The effects of Robertsonian fusions on chiasma frequency and distribution in the house mouse (Mus musculus domesticus) from a hybrid zone in northern Scotland
The effects of Robertsonian fusions on chiasma frequency and distribution in the house mouse (Mus musculus domesticus) from a hybrid zone in northern Scotland
复制标题
DOI：
10.1046/j.1365-2540.2001.00877.x
复制
发表时间：
2001-09-01
期刊：
影响因子：
3.8
通讯作者：
Searle, JB
中科院分区：
文献类型：
--
作者：
Bidau, CJ;Giménez, MD;Searle, JB
研究了苏格兰北方John O 'Groats标准染色体杂交区雄性小家鼠的交叉频率和分布。个体的约翰O 'Groats种族（2n=32;纯合子的罗伯逊融合4.10，6.13，9.12和11.14）和标准的种族（2n=40，所有端着丝粒），并与各种核型的杂交，进行了检查。交叉频率与减数分裂细胞中罗伯逊构型的数目呈显著负相关。交叉频率的降低可归因于染色体内效应，其减少罗伯逊二价体（在罗伯逊融合的纯合子中形成）和三价体（在杂合子中形成）中的交叉数目。然而，这种减少在罗伯逊二价体中更为明显，并且与交叉向染色体臂远端的移位有关。在三价体中，近端和间质交叉显著增加，发生不同类型的再图案化。
Chiasma frequency and distribution were studied in male Mus musculus domesticus from the John O'Groats-standard chromosomal hybrid zone in northern Scotland. Individuals of the John O'Groats race (2n=32; homozygous for the Robertsonian fusions 4.10, 6.13, 9.12 and 11.14) and the standard race (2n=40, all telocentric), and hybrids with various karyotypes, were examined. Chiasma frequency was significantly negatively correlated with the number of Robertsonian configurations in the meiotic cell. The decrease of chiasma frequency can be attributed to intrachromosomal effects that reduce the number of chiasmata in Robertsonian bivalents (formed in homozygotes for Robertsonian fusions) and trivalents (formed in heterozygotes). However, the reduction is more pronounced in Robertsonian bivalents and is related to a shift of chiasmata to the distal ends of the chromosome arms. A different type of repatterning occurs in trivalents where there is a significant increase in proximal and interstitial chiasmata.