Pachytene pairing and oocyte numbers in mice with two single Robertsonian translocations and the male-sterile compound with monobrachial homology

1990 ◽  
Vol 53 (2-3) ◽  
pp. 144-147 ◽  
Author(s):  
U. Mittwoch ◽  
S.K. Mahadevaiah ◽  
L.A. Setterfield
2019 ◽  
Vol 20 (18) ◽  
pp. 4466 ◽  
Author(s):  
Svetlana A. Romanenko ◽  
Elena A. Lyapunova ◽  
Abdusattor S. Saidov ◽  
Patricia C.M. O’Brien ◽  
Natalia A. Serdyukova ◽  
...  

The involvement of chromosome changes in the initial steps of speciation is controversial. Here we examine diversification trends within the mole voles Ellobius, a group of subterranean rodents. The first description of their chromosome variability was published almost 40 years ago. Studying the G-band structure of chromosomes in numerous individuals revealed subsequent homologous, step-by-step, Robertsonian translocations, which changed diploid numbers from 54 to 30. Here we used a molecular cytogenetic strategy which demonstrates that chromosomal translocations are not always homologous; consequently, karyotypes with the same diploid number can carry different combinations of metacentrics. We further showed that at least three chromosomal forms with 2n = 34 and distinct metacentrics inhabit the Pamir-Alay mountains. Each of these forms independently hybridized with E. tancrei, 2n = 54, forming separate hybrid zones. The chromosomal variations correlate slightly with geographic barriers. Additionally, we confirmed that the emergence of partial or monobrachial homology appeared to be a strong barrier for hybridization in nature, in contradistinction to experiments which we reported earlier. We discuss the possibility of whole arm reciprocal translocations for mole voles. Our findings suggest that chromosomal translocations lead to diversification and speciation.


Author(s):  
М.В. Андреева ◽  
М.И. Штаут ◽  
Т.М. Сорокина ◽  
Л.Ф. Курило ◽  
В.Б. Черных

Обследованы 19 мужчин с нарушением фертильности, носителей транслокаций rob(13;14) и rob(13;15). Показано, что нарушение репродуктивной функции обусловлено блоком сперматогенеза в профазе I мейоза, приводящего к азооспермии или олигоастенотератозооспермии и мужскому бесплодию. We examined 19 infertile men, carriers of translocations rob (13;14) and rob (13;15). We assume that fertility problems are resulted from spermatogenesis impairment because of meiotic arrest at prophase I stages, that leads to azoospermia or oligoastenoteratozoospermia and male infertility.


Author(s):  
Hao Fu ◽  
N. P. Goncharov

Aim. To present the wheat endemics of China as source material for breeding and historical heritage. Results and Discussion. Wheat in China is the second most widely distributed cereal crop after rice. It is cultivated in China from the extreme northern border to the southern one, at altitudes from 154 m below sea level to 4450 m above sea level. The Chinian wheat is originated from South-West and West Asia and has a history of more than 2.8 thousand years. Since ancient times, the wheat species have been grown in China: bread (Triticum aestivum L.), compactum (T. compactum Host), polonicum (T. polonicum L.), turgidum (T. turgidum L.), durum (T. durum Desf.), turanian (T. turanicum Jakubz.). The Chinese ancient bread wheats are of interest for breeders because presence among them of early ripening, multi-flowering with the grain number in a spikelet up to 7-8 and in the ear up to 90-100, drought and winter hardy, resistant to powdery mildew and leaf rust; forms with good crossability with rye and Aegilops species. Among the endemic Chinese wheat, an important place belongs to the Chinese Spring variety which played an outstanding role in wheat genetics; super dwarfs Tom Pouce and Tibetan Dwarf; three-grain wheat, in which 3 grains are formed in one flower; Charklyk ancient wheat – a boneless form of polonicum wheat; dwarf blue wheat turgidum – with a strong waxy coating; Taigu-Male-Sterile Wheat – with gene male sterility; a wheats having species and subspecies status: wheat of Petropavlovskyi – Triticum petropavlovskyi Udacz. et Migusch.; Tibetan wheat – T. spelta L. ssp. tibetanum (Shao) N.P. Gontsch comb. nov .; Yunnan wheat – T. spelta L. ssp. yunnanse (King ex S.L. Chen) N.P. Gontsch comb. nov. The origin and genetic characteristics of China's endemic wheats are discussed. Conclusions. China's wheat endemics need careful study and conservation as a reserve of valuable genes and their complexes for breeding, and as an embodiment of the history, culture, talent and work of the people who created them, and an integral part of human cultural heritage.


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