Histological and morphometric characteristics of chicken embryos with different genotypes

Background: The GFP gene is commonly used in biotechnology and is used as an indicator. Chicken embryos are also the most important experimental animals used in modern research for easy access to embryos, as well as easy gene injection at an early stage. Study design: Study of the influence of genetic engineering manipulations on the histological and morphometric parameters of organs and tissues of chicken embryos. Methods: We took the three groups: - Normal (H), Transgenic (G) and Crossbred (HxG). Research stage was divided into two parts: The first step was to study the internal and external characteristics of the eggs. At the second stage, morphological and histological changes in organs and tissues in embryos were studied. Results: The incubation eggs of the studied genotypes met the regulatory requirements for morphometric indicators of egg quality. Eggs from transgenic chickens (group 2) had statistically significantly lower values of the quality index of dense protein - units of Hough. Compared to the eggs of the 1st and 3rd groups, the difference was 4.8 and 3.6 Hau units, respectively (P≥0.95). On the 14th day of incubation, the embryos of the 1st and 3rd groups were statistically significantly superior the weight of group 2 embryos was 17.4% and 13.5%, respectively (P≥0.95). By day 18, differences in the weight of the embryos persist. Embryos from eggs from genetically modified chickens (group 2) on the 18th day of incubation had the smallest absolute values according to linear indices of individual parts of the body. Genetic engineering manipulations affect the morphology of the internal organs of embryos. Embryos of the 2nd group of 18 days of age have a heart mass of 7.6 and 5.7% more than peers from the 1st and 3rd groups, and liver mass is 13.0 and 19.3% less, respectively. the mass of the stomach is 4.4 and 20.8% less, respectively (P≥0.95). In group 2 embryos, the number of convoluted seminiferous tubules in the field of view of the microscope is 1.7 and 1.5 times less compared to groups 1 and 2 (P≥0.95). Conclusions Genetic manipulations significantly reduce almost all morphological and histological parameters in group 2 embryos and cause negative consequences in the development of chicken embryos.