA species and to amplified DNA sequences in the HSR+ genome. The combined sequence of four overlapping cloned cDNAs is 959 nucleotides long and includes an open reading frame encoding a putative protein of 208 amino acids. The pertinent gene is unidentified. No homologous sequence is stored in the EMBL data base. A stretch of 109 nucleotides at the 3' end of the 1.3-kb RNA homology region in the same genomic fragment, as indicated by hybridization data and sequence motifs resembling promoter elements. Thus, our data suggest that at least two genes or gene families are encoded in the HSR.

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Transcripts from amplified sequences of an inherited homogeneously staining region in chromosome 1 of the house mouse (Mus musculus).

Molecular and Cellular Biology ◽

10.1128/mcb.11.4.2229 ◽

1991 ◽

Vol 11 (4) ◽

pp. 2229-2235 ◽

Cited By ~ 15

Author(s):

W A Eckert ◽

C Plass ◽

A Weith ◽

W Traut ◽

H Winking

Keyword(s):

House Mouse ◽

Dna Sequences ◽

Mus Musculus ◽

Genomic Sequence ◽

Gene Families ◽

Chromosome 1 ◽

Homologous Sequence ◽

Sequence Motifs ◽

Reading Frame ◽

Hybridization Data

Several populations of the house mouse, Mus musculus, are polymorphic for the presence or absence of an inherited homogeneously staining region (HSR) in chromosome 1. The HSR consists of highly amplified DNA sequences, present in low copy numbers in the HSR- genome. A cloned HSR-derived genomic sequence detected transcripts of about 1.3 and 4.5 kb on blots of poly(A)+ RNA from liver of HSR+ mice but not from that of HSR- mice. A cDNA library was established from RNA of HSR+ mice and screened with the HSR-derived genomic clone. Positive clones were isolated and shown to be complementary to the 1.3-kb RNA species and to amplified DNA sequences in the HSR+ genome. The combined sequence of four overlapping cloned cDNAs is 959 nucleotides long and includes an open reading frame encoding a putative protein of 208 amino acids. The pertinent gene is unidentified. No homologous sequence is stored in the EMBL data base. A stretch of 109 nucleotides at the 3' end of the 1.3-kb RNA homology region in the same genomic fragment, as indicated by hybridization data and sequence motifs resembling promoter elements. Thus, our data suggest that at least two genes or gene families are encoded in the HSR.

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Distortion of Mendelian recovery ratio for a mouse HSR is caused by maternal and zygotic effects

Genetics Research ◽

10.1017/s0016672300034017 ◽

1996 ◽

Vol 68 (2) ◽

pp. 125-129 ◽

Cited By ~ 14

Author(s):

Dieter Weichenhan ◽

Walther Traut ◽

Bärbel Kunze ◽

Heinz Winking

Keyword(s):

Long Range ◽

Mus Musculus ◽

Chromosome 1 ◽

Recovery Ratio ◽

Mus Musculus Domesticus ◽

Reciprocal Crosses ◽

Feral Populations

SummaryAn HSR in chromosome 1 which is found in many feral populations of Mus musculus domesticus was shown in previous studies to consist of a high-copy long-range repeat cluster. One such cluster, MUT, showed distorted transmission ratios when introduced by female parents. MUT/ + offspring were preferentially recovered at the expense of + / + embryos in the progeny of ♀ MUT/+ x♂ +/+ but were found at the expected 1:1 ratio in reciprocal crosses. Preferential recovery of maternal MUT was due to lethality of postimplantation + /+ embryos. There was no distortion of the recovery ratio in MUT/+ x MUT/MUT progeny: maternal MUT and + clusters were present among live implants at a 1:1 ratio. Maternal and zygotic effects therefore contribute to the phenomenon. The mechanism of their interaction is unknown.

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