0000000000241787
AUTHOR
Erich Jost
Meiosis in translocation heterozygotes in the mosquito Culex pipiens.
Adult Culex pipiens males irradiated with both X-rays and neutrons were crossed to untreated females and F1-egg rafts were checked for dominant lethality. F1-progenies were outcrossed with normal individuals in order to obtain lines with inherited semisterility. From a total of 120 lines that showed a certain amount of sterility 12 lines were studied cytologically. 10 lines showed reciprocal chromosome exchanges.—At late pachytene and diplotene cross configurations with large asynaptic regions at the center of the cross are obligatory. Bivalents, chains of three, chains of four, and ring configurations are present at metaphase and anaphase I. The different frequencies of the occurrence of s…
Genetische Untersuchungen zur Inkompatibilität im Culex-pipiens-Komplex
In crosses between populations of the mosquito Culex pipiens of different geographical origin three crossing types have been found (1) crosses with normal offspring (2) crosses with reduced offspring and (3) crosses that show almost total incompatibility. In the case of incompatible crosses 99.9% of the developing embryos are lethal and only about 0.1% of the embryos hatch and develop into fertile diploid females. The origin of the exceptional diploid females has been investigated by means of the marker genes Kuf, r, w, var, y and ru. These females develop from a diploid oocyte or from a diploid nucleus that originated by fusion of the pronucleus and the last polar body. This has been concl…
DNA content in nine species of Nematocera with special reference to the sibling species of the Anopheles maculipennis group and the Culex pipiens group
DNA values were determined for the nine species: Telmatoscopus meridionalis (family Psychodidae), Dixa obscura (family Dixidae), and Culiseta litorea, Culex pipiens, Aedes caspius, Anopheles labranchiae, Anopheles atroparvus, Anopheles stephensi, and Anopheles freeborni (family Culicidae). The DNA content indicated that the species could be divided into three categories: The Culex group with Culex pipiens, Culiseta litorea and Aedes caspius containing 1.02, 0.92 and 0.99 pg DNA in the haploid set, the Anopheles group including the four Anopheles species A. labranchiae, A. atroparvus, A. stephensi, A. freeborni and Telmatoscopus meridionalis with 0.23, 0.24, 0.24, 0.29 and 0.24 pg DNA and th…