Aneuploidy in the embryonic progeny of females heterozygous for the Robertsonian chromosome (9.12) in genetically wild Peru--Coppock mice (Mus musculus)

Abstract

The spontaneous appearance of a Robertsonian translocation in a laboratory colony of genetically wild Peru-Coppock mice gave the opportunity to study potential meiotic nondisjunction soon after the formation of the new chromosome and also in a hitherto untested combination of genotype and environment Metaphase II scores from the progenitor male had indicated a nondisjunction rate of approximately 10%, a figure that was confirmed by the finding of an estimated 12-16% total trisomic and probable monosomic zygotes in chromosomal studies of Day 9 embryos from heterozygous females. The chromosome studies also showed the presence of a significant excess of normal embryos that were heterozygous for the Robertsonian chromosome.

Chromosomal and allozyme analysis of a hybrid zone between parapatric Robertsonian races of the house mouse: a case of monobrachial homology

“…In contact zones between Rb and all-acrocentric populations, hybrids will carry trivalents at meiosis, formed by pairing between the Rb fusions and the homologous acrocentric chromosomes. Such meiotic configurations result in very low nondisjunction rates when few in number, but the level of gametogenetic disturbance does increase when many are present (Harris et al, 1986;Winking, 1986;Garagna et al, 1990;Wallace et al, 1992;Hauffe and Searle, 1998;Rizzoni and Spirito, 1998;Castiglia and Capanna, 2000). Parapatric Rb races, in contrast, often differ by monobrachially homologous fusions (MHFs), namely, Rb fusions that have one chromosome arm in common.…”

“…The decrease in fitness due to chain configurations is documented in house mice and is known to produce high rates of infertility (Gropp et al, 1982a;Garagna et al, 1990;Hauffe and Searle, 1998;Pialek et al, 2001). By contrast, the effect of trivalents on fertility is much less severe when only one or two are present (Harris et al, 1986;Garagna et al, 1990;Wallace et al, 1992;Hauffe and Searle, 1998;Castiglia and Capanna, 2000). Thus, the difference in fitness between these two types of hybrids would lead to a selective advantage of acrocentrics in the center of the hybrid zone.…”

Meiotic drive favors Robertsonian metacentric chromosomes in the common shrew (<i>Sorex araneus,</i> Insectivora, Mammalia)

“…3a). Unequal transmission of one chromosomal type into the first polar body in female heterozygotes is generally advocated to explain chromosomal drive for Rb fusions (Gropp and Winking, 1981;Harris et al, 1986;Redi and Capanna, 1988;Searle, 1988). As a consequence, it is believed that chromosomal drive occurs preferentially in females (Little, 1993).…”

“…Chromosomal drive does not alter the total number of functional gametes but, rather, increases the number that carry the driven chromosome (Little, 1993). Chromosomal drive has been investigated in the sheep blowfly, Lucilia cuprina (Foster and Whitten, 1991); the blue fox, Alopex lagopus (Mäkinen and Lohi, 1987); the house mouse, Mus domesticus (Gropp and Winking, 1981;Harris et al, 1986;Britton-Davidian, 1990); man (Hamerton, 1971;Boué, 1979;Balkan and Martin, 1983); and several flowering plant species Wilby and Parker, 1988).…”

Chromosomes and speciation in <i>Mus musculus domesticus</i>

“…In this model, the ability to cross carriers of selected karyotypes allowed the design of peculiar meiotic configurations (single or multiple independent trivalents, chain or ring configurations) variably subject to malsegregation events, thus leading to chromosome-derived subfertility or sterility and to the production of trisomic (and monosomic) animals. This opportunity opened the field of dynamic embryological studies in reproductive and developmental biology (Harris et al, 1986;Mittwoch et al, 1984;Redi et al, 1984Redi et al, , 1985Redi et al, , 1991Redi et al, , 1993Redi and Capanna, 1988;Redi and Garagna, 1992;Garagna et al, 1990Garagna et al, , 2002Wallace et al, 1991b).…”