Reduced meiotic fitness in hybrids with heterozygosity for heterochromatin in the speciating Mus terricolor complex

Journal of biosciences

Amit Bardhan²  Min Bahadur¹  Tikaram Sharma1² 

[1] Department of Zoology, North Bengal University, Darjeeling 734 430, India$$;Cytogenetics Laboratory, Department of Zoology, Banaras Hindu University, Varanasi 221 005, India$$

关键词: Backcross hybrids;    heterochromatin;    meiotic fitness;    Mus;    reproductive barrier;    speciation;   

DOI  :  

来源: Indian Academy of Sciences

【 摘 要 】

Mus terricolor I, II and III are the three chromosomal species which differ in stable autosomal short-arm heterochromatin variations established in homozygous condition. Analysis of meiosis in the laboratorygenerated F1 male hybrids from crosses (both ways) between M. terricolor I and II and between M. terricolor I and III shows high frequencies of pairing abnormalities at pachytene. The backcross (N3 generation) male hybrids between M. terricolor I and II have meiotic abnormalities as in the F1 male hybrids, though to a lesser extent. They show difference in pairing abnormalities in the different karyotypic forms; the backcross hybrids heterozygous for the heterochromatic short arms have more anomalies compared to the homokaryotypic hybrids. This suggests a negative influence of the heterochromatin heterozygosity in meiotic pairing. The results indicate a role for heterochromatin variations in the development of a reproductive barrier in the speciating M. terricolor complex.

【 授权许可】

Unknown