Mammals have two genes (SRY and DMT1) for testis formation-androgenesis, an anti-testis gene, DAX1, an anti-Mullerian duct hormone, and steroid sex hormones. Drosophila uses the sex-lethal, transformer and doublesex genes for sexual differentation and is supposed to lack sex hormones. However, the statement that insects do not have sex hormones los...
The objective of the present study is to describe the karyotype of the fruit fly Tomoplagia rudolphi (Lutz & Lima, 1918). This fly induces the formation of galls on the stems of Vernonia polianthes (Asteraceae). The cytogenetic analysis of cerebral ganglia (larva and pupa) and testis (adults) of T. rudolphi showed a diploid chromosome number of 2n ...
Published in Genetic Resources and Crop Evolution
Hemp is one of the oldest crops in the world and can be used in very different ways. Hemp cultivation was forbidden in Germany since 1982. Since 1996 hemp with less than 0.3 per cent THC content can be grown. To evaluate the available genetic hemp resources 14 monoecious and 26 dioecious hemp varieties and strains were grown in the field in 1996 an...
Published in Journal of Genetics
Drosophila melanogaster females homozygous forflex, an X-linked recessive mutation, do not survive. Hemizygous males are unaffected. Homozygous embryos appear to lack SXL, the product of theSex-lethal (Sxl) gene, apparently as a result of disruption ofSxl splicing. It is known that bothSxl and its somatic splicing regulators [snf andfl(2)d] also fu...
The genetic structure of M. destructor and M. hordei was investigated by sampling 21 fields of cereals in 14 localities of central and southern Tunisia. As previously shown, there was no strict association between the cereal species (wheat, barley and oat) and the Mayetiola species. M destructor males displayed no heterozygosity at the Pgm3 locus, ...
Genetic structure of Hessian flies in Tunisia. The genetic structure of M. destructor and M. hordei was investigated by sampling 21 fields of cereals in 14 localities of central and southern Tunisia. As previously shown, there was no strict association between the cereal species (wheat, barley and oat) and the Mayetiola species. M. destructor males...
In some parasitoid wasps, infection by the micro-organism Wolbachia leads to asexual reproduction. Within the Hymenoptera, the limits of distribution of parthenogenesis inducing Wolbachia have not yet been established. To address this issue, we screened all known thelytokous social hymenopteran species using a PCR assay. None was infected, and ther...
Gynogenesis is thought to be a useful method to generate fully inbred lines in teleost fish. Endomitosis, which refers to the inhibition of first mitosis, should lead to fully homozygous offspring. In this study, the optimal conditions to induce mitogynogenesis (endomitosis) by heat shocking of the eggs were determined in the African catfish Claria...
Published in Wuhan University Journal of Natural Sciences
By amplification of the polymerase chain reaction (PCR), the two fragments of 680 bp and 640 bp of 5’ regulatory region of Chinese bovine Sry gene were subcloned into pUC18. Sequence analysis shows that the fragment of total 1040 bp, which is highly conserved within bovine species, contains a start code ATG and a core promoter.
Published in Biochemical Genetics
Sex determination in the mammalian embryo begins with the activation of a gene on the Y chromosome which triggers a cascade of events that lead to male development. The mechanism by which this gene, designated SRY in humans and Sry in mice (sex determining region of the Y chromosome), is activated remains unknown. Likewise, the downstream target ge...
