Nonrandom segregation in multiple Robertsonian heterozygotes in the house mouse (<i>Mus musculus domesticus</i>): Analysis of metaphases of spermatocytes II of mice from a hybrid zone between a Robertsonian population and a population with the standard karyotype

Rizzoni, Marco; Spirito, Franco

doi:10.1080/11250009909356232

Cited by 4 publications

(7 citation statements)

References 7 publications

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“…Therefore it is necessary to investigate the immediate meiosis II products to verify whether cosegregation takes place. Present data are in agreement with some estimates of cosegregation in multiple heterozygous male mice (Rizzoni and Spirito, 1999).…”

Section: Specimensupporting

confidence: 81%

“…Results of the karyotypical analysis of a backcross progeny from males heterozygous for three Rb metacentric chromosomes , although compatible with a random segregation, fit better with a P value (see below) of preferential segregation of 0.66 (95 % confidence limits: 0.50-0.75) (Rizzoni and Spirito, 1999). Data derived from karyotypical analysis of embryos obtained by backcrossing heterozygotes for nine centric fusions (Said et al, 1993) show preferential segregation (0.66, 95 % confidence limits 0.56-0.71) (Rizzoni and Spirito, 1999).…”

mentioning

confidence: 78%

“…metacentric) to migrate to its "preferential" meiosis I pole, which is the same for all the isomorphic chromosomes. This variable has been reported in literature as a measure of cosegregation (Rizzoni and Spirito, 1999). Preferential migration could be due to a co-orientation of the centromeres of the isomorphic chromosomes when spindle is organised; by this way they may interact with a high probability with the same spindle pole.…”

Section: Analysis Of Datamentioning

confidence: 99%

“…A hypothesis of selective processes occurring during embryo development is suggested, in which competition between embryos carrying Rb metacentric or acrocentric chromosomes occurs at two stages of embryogenesis, pre-and postimplantation. Analysis of segregation pattern of trivalents in quadruple heterozygous males caught in a chromosomal hybrid zone, by cytogenetic analysis of spermatocytes II (Rizzoni and Spirito, 1999) show that Rb metacentrics do not segregate independently of each other, but tend to cosegregate with a probability value of segregation towards the preferential pole of 0.71 (95 % confidence limits: 0.62-0.77). Contrasting cosegregation data from the same hybrid zone (Castiglia and Capanna, 2000) have been recently obtained with evidence of random segregation for these chromosomes in studies of spermatocytes II, but also with some evidence of cosegregation after karyotype analysis of F 2 individuals.…”

mentioning

confidence: 99%

“…Data derived from karyotypical analysis of embryos obtained by backcrossing heterozygotes for nine centric fusions (Said et al, 1993) show preferential segregation (0.66, 95 % confidence limits 0.56-0.71) (Rizzoni and Spirito, 1999). The chromosomal analysis of backcross progeny from crosses between the two subspecies Mus musculus domesticus and M. m. musculus shows a random segregation of the three Rb fusions inherited from M. m. domesticus (Lenormand et al, 1997).…”

mentioning

confidence: 99%

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Cosegregation of Robertsonian metacentric chromosomes in the first meiotic division of multiple heterozygous male mice as revealed by FISH analysis of spermatocyte II metaphases

Scascitelli

Pacchierotti

Rizzoni

et al. 2003

Cytogenet Genome Res

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Contrasting results (random segregation or cosegregation of isomorphic chromosomes) have been reported up to now on the segregation pattern of Robertsonian metacentric chromosomes of Mus musculus domesticus in multiple heterozygotes, using different approaches (karyotypical analysis of the progeny or of second meiotic metaphases). In the present contribution data are presented based on FISH (Fluorescence In Situ Hybridisation) analysis with telomeric probes, which allowed us to distinguish metacentric chromosomes from pairs of acrocentric chromosomes with their centromeric regions close to each other. Probes were hybridized to DAPI stained metaphases of spermatocytes II of mice heterozygous for two, three or four Robertsonian metacentrics in an all-acrocentric background, the karyotype of which has been reconstructed starting from laboratory strains. Isomorphic chromosomes tend to cosegregate (metacentrics with metacentrics, acrocentrics with acrocentrics); the values found for cosegregation have a clear even if moderate effect on the reproductive isolation caused by underdominant chromosomal rearrangements.

