Beermann, W
ثبت نشده
چکیده
Inversion polymorphism is very common in Diptera (Da Cunha 1955). Its occurrence is generally interpreted as an effect of heterosis. The inversion heterozygotes have a selective advantage over the homozygotes. The relative selective value of the genotype depends on the viability and fertility of the phenotype it determines. Hitherto in the discussion of the inversion heterosis the problem of relative viability has stood in the foreground. The problem of relative fertility has on the other hand been previously neglected, because in the chromosomes of Drosophila and Sciara, the genera chiefly investigated, no chiasmata are formed in the male meioses. In the female meioses the chromatid bridges (from a simple interchange in the region of the heterozygous inversion) can indeed occur, however one of the chromatids not concerned in the interchange is always seen to be retained in the presumptive egg nucleus at Anaphase II (Carson 1946; Sturtevant and Beadle 1936); the fertility of the females is therefore not affected in inversion heterozygotes.
منابع مشابه
N-Acetylanthranilate Amidase from Arthrobacter nitroguajacolicus Rü61a, an / -Hydrolase-Fold Protein Active towards Aryl-Acylamides and -Esters, and Properties of Its Cysteine-Deficient Variant †
N-Acetylanthranilate Amidase from Arthrobacter nitroguajacolicus Rü61a, an / -Hydrolase-Fold Protein Active towards Aryl-Acylamides and -Esters, and Properties of Its Cysteine-Deficient Variant † Stephan Kolkenbrock, Katja Parschat, Bernd Beermann, Hans-Jürgen Hinz, and Susanne Fetzner* Institut für Molekulare Mikrobiologie und Biotechnologie, and Institut für Physikalische Chemie, Westfälische...
متن کاملInducing grammar from IGT
We suggest a strategy for incremental construction of deep parsing grammars from Interlinear Glossed Text (IGT). IGT is a format of representation where standard linguistics and NLP in principle meet, since they are a data-type which is often available for digitally ‘less resourced languages’ (‘LRL’). The IGT database is TypeCraft (Beermann and Mihaylov 2009, www.typecraft.org), and the grammar...
متن کاملStreptococcus pneumoniae induced p38 MAPK- and NF- B-dependent COX-2 expression in human lung epithelium
Philippe Dje N’Guessan, Stefan Hippenstiel, Mirabelle O. Etouem, Janine Zahlten, Wiebke Beermann, David Lindner, Bastian Opitz, Martin Witzenrath, Simone Rosseau, Norbert Suttorp, and Bernd Schmeck Department of Internal Medicine/Infectious Diseases and Respiratory Medicine, and Institute for Periodontology and Synoptic Dentistry, Charité Centrum 3 for Dental Medicine, Charité-Universitätsmediz...
متن کاملCatalytically Inactive Form of SHP-1 I-Deficient Targets by NK Cells Expressing a Impaired Natural Killing of MHC Class
متن کامل