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  • Investigation of intersexual polled goats
    11-15
    Views:
    356

    The sex reversal may occur in all mammalian species, but is connected to a favourable trait – the polledness – only in the goat. Later abnormal sex ratio was noticed in these goat populations, in which a part of the phenotypically male individuals was sterile. These males have two X chromosomes. In goats the PIS (Polled Intersex Syndrome) mutation is responsible for the absence of horns in homozygous and heterozygous individuals. This same mutation causes a female-to-male sex reversal, but only in the homozygous polled genetic female goats. The PIS mutation inhibits the expression of the FOXL2 gene which is responsible for ovary development, and a protein encoded by this gene inhibits the activity of the Sox9 gene. The Sox9 gene stimulates the development of the cells of the testis. When the FOXL2 gene is inhibited, the Sox9 gene is activated and transforms the ovary cells into testis cells. In our article we briefly introduce the morphological and chromosome investigations of three intersex individuals we found.

  • Influence of 17-alpha methyl testosterone on the production parameters of common carp (Cyprinus carpio L.) fry
    37-43
    Views:
    588

    During our research we aimed at finding an answer as to what extent the different concentrations of 17-alpha methyl testosterone incorporated in the diet of common carp fries can influence the production parameters of the species, as well as how efficient their sexreversal can be with the use of this method. To this end, an aquarium experiment was conducted in the course of which four different hormone treatments were set and monitored. The fish feed was enriched with 17-alpha methyl testosterone in 50 ppm, 75 ppm, 100 ppm, 500 ppm dosages.

    The obtained figures revealed that the hormone treatments had no influence on the production parameters and conservation of the common carp fries. Further on, our team is to determine the sex of the fish through the examination of gonads during autopsy when they reach the 500 g average weight.

    Furthermore, a male specific test method which was supposed to be of great help in our attempt to select the sex-reversed specimens in the subsequent processes was also put to the trial. During the experiment the DNA-isolation of different sample types (muscle tissue, fin, mucus) of common carp with identified sex was successfully carried out. The extracted PCR product was examined with agarose gel. Our results indicated that the ccmf2 marker was applicable, however, the obtained figures were not reliable.