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Section: Specimensupporting

confidence: 81%

mentioning

confidence: 78%

Section: Analysis Of Datamentioning

confidence: 99%

mentioning

confidence: 99%

mentioning

confidence: 99%

See 3 more Smart Citations

Cosegregation of Robertsonian metacentric chromosomes in the first meiotic division of multiple heterozygous male mice as revealed by FISH analysis of spermatocyte II metaphases

Scascitelli

Pacchierotti

Rizzoni

et al. 2003

Cytogenet Genome Res

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Contact zone between chromosomal races of Mus musculus domesticus. 2. Fertility and segregation in laboratory-reared and wild mice heterozygous for multiple Robertsonian rearrangements

Castiglia

Capanna

2000

Heredity

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Litter size, anaphase I nondisjunction and X±Y dissociation at metaphase I were studied in homozygous and heterozygous house mice from a central Italian chromosomal hybrid zone between the CD (2n 22) race and the standard race (2n 40). We also observed the segregation of the two chromosomal forms (Robertsonian and non-Robertsonian) in male and female multiple heterozygotes from the karyotype of their ospring and chromosomal arm counts of metaphase II. Litter size was signi®cantly reduced in the F1 hybrids, but there was no dierence in litter size between male and female F1s. Fertility in wild mice decreased with increasing numbers of structural heterozygosities (0±5). Some metacentrics appear to be under meiotic drive but there was no rule as to which of the two forms was favoured in backcrosses. An original observation of a negative correlation between the length of metacentrics and transmission rate was described in hybrids. Slight cosegregation of chromosomes with a similar morphology was present in the progeny of males and females. These observations are discussed in relation to the stability of this hybrid zone through time.

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Nondisjunction rates of mouse specific chromosomes involved in heterozygous Rb rearrangements measured by chromosome painting of spermatocytes II. I. The effects of the number of trivalents

Scascitelli

Gustavino

Pacchierotti

et al. 2004

Cytogenet Genome Res

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Dual-colour FISH painting with alternative fluorescent chromosome-specific probes allowed us to distinguish chromosomes 1, 4, 6 and 14. The purpose was to check whether nondisjunction rates of specific chromosomes involved in heterozygous Robertsonian fusions are independent of the number of trivalents, or an epistatic effect among Rb chromosomes takes place affecting nondisjunction rates. Probes were used on DAPI-stained metaphases of spermatocytes II of laboratory strains of mice with reconstructed karyotypes heterozygous for one, two, three or four Robertsonian metacentrics in an all-acrocentric background. The existence of such epistatic interactions was not verified.

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Nonrandom segregation in multiple Robertsonian heterozygotes in the house mouse (Mus musculus domesticus): Analysis of metaphases of spermatocytes II of mice from a hybrid zone between a Robertsonian population and a population with the standard karyotype

Cited by 4 publications

References 7 publications

Cosegregation of Robertsonian metacentric chromosomes in the first meiotic division of multiple heterozygous male mice as revealed by FISH analysis of spermatocyte II metaphases

Cosegregation of Robertsonian metacentric chromosomes in the first meiotic division of multiple heterozygous male mice as revealed by FISH analysis of spermatocyte II metaphases

Contact zone between chromosomal races of Mus musculus domesticus. 2. Fertility and segregation in laboratory-reared and wild mice heterozygous for multiple Robertsonian rearrangements

Nondisjunction rates of mouse specific chromosomes involved in heterozygous Rb rearrangements measured by chromosome painting of spermatocytes II. I. The effects of the number of trivalents

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